PIBO Migration Summary

September 21st – 30th, 2012


‘Western’ Palm Warbler


It was another productive ten days at Fish Point from September 21st – 30th and a nice variety of birds were recorded on most days throughout the summary period. In all, 96 species were documented over ten days and 329 birds of thirty-eight species were captured in 522 net-hours, for an average catch-rate of 0.63 birds/net-hour. Twelve fall ‘firsts’ were noted. By comparison, 85 species were tallied from September 11th – 20th and 271 birds of twenty-five species were banded in 372 net-hours (0.73 birds/net-hour). The weather was cooperative from the 21st – 31st, with just one morning of rain, although the winds were mostly from the west and southwest during the first five days of the summary, which made for a somewhat quiet time up to the 26th. The average dawn temperature was 15° C during the summary period, with a high of 19° C on September 26th and a low of 11° C on the 24th. The average daily species count was 46, with a high of 59 on the 27th and a low of 32 on September 21st.


Migrants were fairly low-key on the 21st and there wasn’t much to report apart from some thrushes (9 Swainson’s and 9 Gray-cheeks were banded) along with small numbers of Red-eyed and Philadelphia Vireos, some Blue Jays and Red-breasted Nuthatches, and three warbler species. There were a few more birds around the next day but the netting area was quiet, with just nine birds captured in thirty net-hours. The highlight on the 22nd was a station-high 15 Bald Eagles (all sub-adult save one) sitting on the tip during the census. The gulls were not very pleased about this! The previous high count for eagles was ten recorded last year. Seventy-seven Blue Jays were noted flying off the tip as well.


Although thrush activity finally dried up in the netting area, a nice range of other species were captured in small numbers on September 23rd including Yellow-bellied Flycatcher, Red-breasted Nuthatch, and six warbler species. Eleven warbler species were recorded on the day along with the first Dark-eyed Juncos of the fall. Almost 3000 cormorants and 1200 gulls were counted at the tip, including at least 60 Bonaparte’s Gulls. Fifty-five species were tallied in the official count area on the 24th including fall ‘firsts’ for Rock Pigeon (likely someone’s racing pigeon), Golden-crowned Kinglet and Fox Sparrow. A small pocket of migrants along the east shore on the census included 13 Red-breasted Nuthatches and a surprising 11 Blue-gray Gnatcatchers. Fourteen warbler species were noted including a couple of Northern Parulas.


While most of the gulls at Fish Point tend to roost far out on the tip (app. 1 km), another nine Bald Eagles encountered on census on September 25th shifted roughly 1100 gulls into better viewing range, which revealed at least 50 adult Great Black-backed and 2 adult Lesser Black-backed Gulls. Ring-bills made up the majority of the flock along with smaller numbers of Herring. Some light but steady rain on September 26th made for just three hours of morning coverage and not many birds were recorded with the exception of small numbers of eight warbler species, 10 banded Swainson’s Thrushes and 9 Gray-cheeks, and a few White-throated Sparrows.       


Strong northeast winds the following day prompted a good pulse of migrants and 59 species were documented on the 27th during the morning coverage period, including fall ‘firsts’ for Pine Warbler, Chipping, Lincoln’s and Eastern White-crowned Sparrow. Highlights included 6 Northern Harriers, 4 flycatcher species (including a fairly late Eastern Wood-Pewee), 175 Blue Jays, 15 warbler species, and 82 White-throated Sparrows. The 28th was not quite as active – 51 species were tallied, including nine warbler species, and 54 birds of sixteen species were banded. An Eastern Towhee was new for the fall.


The final two days of the month were also moderately active, with 48 species noted on the 29th including 100 Blue Jays, 77 Golden-crowned Kinglets, six warbler species, and 27 White-crowned Sparrows, and 43 species on September 30th. Thirty-four individuals of fourteen species were captured on the 30th including ones-and-twos of Blue-headed Vireo, House Wren, Winter Wren, both kinglet species, three thrush spp., and a noisy Brown Thrasher.


PIBO’s next migration summary will be posted on October 12th.


Photo: Sumiko Onishi