Nature's Archive Podcast

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[00:00:00] Michael Hawk: Alan, thank you so much for making time in there this time of year, exceptionally busy schedule to show me around Hawk Hill. And tell me about G G R O.

[00:00:08] Allen Fish: Pleasure. This is it is busy, but it’s busy, fun, busy really nice that you could have time to come up.

[00:00:12] Michael Hawk: Oh, absolutely. . I’ll make time for this any year, anytime.

[00:00:15] And as we’re talking, there’s a raven approaching you. Yeah.

[00:00:19] Allen Fish: Don’t make eye contact. . The Ravens own the hill and they rent a space to do the hawk count every year. They’re what I call tourist ravens, and they’re looking for any food particle that might come their way.

[00:00:30] They’re very smart.

[00:00:31] Michael Hawk: So unfortunately right now we’re standing on top of a hill where there’s a beautiful view, but we can’t see any of it because of the fog . We’ll see how the day goes, but what’s your. forecast for the weather today and whether we’re gonna see any hawks.

[00:00:45] Allen Fish: Yeah, this is a dismal day.

[00:00:47] And it’s so hard when it times perfectly with we’re kind of of coming off the peak of migration. It’s October 15th and we’re usually see a wonderful crescendo of the migration right around October 1st and then a slow fall off that goes through the month of October. And then still migration into November mid-November.

[00:01:07] It’s disappointing to not have a clear day today. We’re in about the eighth day of a run of fog days that are very unusual for October in the Bay Area, but it feels a little bit of a, there’s a little bit of resolution in that we’re not in a fire scare period, which is usually where a lot of us are used to being in October in California.

[00:01:27] Michael Hawk: I know in October the weather pattern starts to change usually. Yeah. And we get these troughs of low pressure coming in and it causes offshore winds. And those are like downsloping drying. Yeah. Fire prone winds. So that’s the silver lining of the misty fogginess that we have right now.

[00:01:45] Allen Fish: And it’s totally it’s totally related to the bird migration, right?

[00:01:48] It’s totally related to how birds move around and what they respond to, whether it’s the temperatures and the the wind movement and the jet stream movement and the lack of jet stream movement as well as all of the prey cycles that may result from that too. The Raptor migration is a neat.

[00:02:03] Probably 2, 3, 4 orders removed from some kind of base understanding of what climate change is doing. But one of the reasons of doing this work is to look for climate change impacts and indicators.

[00:02:16] Michael Hawk: So let’s spend a moment since we can’t see much talking a bit more about the weather before we get into Sure.

[00:02:22] The broader mission of G G R O, I definitely want to get there, but what I was thinking is you were describing this has been an eight day run of fog. So do you think when this clears that there’ll be a bigger push because there’s pint up. Migration energy, so to speak? Or do you think the birds are just maybe taking the Central Valley Flyway or some other route?

[00:02:42] Allen Fish: or unknown ? Yes. ABC and D. Yeah. Yeah I, we have seen pulses certainly over the last 38 years of doing hawk counts, we’ve seen pulses between fog stretches. And usually a fog stretch for us is a two to three days, at worst, about four to five days. Eight days is pretty long. And we did have some count days in the middle of it a few days ago that the fog went high enough to be able to get us, give us an open canopy above the hill in order to see the migration.

[00:03:10] But for the most part, predominant fog all around the golden gate, , I think, does suppress the migration. I think a lot of birds don’t wanna migrate when there’s not tangible lift And tangible lift comes in the form of. Thermals coming off of , warming land surface, and a lot of the raptors are extremely queued into that looking for thermals and how to find them and stumbling on them.

[00:03:35] And that’s a, it’s a really interesting thing to talk about. We can get into but also updrafts from wind hitting west winds hitting the sides of the coast range, provide a corridor of air for the raptors to follow too. The fog tends to soften a lot of those opportunities. And

[00:03:50] I think a big part of , what’s creating the Raptor migration is the chance to migrate where there’s enough lift that when they can finish their migration, they. Completely on the edge of expiring. And that gets into a whole area of how high first year mortality is for birds of prey, which is generally around 60%.

[00:04:10] Wow. The raptors are preserving their energy to survive the winner. It’s a fine line. It is, Yeah. Yeah. Yeah. So

[00:04:17] Michael Hawk: If we could see right now, act as if we could. And let’s walk around the hill and tell me what you would ordinarily see, because I know there’s some beautiful sight.

[00:04:25] Oh yeah, it’s spectacular. Give listeners a at least

[00:04:28] Allen Fish: imagery, . Should we tell them that we’re just looking at about 50 feet of sky and then white . We’ll start looking toward the east. And up on Hawk Hill, we call this the East Quadrant cuz there’ll be a counter that’s dedicated to just counting in this area or at least spotting all the birds that they can see.

[00:04:44] We’re hearing the Golden Gate Bridge traffic. We’re looking right toward the North Tower of the Golden Gate Bridge, but the South Tower is a little bit to the right. Left of the . North Tower is Alcatraz Island, which is due east from the top of Hawk Hill and is an important marker for us.

[00:04:59] Moving northward from the east to the northeast. You climb up Slacker Ridge. The ridge line. Eventually that works its way to becoming the hill over the Robin Williams tunnel and it’s the ridge line that turns into Wolf Back Ridge, which is the ridge above Sausalito. So one of the great things here is getting to watch a raptor for more than a few minutes and getting to see the trajectory of its flight, how it behaves relative to wind and heat, and sun and potential thermals and all other raptors as well.

[00:05:31] Cuz raptors cue each other a lot to where the lift zones are looking off toward the north. There’s a large set of FM towers right above Sausalito that kind of form the dominant ridge line. We’re at about 900 feet here at Hawk Hill, and I think that’s about 1400 feet.

[00:05:47] So that’s one of the higher hills in the area. High Hills are a really important phenomenon to raptors because High Hill means more slope and more chance at both thermals and updrafts. And so there’s a benefit that the Raptors seem to gain by staying on top of the High Hills here. , right off to the Northwest, you can see the gorgeous Okay.

[00:06:07] You can’t see it, but if we were looking through the fog, we would see the very top of Mount Tamalpais and then the Tamalpais Ridge itself runs east to west. So it’s quite a wonderful long visual feature and it provides a lot of uplift for the raptors that are heading, mostly southward from Mendocino, Marin Sonoma, down toward the golden.

[00:06:29] Yeah, it’s a

[00:06:30] Michael Hawk: landmark that I think a lot of people recognize in the Bay Area.

[00:06:32] Allen Fish: And off to the west we’ve got Rodeo Lagoon which is one of the biggest natural estuaries. It’s actually a mixed estuary that is saline. And freshwater both, which is neat. It’s got some special fish species in there that occur rarely along the California coast because of the mix of saline and freshwater.

[00:06:51] And it’s just a beautiful center point, Great birding spot next to Fort Cronkite. Big Surfing Beach . And then moving a little bit again toward the, Southwest, we can pick up the Farallon Islands , on a really clear day.

[00:07:05] definitely not today. And then south is pretty much lined up with the very northwest corner of San Francisco, what we’d call Land’s End, or Cliff House, that area

[00:07:15] and then this incredible. East to south centered on Southeast is the whole view of San Francisco and the peninsula heading south. It’s really fun to say, Hey, there’s a Peregrine Falcon over the Transamerica building and everybody knows exactly where to put their

[00:07:30] Michael Hawk: binoculars.

[00:07:31] Yeah. Yeah. I guess that’s a really good point because I’m thinking about the interesting sites. From San Francisco to the Golden Gate and Alcatraz and Mount Tam. But those are all reference points for when you’re pure functionality .

[00:07:43] Allen Fish: Yeah. It’s interesting when you’re in the Raptor migration spotting business and you go to a new location, the first thing that the main counter does is grabs you by the shirt and says, Okay, here’s all of the identifying features in this landscape that we use.

[00:07:59] And you’re gonna hear somebody say, Here’s a broad wing kettle over knoll one. And if you don’t know what Noll one is, you’re messed up. And you need to also be ready to communicate that because of course that’s what gets everybody on a bird really quickly.

[00:08:12]

[00:08:12] Michael Hawk: now in the context, this spot here, you’re talking about some landmarks in the South Bay that’s, 60 miles away, roughly. So there’s just such a long viewpoint.

[00:08:22] Yeah. How does this spot fit in the broader context of Hawk migration along the West coast?

[00:08:27] Allen Fish: accurately, the Marin Headlands migration. Concentration point is super unique on the Pacific coast. There’s a relatively new site that some colleagues up in Sonoma County have put together at Jenner at the mouth of the Russian River, which is spectacular location.

[00:08:41] And they’re getting great migrations there, which is wonderful cuz we’re probably. 60, 70 miles from there. And we’re trading data and talking a lot about what we’re seeing coming through. North of Sonoma, there really hasn’t been a migration site that’s been monitored ever.

[00:08:57] A variety of places like Trinidad, Head on the northern California coast and some mountains around Arcata with especially all the birders and biologists that are in the Humboldt area have been located but not ever monitored on a regular basis. I don’t know anything from the Oregon or Washington coast, although there are some really rich Raptor locations there.

