Ornithologi

A studio for bird study

Tag: california

The Benefits of Photography for Mapping Avian Movements

by Bryce W. Robinson

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Above is a photo of an immature light morph Swainson’s Hawk that I took on the 7th of September, 2013 at the Goshutes Raptor Migration Sight in eastern Nevada. Notice the red band on the birds left leg. I’ve cropped the image a great deal, but below I’ve enlarged the section of the image to show the band in greater detail. At this resolution, the image becomes pixelated, which is unfortunate.

SWHA MAGI contacted the BBL in hopes of tracking down someone that might recognize the band. I am so very grateful for their organization, as they quickly sent out emails asking those they have permitted for color banding SWHA. Within a day or two, I had a hit.

A man name Chris Briggs contacted me and gave his firm assurance that this bird was a bird he had banded earlier this year as a nestling. He mentioned his use of special characters such as the obvious < symbol on this birds color band. He thought that the other character on the right was either an 8 or a 9. One cannot be too certain, but he did assure me that the band was certainly his.

As the birds age was apparent from its plumage, I was really interested in where the bird originated. Chris informed me that this bird was banded as a nestling near Macdoel, California, a town near the northern border just south of Klamath Falls, OR. He sent me the photo below.

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Photo courtesy of Chris Vennum

How exciting! It is nearly certain that this bird is the same bird as the bird I photographed in Nevada. I am so thankful that the organization exists such that a photographer can capture a photo of a bird with a band, and if the band is legible, can track that very same bird to the place that it was banded, without ever trapping the bird. The invasiveness of trapping hawks is curbed with the advent of the camera! Revolutionary….

Well, my question is then why are we as raptor researchers, or ornithologists as a whole not employing this technique more often? Some may state the added detriment of more bands is not worth while, and I do not discount this contention. However, how much more detrimental will one color band be to an already banded raptor? It is a discussion worth having, because with the amount of folks armed with cameras today, we could find ourselves with a lot more re-sight records, and a better understanding of spatial ecology in particular species.

I’d like to include another recent instance for emphasis. A few months ago, my friend and obscenely talented photographer Ron Dudley photographed a young Prairie Falcon in Montana. It happened to have a color band, and he was able to track down where the bird was banded. As it happened, his bird was also from California. You can read the story in detail on his blog.

How peculiar, this bird that fledged from its nest, and for whatever reason did not disperse directly south, but in a somewhat north east direction. North east enough that it passed by the Goshutes in early September on its way south. In my own personal study, I’ve learned that this non southward directionality of post fledging dispersal is something many people tracking birds of prey are seeing. The old north to south paradigm is becoming a bit more complicated than initially thought, and young birds seen traveling south on their fall migration, aren’t necessarily birds fledged from the north.

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Beatnik Birding: Sea Watching on the Pacific Coast

by Bryce W. Robinson

Surf Scoter- Melanitta perspicillata migrating north

Surf Scoter- Melanitta perspicillata migrating north

Well, it has happened once again, I’ve lapsed in my blogging. I’ve been through Utah, Nevada, and back to California again. There have been great birds along the way. I’d love to share some of the photos I’ve gathered along the way, but I want to share an experience I had yesterday. It was new and exciting for me, and carries potential for a whole new avenue of learning in my bird study.

I’ve yet to venture into the ocean to bird. I’ve only made it to the coast. Seabirds fascinate me, and I plan to make a pelagic tour soon enough. Until then I am standing on solid ground, watching what I can. I’m not seeing any true seabirds such as the Black-footed Albatross or Wilson’s Storm-petrel, but I am seeing unfamiliar birds passing over the ocean at a distance. My hawk watching instincts have kicked in on a whole new group of birds.

Pacific Loon- Gavia pacifica

Pacific Loon- Gavia pacifica

All the training I’ve had with raptors comes into play with passing sea migrants. There are particular field marks to pay attention to, but after enough exposure, I am sure I will be making my ID’s from shape, form, and flight style.

