Mantled Howler
Encyclopedia
The mantled howler or golden-mantled howling monkey, is a species of howler monkey
, a type of New World monkey
, from Central
and South America
. It is one of the monkey species most often seen and heard in the wild in Central America. It takes its "mantled" name from the long guard hair
s on its sides.
The mantled howler is one of the largest Central American monkeys, and males can weigh up to 9.8 kg (21.6 lb). It is the one Central American monkey whose diet is composed mostly of leaves. The mantled howler has several adaptations to this folivorous diet. Since leaves are difficult to digest and provide less energy than most foods, mantled howlers spend the majority of each day resting and sleeping. Male mantled howlers also have an enlarged hyoid bone, which is a hollow bone near the vocal cords. This enlarged bone amplifies the calls made by the male, which give the monkey its common name of "howler". Howling allows the monkeys to locate each other without expending energy on moving or risking physical confrontation.
The mantled howler lives in groups that can have over 40 members, although groups are usually smaller. Most mantled howlers of both sexes are evicted from the group they were born in upon reaching sexual maturity, and so most adult group members are unrelated. The most dominant male, the alpha male
, gets preference for food and resting places, and mates with most of the receptive females. The mantled howler is important to the rainforest
ecology as a seed disperser and germinator. Although it is impacted by deforestation
, it is able to adapt better than other species, due to its ability to feed on abundant leaves and its ability to live in a limited amount of space.
, the family that contains the howler monkey
s, spider monkey
s, woolly monkey
s and muriqui
s. It is a member of the subfamily Alouattinae and genus Alouatta, the subfamily and genus containing all the howler monkeys. The species name is A. palliata; a pallium
was a cloak or mantle worn by ancient Greeks
and Romans
.
Three subspecies
are recognized:
Two additional subspecies of the mantled howler are sometimes recognised, but these are more generally recognised as subspecies of the Coiba Island howler
, Allouatta coibensis. However, mitochondrial DNA
testing of their status has been inconclusive:
The mantled howler's appearance is similar to other howler monkeys of the genus Alouatta except for coloration. The mantled howler is primarily black except for a fringe of gold to buff hair on each side that gives it its common name. When the males reach maturity, the scrotum turns white. Females are between 481 and 632 mm (18.9 and 24.9 in) in body length, excluding tail, and males are between 508 and 675 mm (20 and 26.6 in). The prehensile tail is between 545 and 655 mm (21.5 and 25.8 in) long. Adult females generally weigh between 3.1 and 7.6 kg (6.8 and 16.8 lb), while males typically weigh between 4.5 and 9.8 kg (9.9 and 21.6 lb). Average body weights can vary significantly between monkey populations in different locations. The brain
of an adult mantled howler is about 55.1 g (1.9 oz), which is smaller than that of several smaller monkey species, such as the White-headed Capuchin
.
The mantled howler shares several adaptations with other species of howler monkey that allow it to pursue a folivorous diet, that is, a diet with a large component of leaves. Its molars
have high shearing crests, to help it eat the leaves, and males have an enlarged hyoid bone near the vocal cords. This hyoid bone amplifies the male mantled howler's calls, allowing it to locate other males without expending much energy.
usually ranges from 10 to 20 members, generally 1 to 3 adult males and 5 to 10 adult females, but some groups have over 40 members. Males outrank females, and younger animals of each gender generally have a higher rank than older animals. Higher ranking animals get preference for food and resting sites, and the alpha male gets primary mating rights. Animals in the group are generally not related to each other because most members of both sexes leave the group before sexual maturity.
Grooming activity in the mantled howler is infrequent and has been shown to reflect social hierarchy, with dominant individuals grooming subordinates. Aggressive interactions between group members is not often observed either. However, studies have shown that aggressive interactions among group members do occur, and are probably not often observed because these interactions tend to be quick and silent.