[00:09:17] Fallen wintering spots places like Grays Harbor and Washington and the Skagit flats up north of Seattle. There is a Raptor migration site at the bottom of Vancouver Island called Rocky Point. That also gets monitored regularly but for the most part for California, this is really a unique location.

[00:09:34] In a unique migration. There are some inland sites for Raptor migration in the Oregon Cascades and the Washington Cascades. No one’s ever picked up on a regular location in the Sierra Nevada, there are hundreds of Raptor migration sites across the.

[00:09:47] And thousands around the world. That’s a whole topic under itself. But the interesting thing is that it takes a lot of work to locate a spot and monitor it for all the peak days that you might hit, around here, September 20th, October 20th.

[00:10:02] And then try and locate a migration. And if they’re high birds, you might miss it. Even though you’re in a perfect spot, they might be just too far overhead. ,

[00:10:10] Michael Hawk: you started to talk about the topography here. Yeah. Creating the thermals and the, updraft as well if the wind is coming in.

[00:10:16] I assume that’s partly why this is a migration route for the Raptors because you have that, those topography features all up and down the coast.

[00:10:25] Allen Fish: Yeah and that’s a really key idea, is up and down the coast cuz figure a raptor that’s coming from Oregon into California they’re hitting the coast range immediately and that coast range is a free ride.

[00:10:36] That coast range is what will allow them to get updrafts and continue to fly with minimum. Physical cost and allow them to get, let’s say, to Mexico or to somewhere where they winter with enough of their body mass that they’re gonna survive. Or at least until they locate enough prey to be able to survive.

[00:10:53] So yeah the Marin Peninsula, the shape is perfect. , heading south on the right side we’ve got Pacific Ocean you got San Francisco Bay. On the left side, you come smack into this enormous, gorgeous river mouth we call the Golden Gate, which is a mile at its shortest, but it’s about three to four miles.

[00:11:11] If you go out toward the west side . on some days, the raptors look like they get out here above hawk hill and go, Whoa, there’s a big body of water here. Better get some altitude. And they seem to drift up and get some nice sky and then you can see them peel off towards San Francisco.

[00:11:25] Some days the tailwind is just fine and they skim the top of Hawk hill at 900 plus feet and they just zoom over to San Francisco and, don’t seem to have any problem at all.

[00:11:35] Michael Hawk: You commented how it seems like the Raptors might get here and they see the big body of water and they go higher.

[00:11:40] I’ve heard stories before at different Hawk watch locations where people pontificate that, that like maybe it’s getting late in the day or. If the weather is changing or something, and the raptors almost seem like they’re making a decision and they’re going higher to figure out like, what do I do next?

[00:11:58] Is this just all guesswork?

[00:12:00] Allen Fish: There’s a lot of anthropomorphizing in this and the projection but we’ve actually seen that in during the 1990s and two thousands we had incredibly energetic and absolutely stellar volunteer team who put radio tracking devices on about 80 raptors during a 25 year period.

[00:12:20] And one of the things we noticed regularly is that if we trapped a hawk, put a radio transmitter on it, released it anytime after. Two 30 or three o’clock. It didn’t go to San Francisco, it didn’t go to the peninsula. It didn’t travel over to San Bruno Mountain. It stayed in the Marin Headlands and often went into one of the local coastal valleys and just seemed to Lilo for a little bit. And I think it’s exactly what you’re talking about. I think there’s a general recognition that the cool air at the late of the day that it’s a better thing to, to just. To sit down.

[00:12:51] There have been a variety of studies, different locations on what the peak hours of Raptor migration are, which work differently for different species as you can imagine. A buteo, a soaring hawk, like a red-tailed hawk or a golden eagle, is gonna be spending more time looking for lift in the hot part of the day.

[00:13:08] An accipiter with a lot of flapping and gliding falcon with a lot of flapping aren’t as restricted to warm times of the day and tend to be more morning and evening flyers. So we’ve done a few analyses of time of day that different species fly and it, our data all bear out that way

[00:13:26] Michael Hawk: too. I know there’s some history to this location beyond the Hawk Watch, and I see these, there are these concrete slabs that are what, like 10 feet by 10 feet and who knows

[00:13:37] how

[00:13:37] Allen Fish: deep, Who knows how deep?

[00:13:39] Yeah. Yeah. I can give you a surface I guess is appropriate, a surface touch on with the history. Hawk Hill was highly modified after the beginning of World War II in order to be a spotting location for enemy craft of any kind .

[00:13:55] As well as for two cannons that were gonna be placed facing out toward the Farallons. Think of them as a cannon set onto a massive ball bearing system in order to be able to rotate and could shoot , a one ton trajectory out for about 25 miles could have hit the phons.

[00:14:11] The cannons were incredibly huge and powerful and a lot of the. The carving up quality and the cement structures were all built around this support system for these incredible gun in placements. Amazingly, the gun in placements were all put together and before the canons could be put in place, the war was over.

[00:14:32] One of the cannons is still available to see at battery Townsley, which is just north of Rodeo Lagoon, and actually what’s fascinating to me is there’s one picture of Hawk Hill prior to 1944, and it’s a big grassy hill with some coyote brush and there’s not a tree around and there’s not a cement platform around.

[00:14:53] And it’s quite spectacular. And it’s just anonymity as a grassy hill in California. And it’s. Carved up and changed in profound ways. There’s huge tunnels underneath that were all set up in order to pull the guns underneath the tunnel. um, .. We’re both distracted by band tailed pigeons. Yeah. Yeah. I, It’s funny, I haven’t seen them stop and land on Hawk Hill here

[00:15:15] Michael Hawk: before, but all I can see is a silhouette. They look like pigeons. I’ll get a photo of

[00:15:19] Allen Fish: the silhouette. At least these are the good pigeons.

[00:15:21] Yes. We see some spectacular big band tailed pigeon flocks usually in October.

[00:15:27] And

[00:15:27] Michael Hawk: That was a good 25.

[00:15:29] .

[00:15:29] Allen Fish: Yeah, that was a nice flock size. Interestingly, the last few days we’ve had a pair of adult peregrine falcons contouring the south, edge of the hill, and several of the volunteers have seen them tail chase band held pigeons as and we think that’s part of what they’re doing, but that’s the first time I have ever seen band tails land up here.

[00:15:50] Usually they’re particularly in the sky or traveling into some of the trees.

[00:15:55] Michael Hawk: the history is interesting and there are a lot of sites along the coast where you have really good visibility that were. Repurposed for military . Yeah. Uses over the years mainly, during World War

[00:16:07] Allen Fish: ii.

[00:16:07] Yeah. And, you can’t miss it up here that we’re it not for the military presence back to the 1880s this would all be just part of the city scape of the Bay Area. It would’ve been highly developed and there were attempts to develop the Marin Headlands as late as the early 1970s that.

[00:16:26] Shut down sometimes just by a hair’s breath. and truly lucky that the military held onto this for so many years. It wasn’t transferred until 1972 when the Golden Gate National Recreation Area was patchwork together from Alcatraz and Cliff House in Fort Point, Muir Woods and the Marin Headlands in order to create a one of the earliest urban national parks.

[00:16:50] Michael Hawk: Something that you commented about is finding haw watch sites may not be the easiest thing in the world. So tell me a bit about what it’s like to even see the hawks. when it’s a good, clear day and there’s a good push coming through , you have spotters looking in different directions.

[00:17:08] How far away are they when they first get spotted? How high, how quickly are they moving?

[00:17:12] Allen Fish: It’s all over the map and it depends really on the conditions of the day. On a fairly warm day, sometimes with a little east or southeast wind, the raptors heading roughly southward tend to take that headwind and rise up on it and end up on a really high line that sometimes is almost impossible to.

[00:17:32] On a day like that, we’ll actually have volunteers just watch as much as they can torque their neck upwards with their binoculars to watch the high angle. Very rarely do you see a raptor just with your binoculars. Mostly what you’re doing is spotting with your eyes, picking up a flicker of movement, putting your binoculars up, and then trying to figure out what the bird is.

[00:17:53] And if it’s really hard to get, then you try and get on a scope and try and get a tighter view with the scope at, 20 power or something like that. But tracking a raptor through the sky with a scope, as you can imagine that’s a pretty good talent and some people are great at it.

[00:18:08] And it’s it’s a beautiful payback cuz you could see such lovely detail, but it’s hard for

[00:18:13] Michael Hawk: everybody to do. So it took a lot of practice, I would imagine. It does, yeah. It takes practice just to, to see a little flicker in the sky and get your binoculars on it.

[00:18:20] Yeah,

[00:18:20] Allen Fish: you’re right. I’ve learned a trick is a lot of us use eight power or 10 power binoculars for this. I recently picked up a really nice pair of six powers, meaning I get a bigger piece of the sky than most people do. And I use those just to get a broad sense of everything going on in a particular spot.

[00:18:39] But then I also switched to tens when I, I want to get the pretty detail as well.

[00:18:43] Michael Hawk: Yeah. That’s some of the trade off with different power binoculars.

[00:18:47] Allen Fish: Yeah. On a regular day up here, the wind is a little bit from the No.

[00:18:51] There’s quite a mix of hill faces it’s not really just one clean line of hills coming from north to south. As a result there’s a lot of different potential hill faces that are getting updrafts from a west wind or a northwest wind. So depending on exactly where those updrafts are, the raptors seem to of come in on flight lines from either of those directions moving where the lift zones are.

