If you look at the distribution map for the Purple Martin in the 2nd Atlas of the Breeding Birds of Ontario: 2001-2005, you will see a bunch of little boxes, many of them with little black dots in the centre of them (see the picture below). The boxes represent 10-km squares which are the units within which observers try to determine whether a bird is breeding or not. The dots are the concerning feature. The first Atlas was conducted between 1980 – 1985. If a bird species was present in a 10-km square during the first Atlas but not in the second, there is a dot. And there are a LOT of dots. The main decrease indicated by these dots is in the north and inland areas of Ontario. In fact, it was calculated that there was a 46% decline in the probability of seeing a Purple Martin between the two Atlases. It would appear that this is another “aerial insectivore” that is being hard hit.
Our martin colony at Ruthven continues to do fairly well. We were out today banding those nestlings that were big enough. The adult birds were not particularly put off by our being there. They waited patiently on the cross trees of the new gourd housing unit 5 meters away for us to finish and then went back to busily feeding their young. This gave us a good chance to see what they were feeding – one had a butterfly (the consensus opinion was that it was a Comma) but most who had food were carrying dragon flies and one even had two!
We had the nets open for about 5 hours this morning to try to band the young birds that are beginning to fledge now in increasing numbers. Tufted Titmice seem to have had a good breeding season as we banded another 5 young ones this morning. We also got a young Carolina Wren. On the whole we banded 51 birds (including 25 Purple Martins). Soon the young will disperse, the adults will hunker down and go through a complete moult, and then the big trek south will begin in earnest.