A studio for bird study

Tag: nature

January 30, 2016

Banded Golden-crowned Kinglet

by Bryce W. Robinson

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This past fall I helped the Intermountain Bird Observatory band birds on a number of occasions at a site along the Boise River. I’ve returned to the location on occasion throughout the winter to bird, and every time I find a small mixed flock with banded individuals throughout.

The other day I made attempts to photograph banded birds to capture band numbers and identify individuals. Easier said than done when the flocks are busy foraging. I came away with some good photos, but nothing that put together a full sequence or even the last few digits.

It can be said, however, that these birds are most likely the same birds that were banded here in October. The other most plausible explanation is that some were banded at IBO’s other site, only a few miles away on the top of Boise Peak. I’m unfamiliar with the literature on winter movements of the Golden-crowned Kinglet, so I don’t have an idea if holding a small range throughout winter is common for this species. Still, the birds I photograph seem to be staying put which surprises me in some way. Perhaps the inclination of the flock to stay within a small range speaks to the quality and perhaps importance of the habitat provided by this relatively wild portion of Boise’s section of the river.

Time to read, and think some more.

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January 21, 2016

Black Rosy-Finch Use Cliff Swallow Nests to Roost

by Bryce W. Robinson

 

East of Boise, Idaho, on a cliffside along the Boise River is a conglomerate cliffside of volcanic rock. On this cliffside is a group Cliff Swallow (Petrochelidon pyrrhonota) nests. The Cliff Swallow is migratory, so during the winter months the Cliff Swallow does not occupy these nests.

In winter, the mud cavity nest sites are utilized by other bird species as roost sites. Interesting, to me, is that wintering Rosy-Finch species use these nest sites as well. I finally succeeded in capturing a video clip of a Black Rosy-Finch (Leucosticte atrata) entering a mud cavity to roost for the evening.

The composition of the flocks at this particular site are also of interest. Take a look at the eBird checklist of the time I spent filming this small flock. Most were Black Rosy-Finch, the next most numerous were “Hepburn’s” which are a coastal breeding subspecies of Gray-crowned Rosy-Finch, and there was only one “tephrocotis” Gray-crowned Rosy-Finch, the interior subspecies.

http://ebird.org/ebird/view/checklist?subID=S27027048

The regularity of this Cliff Swallow – Rosy-Finch relationship is of interest to me. I have read accounts of the behavior in California and Washington, but these accounts are few. I do not know of other areas that these birds currently use Cliff Swallow nests, but I will be searching for them and would appreciate any information from other’s observations.

Wintering ecology, what a fascinating faction of bird study.

 

 

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Video | January 5, 2016

American x Eurasian Wigeon Hybrid

by Bryce W. Robinson

 

The phenotypic expression that results from hybridization is fascinating, especially in colorful birds such as the male ducks. One duck hybridization I enjoy is the American x Eurasian Wigeon. The subtle combination between the traits of the two species is pleasing to the eye, but also presents a fun and satisfying ID challenge.

I found a drake American x Eurasian Wigeon the other day in a large group of American Wigeon feeding on a grass field at a large sports park in Boise, ID. The winter group that frequents this field every year generally holds a drake Eurasian Wigeon. This year no Eurasian, but a hybrid.

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Note the retention of the American Wigeon head pattern. The Eurasian has a beautiful red-orange head with a golden fore-crown. The neck and auriculars do not differ in color than the superciliary and hind-neck as in the American. This hybrid holds the American pattern, but with strong Eurasian coloring throughout the head. The other most obvious quality on this bird is the gray flanks unlike the American Wigeon which have rufous flanks. Thus, the combination of American head pattern with reddish hints and the gray flanks are enough to confidently call this bird an American x Eurasian Hybrid.

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Eurasian Wigeon sure show up regularly each winter in N. America. I’d love to know if the regularity of Eurasian in N. America mirrors the regularity of American in Asia. It’s fun to wonder, but with the growing popularity of eBird, answering these types of questions are beginning to seem more and more possible.

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September 6, 2015

Swallow-tailed Kite Movements

by Bryce W. Robinson

Swallow-Tailed Kite - Elanoides forficatus. 11 x 17

Swallow-Tailed Kite – Elanoides forficatus. 11 x 17″ prismacolor on bristol.

I illustrated this Swallow-tailed Kite for my friend Russ. He found Arizona’s first state record back in 2012, so understandably the Swallow-tailed is a special bird to him. You can see the accepted record here:

http://abc.azfo.org/ABCVote/_ABCReports_Public_View_list.aspx

It would be so exciting to see an unexpected X soaring high above the desert. Lately, Swallow-tailed Kites have been showing up in some odd places. For whatever reason a few birds have strayed farther north than their normal range. In this past weeks Rare Bird Alert on the ABA Blog, four separate sightings of the species were made in three different states: Illinois, Indiana, and Kansas. Sometimes birds make strange movements in great distances. You never know, you might be at a hawk watch this fall somewhere in the west and see a large X soaring in the sky. Better start scanning…

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