[00:19:17] So for a few hours you might get a whole bunch of birds popping up visibly in the Western sky. Or popping up along the radio towers going down the spine of Sausalito . And a lot of times those are very different flight lines that seem to work independently of each other.

[00:19:33] And so one of the key things we’ve learned here is to spread our attention out. In the very earliest years of running the hawk watch I would just hand people a clipboard, binoculars and say, Go count the hawks. I had no idea how much methodology might be required to make it consistent. And you can imagine what happens might be a terrific bird, a golden eagle , and suddenly five people are watching the golden eagle and nobody’s watching the west for 10 minutes.

[00:19:59] So we have this quadrant system that’s designed to. Sky to four quadrants. Each spotter of four spotters are assigned a quadrant that then they track the birds in, they communicate amongst each other so that they’re not recounting a bird as long as it’s continuously visible.

[00:20:16] But the point that a raptor disappears behind a hill for a half an hour or longer then it becomes another raptor in the count. Which is to say that no human being could ever count a hawk once and only once they’re not on a raptor freeway. They’re not zooming from north to south and only north to south. Many of them seem to be double backing. We’ve put radio transmitters on birds that circled the bay and came back here a week later. One, one that went to Oregon in four days, and then three weeks later it was found south of here

[00:20:47] But there are some raptors by species and by population that move north to south through here. Swainson’s hawks are booking through broad-winged.

[00:20:55] Hawks are booking through many of the osprey are booking through. They’re heading on a long migration that’ll take them to Central and South America. Many of the raptors and the ones that probably are most common folks here are Redtails, Cooper’s Hawks, Harriers Kestrels are potentially staying some of them are moving through, some of them making Mexico migrations and some are never leaving the Bay Area and might even end up north of here or in the High Sierra September, October in the High Sierra before the snows hit.

[00:21:23] Great place to be a Raptor and eat ground squirrels and and late season prey. So California’s a really complex. Raptor landscape because of that, we have migrations going up slope and down slope on the Sierra Nevada. . Just birds moving in a lot of different ways to find pockets of pray, spend the winter. So it’s it’s both challenging to figure out.

[00:21:46] It’s a wonderful complex of movements here that’s a lot more mysterious.

[00:21:49] Michael Hawk: That’s a good point because I think pe some people listening that maybe are in the Northeast or the Midwest may not realize that, that there are a lot of overwintering raptors here too. So yeah, that adds another variable to the mix

[00:22:02] Allen Fish: so

[00:22:02] Michael Hawk: in the course of our discussion, you’ve mentioned two birds in particular that I was going to ask you about. Swainson’s Hawk and Ferruginous Hawk, I think of. More as prairie, inland. Yeah. Kind, species. Yeah. Do you see these inland hawks migrating along the coast, or do they tend to stay more inland in their

[00:22:20] Allen Fish: migration?

[00:22:20] For sure. Many of them stay inland in their migration. But here’s the twist to think about. And let’s start with ferruginous hawks. Fr hawks don’t nest in California. They nest right up to the edge of California, and they do winter in California, there’s quite a lot of ferruginous hawks in the Central Valley grasslands down in the Monterey hills and all the way down to Los Angeles.

[00:22:41] So frus hawks come in for the winter and they’re a good example of, imagine for a second that a bird that’s migrating south to get to a warmer climate and better prey availability instead goes, Oh yeah, coastal climates. I could do the same thing by cutting a right hand turn. And heading out to the left coast and getting my ground squirrels in Monterey County rather than in Sinoa.

[00:23:09] Forus Hawks are known and we’re known for many years back to the thirties and forties as being at least partly in East West migrant as well as a north south migrant. And there’s a few raptors that kind of fall into that category more often than not. A good number of Red tails do that too.

[00:23:25] Inter Mountain, Rocky Mountain, Northern Canadian, Rocky, Red Tails. Probably some of them come out to the California coast. I tend to think of the California coast and the Central Valley as a kind of combined winter Raptor magnet and thinking of them as is, if you’re gonna survive the winter and you wanna get to some good prey supplies, these are good places to come cuz you’ll be able to get through the winter

[00:23:48] Michael Hawk: here.

[00:23:48] . And the swainson’s, they’re heading all the way to South America. How do you

[00:23:51] Allen Fish: pick up on that gear? Yeah. Swainson’s are really interesting for a lot of reasons. The Swainson’s are, they’re about grasslands, but they’re not nearly as flexible in their nest sites. They like a big nest tree the way a Redtail does.

[00:24:02] So they tend to be in places like there, there are lots around Central Valley Los Banos, Stockton, Davis Woodlands, Sacramento, North Sacramento, Elk Grove. So there’s a lot of good Swanson’s numbers now nesting around those areas. And. Important to say there are only state threatened raptor species, so they get a lot of love and care, or at least political infighting when someone’s challenging habitats.

[00:24:28] We’re also getting a general movement in the last 10 years of swains and hawks nesting toward the coast. So areas like like Coyote Valley in the South Bay, but also like Sonoma Valley and Sonoma and Napa Rivers are getting swainson’s hawks nesting now. So some of those birds come coastal, not very many.

[00:24:47] It’s very easy and around the 1st of September to go find a hundred swainson’s hawks in their pre migratory stage around Stockton or Sacramento. . We’ve never seen anything quite like that around the coastal areas. But it might happen someday. There’s definitely an influx, interesting ofs, swainson’s moving coastal in the central part of California, which is neat to see.

[00:25:09] 40 years ago when Swainson’s were being evaluated for there status in California no one could find any Coastals, swainson’s, hawks within 50 miles of the coast. It’s it’s one of those unexpected phenomena that that has surprised.

[00:25:23] Michael Hawk: Is this a sign? Do you think that the populations are stabilizing or are doing better or any other thoughts as to, to why you might be seeing more numbers

[00:25:32] Allen Fish: towards the coast?

[00:25:33] That’s a great question. I’m not quite sure I jumped to the populations or species level in Swainson’s cuz the reason that they were declared threatened was because Swainson’s historically, meaning going back a hundred years, were very reliant on the big riparian stands along the major river, Sacramento River, San Joaquin. And and a huge amount of that habitat was just lost. 90% of it was just devastated over a hundred years. So that was the Swainson’s Hawk foothold for many years. Now what’s happening with Swainson’s and with a few other species is we’re seeing some adaptation for.

[00:26:10] Human planted habitat and Swainson Hawks are nesting in a few spots around the city of Davis in cottonwood trees and elms and trees. Even some conifers that you wouldn’t have expected would be swainson’s hawk habitat, but they seem to be doing okay and maybe as long as they’re adaptable on that habitat preference level and there’s enough, pray for them, they can do.

[00:26:34] Okay. It’s exciting to see because it wasn’t a species that was well known or well understood, and because of their political status, they’re a little better studied than most species now. And yeah, most of the Swainson talks are thought to go to a lot of the trackings at least take birds either fully down to Argentina, which is exciting cuz it’s truly an American, It’s an inter-American raptor. A lot of times we use that word American to refer to, of course, just the United States. But these birds took it seriously and they go to Argentina and Bolivia and Erway. Probably some of them migrate just to western Mexico. There’s some evidence from some of the California birds that they might stop out in Mexico, and you may know this, there’s a handful of birds.

[00:27:18] I, I shouldn’t say handful. No one knows quite how many, but there’s a small wintering population in the Delta that stay in California that stay around Rio Vista. And that often are associated with the eucalyptus groves. And it may be a few 10 years ago it was a few dozen birds.

[00:27:32] But it seems to be a fairly stable annual population too. One of the great things about the distribution of Raptor migration sites is actually that some of them track the actual passage. Bird or a flock of raptors from north to south in the fall. And one of the amazing places to see the Swanson’s migration and the Broadwing Hawks also is Veracruz Mexico.

[00:27:57] . And on the coast of Mexico, on the Gulf Coast, there’s a lovely convergence of raptors following the edge of the Gulf Coast around from Corpus Christi, and then continuing south into the state of our Cruz, and then also raptors following the Sierra Madre Oriental Mountain range, and coming within about 10 miles of the very edge of the coast as well.

[00:28:20] And these two Raptor lines converged between about September 20th and about again, mid-October to produce the biggest Raptor migration numbers in the. the swainson’s numbers have been estimated at at least one to 2 million birds passing through, usually in the course of about two weeks. then Broadwing talks also traveling through that.

[00:28:43] Again, with the hundreds of thousands of birds in the sky. Some colleagues of mine had a million bird day where they got to see these soaring hawks looking like bees in a swarm overhead. And part of the loveliness of it is that at that point you’ve got tens of thousands of birds in the sky working together, and they’re either working together.

[00:29:03] To identify by gliding on a broad front that might be 30 to 50 birds across east west. They’re gliding, southward to figure out who’s gonna stumble onto the next thermal, and then when one or two of them hit that thermal, which they cannot see presumably any better than you or I can, that then everybody jumps into the thermal moves towards those birds, and you get this incredible cyclone of what looks like what we call a kettle of raptors, but a kettle of raptors moving upwards in a thermal.

[00:29:35] Everybody’s fully expanded wings and tail out trying to maximize their lift, and then they get up to the top of the thermal, which is often about where the cumulus cloud layer starts, and then they peel off the top and continue on a southward. So the question is do they like migrating with each other?

