A woman watches Red Howler monkeys at the Parque de Las Leyendas zoo in Lima, Peru, February 14, 2018. REUTERS/Guadalupe Pardo

A Red Howler monkey is seen at the Parque de Las Leyendas zoo in Lima, Peru, February 14, 2018. REUTERS/Guadalupe Pardo

Veterinary Connie Tien tries to adapt a rescued baby howler monkey to a substitute mother at the Costa Rica Animal Rescue Center in Turrucares, Costa Rica March 2, 2016. Mauricio Jimenez, coordinator of the Wild Animals hospital, said the drought in the northern region of the country is killing and affecting wild animals. REUTERS/Juan Carlos Ulate

Veterinary Connie Tien gives vitamins to a baby howler monkey at the Costa Rica Animal Rescue Center in Turrucares, Costa Rica March 2, 2016. Mauricio Jimenez, coordinator of the Wild Animals hospital, said the drought in the northern region of the country is killing and affecting wild animals. REUTERS/Juan Carlos Ulate

A rescued baby howler monkey is fed by veterinary Connie Tien at the Costa Rica Animal Rescue Center in Turrucares, Costa Rica March 2, 2016. Mauricio Jimenez, coordinator of the Wild Animals hospital, said the drought in the northern region of the country is killing and affecting wild animals. REUTERS/Juan Carlos Ulate

A rescued baby howler monkey looks on at the Costa Rica Animal Rescue Center in Turrucares, Costa Rica March 2, 2016. Mauricio Jimenez, coordinator of the Wild Animals hospital, said the drought in the northern region of the country is killing and affecting wild animals. REUTERS/Juan Carlos Ulate

A rescued baby howler monkey tries to adapt to a substitute mother at the Costa Rica Animal Rescue Center in Turrucares, Costa Rica March 2, 2016. Mauricio Jimenez, coordinator of the Wild Animals hospital, said the drought in the northern region of the country is killing and affecting wild animals. REUTERS/Juan Carlos Ulate

Veterinary Connie Tien examines a rescued baby howler monkey at the Costa Rica Animal Rescue Center in Turrucares, Costa Rica March 2, 2016. Mauricio Jimenez, coordinator of the Wild Animals hospital, said the drought in the northern region of the country is killing and affecting wild animals. REUTERS/Juan Carlos Ulate

Veterinary Connie Tien, examines a rescued baby howler monkey at the Costa Rica Animal Rescue Center in Turrucares, Costa Rica March 2, 2016. Mauricio Jimenez, coordinator of the Wild Animals hospital, said the drought in the northern region of the country is killing and affecting wild animals. REUTERS/Juan Carlos Ulate

Red Howler Monkey (Alouatta caraya) babies are seen at the Hacienda Miraderos forests in the Municipality of Armenia, Antioquia, Colombia, December 14, 2015. REUTERS/Fredy Builes

A volunteer holds a baby Red Howler Monkey (Alouatta caraya) at the Hacienda Miraderos forests in the Municipality of Armenia, Antioquia, Colombia, December 14, 2015. REUTERS/Fredy Builes

A baby Red Howler Monkey (Alouatta caraya) is seen at the Hacienda Miraderos forests in the Municipality of Armenia, Antioquia, Colombia, December 14, 2015. REUTERS/Fredy Builes

A baby Red Howler Monkey (Alouatta caraya) is seen at the Hacienda Miraderos forests in the Municipality of Armenia, Antioquia, Colombia, December 14, 2015. REUTERS/Fredy Builes

A volunteer holds a baby Red Howler Monkey (Alouatta caraya) at the Hacienda Miraderos forests in the Municipality of Armenia, Antioquia, Colombia, December 14, 2015. REUTERS/Fredy Builes

A baby Red Howler Monkey (Alouatta caraya) is seen at the Hacienda Miraderos forests in the Municipality of Armenia, Antioquia, Colombia December 14, 2015. REUTERS/Fredy Builes

A baby Black Howler Monkey (Alouatta caraya) holds on to its mother on a tree branch at the Singapore Zoo January 29, 2010. Only the male of this species is black, the females are pale buff. REUTERS/Tim Chong (SINGAPORE - Tags: ANIMALS SOCIETY)

