Double-crested Cormorants

Double-crested Cormorants (13)

loafing on stone blocks in Bantam Lake's N. Bay

Photo by Bob Stanowski

Double-crested Cormorants perched on a

stone block in Bantam Lake's N. Bay

Photo by Leo Kulinski, Jr.

http://www.whalesandwolves.com/

A total of 33 Double-crested Cormorants

swimming and loafing in Bantam Lake's N. Bay
Photo by Leo Kulinski, Jr.,

http://www.whalesandwolves.com/

Double-crested Cormorants are fish-eating birds that have undergone a phenomenal population increase throughout North America over the past 25 years. Prior to that, they were relatively uncommon due to a combination of persecution by humans and environmental contamination by pesticides. With full protection under federal and state laws, coupled with laws forbidding the use of DDT and other pesticides, the populations of D.c. Cormorants, Bald Eagles, Ospreys, and many other birds have rebounded, and then some. The D.c. Cormorants have become so numerous in some places that they have become a problem for some other species. They are colonial nesters, so they like company, not only of other cormorants, but also of herons and egrets. Unfortunately, they have ruined some of these mixed rookeries for other species by their defecating habitats. Their poop is so foul and acidic that it kills the vegetation it coats. Herons and egrets need this foliage to protect their eggs and young from predators and too much sun. Cormorants seem to do okay under the hot sun. They do however suffer losses to predation by Bald Eagles. This has been increasing in Maine for a few years as the eagle population continues to increase and more and more of them find that young cormorants are easy prey. Eagles are also known to eat young herons and egrets and will occasionally take adults, too. Predation is less of a problem when the nests are under a sufficient amount of vegetative cover. Cormorants also annoy fishermen by eating lots of fish. In an effort to address the increasing number of complaints about cormorant behavior and their huge population increase, the U.S. Fish and Wildlife Service has granted special permits to state wildlife agencies to abort eggs either by addling (shaking) or by coating them with natural vegetable or mineral oils. This is a humane way of trying to bring their population under control. This species isn't trying to nest yet at Bantam Lake, but it could. They are common as nesters on Lake Champlain, in some of New York's Finger Lakes, and all around Long Island Sound. They seem to do equally well in freshwater as in saltwater. We have seen a steady increase in the numbers of D.c. Cormorants passing overhead and stopping at Bantam Lake and Little Pond during the spring and fall migrations for the past several years. The total of 33 that we counted in North Bay this past Friday 4/15 might be a record high for Bantam Lake. Every year more and more non-breeding individuals of this species stay throughout the summer at the Lake. It will be interesting to see what happens if they start breeding here. If you see these birds carrying sticks or sitting on definite stick nests on rocks or on the ground or in trees or shrubs (they will nest in all of these situations) please notify me via e-mail, which is dave@whitememorialcc.org.