As temperatures rise, baby geckos are more at risk

By Angela Heathcote 16 June 2017
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Scientists say that increasing temperatures and land clearing are the two biggest threats to the velvet gecko.

AS HEAT WAVES BECOME more common, scientists have found that gecko embryos and young hatchlings are at risk of growth deficiencies and affected cognitive abilities, lowering their survival rate.

Author of the study, Jonathan Webb a wildlife ecologist from the University of Technology Sydney said that velvet geckos are the major prey of juveniles of the endangered broad-headed snake.

According to Jonathan, “If we lose gecko populations due to warming, then the snakes may follow.”

While adult reptiles will be able to deal with increasing temperatures, Jonathan is concerned for young geckos as they do not have the ability to thermo regulate.

During the research, gecko eggs were incubated at high and moderate temperatures.

“Eggs incubated at temperatures that mimicked temperatures likely to be experienced inside nests in 2050 produced geckos that were smaller and lighter. By contrast, eggs incubated under current nest temperatures produced hatchlings that were larger and heavier,” said Jonathan.

On national scale, Jonathan said that reducing CO2 emissions is crucial, but also noted that velvet geckos are under threat due to land clearing in Queensland, which has wiped out their habitats.

“At some of the sites that we’ve been monitoring in Morton National Park, female velvet geckos have laid their eggs inside the same communal nests for the last 25 years. This suggests that females may lack plasticity in nesting behaviour,” Jonathan told Australian Geographic.

“However, we know that females use old eggshells in crevices as a cue when they are choosing nest sites. Thus, if one female chooses a cooler crevice to lay her eggs, then other females may follow suit, and this plasticity will protect populations from climate warming.”

One option identified by Jonathan is to deploy chemical cues in cooler crevices to encourage female velvet geckos to lay their eggs in more suitable conditions. However, Jonathan said that if temperatures continue to increase and female geckos do not take these cues, then translocation may be the next option.

Currently, Jonathan is working with Martin Whiting from the Faculty of Science and Engineering at Macquarie University, to analyse how nest temperatures affect the brain structure and function, and cognitive abilities of other species of lizards.