Reports of wallabies living wild in Buckinghamshire, Oxfordshire and surrounding areas, have increased.
It is thought the animals have escaped from country estates or wildlife parks in the area.
The marsupials have been spotted near Henley, Oxfordshire, and Stokenchurch, Buckinghamshire, a wildlife hospital
said on Tuesday.
Wallabies cannot legally be released in the UK, under the terms of the Countryside and Wildlife Act.
'Stuck in silly places'
They are found naturally in Australia or Papua New Guinea.
But Tiggywinkles Wildlife Hospital in Buckinghamshire has had half-a-dozen calls about wallabies in trouble so far this year.
One drowned in a swimming pool, while others were killed on the road.
A spokesman for Tiggywinkles said: "We're starting to get calls, especially from the Stokenchurch area, for wallabies, which weren't there before.
"We only get calls about wallabies when they're in trouble.
"The more animals you get, the more trouble you get.
"They get in silly places, so we'll just get out there and rescue them."