DDT contaminants in marine mammals may threaten condors
SAN DIEGO — The California condor’s dramatic recovery from near-extinction was aided by removal of toxic substances from the land, which accumulated in animals whose carrion they ate.
But that recovery may be threatened in coastal condors by DDT-related contaminants in marine mammals, according to a preliminary study led by a San Diego State University researcher.
Coastal-dwelling condors have more of these compounds than those living inland, the study found. These are presumably absorbed from marine mammal carcasses, said study leader Maggie Stack. This might explain why coastal condors have thinner eggshells than those inland.
The preliminary findings were reported Wednesday by a team led by Stack, a California Sea Grant trainee and a graduate student at San Diego State University. Because the study has not been peer-reviewed, it requires further validation before it can be published, Stack said.
If the link is confirmed, reintroduced condors can be given a better chance of survival by choosing locations with a lower level of these contaminants, Stack said.
Condor populations have recovered from a low of 22 wild birds in 1986 to about 300 living in the wild today. The conservation work is assisted by the San Diego Zoo, which nurtures chicks from captive birds at the San Diego Zoo Safari Park.
A male condor takes in the view at the Hopper Mountain National Wildlife refuge, north of Fillmore on Nov. 6, 2014.