A duck which became a social media star due to his height is feared to have died after going missing for two months.
The mallard-Indian runner cross, named "Long Boi" due to his tall stature, arrived on the University of York campus in 2019.
He went viral after a post on social news site Reddit incorrectly described him as "the tallest mallard to have ever lived...over 1m tall".
It was later confirmed the bird stood at around 70cm (2.3ft).
The university - which describes Long Boi as a "York celebrity" on its website - said it had been "forced to conclude" he had died.
A Facebook post said: "Following a period of almost two months without a confirmed sighting of Long Boi, we are today forced to conclude that he has passed away.
"We appreciate this is not the resolution that many people were wishing for, but hope that acknowledging his passing allows us to focus on celebrating his life and commemorating the time he spent with us.
"During his time on campus, Long Boi brought joy to staff, students, alumni and visitors to York.
"Our beautiful campus and wonderful grounds team provided a rich life for him during the four years he lived with us."
The university paid tribute to the "incredible community of fans" who have celebrated Long Boi - urging people not to leave floral tributes but instead to do something for the environment, such as feeding the ducks at a local pond or making a charitable donation in his memory.
The university's students' union is working on plans to organise a "fitting tribute" to their beloved bird, the Facebook post added.
An Instagram account devoted to Long Boi had earlier shared fears for his welfare.
Zoe Duffin, who runs the account, wrote on 3 May: "As many of you will be aware from the recent news, Long Boi has not been seen on campus for a number of weeks.
"This is very worrying and not like Long Boi, who can almost always be found in his favourite spot by the lake on campus West.
"Very sadly, this disappearance suggests a strong possibility that Long Boi may have passed away. It is unclear how or exactly when this may have happened, and we can only hope that if Long Boi really is gone, his passing was peaceful."
She hailed the impact the Long Boi had on the duck-loving community in York - with the "incredibly unique" animal becoming an unofficial mascot for the University.
Heartbroken fans wish for Long Boi to 'rest in pond'
The post was liked more than 25,000 times, with people across the globe describing their sadness and wishing for him to "rest in pond".
One person from the USA wrote: "Heartbroken. I live in the States and was saving up to see him. He made me smile through some tough times. Thank you for sharing his life, I absolutely adored him."
One fan got a tattoo of Long Boi on a trip to Portugal with the university's volleyball club - and is still hoping he will return.
Ecology student Tom Howes, 21, said: "The day his disappearance was announced was very ominous, it was like thunder and lightning on campus.
"I think people will come to terms with it though, today's announcement gave some closure."
Long Boi even earned a mention on The Late Late Show by James Corden, who said: "Put a trench coat on that duck and he looks like two ducks trying to get into an R-rated movie".
York student union said it is working to organise "a fitting tribute" to the duck, with students asked to keep their eyes peeled for an official fundraising campaign.
Mr Howes and others have now called for a statue of Long Boi to be put up to commemorate his time on campus.
He added: "He's more of a symbol anyway, he was very easy to find, most people viewed him as a mascot for the university, so not much is needed for him to be remembered.
"He will definitely live on."