A studio for bird study

Tag: biology

February 18, 2016

California Gnatcatcher – Polioptila californica

by Bryce W. Robinson

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This month I found myself fortunate to have the opportunity of illustrating a “Coastal” California Gnatcatcher (Polioptila californica californica). I was asked to do an illustration for Sea and Sage Audubon in southern California, and I decided to illustrate the California Gnatcatcher because it is perhaps the most pressing avian conservation issue facing southern California.

A few decades of rapid urban development in southern California’s coastal sage scrub habitat has left California Gnatcatcher’s with shrinking suitable habitat and a fragmented range. These pressures have taken their toll on the United State’s only California Gnatcatcher populations, to a point that in 1993 the gnatcatcher received threatened status.

Today it seems that the California Gnatcatcher’s presence and future in the coastal sage scrub is that of small fragmented populations. In essence, the damage has been done, and efforts now focus on preserving what quality habitat is left and ensuring that the small populations remain.

My choice to illustrate this bird was founded on 1. maintaining awareness for the plight of this incredible bird, 2. supporting a feeling of identity for those that live in the area and invoking the California Gnatcatcher as an important part of that identity, and 3. a reminder that these birds act as a symbol for the broad impacts human development has to the ecosystem, a symbol that goes well beyond single species conservation.

For more information on the history of the conservation effort for this species, and to stay updated on current action visit:

The USFWS’s Environmental Conservation Online System page for the Coastal California Gnatcatcher.

 

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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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January 21, 2016

Black Rosy-Finch Use Cliff Swallow Nests to Roost

by Bryce W. Robinson

 

East of Boise, Idaho, on a cliffside along the Boise River is a conglomerate cliffside of volcanic rock. On this cliffside is a group Cliff Swallow (Petrochelidon pyrrhonota) nests. The Cliff Swallow is migratory, so during the winter months the Cliff Swallow does not occupy these nests.

In winter, the mud cavity nest sites are utilized by other bird species as roost sites. Interesting, to me, is that wintering Rosy-Finch species use these nest sites as well. I finally succeeded in capturing a video clip of a Black Rosy-Finch (Leucosticte atrata) entering a mud cavity to roost for the evening.

The composition of the flocks at this particular site are also of interest. Take a look at the eBird checklist of the time I spent filming this small flock. Most were Black Rosy-Finch, the next most numerous were “Hepburn’s” which are a coastal breeding subspecies of Gray-crowned Rosy-Finch, and there was only one “tephrocotis” Gray-crowned Rosy-Finch, the interior subspecies.

http://ebird.org/ebird/view/checklist?subID=S27027048

The regularity of this Cliff Swallow – Rosy-Finch relationship is of interest to me. I have read accounts of the behavior in California and Washington, but these accounts are few. I do not know of other areas that these birds currently use Cliff Swallow nests, but I will be searching for them and would appreciate any information from other’s observations.

Wintering ecology, what a fascinating faction of bird study.

 

 

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August 8, 2015

Short-tailed Shearwater

by Bryce W. Robinson

I’ve seen a lot of North America’s birdlife, but there are certain bird groups where my exposure is lacking. One area is birds of the sea, or what we refer to as pelagic species. I haven’t seen many of these birds, particularly those that belong to the order Procellariiformes. In fact, I can count on one hand the number of species from this group that I’ve seen. So understandably I’d be interested in gaining more exposure in any way.

The other day I was birding the western Alaska coastline with my friends Neil Paprocki and Ellen Whittle. We were paying a lot of attention to the sea because we were looking to see puffins and a few loon species. I myself have spent a great deal of time watching the sea from the Alaskan coast, and I’ve never seen anything from the order Procellariiformes. On this day I had a first. We noticed a dark bird floating along the shoreline, maybe 100 m out. After scoping the bird, I knew that it was a Short-tailed Shearwater, a lifer for me and a long awaited bird. I was, to understate it entirely, excited.

The sight raised one thought in my mind, that the bird was obviously ill in some manner. It seemed to be sleepy, unconcerned by our presence, and very near shore (uncommon among these types of birds). So, something was likely wrong with the bird. Still, I took the proper satisfaction from studying the bird and enjoying its subdued behaviors.

I took some video (above) using my Zeiss Victory Diascope 65 F* TL that show the bird at a peak in its activity while we were watching. Notice the bird take a drink at the end of the video. If we drank seawater we’d in effect die of dehydration due to the high salt concentration. But, seabirds can drink saltwater. They excrete the excess salt through their nostrils. Observing this bird drinking the saltwater, and recalling their adaption for surviving life on the ocean was another moment where I saw something in real time that I had read about previously. Such an incredible experience, and behavior birding at its best.

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