MIAMI (AP):

Florida's "Python Challenge" is more than halfway through, with more than three dozen Burmese pythons killed so far.

The Florida Fish and Wildlife Conservation Commission said Tuesday that 37 of the invasive snakes have been killed in the Everglades since the competition began Jan. 12.

University of Florida researchers examine each snake, hoping to learn more about the elusive species that's considered a menace to the fragile Everglades ecosystem.

No one knows for sure how many pythons live in South Florida. A tally of 37 may seem low, but researchers say that number reflects how hard it is to spot pythons in the swamps.

More than 1,000 people signed up to hunt pythons through Feb. 10 in the hopes of winning cash prizes.