Driving along, I glanced over and saw a bird’s nest. Woven into the tangle of a dense roadside shrub, it stood out because nature had placed a large snow blob upon it. The nest appeared baseball-sized, maybe a cardinal or catbird’s in light of its shrubby location. Seeing it inspired me to contemplate nests. Every one is a marvel of nature.
I got thinking about strong nests and realized one of them happens to be about half-dollar-sized. Ounce for ounce, a ruby-throated hummingbird’s nest matches up against others much larger. Its inch-wide cup fashioned from milkweed fluff and plant down draws strength from a special covering. This covering’s first component is a coating of pale green foliose lichens. But that’s not the secret ingredient. Once the lichens are positioned, hummingbirds lash them in place with spider silk. If there happens to be an invasion of tent caterpillars nearby, hummingbirds sometimes will substitute tent webbing for silk.
Nature’s most complex nests might be those of the orioles, hanging baskets of perfect design. Woven in seven short days from bits of string, strips of grapevine bark, plant fibers and animal hair, an oriole nest takes shape initially as two separately fabricated walls. When they’re completed, the female oriole weaves them into a drooping sac lined with a bed of fine grasses. This bed assures chicks a pillow to rest on while spring breezes rock their knit cradle.
One other species might contend with orioles for the bird world’s most intricate nest. That’s the cliff swallow and the mud gourd it builds. Cliff swallows create these gourd nests by scooping mud into their beaks. They then roll the mud into small globs, pasting one glob at a time onto those already positioned. The end result: an adobe abode with an entrance that tilts slightly downward to keep the rain out.
Cliff swallows nest colonially, fastening one gourd above another on a building, bridge abutment or cliff. Secure in their brick-like nests, cliff swallow chicks needn’t fret over tumbling out. That’s not true in the case of most mourning dove offspring. Their parents lay claim to the dubious distinction of creating one of nature’s most insecure nests.
Often found on a horizontal branch in an evergreen tree, these jerry-built platforms of twigs appear destined to crumble within a few days. Incredibly, they don’t, despite the fact someone gazing up from below could look right through a loose grid that reminds one of tossed Pickup Sticks.
I’ve read one theory that attempts to explain such slipshod construction. Because the male mourning dove collects every nest twig, it postulates, and because he always stands on his mate’s back before giving them to her, by the time she begins weaving them into a nest, her attention to detail has somehow flown out of the window.
Despite this, things work out and mourning doves prosper. I await their loud cooing this spring.
