When I see spider webs this time of year, I think of nesting birds, especially the smaller songbirds that build cuplike nests in trees and shrubs.
Spider silk is one of the prime materials that these birds — least flycatchers, blue-gray gnatcatchers, most warbler species and others — use in nest construction. Spider silk is amazingly strong, light and maneuverable, easily handled by songbirds that may weigh less than two nickels.
In building their nests, the birds use spider webbing as a “glue” to bind other nesting materials, such as straw, twigs, rootlets and lichens, together. Sticky spider silk also is important as an adhesive to attach nests securely to leaves, twigs and branches.
Perhaps no other Georgia bird relies on spider silk for nest building as much as the state’s tiniest bird, the ruby-throated hummingbird. In fact, encouraging spiders to live in your yard might make it more appealing to ruby-throats.
The hummingbirds are arriving here daily now from winter grounds in Mexico and Central America for the summer nesting season. Some early arrivals already have started building their tiny nests — all females, because the males do not assist in nest construction or baby-rearing.
To build a nest, a female ruby-throat selects a site usually near the tip of a down-sloping tree branch with a fairly open area beneath and a dense leaf canopy above. Nest building usually takes 6-10 days.
First, she builds a flat base from the down of thistles and dandelions. Using spider webbing, she attaches the base to the upper side of the branch. With her feet, she stamps down the base until it becomes stiff.
She then proceeds building the side walls. Using a figure 8 motion with her bill, she uses spider silk to weave soft plant material and bud scales together. The superstrong spider silk can stretch up to 40 percent of its length without breaking, allowing a ruby-throat’s nest to expand as her nestlings rapidly grow. She finishes the nest by covering its exterior with lichens, an effective camouflage for the minuscule structure.
IN THE SKY: The moon will be full on Tuesday — the "Flower Moon," as the Cherokee peoples called April's full moon, said David Dundee, Tellus Science Museum astronomer. Very early on Tuesday, a total lunar eclipse will be visible in Georgia beginning at 1:58 a.m. and ending at 5:33 a.m.
Venus rises out of the east about 3 hours before dawn. Mars rises out of the east at dusk and will appear near the moon on Monday night. Jupiter is high in the southwest at dusk and sets in the west before midnight. Saturn rises out of the east a few hours after sunset and will appear near the moon Wednesday night, April 16.
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