Alouatta palliata (Gray, 1849)

3.2.1 Alouatta palliata (Gray, 1849) View in CoL

Type: Syntypes, adult female, skin and skull, No. 1848.10.26.1 , and adult male, skin, 1848,10.26.2 , British Museum (Natural History) ( Napier 1976).

Type locality: Nicaragua (shores of Lake Nicaragua ).

Common name: Mantled howler.

This species ranges from southern Veracruz State in Mexico, south through Central America and the Pacific slopes of the Andes in Colombia and Ecuador reaching the Tumbes region in northern Peru ( Fig. 3.1 View Fig ).

Only five of the seven subspecies recognized by Lawrence (1933) for A. palliata are currently accepted: A. p. mexicana, A. p. palliata , A. p. aequatorialis , A. p. coibensis , and A. p. trabeata. Lawrence (1933) commented on the difficulty in distinguishing the subspecies of A. palliata , with the exception of the Guatemalan ( A. p. pigra ) and the Coiba Island ( A. p. coibensis ) forms. Smith (1970), likewise, analyzed cranial and dental patterns, and pelage coloration of A. palliata , and concluded that the forms palliata , mexicana, coibensis , and trabeata were only weakly definable as subspecies. Froehlich and Froehlich (1986, 1987), however, analyzed patterns of dermal ridges of howler monkeys from Nicaragua, Costa Rica, and Panama, and found that individuals from Coiba Island and the Azuero Peninsula were distinct from those of Nicaragua, Costa Rica, and the rest of Panama. They considered that differences in the dermal ridge patterns of the hands and feet were congruent with genetic distances, and that the difference found between coibensis / trabeata and palliata / aequatorialis groups was comparable to that of either of them and the South American howler monkey species. They, therefore, suggested that the forms coibensis and trabeata be treated as subspecies of a distinct species, A. coibensis . Glander and Pinto (2013) adhered to this view, Groves (2001, 2005) considered trabeata to be junior synonym of A. coibensis , and Rylands et al. (1995, 2000) maintained them as subspecies of A. palliata (as per Lawrence 1933). The molecular genetic studies (mtDNA) of Cortés-Ortiz et al. (2003) produced no evidence to back this distinction. Alouatta palliata coibensis individuals were found to share mitochondrial haplotypes with A. palliata from Costa Rica and Mexico, and A. p. trabeata individuals shared haplotypes with A. p. aequatorialis from central Panama. These two clades represented northern and southern mitochondrial lineages separated around the Sona Peninsula in western Panama ( Cortés-Ortiz et al. 2003). Interestingly, recent phylogeographic analyses based on nuclear markers (microsatellites) support the phylogeographic brake between A. p. palliata and A. p. aequatorialis , but show closer proximity of A. p. coibensis and A. p. trabeata to A. p. aequatorialis (Cortés-Ortiz et al. unpublished). This discrepancy between mitochondrial and nuclear markers in the Coiba population may be the result of a secondary intergradation between formerly distinct lineages when Coiba Island was connected to the mainland (see Ford 2006). Studies including a larger number of individuals from Coiba Island, the Azuero Peninsula, and other regions in western and central Panama are necessary to corroborate the subspecific status of A. p. coibensis and A. p. trabeata, as well as to identify the limits of the ranges of A. p. palliata and A. p. aequatorialis .