I have received some very complete replies to my question about the longevity of Varied Thrush stays in CO from both Brandon Percival and Doug Faulkner. Thank you.
Apparently the longest documented stay was 70 days for a bird in Beulah (Pueblo County) from 13Dec1986 to 21Feb1987. However, in checking the notes scribbled in my Andrews and Righter, we (David Ely and I) found a bird at the Colorado State Forest Service Nursery on the west side of Fort Collins (Larimer) during our running of the Fort Collins Christmas Bird Count on 16Dec1995. I last saw this bird on 16March1996 - which makes for a 92-day stay. The bird detected January 15, 2013 and still present in Ken Allen's backyard in Fort Collins has, thus, persisted 77 days. If it stays until April 19, it will be the record holder, as far as we know. As many who have seen this individual have observed, it has an abnormally long bill, which appears incapable of closing completely. Perhaps this abnormality has contributed to its reluctance to leave a feeding operation where food acquisition is made easier. Of note, this bird takes whole peanuts in addition to more normal feeder fare. I thought this a bit odd for a thrush, but the BNA account mentions acorns in the diet of this species. All very interesting.
I should point out, as Doug notes in his message, going by documentation alone, the stays of most Varied Thrushes appear to have a duration of only one or two days. That is probably NOT the case, given the secrecy of the birds, and the shortage of documentation we birders do (myself included). Two to three-month stays (beginning in early winter and ending in early spring) are probably the norm. All it takes to give a bird the appearance of "moving on" would be detection by a birder in their yard one day and it finding the non-birding neighbor's yard better the next day.
Dave Leatherman
Fort Collins
Apparently the longest documented stay was 70 days for a bird in Beulah (Pueblo County) from 13Dec1986 to 21Feb1987. However, in checking the notes scribbled in my Andrews and Righter, we (David Ely and I) found a bird at the Colorado State Forest Service Nursery on the west side of Fort Collins (Larimer) during our running of the Fort Collins Christmas Bird Count on 16Dec1995. I last saw this bird on 16March1996 - which makes for a 92-day stay. The bird detected January 15, 2013 and still present in Ken Allen's backyard in Fort Collins has, thus, persisted 77 days. If it stays until April 19, it will be the record holder, as far as we know. As many who have seen this individual have observed, it has an abnormally long bill, which appears incapable of closing completely. Perhaps this abnormality has contributed to its reluctance to leave a feeding operation where food acquisition is made easier. Of note, this bird takes whole peanuts in addition to more normal feeder fare. I thought this a bit odd for a thrush, but the BNA account mentions acorns in the diet of this species. All very interesting.
I should point out, as Doug notes in his message, going by documentation alone, the stays of most Varied Thrushes appear to have a duration of only one or two days. That is probably NOT the case, given the secrecy of the birds, and the shortage of documentation we birders do (myself included). Two to three-month stays (beginning in early winter and ending in early spring) are probably the norm. All it takes to give a bird the appearance of "moving on" would be detection by a birder in their yard one day and it finding the non-birding neighbor's yard better the next day.
Dave Leatherman
Fort Collins
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