▶️ Northern Saw-whet Owl

[Probatim]

3. It is indeed a male call - but they say it does not explain the disparity. Here's a helpful link:

https://www.projectowlnet.org/methods/migrant-owl-netting-protocols/

Age/sex class differences. Summarizing six years of data from Pennsylvania, immature (fall HY) owls were found to migrate significantly earlier than adults, which had significantly higher mass and averaged longer periods of stopover than HYs. Most stations report a significant female bias; at three sites in Pennsylvania, saw-whets categorized as male using a mass/wing chord discriminant analysis accounted for only 6 percent of fall captures, while females were 77 percent; the remaining 17 percent could not be assigned to gender. The use of a male advertisement call as an audiolure does not wholly explain this disparity (Duffy and Matheny 1997).