Fall 2002 results
Northern Saw-whet
Owls wintering on campus
Introduction
The smallest owl in the eastern U.S. (about the size of a pop can),
the Northern Saw-whet Owl is highly migratory (for more information on
this species, see the status
of saw-whet owls in Ohio). In limited experiments with owl banding
prior to 1999, RRBO captured 15 saw-whet owls on campus. In 1999,
Jeff Schultz, President of Southeast Michigan Raptor Research, joined us
to begin a more determined effort to gauge the extent of saw-whet owl migration
through our area.
Whitefish Point Bird Observatory in Michigan's Upper Peninsula and other
sites in the Great Lakes and eastern U.S. band hundreds saw-whet owls each
fall, greatly increasing our knowledge of the habits of this otherwise
very secretive species. These banding projects are almost exclusively
conducted in coastal or extensively forested sites. RRBO's owl banding
program will be the first to study the migratory use of an inland, urban
area by saw-whet owls.
Protocol
Passive mist netting (setting up lines of nets in areas where owls
are thought to travel) is one way of capturing saw-whet owls. However,
the use of an audio lure, a continuously looping tape of a saw-whet owl
call, increases capture rates spectacularly. Our set up consists
of two stations about .25 miles apart (0.4 km). Each station has
three 12-meter mist nets of 38 mm mesh arranged in a triangle or a "V",
with the audio lure placed in the center. Weather permitting, we
operate 3 nights a week from mid-October through mid-November from 8 PM
to midnight. Ideally, we would operate from dawn to dusk, but time
and personnel constraints prohibit this for now. We hope to expand
this program in the future!
| Applying a band to a saw-whet owl |
 |
We are part of Project
OwlNet, a network of saw-whet owl banders across North America.
Visit their web site for more information on NSWO banding, including how
we determine age and sex, general protocols, and other information!
 |
Fresh, uniform flight feathers indicate
this is a hatching-year bird |
Age and sex codes used below:
HY = hatching-year (juvenile); SY = second-year (born last calendar
year); ASY = after second year (at least 2 years old); M = male; F = female;
U = unknown age or sex
2002 banding results
| October 14 |
No owls |
| October 17 |
Rain |
| October 19 |
No owls |
| October 21 |
1 Eastern Screech-Owl (gray) |
| October 24 |
No owls |
| October 27 |
1 Northern Saw-whet Owl - HY-F |
| October 28 |
1 Eastern Screech-Owl (gray) |
| November 2 |
1 Eastern Screech-Owl (gray) |
| November 3 |
No owls |
| November 4 |
No owls |
| November 7 |
Wind |
| November 9 |
Rain |
| November 13 |
No owls |
| November 17 |
1 Northern Saw-whet Owl - HY-F |
| November 23 |
1 Northern Saw-whet Owl - HY-U |
| November 24 |
No owls - closed early due to snow |
| November 25 |
Recap of Oct 28 Eastern Screech-Owl |
| November 27 |
No owls |
| 2002 totals |
3 N. Saw-whet Owls (plus 3 screech-owls)
0.6 NSWO per 100 net-hours
HY=3, SY=0
M=0, F=2, U=1 |
2000 results
| October 8 |
No owls |
| October 10 |
No owls |
| October 13 |
1 SY-F
1 SY-U |
| October 14 |
1 HY-F |
| October 16 |
No owls |
| October 17 |
No owls (rained out) |
| October 20 |
No owls |
| October 21 |
No owls |
| October 22 |
1 SY-F |
| October 27 |
No owls (wind) |
| October 29 |
Recap of a 10/13 bird |
| November 3 |
No owls |
| November 4 |
No owls |
| November 6 |
No owls |
| 2000 Totals: |
4 N. Saw-whet Owls (plus 1 recap)
1.9 per 100 net-hours
HY=1, SY=3
M=0, F=3, U=1 |
1999 banding results
| October 24 |
3 hatching year (HY) |
| October 26 |
1 HY |
| October 29 |
1 HY
plus a HY gray morph Eastern Screech-Owl |
| November 5 |
1 recap from October 24
1 recap screech owl from May 1999 |
| November 6 |
2 HY
2 second-year (SY), one a female |
| November 7 |
3 HY, one a male, one a female
1 SY-F |
| November 9 |
3 HY, one a male
one recap from Nov 7 |
| November 11 |
one recap from Nov 9 |
| November 12 |
4 HY, one a male |
| November 13 |
No owls captured; one heard |
| November 14 |
No owls captured |
| 1999 Totals: |
2 E. Screech-owls (1 a recap)
20 N. Saw-whet Owls (plus 3 recaps)
5.43 NSWO per 100 net hours
HY=17, SY=3
M=4, F=3, U=13 |
These curious little birds sometimes don't
know
they're being released!
Copyright Jerry Sadowski.
Please
note: All data is provisional and not to be cited without permission.
