The Nesting Season

A bird’s nest. Neat and tidy, hidden among willow branches or tucked under a drooping maidenhair fern.

warbling vireo nest
Warbling Vireo nest

A bird’s nest. Old and tangled, a pile of sticks right out in the open atop a snag or a crumbling rock pinnacle, or sometimes right on the ground.

A Double-crested Cormorant nest on the ground.

A bird’s nest. Obvious but hidden from view nonetheless, deep in a tree cavity. Only the entry is visible and no one but the resident is welcome.

A northern flicker nest hole that has been used by house wrens in the past.

I have spent the better part of my adult life searching for bird nests. Some are easy, like an osprey or a red-tailed hawk. They make no effort at camouflage. I understand the red-tail’s boldness but not the osprey’s. Obligate fish-eaters, ospreys are not fierce. They are easily pushed around by the larger and more aggressive bald eagle. But what can be done with a five-foot wingspan? And so they build in impossible places: atop rocky pinnacles accessible to few predators except those from above. Can you see the three chicks in the nest pictured below?

An osprey nest atop a rocky pinnacle in the Yellowstone River canyon.

Eagles build wild nests. Layer upon layer of sticks. Sometimes there are a half dozen nests in a single territory. They’ll add fresh green to them each spring. The twigs of some conifers have natural  insecticides that ward off any parasites and mites that may have overwintered. The fresh green branches also let other raptors know that this territory is spoken for.

A bald eagle nest with two mature nestlings.

Some raptors don’t build nests at all. Peregrine falcons use their soft bellies to form a slight depression on a rocky ledge. Sometimes they will re-use old golden eagle nests, but they never add any material to them. Searching for peregrine nests is one of my favorite challenges. Difficult but not impossible.

2009_06_IP chicks copy
Peregrine falcon nest ledge with the adult and three downy nestlings.

But my greatest challenge is finding the nests of songbirds. They are desperate to hide them. They have no defenses except secrecy.  Their young are helpless. Altricial, we call them. Naked and downy, eyes closed, mouths agape waiting to be fed.

And then there are the precocious young. They are ready to go almost as soon as they hatch, like the spotted sandpiper, Wilson’s snipe, and duck nests pictured below. They can’t fly yet, but they have a better chance of escaping predators by taking to the water or being able to run, at least short distances.

The nesting season spans months for raptors, but it can be as short as four weeks for songbirds. Some species begin nesting during winter in order to fit it all in. Even where I live high up in the Rocky Mountains, some species began nesting months ago. Great horned owls, for instance, began nesting in February. Bald and golden eagles began in March, although at least a few pairs began in February. There are even young Clark’s nutcrackers. Their squawks and calls are distinctly different from the adults. Robins have been busy carrying nesting material despite the onset of a spring snow storm. But many of the insectivorous birds haven’t even arrived yet. They must wait for things to warm up and bugs to hatch out. Timing is everything.

cliff swallow colony..
Cliff Swallow colony

A bird’s nest is an intimate glimpse into the animal world. Finding one is a gift and always a surprise. I’d be remiss if I didn’t give at least one bit of advice about nesting birds. Never approach a bird’s nest. It’s a difficult time of year for them and they often only get one chance at breeding. They usually have a lot to contend with without us crashing their efforts. All of these photos were taken from either a good distance or I took them as part of various work projects, with permits, to better understand breeding behavior.

When you have seen one ant, one bird, one tree, you have not seen them all.

E.O. Wilson


6 thoughts on “The Nesting Season

  1. Neysa

    I agree…wonderful piece! And great photos of nests/eggs/nestlings! Two things popped into my mind. First, my husband (a CO/UT “boy”) used to say the raptors showed up early and got their nests going so that when the smaller birds/song birds arrived and set up housekeeping, the raptors would have a great food source for their little ones. Seemed logical to me. The second was a time I was working the desk at the Canyon Visitor Center and someone brought in a duck’s egg! They thought it had been abandoned. Where was this? Somewhere in the northern part of the park! Maybe Lamar Valley or somewhere near there. Ohmigosh, I was dumbstruck. After telling them they should’ve left it there and why, I called on our Resource Management folks…I honestly was so caught off-guard, I couldn’t think what to do. As I recall, they took the egg, gave the visitor(s) a bit more education, and then, I suspect, disposed of the egg, hopefully outside, where it would, perhaps, give something a good meal. Education is so important. These well-meaning visitors had no idea of the consequences of their effort to “save” this duck egg.


    1. I’ve been brought all kinds of birds “in trouble.” None of them were, but well-meaning visitors wanted to “save” something. I’m not sure if it has always been this way, but I think that people want to help in some way. They want to make a connection with wilderness by saving an animal. Unfortunately, they often do more harm than good. I think your husband is right in that birds time nesting to coincide with food availability for their offspring. This is true of any species. Raptors have the additional concern of their young being able to fly and care for themselves by the time migration/winter comes. In August, young ospreys are still in the nest, but they begin migrating south in September, and they have to go since everything freezes over and fish aren’t available here. So it’s a combination of food availability, weather, and development of young.


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