Sunday, April 03, 2005

North Woods Screech-owl Mystery


The other day I realized that there was something extremely odd about the arrival date of the little screech owl family I've been posting pictures of on this website. I sent off the following letter to four bird experts I know well enough to have their e-mail address: Tom Fiore, Starr Saphir, Eric Salzman, and Steve Quinn of the AMNH [Natural History museum]:

Something suddenly struck me about the North Woods Screech-owls. I wonder if any of you you have any ideas.

The first report of the screech owls was on March 19, when Pat Pollock reported seeing 2 adult and 3 fledged screech owls. There is no question that these birds had fledged. They were seen flying out that night, and many times thereafter. Pat reported them to ebirds as being about two months old, although she didn't say how she assessed their age.

But even if they had fledged the day before they were first sighted, , isn't this extremely early for fledged screech owls? I looked it up in the old Bull's Birds of New York State and the earliest HATCH record was in late March -- March 23 or 27 --[I don't have the book right here.] So that would mean fledglings at the earliest in late April! Isn't this very odd?

Furthermore, here's a snippet from a reliable website:

" Chick development of Eastern Screech Owl

The female incubates the eggs for 26 - 28 days. The male will feed the incubating female, who is a close sitter and will not venture far from the nest when taking a break. The chicks are semi-altricial at hatching. Both parents care for the young. Early on, the male will deliver food to the female who tears it into smaller pieces to feed to the chicks. The chicks fledge after about 27 days in the nest, but remain dependent on the parents for 8 - 10 more weeks. "

SO---26 +27 = 53 days. That means that the birds seen on March 19 had come from eggs laid no later than on JANUARY 25!! [Or is my math wrong?] Even Great Horned Owls don't nest that early, and they are known to be the earliest nesters among the owls.

Let's see what they answer!