MANILA - "Bertha" the hippopotamus, Manila Zoo's oldest inhabitant, passed away Friday at 65.

Zookeepers said they found Bertha lifeless in her area this morning. They said the hippo may have died of old age as necropsy results did not point to any disease.

People who were in charge of taking care of Bertha also pointed out that the 65-year-old hippo had been moving slower than usual in the past two to three months.

James Albert Dichaves, director of the Manila Parks and Recreations Bureau which has direct control over the zoo, said Bertha is one of the original animals in Manila Zoo.

Bert, a male hippo who lived with Berth inside the zoo, already died years ago. Dichaves said they are proud that Bertha was able to live at least 15 years more than the average hippo lifespan.

Si Bertha ay isa sa mga orihinal na hayop sa Manila Zoo nang ito ay itayo noong 1959 (📸 @zaaaayr Zilah Rama) @DZMMTeleRadyo pic.twitter.com/dDhWcZsmnG

— Zhander Cayabyab (@zhandercayabyab) July 9, 2017

The remains of Bertha were buried in a vacant lot inside the zoo. Dichaves said they will be waiting until the hippos body decomposes so they can get her bones and preserve it for display.

He said they will be writing a letter to Manila Mayor Joseph Estrada requesting purchase of new animals such as hippopotamuses, zebras and giraffes.--Report from Zhander Cayabyab, ABS-CBN News