Rump bum bum bum

‘Tis the season for just that. After the uncharacteristically heavy rains in San Diego, the insectivorous birds have a feast. I spotted a Yellow Rumped Warbler (Dendroica coronata) just outside of the laboratory. I had seen them before on campus but was never so fortunate to capture a photograph. This was the first time for me to see one loitering in the courtyard of the engineering building.

18 December 2008 just outside of the laboratory

Unlike the Western subspecies, Audubon Warbler (D.c. auduboni), he had a whitish (or at least non-yellow) throat and a white eye-stripe. These are features of the Myrtle Warbler, the nominate subspecies. The only record of occurrence of the Myrtle Warbler in San Diego County that I could find was for the Alaska Myrtle Warbler (D. c. hooveri).^SDNHM

Surveying the building

Yellow coloration of plumage is by carotenoid pigmentation,^{Hill and McGraw} which must be acquired from dietary sources.

Showing off his best side

Yellow Rumped Warblers are primarily insectivorous, but they are seasonal frugivores. The Myrtle Warbler, particularly, is one of a few species to consume wax myrtle or bayberries during winter months, when insects are less available.^Stiles The specialised and relatively rare ability to digest high molecular weight, highly caloric, non-polar lipids of epicuticular wax affords the Myrtle Warbler endurance to winter in more northerly, cooler climates than other American warblers.

Caught mid-hop

But this guy seems content to enjoy insectivory in post-rainy sunny San Diego, for now.

He headed upstairs in order to check out the office space.

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~ by finchwench on Sunday, 21 December 2008.