UTICA, NY (WUTR/WFXV/WPNY) – The Utica Zoo announced on Wednesday, September 27 the death of two of their animals.

Tom and Sawyer, two Cotton-Top Tamarin brothers, passed away just a few days apart, according to the Zoo’s Facebook page. Preliminary findings suggest that both passed away because of a rare, hereditary tumor. A necropsy has been performed on both Tom and Sawyer, but Zoo officials say that it will take several weeks to receive official results from Cornell University in Ithaca.

The two brothers and their mother — 19-year-old Dharma – were popular at the zoo for their livestream on the Zoo’s website. The livestream was deemed one of the 25 Most Interesting Webcams by EarthCam in 2019.

This is the third animal the Utica Zoo has lost in the last five months — losing Breton, one of two Canada Lynx the zoo had, in May.

Cotton-top Tamarins are currently deemed Critically Endangered by the International Union for the Conservation of Nature, as approximately 6,000 of them exist on Earth. They are native to Colombia in South America and live approximately 12 years, according to the Association of Zoos and Aquariums (AZA).

Both tamarins were approximately 17 years of age. The Zoo says that their animal care team is currently monitoring Dharma – who officials say will remain at the zoo — for any changes in behavior. They are also working with the AZA’s Species Survival Plan to explore the possibility of a new companion for her.