Washington | Scientists have found three man-eating crocodiles in the US which can grow to 18 feet long and weigh as much as a small car. Using DNA analysis, researchers at University of Florida confirmed the capture of three Nile crocodiles in the wild.
These crocodiles can eat everything from zebras to small hippos to humans in sub-Saharan Africa, researchers said. The three juveniles of the monster crocodile, have been found in South Florida, swimming in the Everglades and relaxing on a house porch in Miami.
The crocodiles were captured between 2000 and 2014, leading scientists to analyse their DNA, study their diet and one of the animal’s growth. Scientists verified the animals were Nile crocodiles linked to native populations in South Africa, and confirmed the species can survive in Florida – and potentially thrive, said Kenneth Krysko, from the Florida Museum of Natural History.
The odds that the few of us who study Florida reptiles have found all of the Nile crocs out there is probably unlikely, said Krysko. We know that they can survive in the Florida wilderness for numerous years, we know that they grow quickly here and we know their behaviour in their native range, and there is no reason to suggest that would change here in Florida, he said.
Nile crocodiles, Crocodylus niloticus, were responsible for at least 480 attacks on people and 123 fatalities in Africa between 2010 and 2014. They are predators and eat a wide variety of prey. In Florida, everything from native birds, fish and mammals to the state’s native crocodile and alligator would be a fair game for the carnivorous croc.
The study found one juvenile grew nearly 28 per cent faster than wild Nile crocodile juveniles from some parts of their native range. DNA analysis showed the three similar-size Nile crocodiles were genetically identical, suggesting they were introduced via the same source, but Krysko said the source has not been confirmed.
Scientists had extensively sampled DNA of live Nile crocodiles housed in US zoos. The DNA of the three crocodiles did not match with any of those sampled, suggesting they were either acquired by a permitted source later, or introduced by someone without a permit.
Researchers note that over the last decade, large groups of Nile crocodiles have been imported from South Africa and Madagascar for display at places like Disney’s Animal Kingdom and to supply Florida’s flourishing pet trade, with the latter being the most likely introduction pathway, according to the study.
Subscribe to our email newsletter.