Mantled-howler groups that have been studied have occupied home ranges of between 10 and 60 ha (24.7 and 148.3 acre). Groups do not defend exclusive territories, but rather several groups have overlapping home ranges. However, if two groups meet each group will aggressively attempt to evict the other. On average, groups travel up to about 750 metres (2,460.6 ft) each day.
The mantled howler has little interaction with other sympatric monkey species but interactions with the White-headed Capuchin
sometimes occur. These are most often aggressive, and the smaller capuchins are more often the aggressors. However, affiliative associations between the capuchins and howlers do sometimes occur, mostly involving juveniles playing together, and at times the capuchins and howlers may feed in the same tree, apparently ignoring each other.
trees tend to be preferred over other leaves. Although leaves are abundant, they are a low energy food source. The fact that the mantled howler relies so heavily on a low energy food source drives much of its behaviour - for example, howling to locate other groups and spending a large portion of the day resting.
Although leaves tend to make up the majority of the mantled howler's diet, fruit can also make up a large portion of the diet. When available, the proportion of fruit in the diet can be as much as 50%, and can sometimes exceed the proportion of leaves. fig
s tend to be a preferred fruit. Flowers can also make up a significant portion of the mantled howler's diet and are eaten in particularly significant quantities during the dry season. The mantled howler tends to get the water it needs from its food, but it does sometimes drink from tree holes. It drinks from tree holes more during the wet season than during the dry season. It probably also drinks water trapped in bromeliads.
Like other species of howler monkeys, almost all mantled howlers have full three color vision. This is different from other types of New World monkey
s, in which most individuals have two color vision. The three color vision exhibited by the mantled howler is believed to be related to its dietary preferences, allowing it to distinguish young leaves, which tend to be more reddish, from more mature leaves.
The mantled howler is diurnal and arboreal. Movement within the rainforest canopy and floor includes quadrupedalism (walking and running on supports), bridging (crossing gaps by stretching), and climbing. It will also sometimes leap to get to another limb.
However, the mantled howler is a relatively inactive monkey. It sleeps or rests the entire night and about three quarters of the day. Most of the active period is spent feeding, with only about 4% of the day spent on social interaction. This lethargy is an adaptation to its low energy diet. It uses its prehensile tail to grasp a branch when sleeping, resting or when feeding. It can support its entire body weight with the tail, but more often holds on by the tail and both feet. A study has shown that the mantled howler reuses travel routes to known feeding and resting sites, and appears to remember and use particular landmarks to help pick direct routes to its destination.
s, and this allows the bone to act like the body of a drum in amplifying the calls. Females also call but their calls are higher in pitch and not as loud as the males'. The ability to produce these loud roars is likely an energy saving device, consistent with the mantled howler's low energy diet. The roars allow the monkey to locate each other without moving around or risking physical confrontations. The mantled howler uses a wide range of other sounds, including barks, grunts, woofs, cackles and screeches. It uses clucking sounds to maintain auditory contact with other members of its group.
The mantled howler also uses non-vocal communication, such as "urine rubbing" when in a distressful social situation. This consists of rubbing the hands, feet, tail and/or chest with urine. It marks its scent by rubbing its throat on branches. Lip smacking and tongue movements are signals used by females to indicate a invitation to mate. Genital displays are used to indicate emotional states, and group members shake branches, which is apparently a playful activity.
The mantled howler is usually indifferent to the presence of humans. However, when it is disturbed by people, it often express its irritation by urinating or defecating on them. It can accurately hit its observers despite being high in the trees.
(Alouatta seniculus) was reported to use a stick as a club to hit a Linnaeus's two-toed sloth
, (Choloepus didactylus), that was resting in its tree. This suggests that other howlers, such as the mantled howler, may also use tools in ways that have not yet been observed.
