Monday, December 12, 2016

Nests

By Beth Sullivan
Birds are the most fascinating creatures. I do not know anyone who has not wished, at some point, that they could fly like a bird. The more one reads about birds - their lives, challenges, habits and skills - the more you have to be in awe of how such small, fragile creatures survive. Obviously volumes have been written, and courses of studies established, to try and understand the evolution and life histories of these marvelous creatures. Flight, feathers, development, survival strategies are all, to me, miraculous.
The Song Sparrow frequently nests on the ground, hiding under plant material.

Time to look for nests

At this time of year we are given the opportunity to look more closely into one aspect of their lives: their nesting. Leaves are off the trees, hiding places revealed and there is no issue of disturbing a feathered family.
Almost all birds make a nest. We have to say almost, because there are species that never make their own nests, but deposit their eggs into the nests of other birds. Cuckoos and Cowbirds are the most notable of these.
The Chipping Sparrow lines its nest with soft material, and in my yard it is always dog fur.

Some birds borrow the nests made by other birds. Owls have been known to nest on an osprey platform with material already in place from previous nesters. If the timing is right, the owls, which start laying eggs in the dead of winter, will have their young ready to fledge by the time the ospreys return to claim their platform. Other birds barely scrape out depressions in the sand of a beach, or lay their eggs on a rocky cliff edge neither with much additional material.
Terns and Plovers barely scrape a depression in the sand, and the nest is often in harm's way.

But no matter how or where the birds create or use a nest, it is all about where to deposit their eggs. The nests are not to store food; they do not “keep the babies warm” as little children like to assume. Some nests are more protective than others in relation to weather. Each species of bird makes nests characteristic of their species, but always with flourishes of individuality.
Cup nests are the most well known. With a deeper center and higher edges, the eggs are somewhat prevented from rolling out. The smallest bird we have is the Ruby Throated Hummingbird. Their nests are made as if by a fairy: with bits of Lichen, pieces of moss, the fuzzy material that comes from fern fiddleheads as they unfurl in the spring, and it is all wound together with spider-webs - amazing.
The Eastern Kingbird nest is built in a shrub over water.

Another cup nest is made by our American Robin. Every Connecticut school child knows it as our State Bird and that their nests are created first out of mud, carried in their beak and fashioned into a cup that hardens and becomes solid and strong when reinforced by woven plant material. The nest withstands winds and rains and a brood of restless hatchlings.

Sticky saliva glues a nest

The nest of the Baltimore Oriole is a creative mystery - a hanging pouch suspended from the end of a delicate branch often over water, or a road even. It has to be strong. A close up of the woven structure is nothing short of amazing, especially considering the birds have only their beaks and feet to do the weaving, all the while hanging onto the site. Part of the secret is in the birds’ saliva which acts as a ‘glue’ of sorts, to reinforce and strengthen.
The weaving done by the Baltimore Oriole is just amazing.

A Chimney Swift nest is the best example of this. Using only its special saliva, a Swift brings one stick at a time into a cavity, often a chimney. One by one he ‘glues’ the sticks to the wall of the chimney and adds them one by one into a half cup that is firmly adhered and solid.
Chimney Swift nests are held together with their saliva glue.

Woodpeckers as a group, excavate holes in trees for their eggs and young. These nests are certainly more protected from the weather and deter more predators than an open cup nest. Other cavity nesting birds like Tree Swallows, Bluebirds, Chickadees, Titmice, and others, cannot make their own holes, so each year, when the Woodpecker makes a new hole, they leave behind a perfect cavity for another species.
This is a great time to go out and look for nests. While birds generally use their nests only once, it is illegal to remove nests or have them in your possession. Lift your child to look closer, peek inside the nests to look at soft lining, often feathers or plant down. Think of how those little hatchlings quickly turn into young birds eager to stretch their wings and fly. And think of how the marvel of the nest provided that place for them to get a safe start.
Photographs by Beth Sullivan.





No comments:

Post a Comment