NEW YORK (May 17, 2017) – Recent WCS (Wildlife Conservation Society) Queens Zoo surveys of black howler monkeys (Alouatta pigra), translocated to Belize’s Cockscomb Basin Wildlife Sanctuary 25 years ago reveal that the effort has been a great success, with monkeys now thriving throughout the reserve after going locally extinct 40 years ago.

The surveys conducted by WCS’s Queens Zoo in collaboration with the Belize Audubon Society last month counted 66 individual howler monkeys from at least 15 different social units with evidence of many other groups inhabiting areas up to 20 kilometers away from the original release sites. All told, the survey team believes that as many as several hundred howlers are likely to live in the sanctuary.

From 1992-1994, WCS, the Belize Audubon Society, and Community Conservation Consultants Inc. translocated 62 monkeys in 14 social groups from the Community Baboon Sanctuary in northern Belize, to Cockscomb, a 154 square mile (400 square kilometer) protected area 62 miles (100 kilometers) to the south. 

Howler monkeys had disappeared from Cockscomb in the late 1970’s as a result of a combination of factors, including Hurricane Hattie in 1961 that leveled as much as 90 percent of the canopy in the Cockscomb Basin, a yellow fever epidemic, and uncontrolled hunting before the area was protected. The species is currently listed as Endangered by IUCN due to habitat loss and hunting.

During the recent month-long survey effort, the research team found howler monkeys living in nearly all the suitable areas they surveyed throughout the Cockscomb.

Said Scott Silver, Director of WCS’s Queens Zoo, who assisted in the original translocation and co-led the recent surveys with tropical biologist Linde Ostro: “Once again, the deep throated-roar of howler monkeys is a regular sound that echoes through the forests of the Cockscomb Basin, and howling battles can be heard bouncing back and forth over the forest canopy as male howler monkeys announce their presence to neighboring troops.”

The presence of howler monkeys in the Cockscomb Basin benefits other wildlife and plant communities found there. As important seed dispersers, howler monkeys are known to help species whose fruits and seeds they consume to survive and thrive.

Said Silver: “For the last 25 years, the tree community in Cockscomb has likely slowly begun to return to the composition of tree species that was there for thousands of years when howler monkeys were present in the Cockscomb Basin.  This in turn probably benefits many other species that evolved strategies for survival in a forest that grows up with howler monkeys as part of the ecosystem.”

The return of howlers provides opportunities for tourists to observe the charismatic primates. While Cockscomb is famous as the world’s first jaguar reserve, and has an abundance of jaguar, they are rarely seen by the casual visitor. Howler monkeys, on the other hand, are slow moving, active during the day, and regularly seen, and even more often heard, by visitors. 

Said Silver: “The sound of howler monkey roars echoing off the hills and trees is a moving and impactful part of any rainforest visit, and seeing cars pulled over alongside the Cockscomb road as tourists get out to watch monkeys in the trees above is a testament to how much they enhance a visitor's experience to the park.”