The mantled howler uses a polygamous
mating system in which one male mates with multiple females. Usually, the alpha male monopolises the breeding opportunities, but if the alpha male is distracted, a lower ranking male can get an opportunity to mate. And in some groups, lower ranking males do get regular mating opportunities and do sire offspring. Alpha males generally maintain their status for about 2½ to 3 years, during which time they may father 18 or so infants. Adults of both sexes invite mating by flicking their tongues. Females apparently also use chemical signals, since males smell the females' genitals and taste their urine.
The gestational period
is 186 days; births can occur at any time of year. The infant's fur is silver at birth, but turns pale or gold after a few days. After that, the fur starts to darken, and the infant takes on the adult coloration at about 3 months old.
The infant is carried under its mother, clinging to its mother's chest, for the first 2 or 3 weeks of its life. After that, it is carried on its mother's back. At about 3 months the mother will usually start to push the infant off, but will still carry the infant some of the time until it is 4 or 5 months old. After the young can move on its own, the mother will carry it across difficult gaps in the trees. Juveniles play among themselves much of the time. Infants are weaned at 1½ years old at which point maternal care ends. Adult females typically give birth every 19 to 23 months, assuming the prior infant survived to weaning.
Females become sexually mature at 36 months, males at 42 months. The mantled howler differs from other howler monkey species in that the males' testes do not descend until they reach sexual maturity. Upon reaching sexual maturity, the young monkeys are usually evicted from their natal group, although the offspring of a high ranking female may get to stay in its natal group. However, many infants do not reach sexual maturity; high ranking adults sometimes harass or kill the offspring of lower ranking monkeys to eliminate competition to their own offspring for an opportunity to remain with the group upon reaching maturity. When a male from outside the group ousts the previous alpha male, he normally kills any infants so that the mothers come into estrus quickly and are able to mate with him. Predators such as cat
s, weasel
s, snake
s and eagle
s also kill infants. As a result, only about 30% of mantled howler infants live more than one year. If it survives infancy, the mantled howler's lifespan is typically 25 years.
, Costa Rica
, Ecuador
, Guatemala
, Honduras
, Mexico
, Nicaragua
and Panama
. Within Honduras, Nicaragua, Costa Rica and Panama, the mantled howler is found in locations throughout the countries. In Colombia and Ecuador, it is found in a narrow corridor bordered by the Pacific Ocean to the west and the Andes Mountains to the east and also in Colombia in a small area near the Caribbean Sea
close to the Panama border. In Guatemala, the mantled howler is found through the central part of the country, and into southeastern Mexico south of the Yucatán Peninsula
. The mantled howler is among the most commonly seen and heard primates in many Central American national parks, including Manuel Antonio
, Corcovado
, Monteverde
and Soberania
. The mantled howler lives in several different types of forest, including secondary forest
and semi-deciduous
forest but is found in higher densities in older areas of forest and in areas containing evergreen forest
. The mantled howler is sympatric with another howler monkey species, the Guatemalan black howler
, A. pigra, over a small part of its range, in Guatemala and Mexico near the Yucatan Peninsula
.
The mantled howler is regarded as "least concern" from a conservation standpoint by the IUCN. Nonetheless, its numbers may be adversely impacted by rainforest fragmentation which has caused forced relocation of groups to less habitable regions. However, the mantled howler can adapt to forest fragmentation better than other species due to its low energy lifestyle, small home ranges and ability to exploit widely available food sources. The mantled howler is important to its ecosystems for a number of reasons, but especially in its capacity as a seed disperser and germinator, since passing through the monkey's digestive tract appears to aid the germination of certain seeds. Dung beetle
s, which are also seed dispersers as well as nutrient recyclers, also appear to be dependent on the presence of the mantled howler. The mantled howler is protected from international trade under Appendix I of the Convention on International Trade in Endangered Species (CITES).
Howler monkey
Howler monkeys are among the largest of the New World monkeys. Fifteen species are currently recognised. Previously classified in the family Cebidae, they are now placed in the family Atelidae. These monkeys are native to South and Central American forests...
, a type of New World monkey
New World monkey
New World monkeys are the five families of primates that are found in Central and South America: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Platyrrhini parvorder and the Ceboidea superfamily, which are essentially synonymous since...
