A studio for bird study

Tag: migration

Brant Feeding Behavior

by Bryce W. Robinson

I captured this clip two springs ago along the Washington coast. The short clip shows the feeding behavior of an immature Black Brant – Branta bernicla nigrigans. I find it interesting because it portrays the feeding behavior, but also shows one example of what a sea goose eats.

I felt confident that this bird was taking a break from some direct migration. It was with an adult bird who was resting on the rocks just out of view of the camera. One bird seemed distracted by fatigue, the other by the need to feed. I did take advantage of that fact, and captured what I believe is an enlightening clip that can be referenced by others in the future.

Migrating Wood Storks in South Texas

by Bryce W. Robinson

A few weeks ago I was in South Texas for the Raptor Research Foundations annual conference. Corpus Christi in the fall is a mecca for those into raptor migration, and likewise the whole of south Texas is a mecca for those interested in the bird world. While I was visiting the hawk watch platform, run by Hawkwatch International, I saw many birds in large numbers. Of course the Broad-winged Hawk migration was flowing well, but I was able to see something unexpected that was equally satisfying. Large numbers of Wood Stork – Mycteria americana were streaming through in kettles. The kettles were in the same fashion as the migrating raptors, and the numbers were extremely large as well. I captured some video of the spectacle to share and spread the awe of the movement of these large North American Storks.

Falcon Row

by Bryce W. Robinson

Image copyright Caitlin M. Davis

Image copyright Caitlin M. Davis

Caitlin Davis is in eastern Nevada again this fall, trapping migrating raptors at the Goshutes Raptor Migration Site for HawkWatch International. She’s been sending me more of her incredible raptor portraits. I felt compelled to share a composite she put together of this years birds.

The migration is in full swing and they have been catching great birds. Already the Goshutes crew has caught multiple individuals of four of North America’s falcon species: the American Kestrel, the Prairie Falcon, the Peregrine Falcon, and a few early Merlin. Perhaps this year they will get a fifth, the large emblematic falcon of the far north, the Gyrfalcon. I’d love to see that bird in Caitlin Davis portrait style.

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.