Biology Reference
In-Depth Information
Q I was cleaning out my nest boxes and I found a dead adult Tree Swallow in one of
them. How did it die?
A
Tree Swallows migrate a long way — some of the birds that nest in northern Canada
and Alaska winter down in Central America. If they arrive when the temperature is too
cold for flying insects, their primary food, they may die of starvation or hypothermia.
Thisisprobablywhathappenedtoyourswallow,especiallyifswallowsorbluebirdshave
used your nest box successfully in past years.
There are a few other reasons why adult birds may die in a nest box.
If it had obvious injuries, especially on its head, it may have been killed by a House
Sparrow trying to take over the box. In most cases, though, these competitors toss out
birds after they kill them. Find ways to exclude House Sparrows from your nest boxes
at
www.sialis.org/hosp.htm.
Was the inside front of the box, below the hole, rough or grooved? Sometimes birds
get stuck inside boxes because the inside walls are so smooth they can't climb out.
Tackingsandpaperorsmallstripsofwood,makingasortofladder,willpreventthisin
the future.
Sometimes an infestation of blowflies or other parasites can become so intense that it
kills not only nestlings but also adults. If there was no sign of young, that's probably
not the answer in this case.
Some wood preservatives may release harmful gases, especially in hot weather. Make
sure any paints or varnishes that you use on your nest boxes are rated safe for indoor
or playground use.
Nestwatch, a citizen-science project of the Cornell Lab of Ornithology, provides a
wealth of information for people with nest boxes. NestWatch, a citizen-science project
of the Cornell Lab of Ornithology, provides a wealth of information for people with nest
boxes.ConsiderreportingtoNestWatchonthesuccessesorfailuresofyournestingbirds,
to help scientists understand more about our breeding birds.
Q A robin missing an eye has turned up in our yard. He seems to be eating and act-
ing normally. Should we help him?
A
Many birds adapt to monocular vision and survive for years in the wild with one
eye. When the eye is first injured, sometimes potentially dangerous infections set in. If
the bird becomes lethargic and easy to catch, it probably is infected and should be cap-
tured and brought to a wildlife rehabilitator. (You can locate the nearest one to you at
