Here is a summary compiled by Suzanne Miller of the banding effort at
Occoquan NWR
(aka Potomac River NWR) in Prince William county. If
anyone would like to see the spread sheet attachments
let me know off list.
Joanna B. Taylor
Arlington, VA
jandrtaylor@xxxxxxxxxxxxx
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Potomac River National Wildlife Refuge Complex, Occoquan Bay.
Spring 2003, 3rd Annual Banding Summary Report.
The 586 acres of Occoquan Bay NWR are located in Woodbridge, northern
Virginia, Prince William County, along the shores of the Occoquan Bay where
the Occoquan River joins the Potomac River. Lat: 38o38m20s N. Long:
77o14m28s W.
Banding occurred from the first weekend in April through the last weekend in
May, weather permitting, and this year the weather did not permit nicely at
all. Our effort was 80% of normal, 600 volunteer hours for 900 net hours,
netting 80% of the normal number of birds, only 412. In addition to permits
for banding, we could have used degrees in Civil Engineering for flood
control. A couple of net routes were impassable due to MUD, some nets had
to be raised because of high water, some completely closed; our efforts at
digging drainage ditches merely to make the banding station less mucky were
ineffective at best, and pathetic at worst. Only 1/3 of the scheduled days
were the full 6 hours!
Bands were put on 358 birds of 55 species - a great species count for that
number of birds. 54 birds were recaptured: 7 from 2001, 14 from 2002, 32
from 2003, and 1 first "foreign" recapture.
There were no big 80+ bird days this year; there weren't even any 50+ days.
The birds were down to 46 per 100 net-hours. Two of the scheduled
field-trip days worked out quite well, though. The Girl Scouts' ARK
(Audubon Refuge Keepers) day, as coordinated by Bev Smith, was very
fortunate in the timing of birds for their runs. As Bev wrote "...they were
mesmerized...when you can get a group of young girls to stand quietly in one
place for a period of time, you've got their attention!" The Fairfax
Audubon trip had a delayed start due to rain, but they also eventually
trudged happily along with our Barbara Chambers in the MUD, catching Common
Yellowthroats, Yellow and Prothonotary Warblers, Carolina Chickadees,
Swainson's Thrushes, a Baltimore and Orchard Oriole, but just missing the
Yellow-breasted Chats that were waiting for the nets to open when the rain
stopped. The Migratory Bird Day Bird-a-Thon was a wash-out.
The COmmon YEllowthroat and Yellow-rumped (Myrtle) Warbler were the birds
most caught. There were 64 COYEs, slightly more males than females, all
caught in May. 25% were able to be aged to Second Year (SY) (same % as in
2002). 80% were netted before mid-morning; spread out in all the nets, but
less so in Nets 3 and 4, and 10. There were 57 Butter-butts, twice as many
males as females, starting the very first day, April 6, and through by the
first week in May. Half were able to be aged to SY (35% in 2002); they were
netted throughout the day and in all the nets. The Common Yellowthroats and
Yellow-rumps together represented 1/3 of the birds.
The White-throated Sparrow was the 3rd most encountered bird with 29, an
equal number of males as females, for those that could be sexed; movement
heaviest in late April. Over 25% were able to be aged to SY. 70% were
netted before mid-morning; ¾'s of them in Nets 7 to 10. Rounding out the
top handful were 17 Northern Waterthrushes, overwhelmingly of indeterminable
sex and ASY (After Second Year). The first one was caught on May 7, but
most came in late May. They were exclusively in the sheltered nets: 5, 6, 1
and 2; generally before mid-morning.
All told, 55 species were banded bringing the station total for 3 years to
72 species.
Among the highlights were Tree and Northern Rough-winged Swallows, a Rusty
Blackbird, 15 species of warbler with both the Yellow and Western type
Palms, and almost the full complement of thrushes: Veery, Gray-cheeked,
Swainson's, Hermit, Wood and American Robin. We banded 16 orioles: 11
Orchard and 5 Baltimore, and recaptured 1 Orchard from 2002. Our neighbor
in the tree next to the banding station fledged at least 1 Great-horned Owl
chick.
Also, among the highlights at any banding station are the recaptures. We
had a total of 21 birds that had been banded at OCCO in the Spring of 2001
or 2002: a couple each of Prothonotary and Common Yellowthroat,
White-throated Sparrow, and Indigo Bunting; also the local Downy, Hairy,
Red-belly, Chickadee, Titmouse, Carolina Wren, Cardinals, Goldfinches and a
Grackle.
In 2003, OCCO had a first: a "foreign" return! "Foreign" means a bird was
banded at another station. A Prothonotary netted this spring had been
banded in 2001 at a Mason Neck MAPS (Monitoring Avian Productivity and
Survivorship) site.
There was some discussion as to whether banding on Saturday and Sunday, or
sometimes on Friday, Saturday and Sunday, caused the birds to become net-shy
after the first day. Looking at the final column of the Scheduling
spreadsheet, April 20 was not a good day nor was May 25. But April 27, May
3 and May 11 were better than their preceding day, so I don't think any
conclusions can really be drawn.
See the attached 4-part spreadsheet for 3-year banding data, net
productivity, volunteer scheduling and hours, and band inventory. If anyone
can't read these Excel attachments, let me know and I'll print and mail
them.
Bird banding can determine: migration routes, seasonal movement, habitat
use, survival, longevity, population fluctuations, home range, stopover site
faithfulness, nest site fidelity and breeding success. Banding can also
provide data on what birds are using a particular area when, how many birds
are there, and if they are migrants. Conservation priorities may then be
set using this data.
Report any banded birds to the Bird Banding Lab, 12100 Beech Forest Rd.,
Laurel, Maryland 20708-4037, 800-327-2263, 800-327-BAND.
Suzanne
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