Guatemalan Black Howler Monkey
The Guatemalan Black Howler (*Alouatta pigra*), also known as the Yucatan Howler, is an endangered species of howler monkey native to the lush rainforests of the Yucatan Peninsula, which spans Mexico, Belize, and Guatemala. As the largest of the New World monkeys, males typically weigh around 25 pounds (11-12 kg), while females average 14 pounds (6-7 kg). With their distinctive black fur and long, prehensile tails, these monkeys are perfectly adapted to their arboreal lifestyle, spending most of their time in trees. Their diet primarily consists of leaves and fruits, with a particular fondness for breadnut trees, which provide a significant portion of their nutrition during certain seasons. Notably, the Guatemalan Black Howler is a diurnal species, active during the day and known for its loud, resonant calls—thanks in part to their enlarged hyoid bones that amplify their vocalizations.
Social creatures, Guatemalan Black Howlers typically live in groups of up to ten members, although larger groups can form. These social structures facilitate foraging and grooming, essential for their well-being. Despite their social nature, these monkeys are not particularly active, dedicating only about a quarter of their day to eating and minimal time moving between feeding locations. The rest of their day is spent socializing and grooming, highlighting their preference for a leisurely lifestyle. Females reach reproductive maturity by four years of age, while males take up to eight years. With an average lifespan of around twenty years, their slow reproductive rate makes population recovery challenging.
Unfortunately, the Guatemalan Black Howler is facing critical threats to its survival, primarily due to habitat loss, poaching, and the illegal pet trade. The International Union for Conservation of Nature (IUCN) warns that if current trends continue, the population could decline by over 60% in the next 30 years, pushing this species closer to a critically endangered status. With their habitat shrinking and human encroachment increasing, urgent conservation efforts are necessary to protect these remarkable primates and ensure their survival in the wild. As a species that shares its territory with the Mantled Howler, the Guatemalan Black Howler’s plight underscores the importance of preserving biodiversity in their shared ecosystems.
The endangered
Guatemalan Black Howler
(
Alouatta pigra
) (sometimes called the Yucatan Howler or Yucatan Black Howler) is one of many species of howler monkey, which is what is known as a ‘New World’ monkey. Its range is throughout the Yucatan Peninsula, and includes the areas of Mexico, Belize, and of course Guatemala. The Guatemalan Black Howler prefers to live in very lush areas, mostly sticking to all types of rain forests such as the semi-deciduous, lowland and evergreen. Of its cousins and relatives, the Guatemalan Black Howler is the largest, and is also one of the largest ‘New World’ monkeys (which include marmosets, owl monkeys, sakis, spider, and woolly monkeys). It weighs in at 25 lbs on average in males (11-12 kg) and 14 lbs for the females (6-7 kg). Their fur is usually black and their tails are very long, and prehensile (meaning it can grab and be used to hang from branches with). They also have specialized teeth for their diet of mostly leaves, along with the males possessing a larger hyoid bone located near the vocal chords, which enables their loud calls.
The Guatemalan Black is a diurnal howler, which means it is active during the day and it sleeps at night, as well as being arboreal, meaning it dwells in the trees most of its life. They are a social species that lives in groups up to ten members strong, which helps in alerting, foraging, and general upkeep through grooming. Some groups can be as large as sixteen, while larger groups are plausible, however at these sizes it is unlikely to function as well as a smaller group. Their diets consist of mostly leaves, and fruits, however they will snack on a flower here and there and their favorite tree of all is the breadnut, which provides most food during some seasons.
Not a particularly active species, the Guatemalan Black Howler would rather lounge about during the day; eating takes up a quarter of the day while moving locations for eating consists of only about a tenth of their daily activity. The rest of the day is devoted to socializing and grooming, with some other random antics. Females are old enough to have offspring by four years of age, while males may take up to eight years to reach maturity, and their total life-spans are an average of twenty years.
The Guatemalan Black Howler’s binomial name (its species and genus) is Alouatta pigra, the Alouatta’s as a genus make up most of the Howler Monkeys, which are the largest of the New World Monkeys with but a few possible exceptions. Alouatta is home to all of the howler monkeys (ten species and ten subspecies), and belongs to the subfamily Alouattinae. Alouattinae belongs to the family Atelidae which is one of the four families of New World Monkeys; this includes the howler monkeys, along with spider monkeys, woolly monkeys, wooly spider monkeys, and Yellow-tailed Woolly Monkeys. Atelidae belongs to the Parvorder Platyrrhini, which contains all New World Monkeys, and includes
Marmosets
and Muriquis. Platyrrhini belongs to the infraorder Simiiformes, or ‘higher primates’, and this includes all New World and Old World monkeys from South America and Africa, and includes gibbons, great apes, and the family Hominidae of which we are members. Simiiformes belongs to the Suborder Haplorrhini, otherwise called dry-nosed primates; this includes all of the higher primates as well as
Tarsiers
. Haplorrhini belongs to the Order Primates, which is all related apes, monkeys, lorids, galagos, lemurs and human ancestors. Primates are in the class of Mammalia of the phylum Chordata in the Kingdom of Animalia.
Fact
The Guatemalan Black Howler is sympatric with another species, the
Mantled Howler
. Sympatric means that they share the same niche and territory, and encounter each other in the wild, they are also closely related.
Warning
The Guatemalan Black Howler is an Endangered Species, and is close to being classified as Critically Endangered if nothing is done to curb the loss of the species. In the next 30 years the IUCN expects to see a population loss of over 60%, making this species on the more endangered alive today. Major threats are habitat loss, poaching, and capture for use as ‘pets’.
