[Tweeters] Northern Saw-whet Owl numbers

J. Acker owler at sounddsl.com
Wed Dec 4 17:18:08 PST 2013

I completed running statistics on my saw-whet banding data for this past
migration season. It was a down year for them, to be kind. If you encounter
a saw-whet this winter, please treat it kindly and with respect. It had a
tough year.

I put in 405 net hours ( a net being defined as a 12m net open for one hour)
this season and caught 24 saw-whet owls. This is a sharp contrast to last
season in which I had 423 net hours and caught 80 saw-whets. Last year, a
productive year for them, the ratio of young (hatch year) birds to adults
was 3:1. This year it is less than 1:1, indicating a poor breeding year for

My results mirror those of other saw-whet banding stations over North
America. Saw-whets typically go through an approximate 4 year cycle for
reasons that are not clear, but may be related to the availability of their
prey - mice and voles.

Thought this might be of interest to the group.

J. Acker

owler at sounddsl.com

Bainbridge Island, WA

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