One of the interesting but challenging aspects of monitoring wildlife populations or their activities is to document and explain out of the ordinary results. This was the case for the 2012 birds of prey migration count in Manitoba. Since 2005, A Rocha has monitored the spring migration of eagles, hawks and other raptors in the Pembina Valley, about 125 km southwest of Winnipeg. The valley is an important migration corridor for migrating birds of prey as well as for other bird species.
In 2011, observers were amazed to see raptor numbers sky-rocket, at least by Pembina Valley standards, to over 13,000. The end result of that count was a new record for both the valley and Manitoba. An out of the ordinary situation, however, came in 2012 when quite the opposite record was achieved during the standardized count. The migration period started out with an unusually mild winter and relatively little snow cover. A strong showing of eagles seemed to be a good precursor for the count. But a few out of the ordinary observations, in addition to the mild weather, hinted that this migration would be different. The first Red-tailed Hawk made an early showing on March 10 and a Turkey Vulture was sighted on 19 March, about 10 days or so earlier than usually expected. By late March or early April, raptor counters are usually busy documenting the peak of the raptor migration. But in 2012 that was not the case, and they were left wondering where the raptors were.
Best not to give away too much about the 2012 raptor count season – rather, I’ll let you the reader find out for yourself in the following report what the final tally was for 2012 and how the individual raptor species (15) faired during their migration in the Pembina Valley.
