Wednesday, December 2, 2009

MA - Saw-whet update - 12/01

Northern Saw-whet Owl. New Salem, Franklin Co., MA. November 25th, 2009.

The start of a new month seems like a good time to reflect on Northern Saw-whet findings since late October. Over the last month I've had 15 contacts (birds heard or seen) from 45 individual stations with repeat visits to some stations. Of these, I can be fairly certain that two contacts (on different nights) involved the same bird. Overall, I think 14 individual birds have been found. While this might seem like quite a few, the overall success rate is pretty low........about 26%. Success (heard/seen) is being measured against an individual survey, each survey lasting 20-30 minutes. At least some of this can be attributed to vocal response or perhaps more accurately, lack of vocal response. Some birds are doubtless present but simply don't vocalize. On one occasion, we watched a bird fly in silently towards us after just one minute of saw-whet imitation (whistling simple repeated 'tooting'). However, the same bird didn't vocalize until eight minutes later. Many references suggest that saw-whets are silent at this time of year and I think it's quite feasible that the success rate will improve during the course of the winter, especially from late January onwards. We've recorded saw-whets in the following towns: Amherst (2), Hatfield (1), Leverett (1), Montague (1), New Salem (1), Shutesbury (5), and South Amherst (3). Locations in Belchertown, Pelham and Sunderland have also been surveyed but have yet to produce a positive result.

On the whole it's been quite fascinating. An actual 'visual' versus a 'heard-only' makes a huge difference to moral and the five birds seen so far have been very satisfying. Other owls have also been detected, including Barred Owls (9) and Great Horned Owls (2)
, but no Eastern Screech-owls as yet. The absence of the latter may be attributed to elevation and habitat preferences but it's a little too early in the study to say.

Habitat of Northern Saw-whet Owl. Hatfield, Hampshire Co., MA. December 1st, 2009.

All of the locations in our area supporting Northern Saw-whet Owls contain mixed (rather than dense coniferous) woodland and all of the locations, with the exception of one, have at least some Eastern Hemlock within the habitat composition.

Poor attempt at a digibin shot.

I'm very grateful for the comments and help that I've received from fellow owl enthusiasts, and especially to Brian Kane and Larry Therrien who have joined me for several nights in the field.

No comments: