Explore by Animal
Marley and Eleanor: It’s Lonely Being Blue Iguanas
You might have more dollars in your pocket than there are Grand Cayman blue iguanas (Cyclura lewisi) alive in the wild. A 2002 report released by the National Trust for the Cayman Islands (NTCI) said fewer than 30 blue iguanas roam the tiny Caribbean island where they are endemic, making them the most endangered lizard species in the world. If we don’t do something to stop their decline and boost their numbers, they will be functionally extinct by 2007.
Shedd has heard that call to service. In 2005, we moved our resident pair, Marley and Eleanor, into a 1,200-square-foot re-creation of the Grand Cayman shore in the Islands and Lakes gallery of Waters of the World. (They had lived behind the scenes for seven years.) Not only does this give visitors a rare, intimate view of an endangered animal; it also amplifies the likelihood that Eleanor will lay eggs.
Location is everything, after all. The realistic habitat, replete with natural sunlight, high humidity and heated basking rocks amid the craggy landscape offers everything these reptiles need. Normally territorial, when the mood hits in spring—and a rush of hormones brightens their noggins blue—special areas tempt Marley and Eleanor together to head bob, a courting behavior that inspires mating.
As important as the realistic habitat that guests view are the out-of-sight nest chambers. Shedd is a partner in a blue iguana Species Survival Plan (SSP) that includes captive breeding. More than 180 iguanas – about 30 among 10 U.S. zoos and aquariums and more than 150 in the NTCI facility on Grand Cayman—are managed as one population to allow easy exchanges among the SSP members and to ensure a diverse, vigorous gene pool. The ultimate goal is to release the captive-bred blues into protected reserves on their native island. So far, 10 males and 13 females, outfitted with small radio collars for monitoring, have “graduated” from the SSP program.
Human settlement has further eroded the hardscrabble existence to which blue iguanas have adapted. Buildings and roads decimate their original habitat, and non-native predators, such as domestic pets, eat their eggs. While the SSP does not assure their survival, it does offer hope. Visit Marley and Eleanor at Shedd to learn more about these big blue wonders of the wild.
Each year Shedd staff members head to the Bahamas with a group of volunteers to study West Indian rock iguana populations. Read a blog about their experience.