Jonathan the lion: Visitors grieve for passing of 18-year-old lion at Houston Zoo

Jonathan came to the zoo in 2006 and was a ‘guest and keeper favourite’

Jonathan was described as having a 'regal' and 'majestic' mane (Houston Zoo)

Jonathan the lion has died at the age of 18 years old at Houston Zoo in Texas.

His death triggered an outpouring of grief and tributes to the “handsome cat” who was mostly to be found lounging in the sun alongside his pride of three females, often asleep as visitors peered through the glass into his enclosure.

Houston Zoo said it was “heartbroken” to announce his death after he was found to have a “serious blood clotting issue” and a low white blood cell count, conditions which, they said, were not uncommon in “geriatric patients”.

The lion spent the night inside the zoo’s animal hospital and was given a full examination after zoo staff noticed he appeared to be unwell, but he died in the early hours of Wednesday morning.

He was rescued from a private owner and came to the zoo in 2006, and has been a “guest and keeper favourite”, the zoo statement read.

“Jonathan’s impact on our keepers and guests will not be forgotten,” said Dr Adrian Fowler, vice president of animal operations for the Houston Zoo.

“Our team of keepers who have spent more than a decade caring and bonding with this incredible animal are grieving this loss, and we support them through this sad time.”

The zoo’s Facebook post was flooded with pictures, comments and jokes about the big cat which was most often asleep on its back.

Leigh Ann Mitchell said: “I always loved hearing him roar in the mornings. You could hear him clear across the zoo.”

“I am just thankful that he was well cared for and I know in great hands when he passed this morning. R.I.P. big guy,” wrote Elizabeth Garney.

Another user, Janice Ariola Darden, wrote: “I remember when he first arrived. He had the most beautiful mane!! We always stop by to see him every time we visit the zoo.”

His passing is one in a line of well known big animals who have died in the last two years, including Cecil the lion who was shot by an American dentist, Harambe the gorilla who was shot after a young boy fell into his enclosure in Ohio, and 24-year-old gorilla, Bantu, who passed away in a Mexican zoo after he was sedated in order to be transferred to another zoo for mating.

On 3 July, Arturo, described as the “world’s saddest polar bear” also died at the age of 30 in Mendoza Zoo in Argentina.