Out of the Zoo and Into the Wild

Detroit Zoo-bred Siamese crocodiles to be released in Cambodia

August 26, 2015


A critically endangered species will soon see its wild population bolstered due to successful breeding efforts at the Detroit Zoo.  Ten Siamese crocodiles that hatched at the Zoo’s Holden Reptile Conservation Center in early June were transferred in July to the St. Augustine Alligator Farm Zoological Park in Florida, which specializes in crocodile care and conservation.  The hatchlings are being fostered by an adult pair of Siamese crocodiles there before their eventual release into protected areas of the crocodiles’ natural environment in Cambodia, marking the first time captive-bred Siamese crocodile hatchlings will be released in the wild.

“Our conservation efforts have led not only to the successful breeding of Siamese crocodiles but to the addition of zoo-born crocodiles to a critically small wild population – which hopefully will help save the species from extinction,” said Scott Carter, chief life sciences officer at the Detroit Zoological Society.

The Siamese crocodile (Crocodylus siamensis) is a medium-sized crocodilian found in the wetlands and waterways of Southeast Asia.  There are estimated to be around 250 adult Siamese crocodiles remaining in the wild.  The decline of the species is due to habitat loss, degradation of the habitat by humans and the poaching of both crocodiles and their eggs for farms and the skin trade.

The Detroit Zoo’s breeding effort for Siamese crocodiles is part of the Association of Zoos and Aquariums’ (AZA) Species Survival Plan (SSP), a cooperative management program that ensures genetically healthy, diverse and self-sustaining populations of threatened and endangered species.  Three Siamese crocodiles that hatched at the Zoo in 2008 now live in other AZA-accredited zoos as part of the SSP program.

In the most recent breeding event at the Detroit Zoo, the female Siamese crocodile laid 22 eggs in a nest she constructed of soil and vegetation.  Half of the eggs were removed from the nest and placed into incubators, while the remaining eggs were left in the nest.  Over several days in early June, six crocodiles hatched in the nest and five in the incubators.

“We didn’t want to put all of our eggs in one basket, so to speak,” Carter said, adding that the Zoo’s Holden Reptile Conservation Center provides conditions conducive to hatching for these crocodiles.  “We are able to maintain temperature- and moisture-control parameters and simulate nest conditions found in the wild during the incubation period.”

The Holden Reptile Conservation Center is home to 180 reptiles representing 70 species, one-fifth of which are considered threatened or endangered in the wild.