A pair of Trumpeter swans surrounded by a number of Canada geese and a a few mallard ducks were taking advantage of the open waters near the boat docks at the headquarters at the Willow Slough Fish and Wildlife Area near Morocco, Ind., this past week.
A submerged aerator system sending bubbles of air to the surface keeps some small pools open and ice free. The open water attracts waterfowl during the winter when the rest of J.C. Murphey Lake is locked in ice. Getting a close look at the pair of swans, that have been seen at the lake for some months now, show that one of the birds does not have the usual black legs and feet that is normally seen on an adult trumpeter.
While photographing the trumpeters at some distance this past August, I noticed the yellow colored legs on one of the birds and assumed it was a juvenile. I was told at the headquarters at Willow Slough this past week that the swan with yellow legs was believed to be leucistic.
Leucism is a genetic mutation that causes a reduction of pigments. We see the abnormality in mammals, birds, and even in reptiles.
A few times a year while great flocks of starlings are feeding in fields, it is not uncommon to see a flash of white from the wings, tail, or the head of one of the birds in the flock. The birds with white feathers are missing the normal dark colors of the starling and are considered leucistic.
The young cygnet (baby swan) that is leucistic is bright white and the non leucistic young Trumpeter is gray. The leucistic birds end up with yellow legs and feet as adults trumpeters.
These rare leucistic trumpeter swans have been reported and are still occasionally seen in Ontario. The leucistic swans are bit more common in the Rocky Mountain population and are also seen in the Yellowstone summer population.