[00:29:53] No one really knows, but they seem to have dropped a territoriality or even a concern about being too close to their nearest neighbor by the virtue of using each other as indicators of where lift zones are. And it’s called thermal street flying in that they’re either going up in a thermal, in this rising motion in one stack of birds that .

[00:30:14] Might be itself a thousand feet high. . So it’s a kind of spectacular form of migration. You can see that at Corpus Christi also, and you can see it in parts of the Midwest.

[00:30:23] It’s not something we see too much here. Last week we had 30 or so broading talks in a flight together, which was incredibly cool to see. And a behavior that again, looks more like the Midwest in Mexico than it does at California.

[00:30:37] Michael Hawk: Have you had an opportunity to go to Vara Cruz?

[00:30:40] Allen Fish: Peak migration. Yeah, I have I got to be a TA on trips in 97 and 98. And I wasn’t having to count it. I, the responsibility for counting that many birds, as you can imagine, you’re not counting birds.

[00:30:52] , you’re estimating fifties and a hundreds. And actually fascinatingly, you don’t do it When the birds are swirling. When they’re swirling in the kettle, your brain can’t even see it . You’re seeing the animal that is the kettle. You can see the individuals, but counting them, forget it. When they get to the top and then they peel off is when the real counters start working. Cuz then they’re all heading in the same direction and you can do tens and thirties and fifties, even a hundred birds. So it’s a, it’s an estimate.

[00:31:19] But I think they do a really good job of it. There’s a wonderful program at at the town of Cardel, C A R D E L, called the Veracruz River of Raptors, or the Rio de Rapaces, where they keep track of that migration and they do an incredibly good job of it, and they have a great web presence as well.

[00:31:37] It’s a fabulous thing to see. I was laughing because I completely left my, let’s make a quantitative analysis of this flight, and it turned to a neb buckling emotional episode. And actually, I’ll tell you, the feeling I got was we are, we talk about our rights a lot, about civil rights and about different kinds of rights, and that’s great, but boy I would’ve really loved to assert my rights to see the abundance of species, abundance of individual animals.

[00:32:05] in my own backyard that I got to see in Vera Cruz that day. It was emotionally so lovely and so incredible and I, it made me think of what would’ve been like to stand here, stand up here on Hawk Hill 200 years ago in the wintertime and see, Huge flights of geese and brats and ducks in the middle of San Francisco Bay.

[00:32:26] And to see herds of elk, tule elk along the bay edge. And, and salmon runs and, just the, we don’t talk about endangered abundance and that, that actually concerns me quite a lot. We should have some way of saying endangered species, absolutely important, but endangered abundance is also something to be thinking about.

[00:32:44] Yeah, I like

[00:32:45] Michael Hawk: that. I’ve had a few instances where just the sheer abundance of something is, emotionally moving. Yeah. Yeah, it’s a good point. Yeah, it’s interesting stuff I can always count on you for a a deep observation that

[00:32:56] Allen Fish: too many years of standing up here getting bored. So

[00:32:59] Michael Hawk: how was it that you got hooked on Raptors in the first place?

[00:33:04] Allen Fish: I was a nature boy and really lucky to grow up with a family that spent a lot of time in the I Sierra and and mostly a bunch of hunters and fishers and botanists.

[00:33:12] And instantly sometimes in the same individual people that were just, it was a great, I understood that there was stuff to be watched and learned, and it was fun to be outside. It was, and it was fun. That was a really great thing is that the adults around me made it seem fun to, to engage with nature.

[00:33:31] I had the owl thing as a kid, and that started because of a a particular great horned owl behind a particular chicken wire cage at Coyote Point Museum now known as Curiosity and San Mateo when I was a kid. That great horned held my heart for a few years when I was seven, eight years old.

[00:33:49] And I didn’t expect to ever gauge in that as a, an adult. But went up to Davis as an undergrad to do environmental law and quickly got swept into the bird community up there and then realized there are people who get paid to be ornithologists and they work in universities. And the world of consulting biology was just beginning.

[00:34:08] And, , there was a viability to the whole thing that I had never really imagined. So without any sense I would ever get a job in birds. I I finished a bachelor’s degree, UC Davis did. Summer internship, I could do studying raptors or some kind of bird and and then right place, right time was working for Bureau of Land Management doing Eagle surveys up near Cache Creek.

[00:34:31] And um, a colleague called up and said, Hey, we have this new Raptor banding station at the Golden Gate that we’re hiring a director for $15,000 a year. Ah, I thought I was just in, gonna sit pretty. And I applied for it and I had the job within the week and I got a little in-law apartment in Sausalito in 1985, and it was, $500 a month.

[00:34:54] It just felt like the perfect thing. But and the wonderful thing is this was all put together by the Golden Gate National Parks Conservancy with an understanding that this Raptor migration site was both a wonderful way of connecting people to this urban national park, the Golden Gate National Recreation Area.

[00:35:13] And it was also a chance to. W begin to deepen an experience of community science and no one had that word in their head yet. But I was really lucky to get to help put together the pieces here. And I came in as a bird biologist.

[00:35:30] I wanted to study birds by myself with no people around., I laugh now because so much of the good work here that we do is about just engaging people in birds of prey and birds of prayer.

[00:35:41] An incredible magnet for getting people to notice birds and notice nature and to think a little more deeply about what a raptor needs to survive.

[00:35:50] Michael Hawk: So you mentioned something we haven’t talked about yet. Yeah. And that’s banding as well. So you’re monitoring the migration and that’s just fall

[00:35:56] Allen Fish: migration?

[00:35:57] Yeah, so far. There is a spring migration through the marine headlands. . It’s much smaller than the fall migration. And the reason is probably obvious that predominant wind here is from the northwest, so it tends to disfavor a northbound migration of raptors on the coast and probably pushes it inland a little bit.

[00:36:16] And then the second piece is of course, that a lot of wintertime mortality of first year birds has happened in December, January, February. So by the time spring migration happens in March, April, May, there are fewer birds heading north than there were heading south. The previous fall.

[00:36:34] I’ve had different volunteers watch it from different locations. We don’t keep an annual count of it. And more out of just, we have so much commitment to making the fall migration data work. It’s just a whole nother animal to do to spring migration.

[00:36:48] And actually,

[00:36:49] Michael Hawk: It may be obvious or implicit but why, , why count the birds? What information are you gaining from all of this data that you’ve collected over the years?

[00:36:57] Allen Fish: The hawk counts are fascinating because it it really comes directly from, someone you would least expect it to have come from.

[00:37:05] The value of hawk migration counts to study population trends of raptors really jumped into the world from the work of Rachel Carson. Rachel Carson, circa 1945 is living in the East Coast and she’s writing for the US Fish and Wildlife Service. She’s writing some of the earliest forms of what you and I today would call science journalism.

[00:37:27] She’s starting to get noticed by the big publishers. but she loves to get together with her buddy Shirley Briggs, and they go birding a few times a year. And one of the regular places they start birding in 1945 is Hawk Mountain, Pennsylvania.

[00:37:47] And Hawk Mountain, Pennsylvania is really the first Raptor migration count site in the United States. That’s. Turned from a shooting gallery for raptors in my great grandparents and grandparents’ generation Raptors were vermin and you shot them. It’s just what was happening prior to about 19 30, 19 40.

[00:38:07] Hawk Mountain got turned into a place to appreciate raptors and to protect them. And in order to understand what the purchase of the property would produce, the Hawk Mountain staff, which was really a husband wife team named Maurice and Irma Brun. Were counting the hawks as they flew over Hawk Mountain every day.

[00:38:25] A lot of hard work in counting hawks, and at the time it wasn’t because anybody thought that population crashes might happen for bald eagles and paragon falcons and Osprey. Rachel starts going up to watch the Hawks in 1945. She goes at least once a year into the 1950s. at some point Rachel understands that DDT is having a pretty horrendous effect on birds, and she’s looking for sources of data that actually have been collected prior to DDT and post ddt.

[00:38:57] So basically that’s 19 47, 48. It’s after the World War ii, cuz that’s when DDT was developed for use as an insecticide to fight malaria. And at some point around 1960, she is racing the clock to get silent, spring done, because she’s in fact already ducked a few near misses. Cancer. She’s she knows she’s not gonna live a long time.

[00:39:24] She knows she needs to get the story out into the world. And she writes a letter to Maurice Brun and she says, Hey, just realized you’ve been collecting data for 25 years up there. What have you seen? And can I look through your data and study your Excel files? And he of course didn’t have Excel files.

[00:39:42] I don’t even know what the form he had. It would’ve been really interesting to know. But he hands over the data to Rachel. Rachel figures out , not only that the population declines are happening for bald eagles and peregrine falcons but that the population declined for bald eagles, which can be aged to three different age categories, juveniles, sub adults, and adults.

[00:40:04] She recognizes that the juveniles are disappearing faster than the adults. It immediately implicates d d t as a, an attack on the reproductive ability of birds, of prey, or potentially of all birds. That’s part of Silent Spring. And what’s most amazing to me is that it’s five years later after the 1962 publication of Silent Spring.

