Songbirds opt for new nests when raising babies

Many of Georgia’s year-round songbirds — cardinals, bluebirds, robins, mockingbirds and others — already are raising their second broods of the season and may produce a third or even a fourth before their seasons end around September. That means a lot more nest building going on.

For each baby-rearing effort, songbirds usually construct a new nest. One would think that because of all the energy and time it takes to build a nest, a songbird pair would try to reuse an old nest or at least recycle material from it. But many birds opt not to do that.

Each season, for instance, a pair of cardinals will attempt to raise two or three broods — and sometimes four. For each brood, a new nest will be made by the female with some help from the male, who brings twigs and other nest material to her.

Old material is rarely reused. The most likely reason, say researchers at the Cornell Laboratory of Ornithology, is that the used material may still harbor parasites, such as mites and lice, that could get a head start in infesting a new nest.

Also, nests are typically built in new locations, away from old nests. By doing so, researchers say, songbird parents may deter predators such as hawks and snakes from detecting new nest sites before young birds fledge.

When nesting season ends, the nests will be abandoned. Can you remove a nest no longer in use? State and federal bird protection laws indicate that a government permit may be needed. The Migratory Bird Treaty Act, which covers all native Georgia birds, says it’s unlawful “to collect nests, eggs, feathers or any other parts of birds” without a government permit.

(What about cleaning out bluebird boxes? Visit sialis.org/clean.htm for guidance.)

If you have questions about removing a bird nest, check with wildlife agencies such as the Wildlife Resources Division of the Georgia Department of Natural Resources (706-557-3333).

IN THE SKY: From David Dundee, Tellus Science Museum astronomer: The moon will be new by next weekend. Mercury and Venus are low in the west just after dark and set less than an hour later. Venus will appear near the moon on Thursday. Mars rises in the east about four hours before dawn. Jupiter and Saturn rise in the east just before midnight.