Researchers discover where coyote who made epic swim to Alcatraz really came from

A coyote that gained national attention for swimming to Alcatraz Island in California actually swam twice as far as originally thought to the infamous landmark, surprising researchers tracking the wild animal.

The male coyote's sudden appearance in January at the site of the former federal prison in San Francisco Bay stunned scientists and tourists, marking the first time a coyote has been spotted there since 1972.

Experts previously believed it swam from San Francisco, just over a mile away. But new DNA evidence now points to Angel Island, two miles from Alcatraz, the National Park Service said on Monday.

However, its current whereabouts remain a complete mystery.

"We are surprised by the coyote's origin," National Park Service (NPS) wildlife ecologist Bill Merkle said in a news release. "Our working assumption was that the coyote made the swim from San Francisco because it is a significantly shorter distance."

"We couldn't help being impressed by his accomplishment in making it to Alcatraz. Coyotes are known to be resilient and adaptable, and he certainly demonstrated those qualities."

Video recorded by tourists in late January of the coyote swimming to shore through the cold, choppy waters of San Francisco Bay surprised researchers and city residents.

Some took to calling him Floyd, the name of the getaway driver for gangsters Bonnie and Clyde in the eponymous movie.

Officials quickly placed camera traps and audio recording devices around the island to track the animal. They also launched an effort to move him, due to concerns he would eat the native seabird population.

Researchers analysed his tracks and scat, which was taken to a laboratory at the University of California (UC) Davis. The scat confirmed that the coyote was part of a population at Angel Island State Park, where he apparently launched his "epic swim".

The NPS news release - titled "Alcatraz Coyote Wasn't a City Boy After All" - adds that there are three separate and distinct coyote populations in the San Francisco Bay Area.

Despite extensive monitoring, the coyote has not been seen since the initial sighting, and is no longer believed to be on Alcatraz Island.

"We don't know what happened to the coyote," said Merkle.

"But he proved himself an expert swimmer to get to Alcatraz, and I hope he made a successful swim back home to Angel Island."

The native wolf-like canids are found throughout much of the US, including in city parks and upscale neighbourhoods in San Francisco.

Alcatraz island - nicknamed "the Rock" because it was regarded as an impregnable fortress - is home to the shuttered federal penitentiary that housed some of the most dangerous criminals in the US.

It's also the setting of a number of films, notably 1962's Birdman of Alcatraz, starring Burt Lancaster, 1979's Escape from Alcatraz, starring Clint Eastwood, and the 1996 film The Rock, starring Sean Connery and Nicolas Cage.

In April, the Trump administration proposed that lawmakers authorise funding to reopen the site to once again house the most dangerous convicts.

The budget request is seeking $152m (£115m) "to rebuild Alcatraz as a state-of-the-art secure prison facility", with funds covering the first year of costs.