Our 34th annual Manassas-Bull Run Christmas Bird Count was held on December 20, 2015. We got some relief from unusually hot December weather when the day started below freezing and then Count Day temps topped out in the 40s with bright sun and breezes. We had a record high number of participants with 129 people counting just over 20,000 birds among 80 species. While the bird numbers and species were down slightly from last year, they are within past 15 year averages.
At the same time, we counted all-time highs for one-fifth of the species seen. Included in those 16 species were Gadwall, Ring-necked Duck, Sharp-shinned Hawk, Ruby-crowned Kinglet, Eastern Towhee, Song Sparrow, White-Throated Sparrow and American Goldfinch. Incredibly, in six of the seven woodpecker species we saw all-time highs. People all over are reporting high numbers of Red-headed Woodpeckers; we saw 50 (our previous high was 11). For Bald Eagles, we counted more than ever before, both for adults and immatures. Common Raven sightings continue to increase – an all-time high of 9 this year.
We also had some unusual sightings: one sector saw a falcon trifecta (American Kestrel, Merlin, and Peregrine Falcon); our whole count circle has only done this once before, in 2003. Another sector had an owl trifecta (Eastern Screech, Barred and Great Horned); the last time our count circle had three owls was 2006 when we saw Barred, Great Horned and Short-eared Owls. We actually had two Screech Owls, the first time we have had any since 2004. We also saw six Pine Siskins in a year with a very warm fall and no reports of siskin irruptions.
It is difficult to explain many of our all-time highs. Species populations wax and wane. In our count history, Downy Woodpecker numbers surge and decline; Eastern Bluebird numbers this year fell to half of last year’s and well below numbers since 2009. For some species, such as Northern Bobwhite and American Kestrel, the shift in land use in Western Fairfax county seems to explain part of the declining numbers. Other species once reduced by West Nile Virus seem to have rebounded. Our count circle echoes the recovery of Bald Eagle populations from DDT. And some species like Common Raven seem to be expanding their presence into our area; before 2001, we never reported any.
Copies of the full results for the count are available from ASNV website, the ASNV office, any of our sector leaders, or the compiler, Bob Shipman.
We gratefully thank all the enthusiastic birders both new and returning who came out this year; we hope you had a good time and will come back next year.