, from Central
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. It is one of the monkey species most often seen and heard in the wild in Central America. It takes its "mantled" name from the long guard hair
Guard hair
Guard hairs are the longest, coarsest hairs in a mammal's coat, forming the topcoat . They taper to a point and protect the undercoat from the elements. They are often water repellent and stick out above the rest of the coat...
s on its sides.
The mantled howler is one of the largest Central American monkeys, and males can weigh up to 9.8 kg (21.6 lb). It is the one Central American monkey whose diet is composed mostly of leaves. The mantled howler has several adaptations to this folivorous diet. Since leaves are difficult to digest and provide less energy than most foods, mantled howlers spend the majority of each day resting and sleeping. Male mantled howlers also have an enlarged hyoid bone, which is a hollow bone near the vocal cords. This enlarged bone amplifies the calls made by the male, which give the monkey its common name of "howler". Howling allows the monkeys to locate each other without expending energy on moving or risking physical confrontation.
The mantled howler lives in groups that can have over 40 members, although groups are usually smaller. Most mantled howlers of both sexes are evicted from the group they were born in upon reaching sexual maturity, and so most adult group members are unrelated. The most dominant male, the alpha male
Alpha (biology)
In social animals, the alpha is the individual in the community with the highest rank. Where one male and one female fulfill this role, they are referred to as the alpha pair...
, gets preference for food and resting places, and mates with most of the receptive females. The mantled howler is important to the rainforest
Rainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
ecology as a seed disperser and germinator. Although it is impacted by deforestation
Deforestation
Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use....
, it is able to adapt better than other species, due to its ability to feed on abundant leaves and its ability to live in a limited amount of space.
Taxonomy
The mantled howler belongs to the New World monkey family AtelidaeAtelidae
Atelidae is one of the five families of New World monkeys now recognised. It was formerly included in the family Cebidae. Atelids are generally larger monkeys; the family includes the howler, spider, woolly and woolly spider monkeys...
, the family that contains the howler monkey
Howler monkey
Howler monkeys are among the largest of the New World monkeys. Fifteen species are currently recognised. Previously classified in the family Cebidae, they are now placed in the family Atelidae. These monkeys are native to South and Central American forests...
s, spider monkey
Spider monkey
Spider monkeys of the genus Ateles are New World monkeys in the subfamily Atelinae, family Atelidae. Like other atelines, they are found in tropical forests of Central and South America, from southern Mexico to Brazil...
s, woolly monkey
Woolly monkey
The woolly monkeys are the genus Lagothrix of New World monkeys, usually placed in the family Atelidae.There are four species of woolly monkey. All originate from the rainforests of South America...
s and muriqui
Muriqui
The muriquis, also known as woolly spider monkeys, are the monkeys of the genus Brachyteles. They are closely related to both the spider monkeys and the woolly monkeys. There are two species, the southern and northern muriqui...
s. It is a member of the subfamily Alouattinae and genus Alouatta, the subfamily and genus containing all the howler monkeys. The species name is A. palliata; a pallium
Pallium
The pallium is an ecclesiastical vestment in the Roman Catholic Church, originally peculiar to the Pope, but for many centuries bestowed by him on metropolitans and primates as a symbol of the jurisdiction delegated to them by the Holy See. In that context it has always remained unambiguously...
was a cloak or mantle worn by ancient Greeks
Ancient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...
and Romans
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....
.
Three subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
are recognized:
- Ecuadorian mantled howler, Alouatta palliata aequatorialis, in Colombia, Costa Rica, Ecuador, Panama and Peru;
- Golden-mantled howler, Alouatta palliata palliata, in Costa Rica, Guatemala, Honduras and Nicaragua;
- Mexican howler, Alouatta palliata mexicana, in Mexico and Guatemala.