[00:40:25] And actually four years after her death, that biologists in a lab in, in Britain figure out that d D T becomes a derivative called DDE in the bird’s body. It combines with calcium ions and ties up calcium. So it cannot be produced, Do the. Amazing that Rachel was ahead of the game on that and wonderful that she pulled it off . So your question was how does this hawk migration, what’s it for, what’s the data work for? And really, the model that I came in with in 1985 was to look at population trends. And I knew the Rachel story, I knew the more East Broom story and it made sense that now.

[00:41:03] This was Hawk Mountain West. This was the chance we had to actually see what population trends were at the largest migration thoroughfare for birds of prey on the California coast. What a great opportunity to set up a measuring stick for 50 or a hundred years and see what the migration would look like.

[00:41:22] The really fascinating thing is I had my own Maurice b Brun moment in this where although Maurice started collecting data so he could say to his bosses, This is how many raptors we saved by not having shooters up here, shooting hawks. And then his data set turned out to be this incredible tool for understanding population impact from ddt.

[00:41:46] I thought I was going in looking at population trend now I. Part of it is population trend. Part of it is gonna be a climate change story, and climate change has a lot of different potential manifestations on Raptor migration. But the really obvious one is just a phenological shift in where the population peak for species might lie.

[00:42:07] Does migration get early or does it get later? Because of climate impacts and ornithologists have models for both of those, depending on the bird and the actual ecological. Steps that have created the impact from climate change to, let’s say, what a red-tailed hawk population is gonna do in response to it.

[00:42:29] So that’s what we’re looking for now with the data are both population change, but also we have a Sonoma State student and some Davis students that have worked with us on looking for population shifts in, in one species at a time. And I can tell you right now that the one that got noticed already about three or four years ago by a an undergrad at uc Davis, Olivia Wong, is that Sharp-shinned Hawks have delayed their migration, the peak of their migration by about seven days, over 25 years at the Golden Gate.

[00:43:01] And those data bear out really. , Coopers Hawks, interestingly, although those are very closely related species, Coopers Hawks have shown no change in the peak of their migration. So there’s they’re ecologically fairly different. It makes sense because sharp shins are highly specialized in their prey.

[00:43:18] They eat 95% songbird prey, and they’re highly specialized in their habitat type, which is very dense coniferous forest. Cooper’s Hawks are a little more liberal in both those, so that.

[00:43:30] Michael Hawk: Brings to mind another question that’s probably one of those unanswerable questions for a couple of reasons.

[00:43:36] We or I talk about rafter migration as if it’s one thing. And you point out that there, there are these different species with different behaviors and different drivers. So each species might be different in what is triggering them to migrate or in their methods of migration.

[00:43:54] And then climate change , which is so many unknowns. So is there a belief or is there any data, any studies that indicate what the triggering events for maybe individual species or raptors in general are to cause them to start to migrate? Is it weather? Is it their prey moving? Something

[00:44:11] Allen Fish: else.

[00:44:11] Those are, that’s, yeah. The triggering the trigger of migration isn’t well understood. And everything you just mentioned prey lows or prey disappearance from the na the nesting habitat or the natal territory, or let’s just say the natal latitude is for sure a bird gets hungry, it’s gonna start moving.

[00:44:28] So

[00:44:29] Michael Hawk: it reminded me of a good example in the Midwest is the bald eagles will often follow ice formation on water past. Yeah. So that’s obviously weather because the prey is also following the, ice formation, the geese or the ducks or

[00:44:41] Allen Fish: other things. Yeah. but then it raises a question of is the ice flow, the actual cause and effect?

[00:44:45] Is the visual change in the ice flow or is it actually a temperature change that affects both the belt, bald eagle and the ice flow? Yeah. So with 19 species that we’re looking at here, hawks, eagles, falcons vultures, kites, harriers, Osprey and then also a red tail that’s nesting in the San Francisco Bay area is gonna behave very differently from a red tailed hawk nesting, let’s say, in British Columbia.

[00:45:06] British Columbia, much more of probably a really. Really specific trigger that’s gonna quickly create a movement of birds and get them out of that area. Because if they stay around in a November December they’re not gonna live very long or there’s a good chance that they won’t. But then again, it depends on probably temperature too.

[00:45:26] Colleagues of mine up in Washington State talked to somebody last week they’re still getting warm temperatures and the guy said, I’ve still got my windows open and I haven’t started my wood stove yet, and there’s still a lot of red tails in the area. If a red-tailed hawk in Washington state is well fed the ground, squirrel numbers are good, they haven’t gone into hibernation yet.

[00:45:46] It may very well stay put there in Washington state for October, November, maybe even into December. And then if you start getting a lot of big snows, then you might get a big exodus of birds toward the south that might occur then. That’s the sort of behavioral ecological cue model. And then there’s another model I think we could say, which is a bird like the Swainson’s hawk, whereas we talked about before.

[00:46:11] Most of the entire species moves out of Western North America, goes through the Panama isthmus and travels over the court era into eventually the southern hemisphere, summer of Argentina. That’s a very genetically based timing thing, and it might be based on photo period is a lot of times what we’ve detected over.

[00:46:35] There’s a good 70 years of migration, bird migration study. Most of it’s done on pigeons and songbirds of different kinds and the stuff that can be done in a lab generally is not done with raptors. But one of the great things is. Biologists have been able to use different lab devices to change day length photo period in order to invoke a behavioral that’s got a highly technical term.

[00:47:03] The English term is migratory restlessness, which basically means the bird bunks against one side of a pen.

[00:47:10] Michael Hawk: This story in the direction want to migrate.

[00:47:11] Allen Fish: Exactly. Yeah. The German word zugunruhe is a lot more interesting but the idea is fascinating, of course.

[00:47:18] And there’s a lot of really interesting work done with that. As far as I know, it’s never been applied to birds of prey. And so the question is, do birds of prey have that same sort of mechanism or are they responding to prey changes by the birds that are undergoing a more, a genetically based and physiological based form of migratory restlessness and wonderful work that still needs to be done.

[00:47:41] Michael Hawk: There’s an excellent, newer book out by Ed Yong called An Immense World.

[00:47:45] Allen Fish: I haven’t read it yet, but I, but it’s on my shelf and I’ve listened to some podcasts with Ed.

[00:47:50] Michael Hawk: Yeah. And he talks about that he gets into some of these senses that humans have trouble even just considering exist because, we’re, we know the world through our own sensory systems.

[00:48:00] Yeah. I Some of these studies with strong birds in Europe that Ed Yong referenced, and I hope I’m getting this right, , because it was just a couple days ago that I read this.

[00:48:07] But not only was it photo period, but even when they took away the the photo period, like they made that consistent. They still had this zugunruhe behavior at the right time. In the right direction. Yeah. So there was some sort of additional timing and geomagnetic sensory for direction and other things that were providing the overlap.

[00:48:25] Interesting. Yeah. It’s so fascinating. Yeah. You can’t even begin to,

[00:48:28] Allen Fish: There was a, you, there was a great Raptor story that got unearthed in the mid 1990s relative to this, which is uh, finished biologists studying. Kestrels in captivity the Eurasian kestrel and they had a captive project and they also had a wild landscape project.

[00:48:44] We’re trying to figure out if Kestrels could see in the ultraviolet light range one way they were doing this is by putting little soaking pieces of cotton in mouse Urine and basically, Urine, like many forms of mammal urine will reflect a black light.

[00:49:01] It’s, you go, you’re raising a puppy and you wanna know where a peed in the corner of your living room, you go get a black light and you walk around and look for the stains that reflect that neon color. Fascinating study of, of figuring out that kestrels would selectively hunt in areas with lots of mouse urine stains.

[00:49:20] And clearly were using UV light reflection to do that. And then not only did they do that in the lab, but they set up a wild environment where wild kestrels were known to spend time. And the wild kestrels spent time looking for mice in the areas where these mouse urine stains had been artificially increased.

[00:49:40] And the funny thing was, is the rough legged hawks also showed up for the party unexpectedly and showed us that not only do falcons do this, but buteos do also, that they’re also using this. So it was a great, again, thinking just cuz what your senses are and my human senses are, we just can’t get in the umwelt that a another animal can and.

[00:50:02] understanding and imagining that there may be senses out there that are far more fantastic and interesting and deeper than we can even get to. But that’s the lovely thing about Ed Young’s book that I really impressed

[00:50:13] Michael Hawk: by.

[00:50:14] So the Raptor Observatory, can you tell me a little bit about the broader mission, your primary program? And maybe even where it’s going in the future.

[00:50:22] Allen Fish: Ah, I hope I know. Yeah. The Golden Gate Raptor Observatory got started in 1984, as a program of the Golden Gate National Parks Conservancy to engage the public in this incredibly wonderful Raptor migration thoroughfare, and the chance to use it as a measuring tool for Raptor populations, as well as to get people engaged in this new urban national park, the Golden Gate National Recreation Area.

[00:50:47] So we’re very close to the National Park Service staff. The volunteers are actually volunteers of the National Park Service, and then the G G O staff, the Raptor Observatory staff are Staff of the Parks Conservancy. So we’re all working really tightly together in order to create this bigger mission.

[00:51:04] The mission of the observatory is to is I have to admit it, I stole it from the Monterey Bay Aquarium, but it’s to inspire the preservation of raptors in California. and we just have this incredible opportunity in this urban area to bring people up to Hawk Hill and get them excited about Raptors and a place that you can choreograph the event and they can see what’s going by and enjoy it.

