Raptor Tracking

One of the research projects at GGRO that I got increasingly involved with during my internship involved a new and exciting piece of technology called a GSM tracker. Put simply, this is a small device we can affix to a bird. Recharging via solar power, the device will periodically send us the GPS coordinates of its current location, much the same way that text messages are sent cell phone to cell phone.

Of course, if the device isn't able to recharge (for example, if the bird is hanging out underneath dense vegetation or the bird preens a feather on top of the solar panel) the battery will die and we will no longer receive signals. Similarly, if the bird isn't in the range of a cell phone tower, we won't be able to receive the "text messages." Despite these occasional technological hic-ups, however, the technology provides us with a lot of useful information, namely the exact locations of where these birds are traveling. While band recoveries usually give us one location, sometimes two, with these devices, we can track the exact movements of these birds throughout their entire migration (which would be kind of creepy if we were talking about humans…).

I got a chance to see a juvenile, female red-tailed hawk get a GSM device affixed on one of the last days of the research season. The bird is trapped at a banding station. During this process, a traditional falconry hood is put over the bird's head to keep it calm. The device itself is harnessed onto the bird, mimicking the idea of wearing a backpack. The harness is sewn together with dental floss, of all things, because that will decay after about a year, the expected lifetime of the device.

Once the device is secure and we've ensured that it is safe, the bird is released. Each of the GSM-birds gets a name to make it easier to keep track of each of them. The first GSM-bird was named Augusta, and each subsequent birds has had a name starting with the next letter of the alphabet. This hawk was the J-bird, and so the banders named her "Juanita."

After the bird is released, it is a waiting game. And eventually, we started to receive GPS-coordinates from Juanita's device. Juanita flew south from the Marin Headlands, and after only a couple of days, settled into a neighborhood, where she remained for the following month. This map shows the positions of all of the GSM-birds that have reported. Juanita is pink.

Here is a zoomed in version. There's clearly plenty of prey to eat and nice trees to perch on in this neighborhood.

The map can be seen here: http://www.parksconservancy.org/conservation/plants-animals/raptors/research/gsm-tracking.html

So far, eight birds have provided us with interested data-points, all of them red-tailed hawks. And the lesson so far, which further confirms what previous studies of raptor migration have shown, is that there is no rhyme or reason to red-tailed hawk migration in the West coast. It seems that they go where it is most convenient for them to go.

The Glamorous, Fabulous Ferruginous Hawk

(I'm no longer in California. I'll try to get my last few CA-themed blog posts written in the next couple of weeks before moving on to my next adventures!)

This is an article I wrote for the Golden Gate Parks Conservancy February 2014 e-ventures newsletter. It is currently published here:  http://www.parksconservancy.org/about/newsletters/park-e-ventures/2014/02-ggro.html

“Boy, I’d love to see a ferrug right now!”

This is one of the most often spoken statements by hawkwatchers at the Golden Gate Raptor Observatory, and understandably so. Large and majestic-looking, the Ferruginous Hawk (known as the “ferrug” in hawkwatcher short-hand) is arguably one of the most beautiful raptors we see at the GGRO. Adding to its desirability, Ferruginous Hawks are spotted from Hawk Hill no more than 20 times in a given year.

The Ferruginous Hawk is so named for the rusty-brown color infused on adults’ heads, backs, and upperwings. In the world of chemistry, rust is oxidized iron, known in the olden days as ferrous oxide. Add a couple letters and “ferrous” become “ferruginous.” The hawk’s scientific name also indicates its glamorous, physical appearance: Buteo regalis, which literally translates from Latin to mean “royal soaring-hawk.”

Often confused for an eagle because of its size, the Ferruginous Hawk is the largest North American buteo, the genus of hawks that includes Red-tailed Hawks, Red-shouldered Hawks, and Broad-winged Hawks. Identified by its characteristic long, tapered wings, large head, and robust chest, the Ferruginous Hawk is only one of three North American diurnal raptors to have legs feathered all the way to the toes (in addition to Rough-legged Hawks and Golden Eagles). In adults, these leg feathers are rusty-brown, forming a characteristic “V” shape that stands out when seen in flight. The chest of the Ferruginous Hawk is usually pale white, while the underwings of adults will have various amounts of rust-colored markings (brown in juveniles). 

Perhaps the most striking feature of these hawks, however, is the tail. In flight, the underside of the adult tail looks completely white, sometimes with light barring or some rust-color shining through towards the tip. Juveniles often show two to three gray bands towards the tip on the otherwise white tail.

