's Santa Catalina Island rattlesnake has been classified as critically endangered on the 2007 IUCN Red List.
The snake, found on just one island, sports highly desirable patterned skin that has made it a collector's item for hunters.
New reptile surveys are revealing the fragile nature of many reptile populations.
For instance, a major survey of North American reptiles has bumped up the region's Red List reptile species to a total of 738.
The main culprit behind their decline is habitat loss due to expanding cities, Caroline Pollock, a Red List program officer, told National Geographic News.
Unlike birds and mammals, we haven't assessed all the reptiles on the planet, Pollock added.
More Photos in the News
Today's Top 15 Most Popular Stories
Free Email Newsletter: "Focus on Photography"
Photograph courtesy IUCN/Ingo Arndt/naturepl.com