Tower Hill guide John Sutherland said on Thursday 25 long-necked turtles had been killed in one spot, and most were so badly injured they had to be euthanised by volunteers.

Mr Sutherland said he was certain the turtles had been killed by foxes.

He said usually fox-baiting was carried out by authorities to keep numbers down, but none had been done this year.

“This time of year they start having their pups and they’re hungry,” Mr Sutherland said.

He said he wouldn’t be surprised if emu chicks and other young waterbirds, which were usually born this time of year, were also being attacked by foxes.

“This is the first time I’ve seen turtles predated on by foxes,” Mr Sutherland said.

“Usually they predate on rabbits and the emu chicks which appear from about the first week of August.”

He said a rabbit-baiting program had been run this year meaning rabbit numbers were down but also that the foxes had less to eat

“We’ve got a lot of water birds at the moment,” he said.

“We’ve got swans with cygnets, and foxes are known to wade through water to get to their nests.”

Mr Sutherland said recent wet conditions would have brought the turtles out.

“The turtles usually move after rain,” Mr Sutherland said.

“The rain the other day has got them moving and they’re coming to lay their eggs up on the hill.”

Mr Sutherland, who has been involved with Tower Hill for more than a decade, said he had serious concerns about the impact having less rangers on the ground and not running certain programs would have on the wildlife.

"It’s an escalating thing that’s just getting worse and I don’t know where it’s going to end,” he said.

Parks Victoria and the Department of Environment, Land, Water and Planning were not able to provide further information and comment in time for publication.