During my first visit to Point Reyes National Seashore, I spent almost an hour watching a juvenile Ferruginous Hawk hunting over the grasslands. Using its long wings and tail to still in the air and moving its head back and forth, the hawk actively searched for jackrabbits and ground squirrels. Occasionally, it would stoop down and fly low over the ground before returning to its height to continue looking for prey. Cooperative hunting has also been reported in Ferruginous Hawks, where a male and female work together to catch prey.

For the motivated hawkwatchers, there are a few great places in the Bay Area to see Ferruginous Hawks overwintering. In Point Reyes, Pierce Point Road and the trail to Abbott’s Lagoon are surrounded by grassland habitat, ideal for seeing Ferruginous Hawks. Other areas worth checking out include Livermore Valley in Alameda County, Chileno Valley on the Marin-Sonoma County borderlands, and the southern extension of Chalome Valley between highway 41 and Bitterwater Road. The best time of year to look for Ferruginous Hawks in these areas is between December and February.

Seeing a Ferruginous Hawk from Hawk Hill is quite a treat. Although a sighting is rare, it is clear why hawkwatchers consistently consider this elusive bird to be truly glamorous!

(Thanks to Allen Fish, Bob Power, and Tim Behr for tips on where to find wintering Ferruginous Hawks!)

Road Trapping

Yesterday, I got a chance to experience "road trapping," which involves taking our raptor banding show on the road. Essentially, we drove around until we spotted a raptor. We chucked a trap out of the window of the car, waited for a few minutes to see if we could catch the bird, and then banded it right out of the trunk of the car.

Emma and Buzz band an American kestrel. All the banding materials are in the back of the car.

We spent the entire day driving around the Davis, CA, area. However, time flew by as we were constantly stopping and occasionally banding some incredible birds. Three of the six birds we banded yesterday were American kestrels, the charismatic little falcons that I have come to love this year.

Adult, female American kestrel.

Female American kestrels are aged by the final black bar on their tails. In this case, it was an adult bird because the last black bar is so much thicker than the other bars.

We were not successful in catching every bird we set the traps out for. Even so, just getting a chance to see some of these unique raptors was worth the trip.

An adult ferruginous hawk (the first adult I've ever seen). This bird is the definition of majestic.

Dark-morph adult red-tailed hawk.

The highlight of the day, however, was banding three adult red-shouldered hawks. There is a theory the other GGRO interns have developed that any black-and-white bird (especially if there is a hint of red) will automatically qualify as one of my favorites. Recent examples include pigeon guillemots, black phoebes, and California condors. Thus, these beautiful birds immediately won me over. So much so that I am writing in an uncharacteristically gushy way about them. But I'm putting science aside for this entry, because these birds are just plain amazing. See for yourself:

Red-shoulder #1.

Look at the black and the red and the white. Just look at it! Wow!

I demonstrate why this bird is called "red shouldered."

Are you seeing this bird? It's so cool!

Close-up of the feathers. Amazing.

Red-shoulder #2 was much redder on the body. Do you see this bird? Do you see how beautiful it is?

This is another shot of a red-shoulder looking incredible.

Red-shoulder #2 release shot.

This is red-shoulder #3, caught about 27.3 seconds after red-shoulder #2.

Some red-shoulders have particularly prominent hackles (feathers on the back of the skull), giving them a spiky-headed appearance.

So, here's the deal. I like birds (obviously). That being said, I like to think of myself as a scientist, biologist, what-have-you-ist. I like to take an objective perspective of my work and not resort to constant "ohhhhhhhh those birdies are soooooo cuuute!!" gushiness. That's not why I'm motivated to do what I do. However, I think it is important to take a step back every now and then and acknowledge the simple fact that these creatures are amazing, beautiful, incredible. Yesterday was an experience in research, but more importantly, in was an experience in awe-stricken appreciation.

Kiting

Ask most anyone to name some different families of raptors, and the list will usually include hawks, falcons, eagles, osprey, and sometimes even owls. It is rare, however, for someone to mention kites, at least in their first breath. The large, soaring buteos, the swift, agile falcons, and the majestic, charismatic eagles seem to be much more prevalent on our raptor-radars. It is a shame that kites are often absent from these lists, as they are unique and impressive raptors in their own right.

There are five species of kite that can be seen in North America. The one that has become familiar to me during my time in California is the white-tailed kite. Falcon-shaped with flight resembling that of a gull, the most prominent feature of this kite is probably its black shoulder patches. This inspired ornithologists to change the bird's name to "black-shouldered kite" during a brief identity crisis in the '80's.