A female black howler monkey carries its nine-day-old baby on its back as it sits on a branch at the Singapore Zoo January 29, 2009. REUTERS/Vivek Prakash(SINGAPORE)

A female black howler monkey carries its nine-day-old baby on its back as it forages at the Singapore Zoo January 29, 2009. REUTERS/Vivek Prakash(SINGAPORE)

A female black howler monkey carries its nine-day-old baby on its back as it forages at the Singapore Zoo January 29, 2009. REUTERS/Vivek Prakash(SINGAPORE)

Diego, a three-month-old baby black howler monkey, crawls next to a cuddly toy during a photocall at Edinburgh Zoo in Edinburgh, Scotland July 29, 2008. The monkey, born on April 26, was named 'Diego' to reflect the origin of black howler monkeys which are native to South America. Diego has to be fed seven times a day by keepers at the zoo after his mother Molly died . REUTERS/David Moir (BRITAIN)

Diego, a three-month-old baby black howler monkey, sits during a photocall at Edinburgh Zoo in Edinburgh, Scotland July 29, 2008. The monkey, born on April 26, was named 'Diego' to reflect the origin of black howler monkeys which are native to South America. Diego has to be fed seven times a day by keepers at the zoo after his mother Molly died . REUTERS/David Moir (BRITAIN)

Diego, a three-month-old baby black howler monkey is fed by bottle during a photocall at Edinburgh Zoo in Edinburgh, Scotland July 29, 2008. The monkey, born on April 26, was named 'Diego' to reflect the origin of black howler monkeys which are native to South America. Diego has to be fed seven times a day by keepers at the zoo after his mother Molly died . REUTERS/David Moir (BRITAIN)

Diego, a three-month-old baby black howler monkey, sits on its keeper's hand during a photocall at Edinburgh Zoo in Edinburgh, Scotland July 29, 2008. The monkey, born on April 26, was named 'Diego' to reflect the origin of black howler monkeys which are native to South America. Diego has to be fed seven times a day by keepers at the zoo after its mother Molly died . REUTERS/David Moir (BRITAIN)

A white-faced monkey eats at the Zoological Garden in San Jose, August 20, 2007. Populations of monkeys including howler, white face, spider and squirrel monkeys have declined by the thousands, said University of Costa Rica ecologist Ronald Sanchez. REUTERS/Juan Carlos Ulate (COSTA RICA)

A white-faced monkey eats at the Zoological Garden in San Jose, August 20, 2007. Populations of monkeys including howler, white face, spider and squirrel monkeys have declined by the thousands, said University of Costa Rica ecologist Ronald Sanchez. REUTERS/Juan Carlos Ulate (COSTA RICA)

A white-faced monkey rests at the Zoological Garden in San Jose, August 20, 2007. Populations of monkeys including howler, white face, spider and squirrel monkeys have declined by the thousands, said University of Costa Rica ecologist Ronald Sanchez. REUTERS/Juan Carlos Ulate (COSTA RICA)

A zookeeper holds a six-months old howler monkey (Aluoatta palliata) named "Nieve" (the Spanish word for "Snow") at the Nicaraguan National Zoo in Managua February 20,2007.The howler Monkey is a rare albino specimen and was found in a forest in the country's Caribbean lowlands.REUTERS/Oswaldo Rivas (NICARAGUA)

A zookeeper holds a six-months old howler monkey (Aluoatta palliata) named "Nieve" (the Spanish word for "Snow") at the Nicaraguan National Zoo in Managua February 20,2007.The howler Monkey is a rare albino specimen and was found in a forest in the country's Caribbean lowlands.REUTERS/Oswaldo Rivas (NICARAGUA)

Julian, a pet Red Howler monkey (Alouatta seniculus), uses the toilet in La Pintada, Antioquia province, Colombia February 12, 2007. REUTERS/Albeiro Lopera (COLOMBIA)

A black howler monkey in the Singapore zoo January 21, 2004. REUTERS/Thomas White PP04010070 TW