Atlantic Flyway review: Region IV - Fall 2003: Robbins Nest, Laurel, MD (390-0765)

Abstract

The most notable finding at this station in 2003 was the sharp decline in recaptures of previously banded birds and most especially a Crash in the chickadee and titmouse populations. In the autumn of 2001, I recaptured 36 birds banded in previous autumns, but I caught only 24 returns in 2002 and 17 in 2003, a 33% drop each year. In 2002, Tufted Titmouse was my fourth most common species (19 caught) and Carolina Chickadee (15)was in seventh place. This year, I had only four titmice and six chickadees, declines of 79% and 60%. Until now, only the migratory species have been of concern. We suspect West Nile virus is responsible. However, the oldest bird we recaptured this year was Blue Jay 723-42798, banded as HY in 1993, a species known to be especially vulnerable to West Nile. Half of this year's returns were cardinals, the oldest of which was only four years of age. My birds/100nh continues to drop each year without any noticeable change in surrounding habitat. The only banded migrant known to have remained here for more than a week was a Swainson's Thrush that weighed 31.9 g on 4 Oct and 41.6 g nine days later, an increase of 30%.