Since adult Tree Swallows are more likely to return in future years than
nestlings, you may want to concentrate banding efforts on adults.
How can banders catch adults for banding?
The easiest way is to use a simple home-made trap that fits temporarily inside a box.
The trap is made from a thin, stiff plastic flap 3" x 3.5", with a notch cut out lengthwise
(below left). The un-notched end of the flap is fastened inside the box just above the
entrance with masking tape that acts as a hinge. The free end is propped up with a
stiff weed stem set at an angle into a front corner of the box so it isn't easily seen
from outside (below center). Entering birds dislodge the prop and the trap swings
down over the entrance, blocking it (below right).
Once the trap is sprung the bander, who should have moved several hundred feet
away from the box after the trap was set, can return and extract the swallow for
banding and processing.
This method of box-trapping may be unfamiliar to some banders. You may need to
show your bander how. Below, an adult Tree Swallow, still carrying a damselfly for its
young in its mouth, peers out through the trap.
What's the best time to trap and band adults?
There is a specific window when it's ok to trap and band adults: between 1 and 10
days after hatching. Your bander must resist the temptation to trap and band
outside this window.
Be aware that while nests at a project may be fairly synchronized, some nests will be
ahead or behind the optimum time for banding. If your bander can't make more than
one trip to your project, you must leave the out-of-synch birds unbanded.
Doesn't being banded upset the swallows?
Adult Tree Swallows aren't thrilled at being trapped, handled and banded, but their
attachment to their young is so strong they almost never desert.
Warning! Never trap and band adults before their eggs have hatched! Chances of
nest desertion are much greater during laying and incubation.
Warning! Never trap and band adults with nestlings older than 12 days. The
disturbance could cause nestlings to leave the box prematurely and die.
Male Tree Swallows can be harder to trap than females, but most males eventually
enter to feed young and are trapped. If the female of a pair is caught first, it's best to
keep her in a bird bag (out of the sun!) after banding and processing so she won't
alarm the male. Females can be safely held this way for up to one hour. Males
caught first can be released immediately after banding and processing, since their
alarm behavior normally won't prevent nest females from entering to feed young.
Warning! Traps must be removed after use! Both adults and nestlings can die
if traps are accidentally left in a box where they can block entrances and exits.
What does it mean to "process" a bird?
"Processing" is the taking of certain data by banders after they have affixed the band
on a bird. The bander will record the date and location, and will determine the bird's
age and sex as closely as possible. They will also measure some combination of the
bird's weight, wing chord (see below), tail length, tarsus (part of the leg) length, and
bill dimensions. Your bander will have sheets to record data.
What do banders do with the data they take?
Banders are required to collect reliable and useful data, and to submit it to the Bird
Banding Offices in Canada or the United States. The data becomes computerized
and available for use by other banders and researchers.
How do you keep your own banding records?
You will certainly want to keep your own banding records. You can use the Adult
Banding and Recapture Record we offer. It has fields for the following information:
- Box number.
- B/R: Is it receiving a band (B), or is it a recapture, i.e., a previously banded
- Band number.
- Age, by plumage color (see Sexing and Aging ).
- Sex, determined by brood patch (BP) for females, or cloacal protuberance
(CP) for males (see Sexing and Aging).
- Color (blue, or brown) (see Sexing and Aging).
- Wing chord (a measure of wing length).
- Weight (mass in grams).
Your bander should be happy to show you how measurements are taken, and can
also give you good looks at BP's and CP's.
Learn About Birds at Tree Swallow Nest Box Projects