Saturday, June 2, 2012

Tales from Bear Swamp, Part 1

 [Acadian Flycatcher, Bear Swamp, Cumberland County, NJ, May 28 2012. Caught at our MAPS station. Look how green this bird is compared to the brownish Willow Flycatcher pictured in the May 27 post. Check out also the bolder eyering - though note that the Willow pictured in the post below does show a faint eyering. The Acadian's long wings sticking out well past the tertial feathers  rule out Least and Yellow-bellied Flycatchers as i.d. contenders. This bird's wing chord measured 72 mm, average for Acadian, at the max for Yellow-bellied, and too long for Least. This bird's bill was also too long for YBFL and LEFL, and too wide for "Traill's," the name used for Willow/Alder Flycatchers. Beyond the arcane Empidonax flycatcher i.d. details, this is simply a cool bird - when you're with Acadian Flycatchers, you are in a good place, a rich woods with abundant insects and many birds of interest.]

Quality. That describes Bear Swamp, Cumberland County, NJ, where we've run a MAPS banding station the past few years. Birders know Bear Swamp best from birding the area along Route 555 out of Dividing Creek, where Prothonotary, Yellow-throated, and Kentucky Warblers, Acadian Flycatcher, and Summer Tanager are sought after targets. We burrow deep into the swamp for banding, amongst the ticks and flies and quality forest-interior birds.

As part of the MAPS data collection process, we keep a record of all birds we detect at the station, whether we band them or not, and last weekend had two Barred Owls and a persistently calling, probably breeding Broad-winged Hawk. More quality.

Recaptures of banded birds are an important piece of the MAPS equation. Perhaps the most important reason to operate a fixed-effort banding station during breeding season is to evaluate survival and reproduction, and about 1/3 of our birds are recaptures, including for example the Red-eyed Vireo pictured at the bottom of this post. An amazing thought in and of itself - here's this bird, that we banded one summer, that migrated to somewhere in the Western Amazon, spent the winter, and returned here to breed again. Successfully, from the looks of things.

[Quality - What birder hasn't thrilled to the lovely and unique head pattern of a Worm-eating Warbler? As a birder, I love them not in the hand but perched on a branch, singing their steady trill. As a researcher, I want to know how Worm-eating Warblers are doing, how long they're living, how many young they are producing.]

 [Above and below, female Red-eyed Vireo, Bear Swamp, NJ, May 28, 2012. Male and female red-eyeds are the same, plumage-wise, but the fully developed brood patch gives this female's sex away. The pinkish-yellowish triangle at the top of her breast is her furcular hollow full of fat - she's in good condition to incubate and raise a family. The brood patch is shrouded with feathers when you see birds in the field; here we're blowing the feathers out of the way for a look.]

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