While watching for a few hours yesterday, I saw a massive loon migration. Every few minutes, a group averaging ten birds would come through, low over the ocean. It was a chore to check my field guides and learn what to look for with identifying passing loons. I started getting a handle on separating breeding plumage Pacific from Red-throated and Common, as there are some obvious in flight plumage differences. In the afternoon sun, however, I began to realize that lighting was confusing things.

Pacific Loon- Gavia pacifica

Pacific Loon- Gavia pacifica

A field mark for identifying Pacific Loons in flight is two prominent white lines on their scapulars, coupled with a dark throat. It seemed to me that every passing group was a Pacific, even the birds that resembled Red-throated Loons in shape. After some thought, I realized that the harsh sun was likely giving a glare off of the other dark backed loons, making it appear to have the white scapular markings.

Red-throated Loon- Gavia stellata

Red-throated Loon- Gavia stellata

There were other passing migrants, and shore dwellers. I had two Whimbrel fly through, a good number of Pigeon Guillemot, and of course many many gulls. I admit, I have not spent the amount of time studying gulls as I should, but I am working on it. What a daunting task.

 

A first winer in its first pre basic molt Glaucous-winged Gull- Larus glaucescens

A first winer in its first pre-basic molt Glaucous-winged Gull- Larus glaucescens

I’ll be interacting with the ocean quite regularly for the next few months. I hope to find the time to share everything interesting and exciting that I come across. And the road continues ever onward.

 

 

Beatnik Birding: A True Desert Denizen, the Le Conte’s Thrasher

by Bryce W. Robinson

Le Conte's Thrasher- Toxostoma lecontei

Le Conte’s Thrasher- Toxostoma lecontei

The genus Toxostoma is comprised of some of my favorite birds. At the top of these species is the Le Conte’s Thrasher. I love this bird in part because it is rather difficult to find. I’ve spent a great deal of time in the Sonoran Desert, frequenting the sandy creosote scrub that is this birds habitat. Still, I’ve only seen a handful of this desert specialist, and each time has been memorable.

Recently, I found two birds outside of Palm Springs, CA, one of which was singing atop a creosote. I had never heard the song of the Le Conte’s. It is the same wonderful wandering warble of other Toxostoma species, yet it seems a bit more delicate.

The Le Conte's Thrasher signature habit, running along the sand as if it were a Roadrunner.

The Le Conte’s Thrasher signature habit, running along the sand as if it were a Roadrunner.

One of the reasons I am so fascinated by this bird is its habit to run across the sand between Creosote shrubs as it forages for food. It seems to prefer running rather than flying. I can’t help but think of the Greater Roadrunner every time I see this behavior.

Le Conte's Thrasher- Toxostoma lecontei

Le Conte’s Thrasher- Toxostoma lecontei

I find it incredible that this bird is only twenty miles from another southern California Toxostoma species. The California Thrasher is much like the Le Conte’s in appearance, but it frequents the chaparral hills of southern California. This pair of Le Conte’s Thrashers I found are on the western edge of the desert in the extremely arid white sand hills amidst Palm Springs iconic wind mill farms. Its proximity to the California Thrasher’s range is incredible, as the species is very different in habits and habitat. These two species are prime examples of evolution, adaptability, and the affects of environmental pressures.

 

Beatnik Birding: The Limp-legged Surfbird

by Bryce W. Robinson

Surfbird- Aphriza virgata

Surfbird- Aphriza virgata

A few days ago Caitlin Davis and I took a walk along the beach near Santa Monica looking for some spring migrants and remaining winter residents. It was a fairly productive walk with Brandt’s Cormorant, Red-throated Loon, Whimbrel, Western and Clark’s Grebe, Glaucous-winged Gull and more. The highlight for me was a pair of Surfbirds, one of which had a bum leg. The birds leg was lame, and it travelled about the beach without skipping a beat by hopping. It kept up with its compatriot, and seemed lively and healthy.

The lame-legged Surfbird

The lame-legged Surfbird

I was impressed that the bird was healthy, given that it lacked one leg. I appreciate the reminder of the adaptability that is common in nature. Of course, if one cannot adapt to maladies or changing conditions, one dies. It is nice to see a success story every once in a while.

The lame-legged Surfbird, and the compatriot

The lame-legged Surfbird, and the compatriot