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Mantled Howler MonkeyAlouatta palliata

Every figure, record and mechanism on the Mantled Howler Monkey profile was written from a source, and this is the working table behind it: 41 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.

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Source
01

Animal Diversity Web

Alouatta palliata (mantled howler monkey). Animal Diversity Web.

The page saysA leaf-eating monkey whose males' calls seem to help keep neighbouring troops apart.
The source saysSpacing between neighboring troops seems to be dependent, at least in part, upon vocal communication between males ... This leaf grazing (folivorous) dietNote: tagline
The page saysLowland and montane rain forest
The source saysMantled howler monkeys inhabit lowland and montane rain forestsNote: stats.habitat
The page saysin southern Mexico and from Honduras to western Ecuador
The source saysMantled howler monkeys are found in southern Mexico (the states of Veracruz, Campeche, Chiapas, Oaxaca, and Tabasco), from Honduras in Central America to Colombia and western Ecuador in South AmericaNote: stats.habitat
The page sayssea level to 2,500 m
The source saysThis range includes most forest habitats that lie between sea level and 2500 meters
The page saysMostly leaves, fruit and flowers, favouring young leaves
The source saysFood resources consist mainly of leaves, fruit, and flowersNote: stats.diet
The page saysfavouring young leaves
The source sayspreferentially eating young leaves with higher protein to fiber ratio and lower tannin contentNote: stats.diet
The page saysCalls that seem to help keep neighbouring troops apart
The source saysSpacing between neighboring troops seems to be dependent, at least in part, upon vocal communication between malesNote: stats.superpower
The page saysMantled howlers woof, grunt and bark as well as howl.
The source saysCalls include woofs, grunts, barks, and howls, with the characteristic howls occurring at dusk and dawn, and in response to any sort of disturbance
The page saysThe characteristic howls come at dusk and dawn, or whenever something disturbs the troop
The source saysCalls include woofs, grunts, barks, and howls, with the characteristic howls occurring at dusk and dawn, and in response to any sort of disturbance
The page saysMales' calls seem to help neighbouring troops keep their distance from each other.
The source saysSpacing between neighboring troops seems to be dependent, at least in part, upon vocal communication between males
The page saysMales weigh 6 to 7 kg and adult females typically 4 to 5 kg.
The source saysMales have a prominent white scrotum, weigh 6 to 7 kg, and usually have a longer beard than female individuals ... Adult females typically weigh 4 to 5 kgNote: omitted clause on anatomy
The page saysThe body is 38 to 58 cm long, with a prehensile tail (one that can grip) of 52 to 67 cm.
The source saysAdult tail size ranges from 520 to 670 mm, and body length ranges from 380 to 580 mmNote: converted mm to cm; prehensile tail named elsewhere in the same page
The page saysprehensile tail
The source saysthe prehensile tail has a naked pad on the underside near its base
The page saysThey are stocky and black, with long guard hairs on the flanks that give the "mantled" name, and most wear a yellow or brown saddle.
The source saysMantled howler monkeys are large and stocky with black fur, and most individuals have long, yellow or brown fur saddles ... Long guard hairs are present on their flanks, earning the common name "mantled" howler monkey
The page saysLeaves, fruit and flowers make up most of the menu, and howlers favour young leaves, which carry more protein for their fibre and less of the plant chemicals called tannins.
The source saysFood resources consist mainly of leaves, fruit, and flowers ... preferentially eating young leaves with higher protein to fiber ratio and lower tannin content
The page saysThey spend most of their time foraging, and their lifestyle is described as energetically conservative.
The source saysmantled howler monkeys have an energetically conservative lifestyle, perhaps related to diet and feeding style since they spend the majority of their time foraging
The page saysA troop of 10 to 20 monkeys usually holds 5 to 10 adult females and 1 to 3 adult males.
The source saysGroup size ranges from 10 to 20 members, generally 1 to 3 adult males and 5 to 10 adult females
The page saysin one study, 79% of males and 96% of females did
The source saysNatal emigration is performed by both sexes, with 79% of all males and 96% of the females leaving their original social group
The page saysA female has her first baby at about 42 months
The source saysare typically 42 months old by their first birth
The page sayspregnancy lasts about 186 days
The source saysPregnancy lasts an average of 186 days (6 months)
The page saysbirths come about 22.5 months apart
The source saysthe interbirth interval is about 22.5 months
The page saysThe species lives in southern Mexico and from Honduras to Colombia and western Ecuador, in forest from sea level up to 2,500 m.
The source saysMantled howler monkeys are found in southern Mexico ... from Honduras in Central America to Colombia and western Ecuador in South America ... This range includes most forest habitats that lie between sea level and 2500 meters
The page saysWhere rainforest has been chopped into fragments, especially in southern Mexico, many howlers have shifted into cacao and coffee plantations grown under shade trees.
The source saysUnder pressure from rainforest fragmentation, many howlers have moved into shaded cacao and coffee plantations where forest habitat has disappeared, especially in southern Mexico
The page saysAdult males weigh 6 to 7 kg and adult females typically 4 to 5 kg, and a newborn weighs about 0.4 kg. The head and body measure 38 to 58 cm, and the tail adds another 52 to 67 cm.
The source saysweigh 6 to 7 kg ... Adult females typically weigh 4 to 5 kg, and newborn infants weigh 0.4 kg ... Adult tail size ranges from 520 to 670 mm, and body length ranges from 380 to 580 mmNote: FAQ; mm converted to cm
The page saysThe characteristic howls ring out at dusk and dawn, and in response to any kind of disturbance. Besides howls, their calls include woofs, grunts and barks.
The source saysCalls include woofs, grunts, barks, and howls, with the characteristic howls occurring at dusk and dawn, and in response to any sort of disturbanceNote: FAQ

