More than 100 dead and injured ringtail possums have been found by wildlife rescuers along a single stretch of beach in Victoria in what ecologists say is becoming an annual occurrence due to extreme heat.

Rescuers and wildlife carers discovered 127 ringtail possums along the shoreline and in the water at Somers Beach on the Mornington Peninsula on Saturday during a four-day period that saw consistent temperatures in the high 30s, warm nights and bushfires in parts of the state.

Melanie Attard, a wildlife rescuer and foster carer with Aware Wildlife in Frankston, said rescuers suspected the animals had become so dehydrated and desperate they had left an area of scrub and come down to the beach and attempted to drink salt water.

“We assume they’ve come out due to the heat stress heading for the water in desperation,” she said.

“It’s not nice seeing a possum throwing itself into the beach and drinking seawater. It’s really desperate.”

Attard said 100 of the animals had died while the remaining possums had been taken into care. Only half had survived and would be released back into the wild when they had recovered.

Veterinary staff working with Wildlife Health Victoria: Surveillance at Melbourne University are investigating the cause of the deaths.

Malcolm Legg, a Mornington Peninsula-based ecologist who has been monitoring the situation for a decade, said: “It’s pretty much an annual event now whenever we get heatwaves of two days or more.

“The possums are just collapsing, out of trees, run down by cars, taken by cats and dogs.

“Last week they were going down to the water and getting so desperate they were dying on the spot.”

He said the situation was similar to heat stress deaths that have affected other species this summer, including the spectacled flying fox in Queensland.

Scientists have also been monitoring large drops in moth species due to climate change and recent drought.

Legg said there was no comfort in the fact that the ringtail possum was a common species when the situation was occurring with such regularity as extreme weather becomes more frequent.

“This is an indication the populations are starting to crash locally. It might not be so common in the next 10 to 15 years.”

Euan Ritchie, an associate professor of wildlife ecology and conservation at Deakin University, said the extreme weather that had been predicted for decades was now affecting several species.

“These recent heatwaves have been a disaster. The spectacled flying foxes. The bogong moths. This just really adds to that story,” he said.

“It’s not just we’re talking about endangered species. This is a common species and it’s falling over.

“That’s a pretty big reality check.”