PIBO Migration Summary

October 1st – 10th, 2012



Yellow-rumped warbler


Although migrants continued to move through the area in good numbers from October 1st – 10th, activity was somewhat low-key for the time of year compared to previous years. In all, 82 species were recorded in the official count area and 300 birds of twenty-seven species were banded in 350 net-hours, for an average capture-rate of 0.86 birds/net-hour. By comparison, in 2006, more than 450 birds were captured from the 7th – 10th in just eighty-one net-hours (5.6 birds/net-hour), and in 2005, 716 birds were captured during the same ten-day period in 298 net-hours (2.4 birds/net-hour). The daily species count during this summary period ranged from a high of 59 on October 1st to a low of 35 on the 4th. Just three fall ‘firsts’ were tallied compared to twelve during the previous summary (September 21st – 30th).


The month started off on an active note, with 59 species recorded on October 1st and 73 individuals of twenty species banded in forty-five net-hours (1.62 birds/net-hour). A nice variety of species were on hand including eleven warbler species, three flycatcher and vireo spp., and all four catharus thrush spp. (Veery, Swainson’s, Gray-cheeked, and Hermit), among others. It was rainy on the 2nd and there wasn’t much of note on the bird front apart from the first migrant Swamp Sparrows of the Fall and a slight increase in numbers of Golden-crowned Kinglets and White-throated Sparrows. The 3rd was reasonably active, with 43 species documented on the day including seven warbler spp., 57 Blue Jays, and smaller numbers of Red and White-breasted Nuthatch, Brown Creeper, both kinglet spp., and Wood Thrush.


Strong southwest on October 4th made for a fairly quiet morning but the 5th was busy, especially for raptors, with a nice variety of birds noted in small numbers on the morning census including 18 Turkey Vultures, 7 Sharp-shinned Hawks, 3 Ospreys, 2 Bald Eagles, 2 Peregrine Falcons and 1 Merlin and American Kestrel. Forty-eight species were tallied the next day including some more raptor activity, Yellow-billed Cuckoo, a good push of Golden-crowned Kinglets (101 DT), ones-and-twos of five warblers species, including a somewhat late Northern Waterthrush, and 35 White-throated Sparrows.


The wind finally shifted to the north on October 7th and the tempo picked up considerably, with good numbers of 46 species reported during the official count period including 252 Blue Jays, 69 and 29 Golden and Ruby-crowned Kinglets, respectively, 18 Hermit Thrushes, and up to 400 blackbird spp., including a few Rusty Blackbirds. The 8th was busy as well, with 54 species documented and 63 birds of fourteen species captured in 45 net-hours (1.4 birds/net-hour). Highlights included four woodpeckers spp., 10 Tree Swallows, 22 Red-breasted Nuthatches, 15 Winter Wrens, 136 Golden-crowned Kinglets, 7 warbler spp., and 5 sparrow spp. The final two days of the summary period saw a drop off in activity although there were still some migrants around including similar numbers of kinglets, Blue Jays, a station-high 33 Red-breasted Nuthatches, Blue-gray Gnatcatcher, Pine Warbler, and a late American Redstart.


PIBO’s next summary will be posted on October 22nd.


Photo: Sumiko Onishi