The annual Orcas Island Marine Lecture Series is back by popular demand. On Tuesday, Oct. 13 Joe Gaydos of the SeaDoc Society will give a free public talk on Western Grebes. These iconic diving birds, once seen locally in the hundreds, are rapidly disappearing. With it, we are losing one of our most charismatic birds.

With folk names that include “dabchick,” “swan grebe” and “swan-necked grebe,” the Western Grebe is the largest of the North American grebes and can weigh up to three pounds, almost half the weight of a bald eagle. These large, black and white birds have a long neck and a sharp pointed bill designed to spear or grab fish.

A century ago this bird’s elegant, snowy-white plumage was nearly its demise when its feathers were used to decorate women’s hats. Now the Western Grebe faces new challenges including derelict fishing gear, changes in prey abundance and loss of breeding habitat.

The 2009-10 marine science lecture series is free for the general public. The program begins at 7 p.m. at the Camp Orkila Marine Salmon Center. Please park in the upper parking lot at Camp Orkila. Shuttle service from the parking lot to the talk is available before and after the lecture.

Upcoming lecture dates are:

Nov. 10: “Whales, echolocation and noise” by Jason Wood, The Whale Museum

Dec. 8: “Sharks of the San Juan Islands” by Gene Helfman, University of Georgia. Family Night; free dinner at 5 p.m., program starts at 7 p.m.

Jan. 12: “There is no such thing as a sea gull” by Thor Hanson, author and biologist.

Feb. 9: “Tracker dogs: saving killer whales” by Katherine Ayers, University of Washington.

March 9: “Super Suckers: Giant Pacific Octopus and other cephalopods” by Tim Carpenter, Seattle Aquarium.