Posts Tagged ‘Gavia pacifica’

The Eerie Call of the Common Loon (Gavia immer immer)

January 29, 2012

The call of the loon sounds ghostly.  I imagine the howling of dire wolves and the eerie calling of loons made living in the Pleistocene kind of spooky.  Loons are in the order Gaviformes which is always the first order listed in books about North American birds, meaning they are considered the most primitive avian group living on the continent. Of all the North American birds they must be the closest living relatives of the dinosaurs.  Perhaps some species of dinosaurs had a smilar vocalization.  Below is a link to a youtube video from the Cornell University ornithology department that includes eerie cries of loons.

Common loon.

Loons dive under water and catch small fish–their primary prey, though they also feed upon aquatic invertebrates, insects, and some water plants.  They can take large fish as well, but need to drag them to shore and mangle them before dining.  Loons like to nest on uninhabited islands in lakes, explaining why they migrate north during spring to places like Minnesota where there are lots of lakes.  I always thought of loons as a strictly northern bird, but a few years ago a checklist and count of waterfowl on Clark Hill Lake included a few dozen common loons.  I didn’t know they spent winters in wetlands across the south and have never seen one.  They’ve been reported from many counties in Georgia but are most numerous near the coast where small fish are always plentiful.

Counties in Georgia where common loons have been sighted.  The map should include Lincoln County where they’ve been seen on Clark Hill Lake. The common loon winters in Georgia but doesn’t nest here.  Its present day nesting grounds were under glacial ice during much of the last Ice Age.  Did it nest in Georgia then?

During the Ice Age the present day nesting range of the common loon was under glacial ice.  They must have nested farther south then.  The region between the southern lobe of the Laurentide glacier and the Ohio River may have had numerous small lakes created by meltwater pulses which flooded low lying areas.  Perhaps this is where they mostly nested then.  It’s possible they nested and lived year round in the southeast during the Ice Age.  The overall population probably increased as the glacier receded and opened up more favorable habitat in the north, and they eventually abandoned their southern breeding grounds, though they still return to take advantage of ice free feeding opportunities during winter.

Attached Image: Carpometacarpus, Com. Loon.jpg

A loon fossil (looks like an intact wing) found in Florida by a member of the Fossil Forum.  This is a nice specimen. Did they breed and nest in Florida then or was it just spending the winter?

Three other species of loons spend winters in Georgia.  The red-throated loon (Gavia stellata) has been reported from 19 counties; the Pacific loon (Gavia pacifica) has been reported from 4 counties; and the yellow-billed loon (Gavia adamsii) is a rare accidental reported from only 1 county.