Two additional subspecies of the mantled howler are sometimes recognised, but these are more generally recognised as subspecies of the Coiba Island howler
Coiba Island Howler
The Coiba Island howler is a species of howler monkey, a type of New World monkey, endemic to Panama. Although the Coiba Island howler is generally recognized as a separate species, mitochondrial DNA testing is inconclusive as to whether it is actually a subspecies of the mantled howler...
, Allouatta coibensis. However, mitochondrial DNA
Mitochondrial DNA
Mitochondrial DNA is the DNA located in organelles called mitochondria, structures within eukaryotic cells that convert the chemical energy from food into a form that cells can use, adenosine triphosphate...
testing of their status has been inconclusive:
- Azuero howler, Alouatta palliata trabeata, in Panama;
- Alouatta palliata coibensisAlouatta coibensis coibensisAlouatta coibensis coibensis is a subspecies of the Coiba Island howler, A. coibensis. This subspecies lives only on Coiba Island and Jicaron, off the Pacific coast of Panama. A. c. coibensis is smaller than other Central American howler monkeys and has duller pelage than the Azuero howler,...
, in Panama.
Physical description
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
of an adult mantled howler is about 55.1 g (1.9 oz), which is smaller than that of several smaller monkey species, such as the White-headed Capuchin
White-headed Capuchin
The white-headed capuchin , also known as the white-faced capuchin or white-throated capuchin, is a medium-sized New World monkey of the family Cebidae, subfamily Cebinae...
.
The mantled howler shares several adaptations with other species of howler monkey that allow it to pursue a folivorous diet, that is, a diet with a large component of leaves. Its molars
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
have high shearing crests, to help it eat the leaves, and males have an enlarged hyoid bone near the vocal cords. This hyoid bone amplifies the male mantled howler's calls, allowing it to locate other males without expending much energy.
Social structure
The mantled howler lives in groups. Group sizeGroup size measures
Many animals, including humans, tend to live in groups, herds, flocks, bands, packs, shoals, or colonies of conspecific individuals. The size of these groups, as expressed by the number of participant individuals, is an important aspect of their social environment...
usually ranges from 10 to 20 members, generally 1 to 3 adult males and 5 to 10 adult females, but some groups have over 40 members. Males outrank females, and younger animals of each gender generally have a higher rank than older animals. Higher ranking animals get preference for food and resting sites, and the alpha male gets primary mating rights. Animals in the group are generally not related to each other because most members of both sexes leave the group before sexual maturity.
Grooming activity in the mantled howler is infrequent and has been shown to reflect social hierarchy, with dominant individuals grooming subordinates. Aggressive interactions between group members is not often observed either. However, studies have shown that aggressive interactions among group members do occur, and are probably not often observed because these interactions tend to be quick and silent.
Mantled-howler groups that have been studied have occupied home ranges of between 10 and 60 ha (24.7 and 148.3 acre). Groups do not defend exclusive territories, but rather several groups have overlapping home ranges. However, if two groups meet each group will aggressively attempt to evict the other. On average, groups travel up to about 750 metres (2,460.6 ft) each day.
The mantled howler has little interaction with other sympatric monkey species but interactions with the White-headed Capuchin
White-headed Capuchin
The white-headed capuchin , also known as the white-faced capuchin or white-throated capuchin, is a medium-sized New World monkey of the family Cebidae, subfamily Cebinae...
sometimes occur. These are most often aggressive, and the smaller capuchins are more often the aggressors. However, affiliative associations between the capuchins and howlers do sometimes occur, mostly involving juveniles playing together, and at times the capuchins and howlers may feed in the same tree, apparently ignoring each other.
