Reproduction

To find a mate the black and gold howler monkey will flick its tongue out. Males and females may mate with multiple partners during their life.

Females give birth to between one and two young after a 180-194 day gestation period. Juveniles are all the golden tan color of the females. Male infants will transition to black around 2.5 years old.

The parenting duties are shared between the females in the group who will work together to share carrying and protecting the infants.

A female will provide care to her infant for 12 months. Females remain in the birth group for life while the females will leave their group at sexual maturity.

Females tend to produce young every second year.

Behavior

Black howler monkey's will form a group made up of multiple males and females. There are typically more females than males. Typically troops include 5 to 8 members but some have been recorded with as many as 22.

Males focus on the protection of the group and will fend off other howler monkeys which attempt to enter their territory. This allows the females to save their energy for reproduction.

Due to the low amounts of energy provided by their food they work hard to avoid wasting it on fights. This is part of the reason they howl as it allows them to prevent encountering other troops.

Groups will socialize by playing with one another and grooming.

The largest male within the group is considered dominant.

These animals are named for the loud, howling call which they make each morning to warn neighboring troops against entering their territory. Calling sessions may last for up to an hour. These calls are the loudest made by any land animal. They may be heard as much as 4.8km (3 miles) away.

Much of a black howler monkey's day is spent lying in the tree canopy while they digest their food. These animals are primarily arboreal and rarely come to the ground.

These animals mark out a territory using dung or their scent. This helps them to claim their area. They are able to recognize the scents of other monkeys.

Predators and Threats

Natural predators of the black howler monkey include large birds of prey.

Black howler monkeys face a range of threats in the wild including habitat loss to allow for agricultural development or cattle ranching. At current rates 40% of their suitable habitat would be lost by 2050.

These animals are hunted for food. Their populations have also been reduced through outbreaks of disease such as sylvatic yellow fever. Some are captured and used in medical research.

The population of the black howler monkey is decreasing.

Quick facts

The black howler monkey is also known as the Paraguayan howler or the black and gold howler monkey.

Black howler monkeys are the loudest animal to live on land. It can reach up to 140 decibels, just less than a jet engine at around 150 decibels.