[00:51:27] And it to create some insight into what science is and community science is by engaging volunteers in the work that we’re doing here. We have two full-time staff and four part-time staff that help manage 140 volunteers. The volunteers are set up with two main volunteer teams. There’s a , group of people called Haw Watchers and a group called Banders. The Hawk Watchers or Hot Counters come up here to Hawk Hill and they conduct the daily haw count.

[00:51:54] There’s about 70 volunteers broken into teens of about six to eight, and they break the sky up into four pieces and then do this repeat methodology count from ideally 10 o’clock to three o’clock every day. From mid-August to mid-December, there’s a separate team that. Meet down in the offices at Fort Cronkite near Rodeo Beach.

[00:52:18] And that team gets together and go to banding sites that are located, three banding sites that are located in Marin Headlands, and they’ll be a team of, say again, six to eight people per day that go work on trapping and banding hawks during the day while the haw counters are out here. So there’s two different ways of keeping track of what the.

[00:52:41] Migration is doing on any given day, which is great cuz it’s a way of checking our work a little bit. Sometimes the data for those two programs, how many birds we get in a day are close and in sync. Sometimes they’re a little different because we can count a hawk let’s say 2000 feet overhead.

[00:53:00] But if it doesn’t come down into the banding area and get trapped, it won’t be seen by those people. So there are some pluses and minuses different way where the haw count is built around what are the population trends for each of the species and what are the phenological changes? The banding program is built around where are they going where have they nested or where will they nest in the future?

[00:53:22] And also what can we study about a hawk in hand in order to learn more about its biology or stressors or anything that can contribute to its conservation.

[00:53:34] So with the

[00:53:35] Michael Hawk: banding, I’m familiar with songbird banding, and very often you’re measuring weight, you’re aging the bird, you’re sexing the bird. And. Yeah, a few other data points. Is it similar? Yeah,

[00:53:48] Allen Fish: exactly. It’s really similar and in fact, bird banding and raptor banding, raptors are birds, , but it’s, but interestingly, there are very different styles of often trapping and different handling skills that are required obviously to deal with talents and beaks and big eyes and stuff like that.

[00:54:04] And the size of the animals too. But very similar. We’re doing a variety of linear. Weights a physical examination study of malt on every bird. Molt is usually something that only shows up on a bird that is at least past its first birthday. So it’s an adult bird that will give us some malt data.

[00:54:21] We take a feather sample. Feather samples are really valuable in raptors and I’m sure in all birds because you get a little bit of skin at the bottom. With that you can actually use to do population genetic studies. You can get into whole genetics just on that. We have a library of feathers going back.

[00:54:40] We tend to band about a thousand to 2000 birds per year. So if someone decides, ah, we really need to look at mercury in kestrels. In the California coast, we’ve actually got an ability to do that.

[00:54:52] Michael Hawk: So you said a thousand to 2000 per year, so that’s 10 to 20 a day or something like that?

[00:54:57] Allen Fish: It’s across about 120 days I’m not gonna be able to do math a little bit less than that then. Yeah. And there, there’s some days that are zero, We call those skunk days. This is our 40th year of banding 2022. We started in. 83 and we’ve banded more than 47,000 birds during that time.

[00:55:16] And we have band recoveries, which is the other end of the banding system for 1700 plus birds. A band recovery is when a bird that has a band on it, which is a fairly small and discreet silver band with a teeny weenie little number on it. It’s usually a bird that’s picked up and in somebody’s hand cuz it’s hard to read a band unless you have it in hand.

[00:55:41] And that banded bird may be. It may be at a rehab facility. It may be a roadkill, it may be a window kill that ran into your plate glass window. But whatever the chance is for somebody to, to read that band and then return it to the bird banding lab that is run by the U S G S in in Washington dc.

[00:56:00] That roundabout way of getting information back means that we get a band recovery rate of about three to 4% okay. For just the silver band. In the last six years, our banding manager Teresa Ely, has been putting an additional band on the opposite leg that’s called a color band or a v i D band.

[00:56:23] And a v i d band is bigger and colorful with a big digit on it that allows it to be recognized and visible to a good pair of binoculars and someone working hard to get a sighting of it or a good camera of course. And that’s actually increased our band recovery rates by about twice. So Red Tail Band recovery is jumped from 4% to 8%.

[00:56:47] And that might sound small, but imagine if you’re banding, let’s hundreds of red-tailed hawks a year. Jumping from four to eight is a pretty big deal in terms of numbers of band recoveries that result from that. And obviously we want to, we wanna maximize that band recovery rate. As much as we can learn about the birds.

[00:57:03] Michael Hawk: Oh, Oh. Um, Deci. . Ah,

[00:57:06] Allen Fish: great. Oh, we got that on tape. Good. Nice. You just had a little shadow come through.

[00:57:12] Michael Hawk: I could see its tail. Yeah it, it went right behind you and as it went over the ridge here. Yeah. I could see the underside of its tail. Excellent. Good. Good. If somebody forced me to guess, I would say sharp chin, but

[00:57:24] Allen Fish: yeah.

[00:57:25] Yeah. If it looked nice and little that’s, and sharp chins seem to do a lot of like contour hunting on days like this. Yeah. And I’m sure it benefits them. They get some white cro sparrows and things. So

[00:57:35] Michael Hawk: is there anything else that you’d like to say about

[00:57:37] Allen Fish: banding operations? Yeah, banding birds in general has two pretty big benefits that are largely built around the band.

[00:57:44] And either waiting for a band recovery, if you were banding, white crowns, sparrows, you’d be waiting a long time for a band recovery unless you’re working at a location where that same population continues to return. For raptors, there’s not a lot of returning to these locations.

[00:58:00] We’ve had a few birds repeat, and I gotta tell you about one of them. I was in the office one day maybe 15 years ago, and one of the banders radioed to me from a banding blind and said, Alan just caught a female Coopers Hawk. She’s an adult and she’s already banded and it looks like a really old band.

[00:58:18] This gentleman’s name was, And I said, Wow, give me the band number Bill. I’ll go look her up. And so I went on, got onto our banding database, and I pulled up the number and just chills. Went back my head and I said, Bill you were holding her 15 years ago. You were holding that individual Cooper’s Hawk.

[00:58:38] You banded her. And the chances. Three to four banding blinds and hundreds of volunteers who worked for us and trained to be banders over time. Bill, it was one of our longest time banders, but for him to have been in the same blind, to have picked up that bird 15 years later and for that bird to have survived 15 years, for a few years, it was the longevity record for Cooper’s Hawks.

[00:59:01] The other part about banding that G G O has been great at pioneering and largely with the help of a Raptor biology lab at uc Davis run by Dr.

[00:59:09] Joshua Hull. And Josh trained here as a bander, went through graduate school studying raptors is now a endangered species branch chief at US Fish and Wildlife Service, but also runs a Raptor biology lab as an adjunct professor at uc, Davis and Josh has basically taken seriously something that for me was a dream 25 years ago, which is we have these raptors in.

[00:59:34] We have maybe 15, 20 minutes of their time. They’re stressed, they’re not happy about this. But what can we learn in that privileged little segment of time that benefits the Raptor we have in hand? Joshua has pioneered studies of looking at population genetics for raptors and actually collaborated with other raptor banders across the United States in order to understand the population genetics, let’s say, of red shoulder hawks.

[01:00:03] And how does the red shouldered hawk picture genetically look across the United States? Where did Red Shoulders evolve? Where did they form bottlenecks in populations that. Dozens and hundreds of years ago. And also could we possibly say that Red Shoulders were more than one species across the continent and we haven’t gone down this path, but the red shoulders from the California coast and the East Coast are genetically very separated and would justifiably be called separate species.

[01:00:34] We’ve also studied West Nile virus infections. We know that 10 to 15% of red shouldered hawks just coincidentally. Have survived West Nile Virus and actually have antibodies, high antibodies in their bloodstream for West Nile virus.

[01:00:49] That was a really exciting bit of biology to get, cuz West Nile devastated some owl populations and corvid populations. So to get a little bit of a sense that there was a tool here that the Raptors were able to evolve a West Nile virus antibody in some way was really amazing.

[01:01:05] We’ve studied mercury loads. We’ve studied anticoagulant, rodenticides. How many red-tailed hawks carry rod genocides in their bloodstream? The juvenile red tails we’re capturing here, about 8% of them. Wow. Are, they’re only four months out of the nest. They are babies and about 8% of them already have a cocktail of some sort of rod genocides in their bloodstream.

[01:01:26] So really important stuff to again, take a pulse or look for the stressors that the raptors that we have in hand without prolonging their time in hand to understand what they might be going through in their real lives. So banding has some really deep potential. Part of it needs cooperators, scientific cooperators with expertise in areas like genetics and disease, and we’ve been really lucky to have that with the uc Davis lab that Josh has been able to cultivate.

[01:01:54] When we

[01:01:55] Michael Hawk: first met here on the Hill, you were, before we were recording, you were telling me about some DNA bar coating studies as well. Was that through the same lab that you were talking about? Uc, Davis.

