On Saturday, June 10th, we opened the nets for one last time this Spring. In the regular six hours, we banded only seven birds, a clear sign that migration has come to an end once again. Nonetheless, it was interesting to catch a Brown Thrasher, our first banded this year: this species does breed at Cabot Head but seems to be particularly savvy at avoiding the nets. Another fun capture was a female White-throated Sparrow: the plumage of this species is similar between the sexes but this bird had a brood patch, indicating a female getting ready to incubate her eggs. A brood patch is a patch of featherless skin that is visible on the underside of female birds (and in males on some species) during the nesting season. This patch of skin is well-supplied with blood vessels at the surface making it possible for the birds to transfer heat to their eggs in order to incubate them. Males of this species don’t incubate eggs or brood young and so they don’t have this hormonally driven loss of feathers during the breeding season making it easier to differentiate the sexes. There is a small population of breeding White-throated Sparrows on the Bruce Peninsula, even though the core of its summer range in Ontario is in the boreal forest.
The 2017 Spring season demonstrated, once again, that nature is full of surprises and variations to offer. It was certainly a rainy Spring, at Cabot Head of course, but also at a regional level. We cannot open nets when it is raining, so we lost quite a few days to such inclement weather. But it also impedes migration, halting birds on their journey and making it harder for them to forage in order to refuel. Our season banding total is 996 birds of 63 species, the second-lowest Spring total ever recorded. An obvious reason for such a low total is the weather conditions, with the deluge of rain in late April-early May being the major culprit. The Spring report, with more detailed analysis, will be posted on the website when completed.
Despite the low number of birds banded, it was a successful season, thanks notably to dedicated and enthusiastic volunteers. The highlights of the season, which were detailed in previous postings, are, of course, the observations of a Great Grey Owl, a Black Tern, and a Prothonatory Warbler, all new species for Cabot Head.
The nets have now been furled for the last time this Spring, taken down and stored until it will be time to deploy them again. Fall migration will soon enough begin, “officially” on August 15. In the meantime, I wish everyone a wonderful Summer filled with birds and beautiful natural moments.