Home tweet home: Birds don’t take summer vacations, they stay busy building nests and making babies

A mockingbird nest holds two hatchlings and two speckled eggs, one of which was rocking and cracking as a tiny bird struggled to make its way out.
A mockingbird nest holds two hatchlings and two speckled eggs, one of which was rocking and cracking as a tiny bird struggled to make its way out.

Summer nesting season is a busy time for birds.

Two weeks ago a pair of mockingbirds shopped for twigs in my front yard. They picked up twigs that had fallen from a willow oak and tested them for length, weight and flexibility by some standard I could not fathom. If the twig passed the tests, the birds would lift it in their beaks and fly into the thick, leafy part of an ornamental shrub in my neighbor's yard.

If the twig did not pass the tests, they would discard it and look for another.

In 20 minutes, I counted 17 times that a mockingbird made a dive into the shrub's foliage carrying an acceptable bit of nesting material. The mockers may have made as many as a thousand such trips while the nest was under construction. Three days later, I walked across the street to my neighbor's shrub to get a closer look. I could barely see the completed nest they had built, hidden 7 feet above the ground among the leaves and branches of a blooming crape myrtle.

Today, I checked on the nest again with a stepladder so I could look at it from above. The mother mockingbird flushed from the nest as I approached. When I looked down into the nest, I could see and photograph two recently hatched, featherless chicks and two speckled eggs, one of which was rocking and cracking with the tiny, embryonic bird's struggles to make its way into the light.

In another week, I can stand by the shrub and hear the loudly cheeping babies.

If the chicks are lucky and a neighborhood cat doesn't get them, they soon will be able to fly from the nest, never to return. If I am lucky, I'll be sitting on my front porch to watch them take their first flight.

Nests are the places where birds incubate and cradle their young. The nesting habits of most songbirds follow a pattern similar to the one I witnessed with the mockingbirds in my neighborhood. But there is considerable variety in their location, size and construction. The selection of nesting sites, materials and method of construction differs according to species and habitats.

LOCATION, LOCATION

A nesting site is usually within the territory defended by the male bird, although it is usually the female that selects the specific spot, according Attracting Birds to Your Backyard by Sally Roth.

Well before I saw the mockers collecting twigs, I had often heard and seen the male mockingbird singing, from early morning and into the night, too, as he perched on the power line almost directly above where the nest was finally built. His singing served the dual purpose of attracting a mate and notifying rivals that the area was off-limits to other males.

The nesting place is usually chosen because it offers camouflage or some other manner of protection, or because a food source is in abundance nearby. Loons, for example, nest near the water's edge. Orioles build their nests far out on the limbs of trees where the branches are too limber to support heavy bodied predators like raccoons and owls. Cavity-nesting birds, such as woodpeckers, frequently chisel their holes in dying, damaged or diseased trees partly because the excavation is easier in rotten wood and partly because such trees host more insects to feed their young than healthy, robust trees.

An unusual site is described by Allen and Helen Cruickshank in their book 1001 Questions About Birds. The authors say that European starlings sometimes nest in the lower sections of eagles' nests. The eagles and starlings do not interfere with one another's young, and the eagles deter would-be predators of the starling.

The location of the nest has much to do with the survival of the young birds. I once discovered that a mockingbird had built a nest upon a pile of aluminum I had placed in a plastic tub for recycling. There was no camouflage, and the top of the tub was barely 18 inches from the ground. The low plastic tub was open to the elements and might have easily filled with water and drowned the birds, but before that could happen, a neighbor's hound snatched each of the almost-ready-to-fledge birds and ate them in a single gulp.

Most species of birds nest among the branches of trees and shrubs, but some nest on the ground, others in burrows, on buildings, mountain ledges or flat, open beaches. Cliff swallows in Arkansas seem to favor the undersides of bridges.

With the destruction of their natural habitat, birds have turned to human-provided vessels to build their nests, and not just birdhouses. I have seen bluebirds nest in a cowboy boot and a mailbox, a wren nest in an Easter basket, a sparrow nest in the exhaust pipe of my motor home, and house finches nest in a hanging fern flower pot.

FEATHERING THE NEST

The variety of building materials used in birds' nests seems greater than the kinds of sites birds use to build their nests.

