SYDNEY, Australia — Early on the morning of Dec. 27, Phoebe Meagher, a wildlife conservation officer at Taronga Zoo, set off on a rescue mission with colleagues from the zoo and academics from the University of New South Wales. Several platypuses were trapped in quickly shrinking bodies of water in Tidbinbilla Nature Reserve in the Australian Capital Territory, and wildfires were fast approaching. There was a window of a few days before the park would be entirely closed off to the public, and two weeks until the bodies of water would be completely dry.

A five-hour drive brought the team to what was once a lake. Now, it was mostly deep, sucking mud. The air was hot and smoky. “Initially we thought we weren’t going to be trapping until the evening,” Dr. Meagher said. Platypuses are nocturnal, usually waking up around sunset. But these platypuses were already active, which, while concerning, meant the team could see where they were.

“There was hardly any water there,” Dr. Meagher said. “So they couldn’t duck down and hide and be cryptic like they usually are.”

Platypuses are difficult to catch; they are fast, slippery swimmers and desperately shy. The males also have a sharp, venomous spur behind one of their hind feet. The venom is not lethal to humans, but there is no antidote, and the pain can last months.