A Season For Nesting

Great Blue Heron, Ardea herodias

 

“For everything there is a season, and a time for every purpose under heaven”, Ecclesiastes 3:1.  The earth has just passed through the solstice and the seasons have changed yet again.  We have that 23 degree tilt to thank for this welcome variety in our lives.  For the birds the spring migration is over and some of the Arctic nesters are already beginning to feel the urge to head south.  But around here in Chesapeake country, nesting and all its attendant chores is in full swing.

House Wren, Troglodytes aedon

The first task is to choose a suitable site, one pleasing to her, for even in the avian world the female needs to be satisfied.  “Mr. and Mrs. Mallard were looking for a place to live.  But every time Mr. Mallard saw what looked like a nice place, Mrs. Mallard said it was no good.  There was sure to be foxes in the woods or turtles in the water, and she was not going to raise a family where there might be foxes or turtles.  So they flew on and on.”

Mallards, Anas platyrhynchos

That’s the first paragraph of Robert McCloskey’s 1941 classic, “Make Way For Ducklings” and is a favorite of our family.  Mrs. Mallard’s final choice in the middle of urban Boston’s Public Garden makes me question her judgement somewhat, but as the story goes, she did receive welcomed police protection.

Juvenile Bald Eagle, Haliaeetus leucocephalus

This spring I’ve noticed a significant decrease in the Tree Swallow population, leaving the yard’s birdhouses to the Eastern Bluebirds which have had a banner year.  But even their lives are not without controversy.  “Of all the houses, in all the yards, in all the world, this is the one you chose?”  The male bluebird can just hang is head in shame and vow to do better next year.

Eastern Bluebirds, Sialia sialis

I marvel at the variety of nesting strategies.  Some try to hide the nest from predators and the elements, deep in the leafy shrubs, while others nest in plain sight, oblivious to the risks.  The former nests only become apparent in the leafless winter when I’m surprised to see the vacated refuge, often near the front door.

Yellow Warbler, Dendroica petechia

The Killdeer, however, just scrapes a few stones together in the wide open driveway and hopes that I’ll avoid it with the truck, or that he’ll successfully fool me and lead me away with that phony injured wing routine.  Inexplicably the ancient Diamondback Terrapin follows the Killdeer’s lead as she crawls out of the muddy cove, lumbers across the lawn, and digs her nest right in the middle of the driveway.  This is just too easy pickings for the Raccoon and Black Snake who have a great appetite for the leathery turtle eggs, but who am I to argue with eons of evolutionary success.

Anhinga, Anhinga anhinga

The breadth of nesting materials is great, ranging from stones to the soft down lining the nests of passerines.  Larger birds use coarser sticks, more structurally suited to their weight and their exposed sites.  But the Osprey couple often don’t agree on the suitability of every stick.  I’ve observed the triumphant male, with great effort, fly in with a beauty, to my eye the perfect stick, and proudly present it to his mate for placement in the growing nest.  As soon as he flies away to find another she kicks it into the river, probably muttering something unkind under her breath.

Osprey, Pandion haliaetus

Since large nests are difficult to hide, the waders seek safety in numbers, nesting in large, noisy rookeries, often on a island populated by diverse species.  The Venice rookery in Florida, a favorite destination for me and many bird photographers, is a great example.  But one can never completely protect the nest.  J.J. Audubon has wonderfully captured the drama of a rattle snake attack on the Mockingbird nest as these birds valiantly rise to the defense of their young.  There will always be risks.

Mimus polyglottos by J. J. Audubon

Cavity nesters have more choices than ever before.  Bird lovers have made up for the disappearance of natural cavities by building birdhouses galore.  I’ve constructed many of the standard wood variety, but have recently tried a more durable version made from PVC pipe.  It is stark white and suffered a few years of vacancy before its contemporary style was finally accepted.  The Purple Martins, on the other hand, seem to have no problem with the crowded, multi-family, modern look.  To each his own.

Eastern Bluebird, Sialis sialis

Purple Martins, Progne subis

There’s also great variety in the chosen structure of the nest.  Many seem too precarious to be practical.  I refer to the Osprey again, attempting to build on the point of channel marker 2SD, right off our dock.  I suspect this is a juvenile bird, still learning the ropes.

Osprey, Pandion haliaetus

The least appealing in terms of materials, view, etc., are the nests of the Barn Swallows, plastered to the underside of a dock or the ceiling of a dingy porch or barn.  They seem perfectly content with their residential design, however, and who are we to judge.

Barn Swallow, Hirundo rustica

Don’t forget the swinging sacs carefully constructed by the Baltimore Oriole, but the world’s record for the sac design has to be the Baya Weaver’s amazing creation which we saw hanging in India several years ago.

Baya Weaver, Ploceus philippinus

I hate to bring them up again, but must remind you of the dastardly Cuckoos and and Cowbirds that just avoid the entire drudgery of nesting by their successful brood parasitism.  I just hope it doesn’t catch on.

Pileated Woodpecker, Dryocopus pileatus

Is the season of nesting initiated by temperature, hours of daylight, hormones, or some other deep rooted instinct that passes down through the generations?  Nesting is clearly not limited to the Aves.  The American Pregnancy Association clearly recognizes the nesting urge in Homo sapiens, usually, but not always, occurring in late pregnancy.  They have published guidelines to help expectant mothers channel their energy toward making their nests perfect for the new arrivals.

Brown-headed Nuthatches, Sitta pusilla

This nesting season, as they all do, will pass too quickly.  The fawns are already losing their spots and wandering independently.  The fledgling geese, although diminished in number by the Red Fox, are almost full grown.  The Bluebirds and Brown-headed Nuthatches are still busy feeding their chicks, but this also will end soon.  Their nests, like ours, will be empty.  For everything there is a season.