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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

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.

November 1, 2016

Avian Keratin Disorder (AKD), Bill Deformities in Birds and Recent Breakthroughs

by Bryce W. Robinson

Photo 1. Female Black-capped Chickadee (Poecile atricapilla) with bill deformity.

I recently had the pleasure of spending a few days with my friend Rachel Richardson of USGS trapping birds in the Eagle River Valley of south-central Alaska. We captured a few species such as Black-capped and Boreal Chickadees (Poecile atricapilla and P. hudsonicus, respectively), and Red-breasted Nuthatch (Sitta canadensis). USGS has been trapping in these areas for years with the main focus of monitoring bill deformities, the prevalence of Avian Keratin Disorder, and the prevailing causes of a new found virus, Poecivirus.

The Alaska Science Center of USGS in Anchorage is part of a team of researchers, including the California Academy of Sciences, and the University of California San Francisco that have been investigating the causes of Avian Keratin Disorder for over ten years. Avian Keratin Disorder was first documented in Alaska in the 1990’s by Colleen Handel of USGS who leads the research team at the Alaska Science Center. In an article in Molecular Biology that came out in July 2016 (Zylberberg 2016), the team reports on the discovery of a new virus they termed Poecivirus, which may be responsible for the bill deformities.

Appropriately, the discovery is receiving a good deal of press. Below are a few links to national and international articles that detail the work and the discovery. All are worth a read (or a watch):

A new article by the Associated Press

Science Daily’s article

National Geographic article detailing the work effort

Alaska Daily News Article

An APN video on USA Today

Photo 2. Rachel Richardson of the USGS Alaska Science Center holding a female Black-capped Chickadee (Poecile atricapilla) with a bill deformity.

On the day I spent with Rachel in the field trapping birds, we only had one Black-capped Chickadee show up with a deformity. However, the one bird had an interesting story. This female (Photo 1) was first captured in 2015 and had no signs of any deformity. This year she obviously has a developing deformity. Her bill grew 5.1 mm in one year, a 70% increase in length. Whether or not this developing deformity will impact her ability to forage, preen, or even breed and provision young is yet to be determined. There are reports of deformed birds successfully rearing offspring, however it is without question that the deformities present a handicap that will ultimately reduce the individuals fitness.

It is important to track the rates and severity of deformities across the world. Because of this, the Alaska Science Center has developed a submission form for anyone to report their sightings of deformities. Please contribute to this effort and submit details of any sightings of elongated bills, including photos and location along with any other evidence for Avian Keratin Disorder at the following website:

Beak Deformity Observation Record Report

Photo 3. Female Black-capped Chickadee (Poecile atricapilla) with bill deformity.

Below are additional examples of AKD in Chickadees that have been captured as part of the Alaska Science Center’s efforts near Anchorage. These individuals unfortunately have more developed deformities than the chickadee we caught while I was tagging along.

Photo 4. Black-capped Chickadee (Poecile atricapillus) with bill deformity. Photo copyright Rachel M. Richardson.

Photo 5. Black-capped Chickadee (Poecile atricapillus) with bill deformity. Photo copyright Rachel M. Richardson.

Photo 6. Black-capped Chickadee (Poecile atricapilla) with bill deformity. Photo copyright Rachel M. Richardson.

It’s excellent to have a breakthrough and a step forward. However, the problem still remains as well as the daunting task of discovering the correlation between Poecivirus and bill deformities, the causes of both, and what role humanity plays in the prevalence and transmission of either. I’d like to tip my hat to those who have done so much great work on this issue thus far. Keep up the good work.

Referenced Literature

Maxine Zylberberg, Caroline Van Hemert, John P. Dumbacher, Colleen M. Handel, Tarik Tihan and Joseph L. DeRisi. Novel Picornavirus Associated with Avian Keratin Disorder in Alaskan Birds. mBio, July 2016 DOI: 10.1128/mBio.00874-16

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June 3, 2015

Singing American Tree Sparrow

by Bryce W. Robinson

I’ve made it a goal to get footage of as many singing birds in western Alaska as possible. I made out one morning in early May to film what was around. Not many birds are in Alaska in early May, but tree sparrows are the early birds in preparing for the breeding season, busy setting up territories. This bird was tirelessly singing, chasing away intruders, and conducting himself in the way any sparrow should in order to be a successful breeder. I took advantage of his focus and took this recording using my Zeiss Diascope.

Tag: songbird

by Bryce W. Robinson

by Bryce W. Robinson

by Bryce W. Robinson

by Bryce W. Robinson