New Zealand scientists are scratching their heads after discovering a sea lion give birth to a pup 60 kilometres inland.
A farming family, the Hunters, were stunned to find an "incredibly cute" pup on their property near Kononi in the South Island region of Otago, during this summer's breeding season.
"We're absolutely astonished, it's totally amazing," Pam Hunter said, calling it "one of life's little treasures".
"We've been going down to check on the pup, and it has been playing like a child would, including taking swims at the river's edge under the watchful eye of her mum."
Department of Conservation (DOC) rangers are equally taken aback, given the mother - a sea lion known to them called Jade - must have swum 60km up the Clutha River to give birth.
"This mother's behaviour raises a lot of questions for us," DOC's Jim Fyfe said.
"We know the females are very motivated to hide from males during breeding season, but just how far will they go? What trade-offs are they making in terms of access to their normal food?"
The population of New Zealand sea lions - known in the Maori language as pakake - is believed to be around 12,000, giving them a conservation status of nationally vulnerable.
"Because pakake were wiped out on the mainland more than 200 years ago, before returning in recent decades, there is a lot we are learning about their habitat use and behaviour," Mr Fyfe said.
Sea lions are much-loved by New Zealanders, who enjoy - and endure - the marine mammal's intrusive behaviours during breeding season in summer.
Kiwis in southern settlements of South Island, including the university city of Dunedin, delight in spotting the animals on properties, golf courses and popular swimming holes.
DOC say there are "small but growing" populations in Otago, Southland and Stewart Island, with most animals living and breeding on Subantarctic islands.
Three years ago, Dunedin's council made headlines for closing a road to allow a mother and pup safe access to the sea.
Mr Fyfe said it was important that the pup - which is yet to be named - found this summer on the Hunters' farm be given plenty of space by locals.
"The mother will stash the pup while she forages so locals should be aware they may find the pup in unexpected places," he said.
"We expect the pup will remain in the area for the next few weeks, but we have no idea where the mother will take her after that."
