I noted a couple of chickadees checking out a bird house I made just for them a couple of years ago. It attracted nothing but summer house wrens the first couple of years. Chickadees have looked over most of the nest boxes in my yard before. They even built a nest in one of the wren boxes several years ago, but never laid any eggs. I knew chickadees nest early, so I checked inside the chickadee house the next time I was in that area of the yard. There, to my surprise, was a complete chickadee nest already built!
The nest was a perfect example of chickadee handiwork and was unmistakable for any other kind of nest. The base was made of green bits of moss. The little center cup was lined with rabbit fur. I’m sure that soft, fluffy fur helps insulate the tiny eggs that mama chickadee will lay long before Iowa’s weather can promise consistently warm temperatures. Moss is easy to come by, but rabbit fur is usually attached to rabbits when I see it and not just lying around. Chickadees always seem to find enough for their nests, though. In fact, like most birds, chickadees are intimately familiar with their nesting territory and will know about virtually all the available nest cavities and where to find the proper nesting materials.
The little chickadee nest is a relatively simple affair as bird nests go, but I’ll bet a human being would have a great deal of difficulty in shaping a proper chickadee nest, even with all the materials readily at hand. Our dexterous hands are marvels that allow us to manipulate our world in ways that few creatures can, but even our wonderful hands and big brains aren’t equal to the task of building most birds’ nests. That would be true even if we could choose any tools we wanted and use both hands, much less trying to do it with a single pair of tweezers shaped like a bird’s bill. I’m a life-long student of nature, but the intricacy and variety of bird nests still leaves me awed.
I marvel how a mourning dove’s nest holds together when it appears to be little more than a loose platform of twigs lying on a branch. You can see through it. Yet the dove will lay two eggs on that flimsy platform, incubate them, and feed two fat babies until they fledge. I’m even more awed when I spot an oriole’s finely woven grass basket nest hanging from some high branch. How can they get those first strands of grass to stay put, just draped over some twigs, while they weave more into a basket that will soon hang below? Oriole nests are so well made that many are still visible the following spring, having weathered winter ice, snow and wind.
I’m amazed at the “planning” that mother wood duck must do as she lays an egg a day for up to two weeks before she begins to incubate them. She will often bury each egg to hide them if she finds enough wood shavings or chips in the nest and won’t expose them until she’s ready to incubate. Then she’ll pluck down feathers from her own breast to line the nest and help insulate a clutch of eggs that may be too large for her body to cover by itself. She’ll rotate the eggs often to bring eggs from the edge to the center, where they’ll get more warmth. Her extra care insures that all the eggs will hatch within a few hours of each other after about three weeks of incubation.
Each specie’s nest is nearly unique to that specie in the materials it uses, the way it’s constructed and where it’s placed. Some birds lay their eggs on bare ground, with no preparation at all. Constructed nests range from simple to complex, and might include a few rocks, fine grass or plant fibers, course grass, weeds, moss, pine needles, twigs, whole branches, plant down (like thistle), spider webs, hair, lichens, feathers, mud, snake skins and more. Many will combine several things to complete their nests. Some float on water. A few even include a variety of stuff we humans have thrown away. Pause for a moment the next time you encounter a bird nest – and be amazed.
Steve Lewka is a former director of Story County Conservation.