BOLIVIAN RED HOWLER
SPECIES FACT FILE
Scientific name: Alouatta sara
English names: Bolivian Red Howling Monkey, Bolivian Red Howler
Spanish and local names: Mono Aullador Rojo Boliviano, Manechi, Manechi colorado
Size: 52 – 57cm (20.6 -22.4 inches)
Weight: 5.8 – 7.7 Kg (13-17 pounds)
The range of Alouatta sara is limited to the actual border of Bolivia, making this species endemic to this South American country. Howler monkeys are locally named “manechi” and this particular species is called red Manechi or “Manechi Colorado”.
Howler monkeys are part of the atelidae family which are monkeys with prehensile tails. Just like the spider monkeys, they can use their tail as a fifth limb, having a section on the tip of their tails without hair and with a similar texture of a hand, made for gripping to branches. Howlers are called that because of the howling sound they produce with the aid of their unique enlarged larynx and hyoid apparatus, designed to resonate. Howler monkeys are the animal in the Americas that produce the loudest sound, which can be heard more than 2 kilometres away.
Red howler monkeys are called that because of their fur which is reddish orange, they can grow to be the largest of all howler monkeys and have the lowest pitched and loudest howls of all howlers in the new world.
Bolivian red howlers are highly unstudied and it’s believed they prefer riverine, swampy forests, contrary to their colleagues, the black howlers, which prefer drier inland forests. Their range includes all of the low-land Bolivian rainforest, from Pando department to the north to Santa Cruz to the south east, and is limited to the south by the Andes, where they can live up to an altitude of 1,000 meters.
Howler monkeys are the large leaf eaters of the forest. Their diets are comprised of 70% leaves, for which they have special molars designed to shear, and a special pouch in their intestines, a caecum, where they ferment the leaves for better digestion. The rest of their diet is comprised of fruits, seeds, and insects. They live in medium sized groups of up to 20 individuals, mostly juveniles and females and one to three mature males. They sleep for more than 15 hours and spend most of their time hanging around while they digest the leaves they eat, watching out for predators like the jaguar to who they throw sticks to when they see him.
Howler monkey groups normally have only one dominant male that wakes the whole forest up every morning with his loud growls, beginning that way the howling ritual to which the rest of the monkeys join in to. In the evening the same event repeats before sunset. The howling is responded by nearby groups and helps keep their territories from overlapping. Howling monkeys don’t like the rain and will howl when it rains as a way of complaining.
In comparison to spider monkeys, red howlers have very small groups and very small territories, which can be of around 5 hectares. This is due because they can rely mostly on leaves and do not need to travel far in search for fruits. This species of monkeys are one of the few animals that will feed on mature leaves as well as green leaves.
Bolivian red howlers are listed as least concern by the IUCN, which means they are not considered a threatened species. This however is not what we see at La Senda Verde and in Bolivia. We receive many baby red howlers that are taken from their habitats to be sold as pets. People hunt this species in the forests for their meat and their populations are decreasing.
CALLS FOR BALLS- Howler monkeys have developed a louder howling ability in exchange for smaller testicles. You can’t get everything in life.
LOUDEST ANIMALS- Howling monkeys produce the loudest sound of all animals in the American continent.
BOLIVIAN ENDEMIC- Alouatta sara is a species of red howler monkeys that only exist within the boundaries of Bolivia.
Images of Red Howlers at Senda Verde