The Pied-billed Grebe has the widest distribution in the Americas of any grebe, breeding from northern Canada through the West Indies and Central America to southern South America1. I photographed these grebes recently at Lema Ranch, one of the better birding hot spots in Northern California.
The Pied-billed Grebe is an aggressive bird, threatening, chasing, and attacking both members of its own species and other birds. Males, which are larger than females, do most of the territorial defense; attacks are often made from under water, and many birds, especially grebes, react by fleeing when a Pied-billed Grebe dives toward them1.
These grebes are still in their winter, non-breeding or definitive basic plumage.
They can be very boisterous and are often heard before they are seen.
I found this video of a Pied-billed Grebe pair in breeding plumage giving their typical call which you may have heard when visiting a freshwater marsh or lake.
You can see more great bird photos at Wild Bird Wednesday and The Bird D’pot!
References: 1Birds of North America Online