Diet
The mantled howler is the most folivorous species of Central American monkey. Leaves make up between almost 50% and 75% of the mantled howler's diet. The mantled howler is selective about the trees it eats from, and it prefers young leaves to mature leaves. This selectivity is likely to reduce the levels of toxins ingested, since certain leaves of various species contain toxins. Young leaves generally have less toxins as well as more nutrients than more mature leaves, and are also usually easier to digest. Leaves from FicusFicus
Ficus is a genus of about 850 species of woody trees, shrubs, vines, epiphytes, and hemiepiphyte in the family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few species extending into the semi-warm temperate zone. The Common Fig Ficus is a genus of...
trees tend to be preferred over other leaves. Although leaves are abundant, they are a low energy food source. The fact that the mantled howler relies so heavily on a low energy food source drives much of its behaviour - for example, howling to locate other groups and spending a large portion of the day resting.
Although leaves tend to make up the majority of the mantled howler's diet, fruit can also make up a large portion of the diet. When available, the proportion of fruit in the diet can be as much as 50%, and can sometimes exceed the proportion of leaves. fig
Ficus
Ficus is a genus of about 850 species of woody trees, shrubs, vines, epiphytes, and hemiepiphyte in the family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few species extending into the semi-warm temperate zone. The Common Fig Ficus is a genus of...
s tend to be a preferred fruit. Flowers can also make up a significant portion of the mantled howler's diet and are eaten in particularly significant quantities during the dry season. The mantled howler tends to get the water it needs from its food, but it does sometimes drink from tree holes. It drinks from tree holes more during the wet season than during the dry season. It probably also drinks water trapped in bromeliads.
Like other species of howler monkeys, almost all mantled howlers have full three color vision. This is different from other types of New World monkey
New World monkey
New World monkeys are the five families of primates that are found in Central and South America: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Platyrrhini parvorder and the Ceboidea superfamily, which are essentially synonymous since...
s, in which most individuals have two color vision. The three color vision exhibited by the mantled howler is believed to be related to its dietary preferences, allowing it to distinguish young leaves, which tend to be more reddish, from more mature leaves.
Locomotion
However, the mantled howler is a relatively inactive monkey. It sleeps or rests the entire night and about three quarters of the day. Most of the active period is spent feeding, with only about 4% of the day spent on social interaction. This lethargy is an adaptation to its low energy diet. It uses its prehensile tail to grasp a branch when sleeping, resting or when feeding. It can support its entire body weight with the tail, but more often holds on by the tail and both feet. A study has shown that the mantled howler reuses travel routes to known feeding and resting sites, and appears to remember and use particular landmarks to help pick direct routes to its destination.
Communication
The mantled howler gets the name "howler" from the calls made by the males, particularly at dawn and dusk, but also in response to disturbances. These calls are very loud and can be heard for several kilometers. The calls consist of grunts and repeated roars that can last for four to five seconds each. The volume is produced by the hyoid bone — a hollow bone near the vocal cords — amplifying the sound made by the vocal cords. Male mantled howlers have hyoid bones that are 25 times larger than similarly-sized spider monkeySpider monkey
Spider monkeys of the genus Ateles are New World monkeys in the subfamily Atelinae, family Atelidae. Like other atelines, they are found in tropical forests of Central and South America, from southern Mexico to Brazil...
s, and this allows the bone to act like the body of a drum in amplifying the calls. Females also call but their calls are higher in pitch and not as loud as the males'. The ability to produce these loud roars is likely an energy saving device, consistent with the mantled howler's low energy diet. The roars allow the monkey to locate each other without moving around or risking physical confrontations. The mantled howler uses a wide range of other sounds, including barks, grunts, woofs, cackles and screeches. It uses clucking sounds to maintain auditory contact with other members of its group.
The mantled howler is usually indifferent to the presence of humans. However, when it is disturbed by people, it often express its irritation by urinating or defecating on them. It can accurately hit its observers despite being high in the trees.
Tool use
The mantled howler has not been observed using tools, and prior to 1997 no howler monkey was known to use tools. However, in 1997 a Venezuelan red howlerVenezuelan Red Howler
The Venezuelan red howler is a South American species of howler monkey, a type of New World monkey. It is found in the western Amazon Basin in Venezuela, Colombia, Ecuador, Peru, Bolivia and Brazil...
