Birds and Reptiles Feel the Survival Heat

The gloriously-colored forest birds of Hawaii may lose at least half their living space because of climate change, according to new research.

And soaring global temperatures mean that many of the world’s lizards could be in trouble by 2100, and could seriously compromise the loggerhead turtle, whose sex is decided by the heat of the day at the time of incubation.

The plight of lizards is highlighted by Elvire Bestion, an ecologist at the University of Exeter Environment and Sustainability Institute, UK,  and the Experimental Ecology Research Station at Moulis in France and colleagues in a report in the Public Library of Science journal PLOS Biology.
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Lizards are cold-blooded reptiles, and only active in the warmth of the sun, so they might be expected to benefit from an average rise in global temperatures.  But, once again, researchers have found otherwise.

“It leads to faster growth of juvenile lizards and earlier access to reproduction,” Dr Bestion says.  “It also leads to lower survival in adult individuals, which should endanger population survival.”

In fact, the prediction is that lizards at the southern end of their range will certainly feel the heat, and may have to leave life’s kitchen.  Depending on how humans continue increasing carbon dioxide emissions and heating the atmosphere, this might threaten between 14% and 30% of Europe’s lizards.

Lizards are common and occupy a huge range, so there is no danger of wholesale extinction. There will be somewhere they can go, and northernmost species may even benefit.

The rarest birds of Hawaii’s forested mountains, on the other hand, are already at the limits of their range.  And as the world warms, forest habitat is affected, and insect-borne pathogens gain in altitude, birds that already survive in dwindling numbers could disappear altogether.

Lucas Fortini, an ecologist with the US Geological Survey, and colleagues report in PLOS One that they looked into the future by matching sightings of the 20 rarest birds with climate projections and species distribution models.  They report that 10 species may lose 50% of their range this century, and six of these may lose 90% of their range.

Read more at Birds and Reptiles Feel the Survival Heat