Source
02

Human Ageing Genomic Resources, AnAge

AnAge entry for Alouatta palliata. Human Ageing Genomic Resources, AnAge.

The page saysThe AnAge database estimates that wild adults live 16 years on average
The source saysIn the wild, adults are estimated to live on average 16 years
The page saysgives a captive maximum of 24 years
The source saysMaximum longevity 24 years (captivity)
The page saysBy AnAge's estimate, adults in the wild live about 16 years on average. Its captive maximum of 24 years rests on one wild-born female who lived more than 15 years in captivity and may have been as old as 24.
The source saysMaximum longevity 24 years (captivity) Source ref. 671 Sample size Small Data quality Acceptable Observations In the wild, adults are estimated to live on average 16 years [ 0434 ]. One wild born female lived more than 15 years in captivity and could have been as old as 24 [ 0671 ].Note: FAQ

Source
03

Cortes-Ortíz et al. 2021

Cortes-Ortíz et al. (2021). Alouatta palliata. The IUCN Red List of Threatened Species 2021: e.T39960A190425583.

The page saysVulnerable
The source saysIUCN Red List category: Vulnerable (VU).Note: stats.conservationStatus; GBIF copy of the Red List checked against taxon id 39960
The page saysThe Red List rates it Vulnerable.
The source saysIUCN Red List category: Vulnerable (VU).
The page saysThe IUCN Red List rates the species Vulnerable.
The source saysIUCN Red List category: Vulnerable (VU).Note: FAQ; 2021 is the assessment year in the DOI and title

Source
04

Maya Lastra et al. 2024

Maya Lastra et al. (2024). Mantled howler monkey males assess their rivals through formant spacing of long-distance calls. Primates.

The page saysmales were less likely to approach recorded calls that sounded like a large rival, and approached small-sounding ones faster.
The source saysLow formant spacing calls were less likely to elicit approaches whereas high formant spacing calls resulted in quicker approaches.Note: low spacing = emulating large individuals, per the abstract
The page saysResearchers tested this on 11 adult males by playing them calls from strangers.
The source saysWe studied the behavioral responses of 11 adult males to playback experiments of long-distance calls from unknown individuals
The page saysThe males always called back.
The source saysPlaybacks always elicited vocal responses
The page saysa feature of a voice that tracks the caller's body size
The source saysFormant frequency spacing of long-distance vocalizations is allometrically related to body size
The page saysthe males also showed stronger hormone responses to the large-sounding calls
The source saysMales showed stronger hormonal responses to low than to both intermediate and high formant spacing calls.Note: low = large-sounding
The page saysMale mantled howlers judge a rival by the sound of his call: in playback tests they were less likely to approach calls that sounded like a large male
The source saysLow formant spacing calls were less likely to elicit approaches whereas high formant spacing calls resulted in quicker approaches.Note: vibe.reason

Source
05

Bergman et al. 2016

Bergman et al. (2016). Striking differences in the loud calls of howler monkey sister species (Alouatta pigra and A. palliata). American Journal of Primatology.

The page saysthe black howler's exaggerated roars seem better suited to contests between groups, while the mantled howler's calls may suit attracting mates and competing within groups
The source saysThe exaggerated roars and intense calling patterns in A. pigra seem more suitable for intergroup competition, whereas A. palliata calls may be better suited for mate attraction and competition within groups.Note: A. pigra = black howler; the abstract calls the two 'closely related' and 'sister species'

Source
06

Estrada & Coates-Estrada 1991

Estrada & Coates-Estrada (1991). Howler monkeys (Alouatta palliata), dung beetles (Scarabaeidae) and seed dispersal: ecological interactions in the tropical rain forest of Los Tuxtlas, Mexico. Journal of Tropical Ecology.

The page saysone study found them eating the fruit of 35 plant species and spreading the seeds of 28
The source saysHowlers consumed the fruits of 35 species of plants. The seeds of 28 of these were dispersed by the monkeys.
The page saysa clump stayed on the ground for only 2.5 hours on average
The source saysFaecal clumps (20 mg) remained on the ground for an average of only 2.5 h
The page saysDung beetles then bury the droppings quickly
The source saysRapid relocation and burial of dung by dung beetles

How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.