A Grebe with a Superpower

December 5, 2018

Among the scattering of Ruddy Ducks and Buffleheads on the North Basin this morning, this particular bird stood out. It was smaller than everyone else, smaller even than the Ruddy Ducks, which are the smallest ducks. And it was obviously not a duck, not with that stubby, pointed beak. I didn’t know what it was until I got the photo home and up on the desktop monitor. Aha! No doubt a Pied-billed Grebe, a female, in plain winter dress.

A few days later I saw it again and was able to get a few seconds of rough video, below. This is the first one of the species I personally have seen here on the North Basin. The bird sources say that they’re the most common of the grebe clan, but locally the Western and Clark’s Grebes show up rather often, and I see a Horned Grebe from time to time, but the Pied-billed is distinctly unusual.

These birds have the superpower of being able to control their buoyancy. By adjusting the amount of air in their feathers, they can float as high or low in the water as they want. They can, for instance, submerge all of their body except their head, like a submarine with its periscope up. No other grebe, and no duck, can do that. Common nicknames for the bird like devil diver, hell diver, and water witch point to this uncanny ability.

The Cornell bird lab website has these Cool Facts about Pied-billed Grebes:

The Latin genus name for “grebe” means “feet at the buttocks”—an apt descriptor for these birds, whose feet are indeed located near their rear ends. This body plan, a common feature of many diving birds, helps grebes propel themselves through water. Lobed (not webbed) toes further assist with swimming. Pied-billed Grebes pay for their aquatic prowess on land, where they walk awkwardly.
Pied-billed Grebe chicks typically leave the nest the first day after hatching and spend much of their first week riding around on a parent’s back. They usually spend most of their first 3 weeks on or near the nest platform.
Pied-billed Grebes are fairly poor fliers and typically stay on the water—although rare individuals have managed to fly as far as the Hawaiian Islands, Europe, the Azores, and the Canary Islands.
Pied-billed Grebes can trap water in their feathers, giving them great control over their buoyancy. They can sink deeply or stay just at or below the surface, exposing as much or as little of the body as they wish. The water-trapping ability may also aid in the pursuit of prey by reducing drag in turbulent water.
Like other grebes, the Pied-billed Grebe eats large quantities of its own feathers. Feathers may at times fill up more than half of a grebe’s stomach, and they are sometimes fed to newly hatched chicks. The ingested plumage appears to form a sieve-like plug that prevents hard, potentially harmful prey parts from passing into the intestine, and it helps form indigestible items into pellets which they can regurgitate.
When in danger, Pied-billed Grebes sometimes make a dramatic “crash-dive” to get away. A crash-diving grebe pushes its body down with its wings thrust outward. Its tail and head disappears last, while the bird kicks water several feet into the air.
The longest-lived Pied-billed Grebe on record was at least 4 years, 7 months old and lived in California.