Spring banding 2001 took place on 26 days from 19 April to 30 May. Nets were open an average of 4.25 hours per day with average 17 nets (12 meter equivalent). We started out with several species we don’t often band: Blue-winged Warbler, Blue-gray Gnatcatcher, and Savannah Sparrow. We thought we might have a chance at getting a record number of species, but the weather didn’t cooperate and we ended up with a disappointing 58 species.
We banded 510 new birds and had 106 recaptures. A total of 668 birds were netted (this includes birds released unbanded). Our capture rate was 36.0 birds per 100 net-hours. Previous spring means are 528 new birds and 649 total, and 42.8 per 100 net-hours. Thus, according to the numbers, our spring season was “average.”
Our busiest day was 17 May, a good day for migrants around the region. The next day was merely average, and for the rest of the month our total number of birds banded was less than we typically band in a single day! A stubborn low pressure system stalled to our west was a major culprit in shutting of migration to our area. As a result, we completely missed banding many warbler species, including Black-throated Blue, Bay-breasted, Blackpoll, and Black-and-white! Thrushes were also nearly absent with only one Swainson’s netted (spring mean is 16.6, a decline of 94%), no Gray-cheeked, three Veery, and one Hermit. Hermit Thrushes are early migrants and presumably would not have been influenced by the low pressure system, but during their migration window, our net lanes were completely flooded!
Not all was lost, and we did band some species in excellent numbers (total followed by previous spring mean, deviation from mean):
* Nashville Warbler (29, 5.8, +400%). This follows an increase of 188% last fall.
* Lincoln’s Sparrow (19, 9.6, +97.9%) This follows an increase of 367% last fall.
* Baltimore Oriole (16, 2.9, +451.7%). Super-abundant this year.
* Yellow Warbler (25, 15.6, +60.2%)
* Gray Catbird (80, 55.3, +44.7%)
High site fidelity
This spring, the 100th Gray Catbird banded in a previous year returned to our nets after its Central American/West Indies vacation. The oldest catbird to return was a male first banded as an adult in 1998. He’s returned to nest each year since. A Red-eyed Vireo first banded in 1998 also returned; this species winters in the Amazon region! Among our residents, we recaptured a Northern Cardinal from 1994 and a Blue Jay from 1996.
The survey says…
Prior to May 3, seventeen species set new early arrival dates for Dearborn, and most species were Neotropical migrants. These included Black-throated Green Warbler (4/13), Cape May Warbler (4/15), Rose-breasted Grosbeak (4/22), and Bay-breasted Warbler (5/1).
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