Tuesday, October 7, 2014

Threatened and endangered species feature: osprey

Ospreys, large fish-eating raptors, are experts at spotting fish in water from high above. They fold their wings back, thrust their large talons forward and smash into the water, snatch a fish, then take flight again. Larger than most hawks, but smaller than eagles, they have made a comeback in southern Michigan over the past 20 years.
Ospreys were initially listed as a threatened species in Michigan, but were removed from the list in 2009. One important reason osprey were delisted is because of the 10-year-long Osprey Reintroduction Project that took place from 1990 to 2000. This project involved moving 50 chicks from the northern parts of the state to areas in southern Michigan, and there are now more than 30 known nests in southern Lower Peninsula plus dozens of nests in the northern Lower and Upper peninsulas. The species is known to be very faithful to historical nesting grounds, which made the osprey's return to the southern Lower Peninsula progress slow.
After World War II, the use of a new insecticide, known as DDT, increased. Small birds, fish and mammals accumulated the pesticide within their bodies. Raptors feeding on the contaminated fish, birds and rodents were, in turn, poisoned by a progressive build-up of the pesticide. DDT was especially harmful to birds because it caused eggshell-thinning, which resulted in weak eggs that broke under pressure. As a result, very few young birds hatched and made it to adulthood. DDT has not been used in Michigan for decades, and the birds are now reproducing much more normally.
If you live in an area with a large body of water nearby, you may be lucky enough to see an osprey. They will be flying over lakes looking for fish or just waiting for the right time to drop from the sky and grab the fish right out of the water! Their very large stick nests won’t be too far away, in the top of a tree or – in Michigan – it's common to see osprey nests on the top of cellular towers. They prefer to nest over or near the water, where they can see clearly for 360 degrees around the nest.
The osprey restoration program has been successful, but concerns remain. Ospreys still need to be protected from killing or capture, especially in their wintering grounds in Florida, the southwestern U.S. and Central America. With help and support from the public, the osprey will continue to be an awe-inspiring sight.