I stopped by the Shiloh Rd grasslands yesterday and a light morph roughleg was perched right in the interchange, oblivious to all the traffic around it. After a short scan of the extensive grasslands I only came up with one other roughleg, another light morph. This is the smallest number of roughlegs I have seen here in over a month and I have to wonder if the big thaw we are experiencing is to blame. It will be interesting to see if more show up when winter returns next week.
Looking at eBird it appears at first glance that mid-February is when Rough-legged Hawks start heading north and are reported less in Pennsylvania (Figure 1.). However, I believe that this is not quite accurate because we are having an exceptional year for roughlegs and the peak in their abundance on the chart goes right up to the second week of February. After the 2nd week it drops off which is when 2011 sightings are no longer influencing the abundance chart.
If you look at the abundance chart below (Figure 2.) when I exclude 2011, it is apparent that 2011 is disproportionally affecting the chart. The peaks are in late December (artifact from Christmas Bird Counts?) and 2nd week of January.
It will be interesting to see what sticks around and whether hawk counts such as Tussey Mountain (starting up in a week or so) will get higher numbers of Rough-legged Hawks than they typically do.