Raptors, Maybe

Tying up my California adventures with a bow, here's a music video the GGRO interns made to sum up our experiences in raptor research on the Pacific Coast.

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!)

Hawkwatch 9/18: Sun

It was a bright, sunny day on Hawk Hill today!

Another sunny day on Hawk Hill with temperatures in the 70's and a light wind coming from the west. We saw a lot of accipiters today, 28 Sharp-shinned Hawks and 41 Cooper's Hawks. To the great delight of the many hawkwatchers on the hill today (184 visitors on a Wednesday...maybe had something to do with the America's Cup final...), we also got some good looks at a Golden Eagle (subadult), a Ferruginous Hawk (juvenile), and two more Broad-winged Hawks. As usual, there were Red-tailed Hawks and Turkey Vulutres apleanty, and towards the end of the day, a Raven carrying a peanut-butter and jelly sandwhich was sighted as well.

Total Sightings: 235
Hours Counted: 5.5
HPH: 42.73
Total Species: 10

Golden Eagle silhouette.

Species Counts:
Turkey Vulture: 55
Sharp-shinned Hawk: 28
Cooper's Hawk: 41
Red-shouldered Hawk: 3
Broad-winged Hawk: 2
Red-tailed Hawk: 91
Ferruginous Hawk: 1
Golden Eagle: 1
American Kestrel: 3
Merlin: 1

Unidentified...
Accipiter: 8
Falcon: 1

Hawkwatch 9/17: Booby Watch

Oh, get your brain out of the gutter, please.

Birders get excited about seeing rare species, especially those that are keeping lists of birds seen in a certain state. For example, a blue-footed booby would be a big deal for birders listing California birds - this bird is rarely seen in California. So, when the hawkwatchers heard that a booby had been spotted at Land's End (the tip of San Francisco, easily seen from Hawk Hill) at 10:00 AM this morning, they started to get excited at the prospect of it potentially flying right past us. Thus, the south quadrant was given the extra task of "booby watch" today. (I giggled when given that assignment. Apparently, I refuse to grow up). Sadly, we never saw the bird.

Here's the HW report for the day:

Today was slow at the start, slow at the finish, with a flurry of raptor activity in the middle. The day was sunny and the wind direction was "all," seeming to change every three minutes or so. We were hopeful to get a look at the vagrant Blue-footed Booby, spotted just across the bay at 10AM today (thank you, eBird!) However, the raptors certainly kept our attention today. We got a good look at a juvenile Red-shouldered Hawk, followed by an even better look at its adult counterpart, a great lesson in distinguishing the two. Towards the end of the day, a distant dot was identified as a Ferruginous Hawk of unknown age. As for our usual suspects, the Turkey Vulutures beat out the Red-tailed Hawks by one bird today, 94-95.

An adult red-shouldered hawk (above) being ambushed by a juvenile Cooper's hawk (below).

The quintessential GGRO raptor: a juvenile red-tailed hawk.

Total Sightings: 251
Hours Counted: 5.5
HPH: 45.64
Total Species: 9

Species Counts:
Turkey Vulture: 95
Osprey: 2
Sharp-shinned Hawk: 13
Cooper's Hawk: 26
Red-shouldered Hawk: 4
Red-tailed Hawk: 94
Ferruginous Hawk: 1
American Kestrel: 5
Peregrine Falcon: 2

Unidentified...
Accipiter: 6
Buteo: 1
Falcon: 1
Raptor: 1

Hawkwatch 9/11: Tweety Birds

It was a relatively slow day today demonstrated by our brief celebration at 3:00 when the count reached 100 raptors. Overcast with a light breeze, we mostly saw the usual: Red-tailed Hawks and Turkey Vultures (no Cooper's Hawks counted today!). There was some nice movement of non-raptor migrants ("tweety birds" as some hawkwatchers call them) to keep us occupied as well, including flocks of 23 White-throated Swifts, 20 Band-tailed Pigeons, and 15 Cedar Waxwings.

Anna let me play around with her fancy-DSLRey camera during the (great amounts of) downtime today. I took some picture of the non-migrant tweety birds that often hang out with us during the hawkwatch.

White-crowned sparrow.

Western scrub jay.

Total Sightings: 115

Hours Counted: 5.33
HPH: 21.58
Total Species: 6

Species Counts:
Turkey Vulture: 41
Northern Harrier: 2
Sharp-shinned Hawk: 1
Red-tailed Hawk: 65
American Kestrel: 4
Peregrine Falcon: 1

Unidentified...
Buteo: 1

Hawkwatch 9/9: Above the Fog, Away from the Fire

The Golden Gate Bridge, being consumed.

We found ourselves above a thick layer of fog on Hawk Hill today. From our vantage point, the sun was shining, and it looked to be a beautiful day of hawkwatching. My first bird of the day was a prairie falcon flying out of the North quadrant and across the landscape. Then, as the wind began to pick up, we started to count kettles of red-tailed hawks. They seemed tentative to cross over the thick fog in the bay, however, so they began to accumulate in the East. The challenge was to keep track of which red-tails had already been counted, which were joining the kettle, and which were flying away. This proved to be a tricky challenge. There was also an occassional peregrine falcon in the kettle, as well as the usual turkey vultures. By 2:00, the temperature had dropped significantly and we were surrounded by fog, so we ended the count early.

Approaching fog.

Our view by 2:00.

A couple other interesting sights of note:
-A group of five planes flew through the sky, writing some advertising message. However, their handwriting was terrible and we think they were advertising some sort of talent agency, but it was unclear. Maybe they need a talent agency to identify better sky-writers.

