Ornithologi

A studio for bird study

Tag: birding

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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Orange-breasted Falcon Plucking Prey

by Bryce W. Robinson

 

For the Orange-breasted Falcon whose diet consists primarily of avian prey, to eat requires a great deal of work. First, the birds must capture a food item. They specialize in above canopy surprise and pursuit capture, a technique that blends a bit of skill and luck. When the two align and the bird finally captures a meal, they then must prepare it. Falcons prefer to ingest little amounts of feather from their prey items, and thus need to efficiently remove the extraneous feathers to access the muscle. To remove these feathers, they pluck their prey nearly clean. Plucking can be beautiful, as I found with the Orange-breasted Falcon in the video above as it prepared a Great-tailed Grackle. Perched on a limb high overlooking a deep river valley, the bird plucks. The observer can easily recognize the bird’s technique of rip and flick, as it efficiently carries out its daily ritual and feathers calmly drift away in the hot Central American air.

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.