Friday, October 31, 2008

Tuatara Re-Establish Mainland Nests in New Zealand

Adult male tuatara, Karori Wildlife Sanctuary

In the terrific news category, tuatara - with a little help from their human friends - have re-established themselves on the New Zealand mainland, nesting for the first time in over 200 years.

Relegated to offshore islands after egg predation by invasive species such by rats, most notably the the kiore or Polynesian rat, the tuatara were re-introduced to the North Island in December 2005 when 70 tuatara were released into the Karori Wildlife Sanctuary on the outskirts of Wellington, the capital city. A further 130 tuatara were released into the sanctuary in 2007.

The Karori Wildlife Sanctuary is an ecological island of 225 hectares or just under a square mile bordered by a pest-exclusion fence to prevent non-native predators of native birds and reptiles decimating the native species.

Now, during routine maintenance work on the fence, Sanctuary workers have discovered the first known tuatara nest on the mainland. The nest contains 4 eggs. These may hatch anytime between now and sometime in March.

The first four tuatara eggs to be found in the wild on mainland New Zealand

The tuatara is endemic to New Zealand and is often referred to as "a living fossil" because all other species close to the tuatara became extinct about 60 million years ago.

The reproduction rate of tuatara is very low, even without threats from predators, because they breed only every 2-4 years and female tuatara only become fertile around 13 years of age. Their average life span is about 60 years, though some have lived to over 100 years of age.

The tuatara has a legendary "third eye" on top of its head, actually a parietal eye that may play a role in detecting light or in processing UV light to make vitamin D. This "eye" is only visible in the young tuatara, becoming covered over at about 3-4 months of age.

CONGRATULATIONS to the Karori Wildlife Sanctuary for this major contribution towards restoring the Tuatara to the New Zealand Mainland!!!!

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