A studio for bird study

Tag: winter

January 19, 2018

Dark-eyed Junco Subspecies in Idaho’s Winter

by Bryce W. Robinson

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For the Junco lovers that like this image, you can purchase a print by clicking on the image above.

Above is an illustration I just completed of some select subspecies of one of my favorite birds, the Dark-eyed Junco (Junco hyemalis) – Male and female “Oregon” (J. h. oreganus), “Pink-sided” (J. h. mearnsi), “Cassiar” (J. h. cismontanus), and the nominate “Slate-colored” (J. h. hyemalis). I think the junco is a favorite because it is polytypic, with some excellent variation in phenotypes throughout its range. I particularly am drawn to the Cassiar Junco because it is both difficult to diagnose (separate from Slate-colored X Oregon intergrades, if they even are different!) and little understood. For more information on this taxon, check out these links:

http://ebird.org/content/nw/news/dark-eyed-junco-races-oregon-slate-colored-and-cassiar/

http://nwbackyardbirder.blogspot.com/2011/04/not-slate-colored-junco-cassiar-junco.html

Here is information on its current and past taxonomic status:

https://avibase.bsc-eoc.org/species.jsp?avibaseid=DED1C8F9EE711FCF

I also like the Dark-eyed Junco because from what we understand regarding it’s phylogenetics, it is a very recent radiation. Speciation well in process! See this article for an explanation:

Click to access POSTPRINT%20Mol%20Ecol%2025(24)%206175-6195%20(2016).pdf

Further, be sure to educate yourself with the Junco Projects great film – Ordinary Extraordinary Junco. I included a chapter of the film below that discusses the diversification of the species.

 

My illustration comprises the candidate subspecies that make up Junco flocks here in western Idaho. I chose to illustrate the male and female Oregon because they are by far the most common and provide the point with which to contrast and compare any outliers. The others are males, so as to provide simple examples of the other subspecies. Of course first-year and female types of these taxa can blend in appearance with the rest, which makes things much more challenging and fun.

Here I’ve included a rough and disorganized compilation of some information on what we currently understand about the Dark-eyed Junco and its sister species. There is a lot more out there, so if you love this as much as I do then be sure to explore more.

Here is a link and a few  references to investigate.

Speciation mechanisms in the Junco radiation

Milá, B., P. Aleixandre, S. Alvarez-Nordström and John McCormack. 2016. More than meets the eye: lineage diversity and evolutionary history of dark-eyed and yellow-eyed juncos. In Snowbird: Integrative biology and evolutionary diversity in the junco. Ellen D. Ketterson and Jonathan W. Atwell (Eds.), Chicago University Press, Chicago.

Miller, A. H. 1942. Speciation in the Avian Genus Junco. The American Naturalist 76:211-214

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January 16, 2018

North America’s Zonotrichia in Winter: A Plate of Basic and Immature Plumages

by Bryce W. Robinson

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North America’s Zonotrichia: Basic and Immature Plumages. 18×24″ Gouache on paper. From the top: White-crowned Sparrow (Zonotrichia leucophrys gambelii; Adult (L) and immature (R)), Golden-crowned Sparrow (Zonotrichia atricapilla; Adult (L) and immature (R)), White-throated Sparrow (Zonotrichia albicollis; Adult (L) and immature (R)), and Harris’s Sparrow (Zonotrichia querula; Adult (L) and immature (R)).

I’m privileged to be teaching a better birding workshop at the end of the month focused on Idaho’s winter sparrow guild. The workshop is supported as a collaborative effort between Golden Eagle Audubon Society and Southwestern Idaho Birders Association (SIBA). I’ll be leading a 1.5 hour lecture that will present tips for increasing ones birding skills, as well as an in depth identification breakdown of Idaho’s winter sparrow guild (with Calcariidae added by request). We’ll also be taking these skills to the field for some applied learning. I’m excited, as it is the first birding centric workshop I’ve taught, so I’m sure to learn as much as I disseminate.

I have decided to attempt to illustrate all taxa that I will be discussing in the workshop. This is a bit daunting of a task to accomplish in only a few weeks, but I think I can do it! I just completed the Zonotrichia plate, which is shown above. I’ll share the rest as I complete them.

I learned a lot from this plate about the process of illustration. I’m feeling unsettled by the product, because I can’t seem to get past the messiness and untidy nature of my illustration. In the next few, I’ll focus on being more particular and using a lower water to paint ratio. I need to attempt to utilize the gouache not as watercolor but as a layering medium.

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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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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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