A studio for bird study

Tag: gouache

February 22, 2017

Singing Brewer’s Sparrow (Spizella breweri) on Sagebrush

by Bryce W. Robinson

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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.

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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.

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February 4, 2016

Western Grebe with Young

by Bryce W. Robinson

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Western Grebe (Aechmophorous occidentalis) with young. 11 x 15″ Gouache painting. Copyright Bryce W. Robinson

I really enjoy the strange behaviors found in the bird world. The Western Grebe (Aechmophorous occidentalis) is then naturally a favorite, due to a few behaviors that are on the surface quite strange.

The first is the rushing, or the synchronous courtship dance where a pair runs in contorted posture across the water. I’ve never painted, photographed, or filmed this behavior but I hope to this coming spring.

The second is the behavior pictured above. Young grebes ride on their parents back, situated between the wings. The parent dives for fish with young in tow, then surfaces with a catch and feeds it to the young.

The third is perhaps the strangest of the behaviors. Grebes eat their own feathers, and parents feed their feathers to their young. There are many hypotheses of what they may do this, but perhaps the most plausible is to line their stomachs. Grebes of course eat fish, yet their gizzards may not fully crush the bone. To protect the soft tissue of their proventriculus and perhaps parts of the intestines, grebes then eat a large amount of feathers that line their insides.

Rather incredible….

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