[01:02:04] Allen Fish: Yeah, exactly. Let me tell you a little bit about that. So this is the work of recently received his doctorate Ryan Bourbour

[01:02:11] Ryan has been working with Josh Hull and a variety of Raptor projects and working as a volunteer bander for G G O over the years of banding hawks one of the things that we’ve all made fun of is how messy some of the beaks are on some of these raptors coming in, and particularly the bird eating hawks, sharp-shinned hawks, and merlins, which are Falcons, you end up with a lot of.

[01:02:33] food particles sometimes little blood, sometimes even tissue. Around their feet and their beaks. So, Ryan set up a study where all of the banding volunteers had small vials of alcohol and a little swab, and they would collect that material. Off the beaks of sharp shin talks in Merlin specifically. And then work with the genetics lab at uc Davis , using DNA barcoding, analyzing for the full range of possible bird prey species, what all of these might be.

[01:03:06] Ryan just gave a presentation to the British Ornithological Union on this as a, on a tremendous community science project because he did something really interesting with the data. He, first of all figured out all the species that were represented on sharp shin hawk, feet and bills over the course of two seasons.

[01:03:25] And that itself is

[01:03:26] Michael Hawk: amazing, incredible .

[01:03:27] Allen Fish: Yeah and I don’t have the entire heat. Basically out of something like 600 individual swabs, we got something like 1400 different individual birds. So somewhere between One or three prey birds per hawk.

[01:03:41] And then on top of that just an incredible array of something like 50 species of songbirds and some of them extremely common like the thrushes swainsons thrush, hermit thrush really common yellow war are really common. fox sparrow really common and then a whole lot there, like ones of twos and ones and twos.

[01:03:59] A range in size for sharp shin hawks from band-tailed pigeon, which are two to three times as big as a sharp shin hawk to an Annas hummingbird, which are quite small of course. So really interesting range. That was possible as well. What he then did though that was really fascinating is

[01:04:15] he got all the eBird data for the weeks specifically just before those individual raptors were caught, and then considered how raptors selected prey birds, either relative to their proportions that they were existing in eber data in the wild, or actually. Against the proportions, suggesting that there was some really intense selection of that.

[01:04:40] A sharp chin might be like just out for white breasted nut hatches and only nut hatches. So it turned out the former was more the truth that they were collecting prey birds in proportion to the number of birds that were around. Really fascinating data right there. Combining two major citizen science efforts in order to understand um, what he calls what fuels migration, what fuels raptor migration

[01:05:04] we know a lot about Raptors on nesting grounds. We know a pretty fair amount about wintering grounds. We know very little about what’s happening in migration in terms of do they hunt every day? Do. Do they get up in the morning and hunt for two hours and then have a cup of coffee and go to Mexico?

[01:05:21] We don’t know. Ryan’s work was fascinating and gave us some early insights that hopefully is really pioneering work in ornithology and hopefully will be picked up by other people as

[01:05:31] Michael Hawk: well.

[01:05:31] Yeah, I could see a data set getting collected. And then you mentioned merging two different data sets, and I can imagine that as you start to get some satellite tracking or telemetry tracking as well, with some of these birds, you’ll be able to connect more of it.

[01:05:44] Yeah. Maybe that’s a good lead in as to How do you see the world of, where do we go next

[01:05:50] Allen Fish: going?

[01:05:50] It’s a great time to be alive because of nanotechnology. Radio tracking systems have been around for 60, 70 years for birds, and we’ve done a fair number of radio tracking.

[01:06:03] Studies of of some of the common hawks here that could carry a radio tracking device on their body. We’ve tracked birds to the Mexico border from here in four days. And we’ve tracked Red Tails on a variety of weird, interesting migrations that really taught us early on that hawks were not just going from north to south, that there was a meandering quality from any birds.

[01:06:25] We’ve done about 15 satellite trackings of mostly red-tailed hawks, and again, showing a pretty wide range of red-tailed hawk movements. And satellite tracking is also a little bit restricted right now for raptors because tracking transmitters are still not terribly small.

[01:06:45] They get down to around 10, 15 grams a. Depending on how, usually how big the the battery is. The battery is often a solar charging battery, so you need a little solar battery pack. The idea is you wanna keep that weight under 3% and we like to keep it more like at 2% of the bird’s body weight.

[01:07:03] as Satellite transmitters get more nano, which is obviously happening.

[01:07:07] We’re gonna have opportunities to go from Turkey vultures and red tails down to Cooper’s Hawk sharpens Kestrels, Merlins and some of the smaller raptors and understanding more about the nuances of their behavior. And there’s a lot of incredible satellite tracking being done around the world right now, and a lot of it online that allows you to see major international migrations for birds of prey.

[01:07:30] And it’s something that will be really exciting to develop here too. There’s two really interesting forefronts happening in terms of technology, and one of them actually is a radio tracking device which tends to be an old school technology, but it’s a new school application.

[01:07:47] The acronym for this work is Motus, M O T U. And a motus system is very small radio transmitter that could be put on any of the Raptor species or for that matter, a bat. And the idea is the transmitter needs to come within five to 10 miles of a Motus tower, and Modus Towers would be set up in a place so that they are on a receiving line for birds or bats or moving into a particular area.

[01:08:17] There are some places around the Great Lakes where Modus Towers have been stretched. 10, 20 miles in order to create a kind of receiving fence to enumerate the numbers of pass throughs by a bird with a transmitter. So it’s not gonna track a bird from here to Mexico, right?

[01:08:33] But it’s gonna give us a Oh yeah. Bird. So and so just flew by Marin County and try and understand the timing of bird movements. And with enough transmitters on enough birds, which are fairly small and expense, it’s two to $300 per transmitter. It allows us to look at a lot more birds and quantity, as well as to get together with biologists working across a bunch of taxonomic lines like the bat people, like the songbird people, and actually study this On more of a landscape scale.

[01:09:03] . So we’ve got a small group in Marin that’s been talking about how to position towers around Marin or around San Francisco Bay in order to create some of these receiving areas. . A tower costs like 3000 bucks to put up, and of course someone’s land needs to be secured for the tower, so get that power at the location, power at the location

[01:09:21] so I’m really excited about that. For Marin County. It could take five to 10 years to develop, but

[01:09:26] Michael Hawk: lots of good hope.

[01:09:27] And a question that’s been in the back of my mind, take it in a little different direction. So for anyone listening to this who’s interested in Hawk watching, maybe they’re already a birder, maybe they’re new, to the realm. What kind of skills does somebody need to get into this area?

[01:09:45] What do they need to learn? How do they look at a hawk flying through the

[01:09:47] Allen Fish: air? The first thing that came into my head was modesty or humility. And honestly, because when you’re learning burden unification, when you’re learning rap cation

[01:09:55] the resources, the books, the websites whatever they are are never adequate. There are so many variations on a red-tailed hawk and the plumage is of red-tailed hawks that are really difficult to capture in any one book. So your field time is really important. Your field time working with somebody who knows just a little bit more than you do, but is also honest about.

[01:10:17] When they don’t get something right or when they’re not sure of something that you’ve got some humility there too. Beware of perfect experts. . So time in the field is absolutely the best thing. And one of the great things about a place like Haw Hill, and not that there’s many of them in California, but if you can get to a migration spot or a ridge line where you can watch birds and if there’s a few people around that can go, Oh yeah, that’s what a harrier flies like.

[01:10:44] And that’s what a paragon flies like. And just to get that kind of intuitive part is really useful. And I’m a big believer in student. The person I wanna stand next to is the person who’s constantly checking their work, reevaluating their work, reading everything they can get their hands on, watching every video they can get their hands on is outside a lot and is constantly asking new questions about what they knew and what they thought they knew.

[01:11:11] I don’t wanna be around a professor. I wanna be around the best student. And that’s where I’m gonna get the most, but also be excited about what might be out there. So learning nuances of shape and flight is really useful.

[01:11:24] I know for me as a birder and a, as a young birder it was all about the field mark and learning the move beyond field marks to just a whole lot of details about. About size and shape and things like that. We had a palm warbler up here a few days ago and palm warblers are one of the few weird, not very common warblers in California that I feel like I have a pretty good handle on now because I’ve seen so many accidental palm warblers around and that little palm warbler tail tipping and searching style and poking around a bush is just such a, it seems like a really wonderful sort of essence of what a palm warbler, it behaves different from a yellow rump warbler or from the warblers I’m more experienced with and I feel like I’m just starting to get a handle on what Palm Warness is.

[01:12:13] And I guess that’s where I want to go is that each of these raptor species can look really similar in the book, and then there’s some that are very much have their own. Merlin ness or their white-tailed kite-ness or their red-tailed nest or their ferruginous hawk-ness. The exhibitors, sharpp coops very hard to identify, demand a whole different level of practice And every year is a new year for people getting started with hawk counting again.

[01:12:40] I can see people are kind of getting back on that bicycle and practicing again and having a humility about it is really useful. I’ve

[01:12:46] Michael Hawk: seen cases where you might even have an ACIAR perch nicely with good lighting, tens of meters away and people are still not quite sure which one it is.

[01:12:56] Yeah. Much less flying in the air. Yeah.

[01:12:58] Allen Fish: They can even be difficult to tell. It can be, and I’ll tell you what You want, if that bird is perched, if exhibitor is perched in your backyard, if it’s staking out your bird feeder and you wanna figure out if it’s a sharpen or a coupe, what you’re gonna wish for is that you have the vental view, You want the belly view.

