Bird of the Month May 2020

Caption: A female Eared Grebe carries two chicks on her back while her mate feeds them.

Eared Grebe

Podiceps nigricollis

BASIC DESCRIPTION

The Eared Grebe is a small waterbird with a thin straight bill, a peaked head, and a dark body with rusty sides. Most prominent though, is the red-eye and the fan of golden feathers or “ears” that contrast against a dark head. They are strikingly beautiful and the male and female are similar.

Behavior and Habitat

Eared Grebes are social birds and often migrate in huge groups and nest in loose colonies.

Eared Grebes typically nest on lakes and wetlands that are not bordered by trees. Within these lakes and wetlands, males and females select a nest site in shallow waters with cattail, sedges, or rushes.

Like other grebes, Eared Grebes perform elaborate mating dances, seeming to walk on water as they court each other with bows, dives and exaggerated body postures. Unions are monogamous for the season and males stick around and help build the floating nest and care for the 1-8 young produced. The precocial young are ready to swim or walk within an hour of  hatching, but for the first part of their lives, they prefer to hitch a ride on mom’s back.

Eared Grebes feed mainly on aquatic invertebrates. With lobed, not webbed toes, they are excellent divers and swimmers and can hunt along the bottom of the marsh.

Cool Facts from All About Birds website

  • In the fall, almost the entire population of Eared Grebes flies to Mono Lake, California, or the Great Salt Lake, Utah, to fatten up on brine shrimp and alkali flies before migrating farther south. Here they more than double their weight, and the sizes of their muscles and organs change. The pectoral (chest) muscles shrink to the point of flightlessness and the digestive organs grow significantly. Before departure for the wintering grounds, the process reverses; the digestive organs shrink back to about one-fourth their peak size, and the heart and pectoral muscles grow quickly to allow for flight. In the spring (late January through early April) they tend to congregate at the Salton Sea and the Great Salt Lake, skipping Mono Lake. 
  • A cycle similar to that of the fall staging areas occurs 3–6 times each year for the Eared Grebe. For perhaps 9–10 months each year, the species is flightless; this is the longest flightless period of any bird in the world capable of flight at all.
  • The Eared Grebe migrates only at night. Because of the length of its stay at fall staging areas, its southward fall migration is the latest of many bird species in North America.

Similar Species

Eared Grebes are pretty unmistakable during the spring and summer, but if a Horned Grebe happens by, the two might be confused. However, the Horned Grebe has a chestnut-colored chest, long “horns” that go straight back (as opposed to the fan of the Eared Grebe) and have a larger looking head. Juveniles and non-breeding adults might be confused with Pied-billed Grebes but have a longer and slenderer bill of a single color. Pied-billed Grebes are also noticeably smaller. Red-necked Grebes have, well, a red neck, and no golden fan of feathers.

When and where found at Camas NWR

Internationally, Eared Grebes are considered the most common grebe in the world. According to the Camas NWR Bird List, Eared Grebes are common spring through fall on the refuge and they breed there as well (see photo of an Eared Grebe family at Camas NWR). Watch for them any marshes with water.

Conservation

“Eared Grebes are common and their populations were stable between 1966 and 2015, according to the North American Breeding Bird SurveyPartners in Flight estimates the global breeding population at 2.7 million. The species rates a 12 out of 20 on the Continental Concern Score, which means it is not on the Partners in Flight Watch List and is a species of low conservation concern. Like other waterbirds, draining of wetlands and agricultural conversion reduces the amount of available habitat. Mass die-offs of Eared Grebes have happened in the past. In 1992 around 150,000 individuals died in the Salton Sea possibly due to disease. In 2011, more than 1,500 grebes died when they landed in a Walmart parking lot in Utah. It’s thought that stormy weather triggered the migrating birds to land, and the well-lit asphalt parking lot looked like a lake to them. In all, some 3,000 Eared Grebes crash-landed, but luckily many were rescued and released to a nearby lake.” www.allaboutbirds.org/guide/Eared-Grebe/lifehistory

Text by Terry Thomas. Source: https://www.allaboutbirds.org

Photo by Terry Thomas.