Hi Gordon, I counted 58 Chimney Swifts at Robbinsdale Middle School last night. This is higher than my usual count here, typical count was 12. PS, sorry, I didn't use Reply All earlier.
Curt Rawn On Fri, Jul 31, 2020 at 6:05 PM Gordon Andersson <gpanders...@msn.com> wrote: > Ornithophiles > > > > I live in W. 7th neighborhood of St Paul kiddiecorner from a school with a > tall chimney. Every summer the CHSW's start chittering and flying around > in > small and large groups beginning about sunset. On Monday eve I decided to > count them as they dove down the chimney. As you know, the most accurate > count would require a video recording played back in slow motion. The > number dropping into the tower accelerates suddenly and then it is over > except for a few independent spirits. > > > > On Monday eve I counted 92 birds. On Tuesday 142 birds. Last eve Thursday > 122 birds. The last count is probably the most accurate with the smallest > + > and - ranges. But I think the numbers actually fluctuate each evening > also. There might be a rolling average increase before departure for the > south. > > > > For years Audubon MN conducted a volunteer CHSW count at two times during > the summer, with a retired volunteer coordinator. For 40+ years, St Paul > Audubon Socy had a "warbler weekend" every Mother's Day weekend at Villa > Maria in Old Frontenac on Miss River. Every evening Friday and Saturday > people would count the birds going down the chimney of the 4 story > limestone > block residence. It was a scheduled event. > > > > About 15 years ago, on a weekend, I came back from birding somewhere and > decided to sit in my bkyard and count the CHSW's. This was before the AM > organized count. As I remember there were 246 or so birds and I sent the > observation to DNR non-game staff. > > > > My thought with these summer tower roosters has been that they were all > non-breeders. Since they only appear in the evenings, they could not be > feeding young in nests in the chimney. Someone who knows more and has > actually studied CHSW's might offer some facts. I was told once that only > one pair nests in each chimney. Alternatively, perhaps these birds are > already swarming, preparatory to migration to Central America. a long > ways > to go and if young have already fledged they can head south. > > This is from CLO allaboutbirds.org "Unmated swifts continue roosting > together in the summer, sometimes in large groups. But the species does not > nest colonially: you'll find only one breeding pair nesting in any one > chimney. The pair may tolerate other nonbreeders roosting in their > chimney." > > > This represents a huge number of non-breeders. CLO does not mention age of > sexual maturity. The loss of chimneys has been gradual over time so these > numbers are not due to a sudden surplus of adult birds from one year to the > next. > > > > PS I just read Jim Williams article in the Star Tribune from July 28 on > Chimney Swifts. He notes the decline of all four of N America swift > species, that NAS labels as species of "special concern". > > > > GAndersson > > St Paul > > > > > ---- > Join or Leave mou-net: http://lists.umn.edu/cgi-bin/wa?SUBED1=mou-net > Archives: http://lists.umn.edu/archives/mou-net.html > > During the pandemic, the MOU encourages you to stay safe, practice social > distancing, and continue to bird responsibly. > -- Curt Rawn 612-618-6200 ---- Join or Leave mou-net: http://lists.umn.edu/cgi-bin/wa?SUBED1=mou-net Archives: http://lists.umn.edu/archives/mou-net.html During the pandemic, the MOU encourages you to stay safe, practice social distancing, and continue to bird responsibly.
