Climate change impacts tuatara population

Apr 09, 2014

A new study involving researchers from Victoria University of Wellington shows climate change could ultimately result in the extinction of a population of tuatara.

Dr Nicky Nelson, Dr Kristine Grayson and Susan Keall from Victoria's School of Biological Sciences, in collaboration with the Department of Conservation and University of Western Australia, provide a case study of a natural of on North Brother Island in the Cook Strait of New Zealand.

The research, published this week in the international scientific journal PLOS ONE, shows that as a result of warming temperatures, there is an accelerating decline in the proportion of adult female tuatara in the population.

"Our research reveals that as the male-bias in the population increases, female tuatara body condition, fertility rates and survival decline," says Dr Nelson.

Projected temperature increases for New Zealand are expected to further tip the hatchling sex ratio towards males—owing to the pattern of temperature-dependent sex determination in tuatara where males hatch at warmer temperatures.

Dr Nelson says understanding the mechanisms underlying population declines is critical for preventing the extinction of endangered populations.

"If we understand the causes of decline for species, we can consider our options for management, particularly under the various scenarios for climate warming."

Population viability models predict that without management, intervention or an evolutionary response the North Brother Island population will ultimately be made up entirely of males and become extinct.

The study demonstrates that the sex ratio in tuatara populations can be an underappreciated threat to long-term viability, particularly in populations that appear numerically stable.

Explore further: Male extinction prevented by promiscuous females

More information: This study was published in the international scientific journal PLOS ONE and can be read in its entirety here: dx.plos.org/10.1371/journal.pone.0094214.

add to favorites email to friend print save as pdf

Related Stories

Close encounters with tuatara

Nov 13, 2013

Anna Carter is conducting a climate modelling study on Stephens Island in Cook Strait, home to New Zealand's largest tuatara population.

Male extinction prevented by promiscuous females

Apr 01, 2014

Female fruit flies with a large number of sexual partners are playing an invaluable role in preventing the extinction of males, research at the University of Liverpool has shown.

Help at hand to relocate threatened species

Oct 17, 2013

Australian and New Zealand scientists Thursday said they have devised the "first rigorous framework" on deciding whether to relocate endangered animals threatened with extinction by climate change.

Recommended for you

Ninety-eight new beetle species discovered in Indonesia

11 hours ago

Ninety-eight new species of the beetle genus Trigonopterus have been described from Java, Bali and other Indonesian islands. Museum scientists from Germany and their local counterparts used an innovative approa ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.