In the fall of 2002, Rocky Point
Bird Observatory began a pilot study to determine the feasibility
of developing a long-term nocturnal owl monitoring program. On
13 Sept, the nets were opened at dusk and a compact disk player
with a Northern Saw-whet Owl call was turned up! After two hours
of checking the nets, there, in one of the nets was the project's
first Northern Saw-whet Owl (Aegolius acadicus). The nets
were open each Friday and Saturday night for the rest of September,
October and the first weekend of November. By 2 November, 210
Northern Saw-whet Owls and 2 Barred Owls (Strix varia)
had been banded. The movement peaked on the 11, 12 and 13 of October
when 73 Northern Saw-whet Owls were banded over the long weekend.
This was the first time in British Columbia that the fall movements
of Northern Saw-whet Owls had been described in detail.
The results of the pilot study raises many questions. Where do
these owls winter? Where do they nest? Was the fall of 2002 an
invasion year with abnormally high numbers, or a year with abnormally
low numbers? Is the population of Northern Saw-whet Owls moving
through Rocky Point stable, declining or increasing over time?
These questions can only be answered by years of consistent monitoring.
The one question that can now be answered, is that Northern Saw-whet
Owl monitoring at Rocky Point Bird Observatory is feasible, and
is the first step in answering other questions regarding the biology
of these cryptic owls in British Columbia.
2002 FINAL REPORT
Printable, full format PDF version
(3.6 mb), Web formatted, HTML
version.
Fall 2003. Given the success seen in 2002, the owl monitoring
was continued in the fall of 2003. Building on what was learn
the previous fall, one of the nets was moved closer to the audio-lure,
and banding was conducted for the first six hours of the evening
instead of dawn to dusk as in 2002. Direct comparison between
2002 and 2003 results should not be made due to the changes in
the methodology.
Banding started on 12 Sept and ended on 8 Nov, for a total of
25 evenings and 126 hours of banding. This effort resulted in
311 Northern Saw-whets Owls and two Barred Owls being banded.
The owl project has now banded 521 Northern Saw-whet Owls and
4 Barred Owls.
We have had two recoveries of Northern Saw-whet Owls in Washington
State. The first bird was recapture on Bainbridge Island (near
Seattle) on the 25 Oct. 2003, this bird was originally banded
at RPBO on 26 Oct 2002. The other recovery was on 10 Nov 2003
in Sequim, this bird was "found injured in a ditch"
(hit by a car?) and was taken to a raptor rehabber, regrettably
it died latter that day. The Sequim bird had been banded 16 days
earlier at RPBO on 25 Oct. 2003. These two recoveries suggest
that Northern Saw-whet Owls are leaving Vancouver Island for Washington
State in the fall.
Fall 2004. Banding started on 24 Sept. and ended on 10 Nov., for a total of 36 evenings and a 173 hours of banding. This effort resulted in 403 Northern Saw-whet Owls and eight Barred Owls being banded. The owl project has now banded 924 Northern Saw-whet Owls and 12 Barred Owls.
We had a number of interesting band recoveries in 2004. Two
of the Northern Saw-whet Owls banded as Hatch Years at Rocky Point
during the fall of 2002 were recaptured. The banders on Bainbridge
Island recapture another Northern Saw-whet Owl that had been banded
at Rocky Point; this bird had been banded on the 24 Sept. and
was recaptured on 5 Nov. On 1 Oct., a Northern Saw-whet Owl was
capture at Rocky Point that had been banded near Forks Washington
on 17 May 2000. The bander had caught the owl in a nest box raising
five nestlings. The bird was age as an After Hatch Year, meaning
that she was at least six years old. One of the Barred Owls banded
on 31 Oct., was found dead near Royal Roads University on 12 Nov.;
it had been hit by a car.
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 Big Oak - Site Behind |
 Band on Leg |
 Applying a Band |
 Wing Inspection |
 Molt Limits |
 Measuring the Wing |
 Measuring the Tail |
 Field Guide |
 Assistant Project Leader |
 Unusual Colour |
 Applying a Band |
 3 Tail Bars |
 Faint Tail Bars |
 Barred Owl |
 Owl In Hand |
 Four In Hand |
 Ectoparasite |
 Checking the Band |
 Close Look at Feet |
 California Myotis |
Copyright 2008, Rocky Point Bird Observatory.