idaho | | Page 2

January 19, 2018

Dark-eyed Junco Subspecies in Idaho’s Winter

by Bryce W. Robinson

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.

https://borjamila.com/speciation-mechanisms-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

January 16, 2018

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

by Bryce W. Robinson

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.

1 Comment

August 30, 2017

Just Published in Avian Conservation and Ecology: Nest Box Use During the Non-breeding Season

by Bryce W. Robinson

Caitlin just published an excellent paper detailing nest box use in the non-breeding season in Idaho.

This publication is an important contribution because it discusses patterns in nest box use during a period that has received little attention. Additionally, because nest box programs are engineered to supplement natural cavities to saturate an area with nesting habitat geared to benefit species, a full understanding of its impacts throughout the yearly cycle is important. This paper not only reports how nest boxes are used in the non-breeding season, but illustrates some possible negative impacts as well. Such impacts are primarily associated with the variable thermodynamic nature of nest boxes relative to natural cavities, resulting in deaths at temperature extremes.

The paper also details some inter and intraspecific interactions in nest boxes, and patterns of use in other cavity roosting species such as the Northern Flicker and European Starling. With this discussion comes supplementary video of some such encounters, and excellent inclusion to add further context.

WATCH THE VIDEOS (CLICK HERE)

READ THE PAPER (CLICK HERE)

February 22, 2017

Singing Brewer’s Sparrow (Spizella breweri) on Sagebrush

by Bryce W. Robinson

Singing Brewer’s Sparrow (Spizella brewer) on sagebrush. Gouache on watercolor paper.

One of the best parts of spring in the Sagebrush landscape of western North America are it’s singing inhabitants. The Brewer’s Sparrow may be my favorite, because of its subdued but beautiful plumage and distinct trill song. On a spring morning at sunrise, one can walk through a healthy stand of sagebrush, songs erupting all around, as multiple males sing atop their sagebrush posts.

Brewer’s Sparrows have a distinct buzzing song, that sounds superficially simple and distinct. But, their songs can be variable and have multiple types as described in Rich (2002). See the figure below to gain a familiarity with the variability.

Song types of the Brewer’s Sparrow, long (A) and short (B). Figure taken from Birds of North America Online, adapted from Rich (2002).

Rich (2002) found that the variability seen above seems to follow no geographic trend or isolation, nor does there seem to be any song sharing among neighbors. High turnover among territories and potential for natal dispersal could limit the development of local dialects, etc. Interesting stuff…

If you’re unfamiliar with the sound of a singing Brewer’s Sparrow, be sure to visit Xeno-Canto and explore.

My friend Eli is wrapping up some research investigating the impacts of anthropogenic noise on sagebrush inhabitants in southwest Idaho. Breeding Brewer’s Sparrows were among a few focal species of her study. She’s currently working through the publication process, and when her work comes to surface in print, I’ll be sure to share. I expect that anthropogenic noise has some masking impacts on a Brewer’s Sparrow song, and in turn could potentially change the dynamics of song structure under anthropogenic noise blankets, etc. More research and time will tell.

Here is a short clip of a singing Brewer’s Sparrow in Idaho that I took through my Zeiss scope. The song is barely audible because of how distant I was from the singing bird:

Referenced Literature:

Rich, T. D. 2002. The short song of Brewer’s Sparrow: individual and geographic variation in southern Idaho. Western North American Naturalist 62(3): 288-299.

Tag: idaho

by Bryce W. Robinson

by Bryce W. Robinson

by Bryce W. Robinson

by Bryce W. Robinson