The Nesting Drive of Ovenbirds and Tree Swallows

For most species the frenzy of singing has subsided a bit. Only the very tardy and very early are still spilling their hearts out. The mockingbird was sorely missed while he raised his first brood, but now he has returned to his perches, sending out a cascade of notes in endless enthusiasm.

He has talent and brass to spare, but what of his mate? She may be hidden and demur, but she has a skill to match his singing voice. While he was quiet for a time, she was indulging an instinct for nesting. Sometimes men pretend not to understand this nesting drive, but we must admit it to be as marvelous and necessary as any manly pursuit.

The male bird helps a lot in building the nest, but for most species the female is the fine craftswoman. He may fetch and carry, but she does the weaving and the final touches. She does it out of sight for the sake of her young, choosing the safest place she can find, but others cannot. It may be deep in the thickest bush, high in the tallest tree, buried on the forest floor, or dug in the hardest wood.

When all her endeavors fail and the nest is found, then desperate measures are employed. During a long walk on the Appalachian Trail in Tyringham last weekend, many male ovenbirds were belting out their loud two note song around us. Suddenly an ovenbird flew up from near the trail only a few feet from us. It began chattering its harsh call note in rapid succession, fluttering along the ground and spreading its wings. A second joined in this display, trying to distract us from the nearby nest.

She had worked hard to build a small structure beneath the leaf and needle litter, and was not about to let it be lost to marauding mammals without a struggle. This bird gets its very name from the nest it builds, which looks like a small oven, arched over with a roof and a tiny side opening. The ground nest is the easiest for predators to find when a strange scent is left at its door, so we quickly walked on without searching.

The easiest nest to both find and protect is the tree cavity, and we can even help provide places for the few species that use this technique. I made a check of the sixteen boxes scattered throughout the fields behind my house the other day and found all were occupied.

The first one was a used bluebird nest. I suspected they were done with the first brood when the male started singing again in the yard. The bluebird is a neat nest builder, just a woven layer of grasses at the bottom of the box. A second pair of bluebirds was just beginning in another box where three pale blue eggs were laid.

Twelve nests were tree swallows in various stages of incubation and hatching. Five of these contained fully feathered young all flattened down into the cup, the edges of their yellow bills showing brightly. When a parent comes, they lift and open, but to my peering eyes they are still and shut. One nest had naked birds just hatched, hardly visible within the several large fluffy feathers the tree swallow always steals from larger birds to decorate its home.

Six nests had adults sitting on eggs, as quiet and subdued as a bird ever is. When a bird first enters its nest it makes a few twists and turns rocks its breast before settling down in picture perfect comfort. Once down, they are reluctant to leave their settled estate. Except for the extra feathers, the nest is similar to the bluebird's nest, but the swallow is poor housekeeper. When these birds leave the nest it will be a fouled and encrusted mess.

The last two boxes had house wrens, one with young crouched down in a tiny grass cup surrounded by woody twigs. Their heads are smack up against the roof, because the wren fills the entire cavity with these twigs. This tiny comic bird works twigs through the opening that are twice its own length. The second box had a nest just finished without eggs, and the chattering couple were close by, worried for their new creation.

Have no fear little ones. I may be a male, but I have learned not to interfere with the nesting instinct.