Life too hot to handle for NZ living dinosaur
03 Jul 2008
Male tuatara could face a lonely future as global warming continues to affect New Zealand’s living dinosaurs.
The New Zealand native medium-sized reptiles are already rare and are the oldest living genus of reptile in the world, dating back 190 million years to dinosaur times.
Now a new Australian study predicts that if Earth continues to warm, tuatara will produce only male offspring by 2085. With a sex-less, lonely future the reptiles would then face extinction.
New Zealand’s Victoria University senior lecturer Nicola Nelson said they had known of the gender crisis for some time but the research was exciting because it set a timeframe for the male-only scenario.
"I think it's really important that we keep these things around."
Warm nests
Tuatara - which have survived 200 million years of change and turmoil - produce male offspring when their nests reach more than 21.5 degrees celsius.
The Australian researchers studied soil on tuatara nesting islands to predict how the 100,000 survivors of the dinosaur age would fare if global warming continued at predicted rates.
Last year, Victoria University research revealed males were already outnumbering females by 1.7 times at one of the southern-most tuatara breeding spots.
Nicola Mitchell says the tuatara's best chance of survival was continuing to take them south to cooler islands or to protected areas.
"Translocations of tuatara to islands south of their current range are already occurring," Dr Mitchell said. "We now have a tool to identify which locations would produce favourable sex ratios under climate change."
Tuatara inhabit 40 offshore New Zealand islands, including some in Marlborough Sounds and Cook Strait. Many also reside on tiny islands off the east coast.
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