Population Status of the Eastern Phoebe in South-Central North Carolina: Breeding Increase at Water-Based Anthropogenic Sites Congruent with Breeding Bird Survey (BBS) and Christmas Bird Count (CBC) Data

摘要

Few studies in southeastern North America have compared local data sets to locally based results from 2 national surveys (North American breeding bird survey [BBS], Christmas bird count [CBC]). In 2012, I reexamined nest-site type use and nest type of Sayornis phoebe (Eastern Phoebe) at 109 water-based anthropogenic structures originally studied in south-central North Carolina in 1981. In 2012, Eastern Phoebes still strongly preferred breeding at small bridges with ledges, especially at the same structures where I studied them in 1981, even though use of other nest-site types slightly increased except at circular culverts, where no Eastern Phoebes nested. During the 31-year interval between studies, similar to 1/3rd of the bridges (20 of 62; 32%) were replaced with structures less favorable as nest-sites; thus, a lower number and proportion of small bridges with ledges were available in 2012. Although breeding Eastern Phoebes are still slowly increasing in abundance at water-based anthropogenic sites in south-central North Carolina, I project that this population will reach zero growth in 2027 as replacement of small bridges with ledges by other structures continues. The findings from this local water-based anthropogenic nest-site survey in south-central North Carolina was congruent with results from 2 national surveys (BBS, CBC) in a portion of the Pee Dee region in documenting a modest increase in the number of Eastern Phoebes during a time span ranging over 30 years.