Several of the field trips at the Potholes and Prairies Birding Festival in Carrington North Dakota seem to end the day at the same spot: the little rise overlooking the end of Mud Lake, where 50-75 pairs of Western Grebes, and few pairs of Clark’s Grebes, have formed a nesting colony. Grebes build floating nests, loosely anchored to reeds and cattails or underwater vegetation. Nest colonies are probably common among Westerns and Clarks, but the Mud Lake colony is the only one I know of. The first shot is of a pair of Western Grebes.

As you see in the second shot, Grebe eggs are among the largest, relative to body size, of any bird. I visited several weeks ago. By now, the colony must be full of zebra striped baby grebes. Because the nest materials slowly sink, the Grebes are always adding new materials to the top of the nest and rearranging the eggs.

Finally we have a Clark’s Grebe on a well hidden nest. Note the line of black on the face is well above the eye, and the bright yellow of the bill (as compared to the greeny-yellow of the Western’s). In the water, the Clark’s gives an impression of a lighter bird overall, gray where the Western is black, but it is hard to see unless you have the two species side by side.

Canon SX50HS in Program with my usual modifications. 1800mm equivalent flied of view. Processed in Lightroom.