An adult white-tailed kite is a striking sight to behold; in addition to the black shoulder patches, distinctive black carpal patches can be seen on the underside of the wing. The head, body, and tail are completely white, and the underwing becomes progressively dark moving closer to the tips of the primaries. The adult's eyes, surrounded by a patch of black, are a deep scarlet. Juveniles look similar, but with rufous-colored feathers along the breast, a narrow band towards the tip of the tail, and a brown-colored eye.

(photo: www.wikipedia.org/)

During a birding field trip to Skaggs Island yesterday, white-tailed kites were one of the most frequently spotted species of the day. Across the landscape, I spied multiple kites, perched in the bushes or displaying my favorite raptor behavior: kiting. In this hunting strategy, which just so happens to be the origin of their namesake, white-tailed kites hover in place over the landscape, flapping their wings in a way that is necessary to hold them and place and captivating for the hawkwatcher. The kites will continue to do this behavior until they see a rodent (which they prey on almost exclusively) and stoop down to strike or move on to investigate a different area.

When kiting, white-tailed kites look almost angelic in appearance.

Kite populations were declining rapidly at the start of the 20th century due to hunting and egg collection practices; white-tailed kites were all but extinct in California by 1940. However, thanks to protective legislation and the abundance of prey available to them at agricultural sites, their populations have rebounded since this time. Even so, there are rapid fluctuations in white-tailed kite population numbers from year to year due to similar fluctuations in prey availability. This makes it challenging to collect accurate censuses, and many ornithologists believe that we should still be watching white-tailed kites closely for signs of sudden, significant decline.

While white-tailed kites and all their kite cousins may not be the poster children of the raptor world, they are equally impressive and ecologically-essential. This is one bird I am going to miss seeing on a regular basis when I leave California and I believe it deserves equal time in the spotlight as its more-famous raptorial counterparts.

September through December Bird Count

I definitely started off the year pretty gung-ho about birding and listing and what-not. As the year progressed, though, and particularly as I met a variety of different "bird people" in California, I began to tire of the listing idea. For one, I'm not a fan of actual BIG YEARs as I mentioned previously. The idea of jumping on a plane at the drop of a hat to check a species off a list is incredibly unappetizing: it does nothing to benefit the environment and there is no appreciation of the actual awesomeness that is that bird that you went to all the effort to go see in the first place. Midway through the year, I kind of wanted to distance myself from this kind of birding, so I got pretty lax about the listing.

During a hike through Point Reyes (on October 28), however, the very first bird I saw was a juvenile ferruginous hawk, sitting in a field. It was awesome! And I instinctively got out my notebook and wrote it down. Then I proceeded to follow this hawk for nearly a half-hour as it hunted in the fields surrounding the trail. And that was an experience I'll never forget.

Birds are more than just a list of species on a page to me. That list serves a purpose beyond keeping a tally. I can now look back at my list of birds from that hike and remember the awesome experience of following a Ferruginous Hawk, watching a Great Blue Heron intently hunting in the water, or stumbling onto 125 American Coots floating on the lagoon. The list is just some words on a page, but it is representative of something greater: an series of unforgettable experiences, a journal of my discoveries.

And the list serves an important scientific purpose too. In fact, half of my internship, hawk watching, was essentially standing on a hill and creating a list. That list serves to inform biologists about the population trends of nineteen significant species.

I will probably not keep a year list in 2014. I may keep track of raptors or warblers or some of my other favorite bird families. However, I will continue to keep track of my observations and make lists of what I see. Those will forever serve me as both scientific records as well as a record of personal and memorable experiences.

09/03/13
164. Western Tanager (L): Marin Headlands, CA: Hawk Hill
165. Lesser Goldfinch: Marin Headlands, CA: Hawk Hill

09/04/13
166. Vaux's Swift (L): Marin Headlands, CA: Hawk Hill
167. Broad-winged Hawk: Marin Headlands, CA: Hawk Hill
168. Sharp-shinned Hawk: Marin Headlands, CA: Hawk Hill (And then I proceeded to band ~20 over the course of the migration season).

169. Band-tailed Pigeon: Marin Headlands, CA: Hawk Hill

09/11/13
170. Bewick's Wren (L): Marin Headlands, CA: Hawk Hill

171. White-throated Swift: Marin Headlands, CA: Hawk Hill

09/18/13
172. Rock Wren (L): Marin Headlands, CA: Hawk Hill

09/30/13
173. Say's Phoebe (L): San Francisco, CA: San Bruno Mountain

10/01/13
174. Long-billed Curlew (L): Lagoon off of Highway 1, CA

175. American Avocet (L): Lagoon off of Highway 1, CA

10/13/13
176. American Wigeon: Los Gallenas Nature Preserve, CA
177. Eurasian Wigeon (L): Los Gallenas Nature Preserve, CA
178. Cinnamon Teal: Los Gallenas Nature Preserve, CA
179. Northern Pintail: Los Gallenas Nature Preserve, CA