[01:13:15] Cuz if you have the belly view, you can see the full ray and the. The tail is key. You can see the full ray of tail feathers and on a Cooper’s Hawk, the inner tail feathers much longer than the outer tail feathers so that the tail shape at the bottom is a nice big scoop. And sometimes you can see that from the back, but usually the back hides the shorter length tail feathers, so you can’t quite tell.

[01:13:40] So the coop sharp difference see, can be really hard that way. Yeah. But there’s there’s a lot of good online information on accipiters. Highly recommend books by the late Great Jerry Liguori. Jerry just passed away recently and he was just a fierce, incredible writer.

[01:14:01] Jerry was a really wonderful student, again, passionate student, and kept looking for new ways of doing Raptor identification. Wrote two great books Hawks from Every Angle in Hawks at a Distance. And then jerry Lory co-wrote with Brian Sullivan, a wonderful set of text notes for the Photoshopped guide that Richard Crossley has pioneered. And Crossley’s work is for me, it’s a little complex cuz you get one screen of sky and landscape with 35 kestrels on it and you’re never gonna see that in real life.

[01:14:34] So it’s a little bit of a fake, but on the other hand, you do get every different angle on plumage and color and light experience in in that landscape. Yeah. So it’s creative about, with taken with a grain of salt. It’s actually a really interesting technique. So Great bird guides.

[01:14:47] The Wheeler Guide to Rap Identification and the Peterson Guides written by Bill Clark are also very

[01:14:53] Michael Hawk: good. And you mentioned Jerry Liguori and Brian Sullivan. They have an app Raptor ID app. Yes. Includes video and it, Yeah. It adds, And some voiceover is pointing out the field marks showing birds in flight.

[01:15:05] Yeah, that’s, that was helpful for me.

[01:15:06] Allen Fish: Yeah, Hawk Watch International sponsored that and it’s a terrific resource and really good for getting to see the flight styles over and over again. Hope for, hopefully there will be more of those things in the future. So from

[01:15:18] Michael Hawk: What you’ve seen up here, are there any population trends that are surprising or concerning?

[01:15:24] Anything that comes to mind? Yeah

[01:15:26] Allen Fish: We’ve got raptor counts now going back to at least to the early 1990s that I feel pretty consistent and good about. Right now the trends that most concern me are, some of the local and more specialized raptors, white tilt kites big mouse eaters, and very much, if you look at them, the range map in your sibling guide or something like that, you’ll see that they’re fairly contained in California, a little bit in Florida, a little bit in Texas.

[01:15:52] So the separated tiny range areas mean that they’re very vulnerable to possible crashes in populations and being mouse eat. Entirely. They’re very specialized in their prey. So that’s a bird of concern for me. And we’ve been seeing a steady decrease in numbers since about 2004. I say

[01:16:13] Michael Hawk: anecdotally since I moved back to the Bay Area in 2011, it seems like a continual decline in my area.

[01:16:21] Allen Fish: . And it may be as much just mouse population crashes since the drought started.

[01:16:25] Again, it’s one of those things about sharing data that, that getting if you’re doing Raptor studies, having some prey specialists, a good mouse person in your pocket is a great, useful thing to have. Harriers are also mouse eaters, big mouse eaters, Northern Harriers are Very dependent on the condition of baylands and grasslands around California.

[01:16:47] Unlike the kite, they’re found from Atlantic to Pacific and from Tundra down to desert. So they’re probably less at risk, but locally harrier numbers seem to be falling off quite a bit. They’re also our only ground nesting raptor, so it puts them at some vulnerability both to agricultural techniques and grasslands and also just being disturbed by people and predators as well.

[01:17:10] Those are two of the big ones. Sharp shin kind of falling off a little bit from the averages and mostly average numbers of raptors for most of the species have been falling off what we saw 15 and 20 years ago. So the next period of time, We’ll be interesting to see how birds bounce back.

[01:17:29] Some of the raptors that we never thought would be adapted to urban areas are at least nesting is increasing in the Bay area. Coopers Hawks seemed to be doing really well nesting in urban zones, and that wasn’t known about two to three decades ago, and that’s happening all over the United States.

[01:17:45] So that’s neat. And it may be that bird feeding in backyards as well as the development of urban forest landscapes is probably helping them. Osprey numbers are increasing the Bay Area. We didn’t have an osprey nesting population on San Francisco Bay until about 1990 and now there’s something like 50 to 60 nests between the Napa River all the way down to Hayward on the East Bay side and they’re all in human made towers. So it suggests that there’s a sort of recapturing and behavioral adaptation that’s taken place in Osprey numbers, so that’s pretty neat.

[01:18:17] Um, A lot of people are concerned about fire broad fires and impacts on forest hawks, like sharp shins and Cooper’s Hawks. I am two goshawks, of course, high Sierra Raptors that are gonna be impacted by fires. But so far the jury’s still out. So we’ve got things to learn about.

[01:18:33] Michael Hawk: So it’s a mixed bag, but a general downward trend is,

[01:18:37] Allen Fish: yeah. Sadly some adaptability and birds like swainson’s and probably bald eagles and that are slowly eeking their way back and osprey too.

[01:18:46] It’s a well worn statement that raptors are, environmental barometers that they’re in some ways a symbol of health of a local environment, whether it’s a Cooper’s Haw in an oak forest, or whether it’s a Northern harrier in a bayland setting, or white tailed kites and willows.

[01:19:01] And the wonderful thing is Raptors do have some top of the food chain ability to represent a lot more of the health of a local environment than let’s say a white crowned sparrow does. And it’s a good reason to watch Raptors and keep track of their numbers. Aside from just learning them, what other things can people do to help Raptors locally?

[01:19:21] One is to promote open space. Raptors benefit hugely from open space, sometimes even very degraded areas. After a lot of the activity was moved out of Candlestick Park State Park that became a very important raptor refuge because of the ground squirrels there. And I’ve heard that for a variety of park lands around the Bay Area, that when human activity was pulled out a little bit, ground, squirrels, predominated and raptors became very very active in the area.

[01:19:47] There are a lot of local problems like the use of rat poisons rat poisons are a huge problem for birds of prey that we’re discovering more and more about. And California laws are changing really quickly, but not quickly enough.

[01:20:00] A lot of our rat poisons are anticoagulants . They don’t kill the rat outright as much as they weaken it or put it into a dehydrated state that actually sends the rat outside of your house to die looking for water. But at the same time, it obviously sets it up to be a great.

[01:20:19] prey morsel for local raptors, and we have so many local Raptors. Barns, great horns, red shoulders, Coopers red tails, kestrels, nesting in urban and suburban zones that these rat poisons now are becoming the cause of secondary poisoning deaths for a lot of these birds of prey and Marin Wild Care as a rehab organization in 20 12, 20 13, 20 14, put every one of the raptors they received at the rehab center through a blood test, and they discovered that 80% coming in, had some. Anticoagulant rodent side in their bodies. So this is a huge impact and one that kind of hides below the surface.

[01:21:01] Cuz a lot of time the raptor doesn’t die outright of something that looks like poisoning. It looks like it ran into a a power line or it ran into a window, or it did something stupid because it was in a debilitated state. Those are particularly important things to watch out for and anything anybody can do to educate your local community about it.

[01:21:20] There’s a great raptor, , anti rodenticide website called rats and the rats organization has done a huge amount in the last five years in California to eliminate legal loopholes for using rodenticide. , hopefully that’s on its way out.

[01:21:36] The website’s great cuz it has a lot of the science behind a lot of this stuff, which again, doesn’t get a lot of visibility in, in, even in the conservation biology communities. So nice to find all this literature in one spot. And of course, learning the birds. Many years ago I was walking across the Cal campus and ran into a great sign that I’ll never forget that said, How can you save the environment if you don’t know what it is? And it was an advertisement for a plant taxonomy course. It was like basic California plant taxonomy.

[01:22:05] And I. That’s great. Just to put the little idea there, that part of saving the environment is learning what it is and being a responsible student for figuring out what all these great magnificent species that were honored to still have on the planet nearby in California and in the Bay Area.

[01:22:22] There’s a lot of good work to be done and appreciate the chance to get people thinking about it, but also just to come up on Hawk Hill and enjoy these birds during fall migration and any High Hill in California is really a great potential fall migration spot. So you don’t necessarily have to try to the Bay Area, but any High Hill or North South Ridge, we’ll get you a few Raptors migrating in September and October, November.

[01:22:45] Lots of great

[01:22:46] Michael Hawk: thoughts and pointers. Alan, is there anything else that you’ve been wanting to. Holding back on that you’ve been wanting to talk about, but

[01:22:54] Allen Fish: haven’t, I think we should bury this conversation and just let it roll. It is getting cold thanks for the chance to keep talking. I appreciate it

[01:23:00] Michael Hawk: thank you for being willing to still do this despite the weather and the continual it’s, dare I say foggier now? . It’s foggier. Now Bolder. Now Windier. Now . Yeah. Yeah. But thank you for sticking it out and

[01:23:14] Allen Fish: doing. Oh yes. Yeah. This is nice. It’s fun to get a beer and talk with you and get to show off this beautiful foggy.