[Comparison of Northern Harrier numbers on January 23 and February 20, 2010, with 40 inches of snow in between. Click to enlarge.]
CMBO volunteers conducted the second Winter Marsh Raptor Survey of 2010 on February 20, 2010. Full results (updated since originally posted) are available here: winter marsh raptor survey results February 20 2010.pdf
Of interest, major snowstorms occurred February 5-6 and 9-10, dumping upwards of 40 inches on southern New Jersey. Raptor numbers responded, though, as the chart above indicates, not predictably across all sites.