(Alouatta seniculus) was reported to use a stick as a club to hit a Linnaeus's two-toed sloth
Linnaeus's Two-toed Sloth
Linnaeus's two-toed sloth , also known as the Southern two-toed sloth or unau, is a species of sloth from South America, found in Venezuela, the Guyanas, Colombia, Ecuador, Peru and Brazil north of the Amazon River....
, (Choloepus didactylus), that was resting in its tree. This suggests that other howlers, such as the mantled howler, may also use tools in ways that have not yet been observed.
Reproduction
Polygamy
Polygamy is a marriage which includes more than two partners...
mating system in which one male mates with multiple females. Usually, the alpha male monopolises the breeding opportunities, but if the alpha male is distracted, a lower ranking male can get an opportunity to mate. And in some groups, lower ranking males do get regular mating opportunities and do sire offspring. Alpha males generally maintain their status for about 2½ to 3 years, during which time they may father 18 or so infants. Adults of both sexes invite mating by flicking their tongues. Females apparently also use chemical signals, since males smell the females' genitals and taste their urine.
The gestational period
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
is 186 days; births can occur at any time of year. The infant's fur is silver at birth, but turns pale or gold after a few days. After that, the fur starts to darken, and the infant takes on the adult coloration at about 3 months old.
The infant is carried under its mother, clinging to its mother's chest, for the first 2 or 3 weeks of its life. After that, it is carried on its mother's back. At about 3 months the mother will usually start to push the infant off, but will still carry the infant some of the time until it is 4 or 5 months old. After the young can move on its own, the mother will carry it across difficult gaps in the trees. Juveniles play among themselves much of the time. Infants are weaned at 1½ years old at which point maternal care ends. Adult females typically give birth every 19 to 23 months, assuming the prior infant survived to weaning.
Females become sexually mature at 36 months, males at 42 months. The mantled howler differs from other howler monkey species in that the males' testes do not descend until they reach sexual maturity. Upon reaching sexual maturity, the young monkeys are usually evicted from their natal group, although the offspring of a high ranking female may get to stay in its natal group. However, many infants do not reach sexual maturity; high ranking adults sometimes harass or kill the offspring of lower ranking monkeys to eliminate competition to their own offspring for an opportunity to remain with the group upon reaching maturity. When a male from outside the group ousts the previous alpha male, he normally kills any infants so that the mothers come into estrus quickly and are able to mate with him. Predators such as cat
Felidae
Felidae is the biological family of the cats; a member of this family is called a felid. Felids are the strictest carnivores of the thirteen terrestrial families in the order Carnivora, although the three families of marine mammals comprising the superfamily pinnipedia are as carnivorous as the...
s, weasel
Weasel
Weasels are mammals forming the genus Mustela of the Mustelidae family. They are small, active predators, long and slender with short legs....
s, snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s and eagle
Eagle
Eagles are members of the bird family Accipitridae, and belong to several genera which are not necessarily closely related to each other. Most of the more than 60 species occur in Eurasia and Africa. Outside this area, just two species can be found in the United States and Canada, nine more in...
s also kill infants. As a result, only about 30% of mantled howler infants live more than one year. If it survives infancy, the mantled howler's lifespan is typically 25 years.
Distribution and habitat
The mantled howler is native to ColombiaColombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
, Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
, Guatemala
Guatemala
Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...
