The double-crested cormorant (Phalacrocorax auritus) is a member of the cormorant family of seabirds. Its habitat is near rivers and
lakes as well as in coastal areas, and is widely distributed across North America, from the Aleutian Islands in Alaska down to Florida
and Mexico. Measuring 70–90 cm (28–35 in) in length, it is an all-black bird which gains a small double crest of black and white feathers
in breeding season. It has a bare patch of orange-yellow facial skin. Five subspecies are recognized. It mainly eats fish and hunts
by swimming and diving. Its feathers, like those of all cormorants, are not waterproof and it must spend time drying them out after
spending time in the water. Once threatened by the use of DDT, the numbers of this bird have increased markedly in recent years (WikipediA).
large numbers of cormorants congregate in a roosting or nesting area, their droppings can kill trees and other vegetation. They also
compete with loons and other fish-feeding birds for food.
Cormorants have been using White Lake for many years. However, their numbers
have always remained small. In recent years, we have noticed that the White Lake population of cormorants was increasing. As part
of our water quality monitoring program, we decided to start monitoring cormorant numbers on White Lake. Every two weeks we patrol
and sample 9 sites in all parts of the lake. Samples for total phosphorus are collected as are plankton samples, water temperature
and secchi depth. During this two-hour period, we collect data on the location and numbers of cormorants at all roosting sites,
where they have been observed. We do not know the location of the nesting sites at this time, but it is common for cormorants to nest
in communal settings kilometres away from their preferred feeding lake.