Successfactors?

-Yesterday afternoon, a fire started at Mt. Diablo, one of our distant landmarks. Throughout the day, we could see smoke billowing off of Mt. Diablo. At times, it looked like the fire was calming down and then, out of nowhere, a new, huge plume of smoke would appear. Pretty crazy to watch.

Distant wildfires.

Total Sightings: 152
Hours Counted: 4.25
HPH: 35.76
Total Species: 9

Species Counts:
Turkey Vulture: 21
Osprey: 1
Sharp-shinned Hawk: 4
Cooper's Hawk: 7
Broad-winged Hawk: 1
Red-tailed Hawk: 99
American Kestrel: 3
Peregrine Falcon: 4
Prairie Falcon: 1

Unidentified...
Accipiter: 3
Buteo: 2
Falcon: 2
Raptor: 4

Using the Landmarks

Yesterday was my first official day participating in the hawkwatch research. The fog lifted early and we  were actually able to see pretty clearly. We counted a total of 88 raptors, which in the dataset gets recorded as 22.98 hawks per hour, something I will explain when I have a better understanding of it myself. We identified four different species, the highlight of which were two distant juvenile Northern harriers. My excitement and celebration at spotting and identifying these unique birds was worthy of something the rest of the team deemed "Danny's harrier dance."

Hawkwatchers hawkwatching.

The hawkwatch research is pretty structured, Hawk Hill being divided into four quadrants, each being watched by a group of people. Typically, we rotate each hour so no one tires of staring at the same quadrant for too long. Once a bird is spotted in your quadrant, it is important to notify the other observers, so we can work together to identify the bird's species. Describing the location of the bird can be tricky, and over the years, the hawkwatchers have learned to use the natural landmarks to assist. Some of these landmarks are pretty obvious:

We call this "the bridge" but also often refer to "North tower" or "South tower"

Acatraz is another pretty obvious landmark.

There are some buildings around the Marin Headlands that also make for some good landmarks:

The GGRO office is located in the buildings on the right, called "Fort Cronkhite" because of some military history.

The horse pastures are on the left and rifle range on the right (I walk/bike past these every day on my way to the office). Yesterday, I watched four turkey vultures and bobcat hanging out in the rifle range during an otherwise slower hour in the West quadrant.

Point Bonita lighthouse, located funnily enough on Point Bonita.

Despite these obvious landmarks, most of what surrounds Hawk Hill is, well, other hills. Thus, some creativity has come into play as people have come up for clever names to differentiate all of the hills and vegetation. Here are some of my favorites:

The "Steer's Head" - pretty self-explanatory. 

The "Bunny" - also pretty self-explanatory.

This one is "Elvis. His legs are the two ridges coming towards the photo, the arms are the long ridge going across the middle, and Elvis' head is in profile in the upper center of the photo. See it?

For all the science nerds out there, this little patch of grass is simply called the "Petri dish."

The "lobster." The claws are coming towards the photograph, body pointing back to the upper-right corner.

Apparently, one way to have a true GGRO legacy is to coin a term that gets used as a landmark identification tool for years to come. I have another new goal for my time in California. :)

BONUS: Today, during a rather slow banding day, a group of California quails all ran into one of our nets. Families of these birds are seen running around the Marin Headlands, including in my front yard. They're pretty cute, if perhaps a bit dumb. I enjoyed getting a chance to see them up-close in the hand today.

The Hawk Identification Challenge

The GGRO field research season is rapidly approaching. On August 19, the two major research projects (hawkwatch and banding) begin. We've asked the hawks to kindly wait until then to begin migrating. Most of them will cooperate, although a few strays may have missed the memo and might already be on their way south.

A red-tailed hawk hunting in front of the Golden Gate Bridge, a sight to become increasingly more common as migration season arrives.

Meanwhile, one of the main projects of the GGRO interns (aka me) is to "learn." We're learning how to care for lurebirds. We're learning how to set up dho-gaza's, bow-nets, and mist nets for trapping hawks. We're learning how to age buteo hawks based on their molting pattern. We're learning how to fill big holes with rocks. And we're learning how to identify all 19 of the common migratory raptor species, and all of their respective morphs, in flight.

Identifying hawks in flight is a tricky ordeal, but thanks to the fact that a lot of people have been doing it for a long time, there are some tried and true techniques. Through weekly evening ID classes, powerpoint study sessions with each other, and the occasional birding field trip, I feel like I'm slowly gaining confidence in my ability to identify a passing raptor.

It's a daunting ordeal at first - in sum, there are 68 different morphs that we could essentially see (juveniles often look very different from adults in a given species, and some species of dark morphs, light morphs, in between morphs, etc). In the classroom, we focus on learning field marks - what the hawks look like. Words like petagial marks, carpal patches, undersides, uppersides, mottling, barring, and streaking are thrown around a lot.

These are all different morphs of red-tailed hawks.

In the field, however, we get a chance to focus on something birders have termed the GISS: the general impression, size, and shape. In other words, many birders feel that field marks can only get you so far. Once you're in the field, you're going to learn a lot more information by becoming familiar with the relative size, the relative shape, and the typical behavior of a given bird. Last week, we went birding with Steve, a long-time GGRO volunteer who can tell the difference between a juvenile and adult red-tail hawk from miles away, based only on the silhouette.

I'm learning to identify birds like these with no hesitation.

We can study field marks until our brains explode, but once we get outside, that can only give us so much information. The confidence in identification will come from practice in the field. One more week until I'll be putting my hawkwatching skills to the test. Bring on the migration!