The Mexican howler (Alouatta palliata mexicana) is a subspecies of the mantled howler, A. palliata. This subspecies is found predominantly in forests between south eastern Mexico and north eastern Peru.[3] Typical of its species, the Mexican howler monkey has a prehensile tail, a deep jaw, and a large pharynx which it uses to make characteristically deep and resonating howls.[2] Mantled howler monkeys are known for forming unusually large cohorts averaging 14 members and sometimes extending to 40 members.[2]

Mexican howler
A Mexican howler
CITES Appendix I (CITES)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Haplorhini
Infraorder: Simiiformes
Family: Atelidae
Genus: Alouatta
Species:
Subspecies:
A. p. mexicana
Trinomial name
Alouatta palliata mexicana
Merriam, 1902

Taxonomy edit

There are five subspecies of the A. palliata which are Alouatta palliata aequatorialis, Alouatta palliata coibensis, Alouatta palliata palliata, Alouatta palliata trabeata and Alouatta palliata mexicana.[2] Compared with members of the howler monkey genus, the Mexican howler is sympatric with the Guatemalan black howler, A. pigra, in Tabasco, Mexico.[4] The Mexican howler differs from the golden-mantled howler, A. palliata palliata, primarily in aspects of skull morphology, and in some differences in pelage.[4] The golden-mantled howler's range includes parts of Guatemala and Honduras, and it is not clear if the Mexican and golden-mantled howler's ranges currently are in contact.[4]

Geography edit

The Mexican howler monkey is primarily located between south eastern Mexico and north eastern Peru.[5] As of 2008, this subspecies was determined to be critically endangered by the International Union for Conservation of Nature.[1][2] due to the loss of its natural habitat as a result of deforestation.[6] It is now located only in patches of forestry within these regions because loss of habitat has been so extensive.[7] Disturbances to the habitat of the Mexican howler have caused detrimental effects to the spatial organization of the different groups of howler monkeys. These groups are forced into closer proximity to each other contributing to the scarcity of food and depletion of nutrients as these monkeys are forced to scavenge.[8]

Diet edit

The Mexican howler can eat a remarkable variety of foods including leaves, flower, buds, petioles, and fruits. This subspecies of howler monkey is known to be a frugivore[9] and a behavioural folivores. Their digestive system is slow and they have significantly fewer enzymes for protein and fiber digestion than other frugivores, but they compensate for this by selectively eating leaves with less fiber.[3] Consequently, much of this the Mexican howler monkey's activity is dedicated for foraging for fruit and young leaves which it can easily digest.[5] Frugivory is typically observed in New World monkeys instead of Old World monkeys, but howler monkeys are an exception to this categorization.[10]

Behavior edit

This howler monkey species has compensated for its adapted digestive system by minimizing energy output as much as possible. The Mexican howler exhibits limited interaction with members of its species and very minor aggressive behavior.[11] There is evidence of physical aggression between members of the species during migratory periods or changes in dominance.[12] Males, when fighting for dominance, have been observed to target juveniles, sometimes even killing them, and physically injuring older males. For a younger male to take control of a group, he must first kill the dominant male, exhibiting extensive aggression.[13] Females also show aggression when asserting dominance, though this is usually limited to harassment behavior like hair pulling and biting.[14]

References edit

  1. ^ a b "Critically Endangered Primates". Archived from the original on 2008-07-27. Retrieved 2008-08-09.
  2. ^ a b c d e Cuarón, A.D.; Shedden, A.; Rodriguez-Luna, E.; de Grammont, P.C.; Link, A. (2020). "Alouatta palliata ssp. mexicana". IUCN Red List of Threatened Species. 2020: e.T925A17978896. doi:10.2305/IUCN.UK.2020-2.RLTS.T925A17978896.en. Retrieved 12 November 2021.
  3. ^ a b Espinosa-Gómez, Fabiola; Gómez-Rosales, Sergio; Wallis, Ian R.; Canales-Espinosa, Domingo; Hernández-Salazar, Laura (2013). "Digestive strategies and food choice in mantled howler monkeys Alouatta palliata mexicana: bases of their dietary flexibility". Journal of Comparative Physiology B. 183 (8): 1089–1100. doi:10.1007/s00360-013-0769-9. ISSN 0174-1578. PMID 23743799. S2CID 1012753.
  4. ^ a b c Rylands; Groves; Mittermeier; Cortes-Ortiz & Hines (2006). "Taxonomy and Distributions of Mesoamerican Primates". In Estrada, A.; Garber, P.A.; Pavelka, M.S.M. & Luecke, L. (eds.). New Perspectives in the Study of Mesoamerican Primates. pp. 50–51. ISBN 978-0-387-25854-6.
  5. ^ a b Estrada, A., Juan-Solano, S., Ortiz M.T., Coates-Estrada, R., 1999, Feeding and general activity patterns of a howler monkey (Alouatta palliata) troop living in a forest fragment at Los Tuxtlas, Mexico. American Journal of Primatology, 48(3) 167-83.
  6. ^ Van Belle S, Estrada A, 2006. Demographic features of Alouatta pigra populations in extensive and fragmented forests. In: Estrada A, Garber PA, Pavelka M, Luecke L ed. New Perspec- tives in the Study of Mesoamerican Primates: Distribution, Ecology and Conservation. USA: Springer, 121–142.
  7. ^ Arroyo-Rodríguez, V., Mandujano, S., Benítez-Malvido, J., 2008, Landscape attributes affecting patch occupancy by howler monkeys (Alouattapalliata mexicana) at Los Tuxtlas, Mexico. American Journal of Primatology. Vol. 70 (1), pp. 69-77.
  8. ^ Cañadas Santiago, S.; Dias, P. A. D.; Garau, S.; Coyohua Fuentes, A.; Chavira Ramírez, D. R.; Canales Espinosa, D.; Rangel Negrín, A. (June 2020). "Behavioral and physiological stress responses to local spatial disturbance and human activities by howler monkeys at Los Tuxtlas, Mexico". Animal Conservation. 23 (3): 297–306. doi:10.1111/acv.12541. ISSN 1367-9430.
  9. ^ Urquiza-Haas, Tania; Serio-Silva, Juan Carlos; Hernández-Salazar, Laura Teresa (2008). "Traditional nutritional analyses of figs overestimates intake of most nutrient fractions: a study of Ficus perforata consumed by howler monkeys (Alouatta palliata mexicana)". American Journal of Primatology. 70 (5): 432–438. doi:10.1002/ajp.20510. ISSN 0275-2565. PMID 18161827. S2CID 36429725.
  10. ^ Can phenology explain the scarcity of folivory in New World primates? Heymann EW. in the American Journal of Primatology; November 2001
  11. ^ Klein, L. L. (1974). Agonistic behavior in neotropical primates. In Holloway, R. L. (ed.), Primate Aggression, Territoriality, and Xenophobia, Academic Press, New York, pp. 77–122.
  12. ^ Cristóbal-Azkarate, J, Dias, P, & Veà, J 2004, 'Causes of Intraspecific Aggression in Alouatta palliata mexicana: Evidence from Injuries, Demography, and Habitat', International Journal of Primatology, 25, 4, pp. 939-953, Academic Search Premier, EBSCOhost, viewed 7 December 2014
  13. ^ Glander, K. E. (1980). Reproduction and population growth in free-ranging mantled howling monkeys. Am. J. Physical Anthropol. 53: 25–36.
  14. ^ Glander, K. E. (1992). Dispersal patterns in Costa Rican mantled howling monkeys. Int. J. Primatol. 13: 415–436.