, Honduras
Honduras
Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, Nicaragua
Nicaragua
Nicaragua is the largest country in the Central American American isthmus, bordered by Honduras to the north and Costa Rica to the south. The country is situated between 11 and 14 degrees north of the Equator in the Northern Hemisphere, which places it entirely within the tropics. The Pacific Ocean...
and Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
. Within Honduras, Nicaragua, Costa Rica and Panama, the mantled howler is found in locations throughout the countries. In Colombia and Ecuador, it is found in a narrow corridor bordered by the Pacific Ocean to the west and the Andes Mountains to the east and also in Colombia in a small area near the Caribbean Sea
Caribbean Sea
The Caribbean Sea is a sea of the Atlantic Ocean located in the tropics of the Western hemisphere. It is bounded by Mexico and Central America to the west and southwest, to the north by the Greater Antilles, and to the east by the Lesser Antilles....
close to the Panama border. In Guatemala, the mantled howler is found through the central part of the country, and into southeastern Mexico south of the Yucatán Peninsula
Yucatán Peninsula
The Yucatán Peninsula, in southeastern Mexico, separates the Caribbean Sea from the Gulf of Mexico, with the northern coastline on the Yucatán Channel...
. The mantled howler is among the most commonly seen and heard primates in many Central American national parks, including Manuel Antonio
Manuel Antonio National Park
Manuel Antonio National Park, in Spanish the Parque Nacional Manuel Antonio, is a small National Park in the Central Pacific Conservation Area located on the Pacific coast of Costa Rica, just south of the city of Quepos, Puntarenas, and from the national capital of San José...
, Corcovado
Corcovado National Park
Corcovado National Park is a National Park on the Osa Peninsula in the South West of Costa Rica , which is part of the Osa Conservation Area. It was established on 24 October 1975, and encompasses an area of 425 km² . It is widely considered the crown jewel in the extensive system of national...
, Monteverde
Monteverde
Monteverde, Costa Rica is a small town in Puntarenas, Costa Rica. Located in the Cordillera de Tilarán, roughly a four hour drive from the Central Valley of Costa Rica, Monteverde is considered a major ecotourism destination in Costa Rica...
and Soberania
Soberanía National Park
Soberanía National Park is a national park in Panama near the banks of the Panama Canal in the provinces of Panamá and Colón, some from Panama City. The Chagres River runs through the park....
. The mantled howler lives in several different types of forest, including secondary forest
Secondary forest
A secondary forest is a forest or woodland area which has re-grown after a major disturbance such as fire, insect infestation, timber harvest or windthrow, until a long enough period has passed so that the effects of the disturbance are no longer evident...
and semi-deciduous
Semi-deciduous
Semi-deciduous is a botanical term which refers to plants that lose part of their foliage, also Semi-deciduous plants can mean, that plants can lose their foliage for a very short period, when old leaves fall off and new foliage growth is starting. This phenomenon occurs in tropical and...
forest but is found in higher densities in older areas of forest and in areas containing evergreen forest
Evergreen forest
An temperate evergreen forest is a forest consisting entirely or mainly of evergreen trees that retain green foliage all year round. Such forests exist in the tropics primarily as broadleaf evergreens, and in temperate and boreal latitudes primarily as coniferous evergreens.-Tropical evergreen...
. The mantled howler is sympatric with another howler monkey species, the Guatemalan black howler
Guatemalan Black Howler
The Guatemalan black howler, or Yucatan black howler, is a species of howler monkey, a type of New World monkey, from Central America. It is found in Belize, Guatemala and Mexico, in and near the Yucatan Peninsula. It lives in evergreen, semi-deciduous and lowland rain forests...
, A. pigra, over a small part of its range, in Guatemala and Mexico near the Yucatan Peninsula
Yucatán Peninsula
The Yucatán Peninsula, in southeastern Mexico, separates the Caribbean Sea from the Gulf of Mexico, with the northern coastline on the Yucatán Channel...
.
Conservation status
Dung beetle
Dung beetles are beetles that feed partly or exclusively on feces. All of these species belong to the superfamily Scarabaeoidea; most of them to the subfamilies Scarabaeinae and Aphodiinae of the family Scarabaeidae. This beetle can also be referred to as the scarab beetle. As most species of...
s, which are also seed dispersers as well as nutrient recyclers, also appear to be dependent on the presence of the mantled howler. The mantled howler is protected from international trade under Appendix I of the Convention on International Trade in Endangered Species (CITES).