10/18/13
180. Purple Martin: Marin Headlands, CA: Hawk Hill

10/19/13
181. Golden-crowned Sparrow (L): Marin Headlands, POAK Blind

10/23/13
182. Bonaparte's Gull (L): Marin Headlands, CA: the lagoon
183. Wilson's Snipe: Marin Headlands, CA: the lagoon

184. Semipalmated Plover (L): Marin Headlands, CA: the lagoon

10/28/13
185. Ferruginous Hawk (L): Point Reyes, CA: Trail to Abbott's Lagoon
186. Ruddy Duck: Point Reyes, CA: Abbott's Lagoon
187. Eared Grebe (L): Point Reyes, CA: Abbott's Lagoon

10/30/13
188. Orange-crowned Warbler (L): Marin Headlands, CA: Bottoms Drive Front Yard

11/04/13
189. Savannah Sparrow: Point Reyes, CA: Trail to Tomales Point
190. Snow Goose: Point Reyes, CA: Flying overhead on trail to Tomales Point

11/06/13
191. Rough-legged Hawk: Marin Headlands, CA: Hawk Hill
192. Western Meadowlark (L): Marin Headlands, CA: Hawk Hill

11/09/13
193. Horned Lark (L): Marin Headlands, CA: Hawk Hill
194. Varied Thrush: Marin Headlands, CA: Hawk Hill

11/12/13
195. Wrentit (L): Marin Headlands, CA: Hawk Hill

(photo: Anna Stunkel)

11/13/13
196. Bushtit (L): Marin Headlands, CA: Hawk Hill

11/18/13
197. Mute Swan: Los Gallenas Nature Preserve, CA

198. Blue-footed Booby (L): Pacific Ocean, Mile Marker 10.2 on Highway 1

12/21/13
199. Laughing Gull: Naples, FL: Barefoot Beach



12/22/13
Our first birding trip to Corkscrew Swamp outside of Naples, FL, provided me with a nice final boost to my year bird list:
200. Wood Stork
201. Red-bellied Woodpecker
202. White Ibis

(photo: Mike Pirtle)

203. Gray Catbird

(photo: Mike Pirtle)

204. Tree Swallow
205. Great-creasted Flycatcher (L)
206. Anhinga

(photo: Mike Pirtle)

207. Little Blue Heron
208. Yellow-crowned Night Heron (L)

(photo: Mike Pirtle)

209. Limpkin (L)
210. Black Vulture (L)
211. Tricolored Heron

12/27/13
And our second birding trip to Corkscrew (see previous blog entry) provided me with my final bird of the year!
212. Palm Warbler

Corkscrew Swamp: Family Birding

7:11AM: Departing Longshore Lake neighborhood, Dad spotted two rabbits on someone’s front lawn. He correctly identified them as rabbits, and was quite proud.

7:15AM: Grandpa makes a pun about bats.

7:19AM: Dad spots an anhinga on a pipe and attempts to pronounce the bird’s species.

7:22AM: Dad correctly identifies a pelican on a billboard.

7:30AM: We inquire about why our desitnation is called “Corkscrew Swamp.” Katy uses her smarty-phone to discover that it is because the swamp is a part of the “Corkscrew Watershed.” Very helpful.

7:43AM: Arrive at Corkscrew Swamp. Greeted by a large group of common grackles.

Ready to go see some birds (photo: Mike Pirtle)

8:01AM: After walking the Corkscrew Swamp boardwalk for nearly fifteen minutes without seeing a single bird, Katy spots a great egret. Dad still believes this bird is called a great “in grit.”

Great egret (photo: Mike Pirtle)

8:04AM: We spot a yellow-crowned night heron, sitting contentedly on a branch above the water.

8:11AM: Between the four of us, we finally figure out how to get Grandpa’s spotting scope assembled and pointed at the night heron. We are able to get a great look at this bird, funny-feathered crown, expressive red eye, and all. Katy perfects the art of digi-scoping in one try.

Yellow-crowned night heron (photo: Katy Pirtle)

8:17AM: Dad identifies another egret flying overhead. When asked what it was, he says it was “the white one.”

8:18AM: Apparently this perch is quite desirable, because a second yellow-crowned night heron flies in and after a brief scuffle, displaces the one we were watching.

8:25AM: Further down the boardwalk, we see a white ibis, contentedly grazing in the water, close enough that we could touch it.

