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Description

With nearly 11,000 named species, lizards and snakes (together forming the order Squamata) are the second most diverse of all vertebrates. They rank among some of the most adaptable animal groups being found across all environments around the globe, bar the extreme cold of the poles. However many species have tiny ranges, particularly those on islands, and as a result numerous species are highly endangered. The major threats are habitat destruction/fragmentation, global warming, hunting, poaching, illegal wildlife trade, feral predators/competitors, and disease. Luckily squamates generally respond well to captivity, and an improved protection of habitats can lead to rapid rise in populations. The species illustrated all had populations which dipped to below 500 individuals before being rescued by conservation measures.

* Unfortunately the islands of the Caribbean are a hotspot for highly endangered lizards and snakes. Direct hunting and predation has had dramatic affects on the populations of most Caribbean iguanas. Two Cyclura species from the Cayman islands and Jamaica were very close to extinction before being saved by captive breeding. Both of the snakes from Antigua (a racer) and Aruba (a rattlesnake) are restricted to tiny ranges as a result of human impact (with introduced mongooses predating the racer). While captive breeding programs have been successful, reintroduction has only occured on the Antiguan islands due to a lack of protection for the rattlesnake.

* Across a range of oceanic islands are several highly endangered reptiles which have benefitted from captive breeding programs. The Gallotia lizards of the Canaries are an endemic radiation of lacertids, with eight species across the archipelago. Most are threatened by human activity with one species already lost and two highly endangered (see also Extinct Island Fauna - Macaronesia 2 ). Recovery plans have seen population increases in two critically endangered species. On Christmas Island (an Australian territory in the Indian Ocean), a species of skink and gecko were lucky to survive from the combined threats of an introduced snake and crazy ants. Another species of skink died out before a captive breeding program could be initiated. Cobble skinks (an unnamed species of Oligosoma) were restricted to a remnant of it's original range on New Zealand coastline due to habitat destruction and pressure from predators. The Casarea boa on Round Island off the coast of Mauritius also was restricted by habitat destruction caused by introduced goats and rabbits (a second species died out in the 1970s; see Extinct Island Fauna - Mascarenes 1 ). A combination of habitat preservation, predator control and removal of pest species, along with captive breeding programs, has proven to be a success with each of these species.

* Several continental species have also experienced population decreases largely due to habitat restrictions and damage. Pine snakes Pituophis from the southern USA have endured the twin threats of habitat restriction and fire suppression within the remaining forests. Better management of the forests plus a breeding program have been installed. Restricted to a small area of valleys in North-western Australia, rough-scaled pythons have always been rarely sighted (barely a handful have been recorded). However like most Morelia species they have been prolific breeders in captivity. Earless dragons Tympanocryptis are a speciose group found across dry grassland areas across Australia. Species found in the cooler alpine grasslands have come into conflict with graziers and habitat destruction, with one species thought to be extinct and another recovering through captive breeding.

Description

With nearly 11,000 named species, lizards and snakes (together forming the order Squamata) are the second most diverse of all vertebrates. They rank among some of the most adaptable animal groups being found across all environments around the globe, bar the extreme cold of the poles. However many species have tiny ranges, particularly those on islands, and as a result numerous species are highly endangered. The major threats are habitat destruction/fragmentation, global warming, hunting, poaching, illegal wildlife trade, feral predators/competitors, and disease. Luckily squamates generally respond well to captivity, and an improved protection of habitats can lead to rapid rise in populations. The species illustrated all had populations which dipped to below 500 individuals before being rescued by conservation measures.

* Unfortunately the islands of the Caribbean are a hotspot for highly endangered lizards and snakes. Direct hunting and predation has had dramatic affects on the populations of most Caribbean iguanas. Two Cyclura species from the Cayman islands and Jamaica were very close to extinction before being saved by captive breeding. Both of the snakes from Antigua (a racer) and Aruba (a rattlesnake) are restricted to tiny ranges as a result of human impact (with introduced mongooses predating the racer). While captive breeding programs have been successful, reintroduction has only occured on the Antiguan islands due to a lack of protection for the rattlesnake.

* Across a range of oceanic islands are several highly endangered reptiles which have benefitted from captive breeding programs. The Gallotia lizards of the Canaries are an endemic radiation of lacertids, with eight species across the archipelago. Most are threatened by human activity with one species already lost and two highly endangered (see also Extinct Island Fauna - Macaronesia 2 ). Recovery plans have seen population increases in two critically endangered species. On Christmas Island (an Australian territory in the Indian Ocean), a species of skink and gecko were lucky to survive from the combined threats of an introduced snake and crazy ants. Another species of skink died out before a captive breeding program could be initiated. Cobble skinks (an unnamed species of Oligosoma) were restricted to a remnant of it's original range on New Zealand coastline due to habitat destruction and pressure from predators. The Casarea boa on Round Island off the coast of Mauritius also was restricted by habitat destruction caused by introduced goats and rabbits (a second species died out in the 1970s; see Extinct Island Fauna - Mascarenes 1 ). A combination of habitat preservation, predator control and removal of pest species, along with captive breeding programs, has proven to be a success with each of these species.

* Several continental species have also experienced population decreases largely due to habitat restrictions and damage. Pine snakes Pituophis from the southern USA have endured the twin threats of habitat restriction and fire suppression within the remaining forests. Better management of the forests plus a breeding program have been installed. Restricted to a small area of valleys in North-western Australia, rough-scaled pythons have always been rarely sighted (barely a handful have been recorded). However like most Morelia species they have been prolific breeders in captivity. Earless dragons Tympanocryptis are a speciose group found across dry grassland areas across Australia. Species found in the cooler alpine grasslands have come into conflict with graziers and habitat destruction, with one species thought to be extinct and another recovering through captive breeding.