Cuban crocodile survival threatened by breeding with their American cousins

A culturally significant species could be lost

July 2011: Wild Cuban crocodiles are cross-breeding with American crocodiles a new study has found. The team of Cuban and American researchers warn the hybridisation may cause a population decline of Cuban crocodile, which is found only in the Cuban Archipelago.

CULTURALLY SIGNIFICANT: The Cuban crocodile

Known for their leaping ability and aggressive disposition, Cuban crocodiles are a charismatic and culturally significant species to Cuba. Exact population estimates for the species remain unknown, though scientists believe that a minimum of 3,000 individuals remain in the Zapata swamp. A smaller population exists in the Lanier Swamp on the Island of Youth.

Crocs were already cross-breeding in captivity 
The species was extensively hunted from the middle of the 19th century through the 1960s resulting in drastic population declines.

Cuban crocodiles and American crocodiles had already been confirmed to cross-breed in captivity, so there was suspicion they would do the same in the wild - but this is the first genetic study to confirm these worries. 

This findings indicate that Cuban crocodiles and American crocodiles in Cuba may represent two evolutionary significant units (ESUs) - populations considered distinct for conservation purposes and representing an important component of the evolutionary legacy of the species. 

The authors say that cross-breeding may be one of the most important threats to Cuban crocodiles, along with illegal hunting and habitat modification.