Northern Virginia Bird Trends

The 18th annual Northern Virginia Bird Survey (NVBS), ASNV’s comprehensive breeding bird count, took place in June 2011. Many thanks to the forty-three volunteers (nine new to the NVBS) who collected data at 643 grid points located at more than twenty-five sites and counted 9,931 birds representing 99 species. Since the survey began, 175,141 birds have been counted. With the addition of 5,780 new Excel records this year, the database now contains 96,115 records each with detailed count information about a single species at a single survey point.

Northern cardinal was the top species in both numbers and distribution and was followed by tufted titmouse. American robin and red-eyed vireo came in third in numbers and distribution respectively. Crow numbers remained low and were not significantly different from last year. No new species were added this year so the total number of species for the life the survey remains at 151. Species encountered in 2011 but not in 2010 included common merganser, black duck, yellow-crowned night-heron, willow flycatcher, rose-breasted grosbeak, and black-throated green warbler. Present in 2010 but not this year – ring-billed gull, Caspian tern, hooded merganser, spotted sandpiper, American kestrel, and marsh wren.

Long-term Trends

In 2006, ASNV published a 60-page report using data gained from the surveys through 2005. It examined trends in representative species in representative habitats throughout Northern Virginia. After the completion of the 2010 survey, we extended the trend analysis an additional five years, through 2010, and updated the report. Unfortunately, the long-term data show a steady decline in the abundance of birds in the region. The updated report is available in three formats: the full report (79 pages), a shorter pamphlet (14 pages), and a trifold brochure. The full report includes detailed information on the methodologies used in the surveys and on the state of birds in Northern Virginia—overall and in various habitats. It also updates the trends in three individual survey areas—Lorton/Laurel Hill, Occoquan Bay National Wildlife Refuge, and Great Falls National Park.  The pamphlet and the brochure provide the essential findings of the full report in varying levels of detail. All of the versions provide information on ways you can help. You may view or download the documents by clicking on the following links.