The most common nest is a coarse platform of sticks and twigs overlaid with softer blades of grass, leaves, moss and feathers where the tender young birds are cradled. Beyond this, each species has its own preferences for building material. Bluebirds prefer pine needles, titmice use mostly moss, and vireos rely heavily on small leaves and spider webs. Woodpeckers use wood shavings they have made while pecking their holes.

Many birds line their nests with molted feathers, the featherlike seeds of dandelions or other such soft, organic material. Corn silk and corn husks are used, as are flower petals and even shed snake skins. Robins use a little mud; phoebes use even more mud, and swallows use a lot.

As environments change and natural nest building materials become less abundant, birds have adapted by using synthetic materials in their nests. Among those man-made materials are string, plastic sacks, paper and cloth.

Naturalist John Torres reports that he once saw a single robin's nest that contained brown string, yellow string, a piece of blue embroidered silk, the hem of a handkerchief, a bit of white satin ribbon, a longer piece of red satin ribbon with gold lettering and a coarse piece of lace through which the robin had carefully threaded two domestic chicken feathers. Holding all this together, the female had built an encasement of mud.

Without mud, no robin's nest is complete.

ARCHITECTURE

Among the 200 species of birds that nest in Arkansas, and the 9,000 that nest on the planet, there are broad differences in the size and complexity of structures. Some birds hardly build nests at all.

Vultures, whippoorwills and terns, respectively, simply place their eggs on a rock ledge, the forest floor, or in an indentation of the sand.

The killdeer does little more than select a tuft of grass or a likely bed of gravel and leaves before placing eggs that blend into their surroundings.

Eagles, on the other hand, work on a single nest that they use year after year for decades. They construct nests that may weigh up to two tons.

Other birds, like the European and Asian cuckoos, and cowbirds, use nests but do not build them. They lay their eggs in the nests of other birds where the unsuspecting parents of those birds do the forced labor of chick rearing. American cuckoos, (with a greater sense of fair play, I presume) do not engage in such heinous activities; they build their own nests and feed their own young.

Rookeries are a nest type common among social birds. Herons and egrets are the most familiar species to build nests in a rookery. In an apartment building kind of arrangement, each family of egrets maintains its own nest, but the nests are all close together. For years, Bird Island in Lake Ouachita near Lake Ouachita State Park has hosted rookeries for cattle egrets and blue herons.

Rookeries have three advantages:

• Many more birds to fend off predators;

• More eyes searching nearby areas for nourishment;

• Assistance in rearing young.

Nests of birds are uniquely designed to meet the requirements of each species. Birds whose young require a lot of parental care and protection, like the oriole, require complex nests that offer much in terms of protection from the sun, ventilation and camouflage from predators. The oriole knits a socklike nest of tendrils, weeds and vines with a concealed opening. She hangs that nest on the outer edges of a tall tree.

Birds that are precocious, in that the young can manage on their own within hours of hatching (such as the killdeer), do not require an elaborate nest.

SLEUTH WORK

Nests are generally harder to see in summer than in winter because of the leaves on the trees. However, those who watch birds recreationally can also find enjoyment in finding, examining and identifying nests in other seasons after the family has left.

In late fall and winter, when a nest is uninhabited, there is little danger of interrupting anyone's life cycle.

Just as there are field guides to help identify birds, there are guides to help identify nests by species. Most notable for Arkansans is Peterson Field Guide: Eastern Birds' Nests by Hal H. Harrison and Roger Tory Peterson. The field markings of a nest might include its distance from the ground, the habitat type, the type of construction and size.

We might learn more about an architect, painter or sculptor by looking closely at their work. Similarly, it is a challenging exercise for those of us who enjoy solving riddles of nature to deduce which species built a nest by examining its creation.

Jerry Butler writes about Arkansas birds and people who enjoy them. He welcomes your stories and comments at

[email protected]

photo

Special to the Democrat-Gazette/JERRY BUTLER

The oriole weaves a socklike nest of tendrils and vines with a hard-to-see opening. See photos of other bird nests at arkansasonline.com/723nest.

photo

Special to the Democrat-Gazette/JERRY BUTLER

This cliff swallow under the Big Dam Bridge built its nest of mud pellets held together with saliva.

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