Global warming is driving opossum species out of the humid tropics from their mountain homes


In the dead of night on the dark and often misty peaks of far north Queensland, researchers and rangers search for opossum species that are disappearing from their natural habitat.

Climate change is driving them from parts of their mountain homes.

Among them is one of Queensland’s most recognizable animals – the Herbert River ringtail opossum, the state Parks and Wildlife Service logo worn on the uniforms of its rangers.

At an altitude of 600 meters, at the limit of the opossum’s natural range, researchers are making hard discoveries.

“At the moment we just don’t see any; in some places we haven’t seen a single individual for a decade,” said Alejandro de la Fuente, a doctoral student at James Cook University (JCU).

“The opossums that die are not replaced with hatchlings, and that essentially leads to a long-term decline in the net number of ringtail possums there.”

“Herbie” was adopted as the QPWS logo in 1976.(ABC Grand Nord: Mark Rigby)

‘Islands in the landscape’

JCU professor Stephen Williams has been studying and monitoring the effects of climate change on mountain ecosystems for more than 20 years.

“As the summers get hotter and hotter, it basically grows [the possums] at the top of the mountain, and at low altitude, the heat becomes too much for them and they are gone, ”he said.

The researchers joined forces with rangers from the Queensland Parks and Wildlife Service (QPWS) and the Wet Tropics Management Authority (WTMA) to monitor populations of the Herbert River ringtail and other high altitude species suffering from the impact of global warming.

Roger James, ranger in charge of the QPWS Tinaroo base, said the lemuroid and green opossums face the same dire situation as their not-so-distant cousin.

A slender opossum with a dark colored coat and pale rings around its eyes climbs up a tall tree trunk.
Global warming has particularly affected the population of ringtail possum lemurs.(ABC Grand Nord: Mark Rigby)

“The problem is, these mountain peaks are like islands in the landscape,” he said.

“When you are at the top of the mountain there are no other peaks around so if you want to go to another peak you have to go down and through the farmland and the possums just don’t.

“They’re stuck on these islands on top of these mountains, and that’s the critical thing.”

“Nowhere else to go”

QPWS Natural Resource Management Ranger Ben Solowiej said the presence of Rangers in Queensland National Parks places them in a valuable position to help with surveillance of endemic species in the state.

“We have the capacity to provide personnel to undertake the investigations and provide the logistical support,” he said.

“In the last 18 months, excluding the rainy season which would make it about six months, we have managed to contribute over 110 survey nights, whereas in the past it could have taken years.”

A ranger and a university researcher use headlamps to spot possums while another ranger records the details of the sighting.
The location, time and weather at each opossum sighting are recorded.(ABC Grand Nord: Mark Rigby)

As the concentration of possums at altitudes above 1,000 meters above sea level increases, there is no cause for celebration.

As the climate warms, researchers fear opossums will continue to disappear.

“After the mountain peaks, they literally have nowhere to go up to altitude, and it is really difficult to do conservation in an area that is already protected,” said de la Fuente.

Well-protected animals are disappearing

Teams monitoring opossums do not see a shortage of other species in the humid tropics that suffer a similar fate.

Mr. James and his fellow rangers at Tinaroo are witnessing the disappearance of mammals, birds, reptiles and invertebrates that usually inhabit mountain peaks.

“The golden bird, an iconic bird species of the humid tropics, is being watched because, if the effects of climate change occur as expected, it will likely be one of the first endemic species to disappear from the top of the mountain. Mr. James said.

Three men stand at the back of a board to chat and look at maps.
Ben Solowiej, Alejandro de la Fuente, and Roger James discuss their plans for the night’s surveillance trip.(ABC Grand Nord: Mark Rigby)

Professor Williams said the disappearance of endemic species from World Heritage protected areas is a testament to the impact of climate change.

“It’s really critical right now because we’ve already seen a 50% decline in the total population of some species,” he said.

“All of these species that we would have considered completely safe because they are in a well protected and well managed World Heritage area are disappearing before our eyes.”


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