White ibis (photo: Mike Pirtle)

8:27AM: Just beyond the ibis, we see three female anhingas perched above one another on a branch. There are also three males scattered throughout the trees in this area. The only think more awkward than watching these birds try to get up out of the water and onto a branch is listening to my dad try and pronounce the word “anhinga.”

Two female anhingas (photo: Mike Pirtle)

8:28AM: Katy swears she saw a water snake.

8:29AM: A red-shouldered hawk (the Florida subspecies of course!) bursts noisily through the vegetation with something long and skinny in its talons. Was it a snake or a stick?

8:30AM: Katy notices two vultures perched in a distant tree. One has a red head, clearly a turkey vulture, and the other has a dark head. I am unsure whether this second vulture is a black vulture or a juvenile turkey vulture. After a brief consultation with David Sibley about the shape of vulture heads, I decided that it is indeed a black vulture!

Turkey vulture and black vulture (photo: Katy Pirtle)

8:37AM: Katy identifies an alligator. Grandpa confirms that it is not actually an alligator, but a stump, or as identified by him, a “stumpigator.”

8:50AM: After nearly 25 minutes in the same spot, Dad reminds us that we should probably move on, since we have a flight to catch at 6.

8:52AM: Just past the anhingas, we see a little blue heron. It is intently staring into the water, carefully taking steps so as not to disturb whatever it is that it’s watching, much the same way we act when watching a bird. After a couple minutes, it strikes, pulling a small fish out of the water. Yum.

Little blue heron (photo: Mike Pirtle)

8:56AM: Katy notices a pretty flower.

9:05AM: Dad notices some leaves with a lot of white splotches on them. He wonders why the birds seem to be leaving droppings on these few particular leaves and we postulate that there is a nest above them. Shortly thereafter, we notice an anhinga perched over a similarly whitewashed leaf. Grandpa postulates that this anhinga has an upset stomach.

9:06AM: Our second little blue heron sighting, this one with a giant crayfish in its beak. We watch as it picks it up, puts it down, picks it up a different way, and tries to figure out how its going to consume its prize catch.

Little blue heron with a crayfish (photo: Mike Pirtle)

9:14AM: At Lettuce Lakes, we see a juvenile white ibis, beginning to molt into its adult plumage.

9:17AM: Dad notices another great egret (“ingrit”) in flight, calling as it flies over our heads. With each call, the bird extends its neck all the way out.

9:21AM: Our first mammal sighting! A raccoon balances along the handrail of the boardwalk, before jumping into the water in search of anything edible.

Raccoon (photo: Katy Pirtle)

9:22AM: Am I hearing sandhill cranes or am I going crazy?!

9:39AM: Another mysterious sound continues to elude me, a soft, whining. After much searching, I discover the culprit – a squirrel! I’ve never heard a squirrel sound anything like this – this is a weird place.

Squirrel (photo: Mike Pirtle)

9:45AM: Grandpa spots a stump that looks like a partridge. It is not in a pear tree.

9:52AM: Five white ibis, three adults and two juveniles, all grazing together!

9:54AM: We see another (or the same?) red-shouldered hawk perched in a tree, making loud screeching calls. We watch as it grabs a branch and proceeds to pull it right off the tree. Then it takes off and perches in a nest in a nearby tree. Why are red-shouldered hawks building (or maintaining?) a nest? Seems a little early.

The underside view of a FL subspecies red-shouldered hawk (photo: Mike Pirtle)

9:59AM: We notice a second red-shouldered hawk doing the same thing – it grabs a stick, flies to a nearby branch, and then just chills for awhile before dropping the stick, which falls all the way to the ground below. We imagine this hawk’s mate being quite disappointed as it comes home with no stick.

Red-shouldered hawk with a stick (photo: Mike Pirtle)

10:10AM: The number of tourists on the boardwalk are increasing steadily. Our choice to go birding as early as the swamp was opened was clearly a wise decision.

10:16AM: Dad notices a mysterious, small bird in a dead tree. I can tell it is a warbler and take careful note of its fieldmarks: yellow eye-stripe, subtle streaking on the chest, bright yellow undertail coverts, with black and white rectrices. A quick flip through Sibley yields no suitable results for me.

Lookin' at a warbler (photo: Mike Pirtle)

10:25AM: Back at the visitor center, I peek into a Peterson Warbler field guide at the gift shop and, thanks to the unique undertail coverts and rectrices, identify our mystery warbler as a palm warbler! Our last bird of the day and, quite possibly, the last new species I will add to my 2013 bird list.

11:04AM: Driving back into Longshore Lake neighborhood, we see some Muscovy ducks on the lake. Grandpa articulates what we’re all thinking: “they’re ugly as sin!”