Alouatta palliata occupies several distinct vegetation types, including mature evergreen forests, deciduous and riparian forests, mangroves, and anthropogenically disturbed forests (Neville et al. 1988, Baumgarten and Williamson 2007). Although mantled howlers spend most of their time resting (65-74%), their daily activities vary considerably according to season and food availability (Glander 2013).

The diets of Mantled Howler Monkeys have been extensively studied across the distribution range of the species in Central America. In average mantled howlers spend 21% of their time feeding (range 8–40 %, Dias and Negrin 2015). They mainly consume fruits and leaves, but the relative proportions vary by study site, with some populations being mostly folivorous while others have a more equal share of fruits and leaves in their diets. Other food items include flowers, petioles, buds, etc. (see Dias and Negrin 2015 for a detailed review of howler diets).

Group size varies considerably, with some locations reporting sizes of 40 or more individuals in a single group (in Mexico and Costa Rica), although the average group size is 15.2 individuals (Dias and Negrin 2015). Groups include multiple males and females, with a sex ration of 1.79 females per male (Chapman and Balcomb 1998). Group home ranges vary between 8 and 75 ha (see Arroyo-Rodriguez et al. 2015, and references therein).

Mean adult male weight ranges from 5.80 ± 0.69 kg in Mexico (Kelaita et al. 2011), 5.79 ± 0.58 kg in La Pacifica, Costa Rica, 6.57 ± 0.48 kg in Santa Rosa, Costa Rica, and 7.56 ± 0.73 kg in BCI, Panama (Glander 2006), while mean adult female weight ranges from 4.39 ± 0.48 kg in Mexico (Kelaita et al. 2011), 4.73 ± 0.62 kg in La Pacifica, Costa Rica, 5.16 ± 0.54 kg in Santa Rosa, Costa Rica, and 6.45 ± 0.55 kg in BCI, Panama (Glander 2006).

Behavioural and ecological field studies have been carried out mostly in Mexico, Costa Rica, and Panama and at a lesser extent in Nicaragua and Ecuador (see recent reviews in Kowalewski et al. 2015a,b).

Alouatta palliata is distributed from the southern portion of the state of Veracruz in Mexico, and extends south through the Mexican states of Oaxaca, Chiapas and Tabasco, throughout Central America and the Pacific Coast and western slopes of the Andes in Colombia and Ecuador, reaching the Tumbes region in northern Peru.

There are five recognized subspecies:

Alouatta palliata palliata
This subspecies is distributed from southern Guatemala to western Panama. However, the limits separating A. p. palliata from A. p. aequatorialis are not clear. Lawrence (1933) cited a specimen of A. p. palliata from Cotó, extreme western Panama, and Hill (1962, p.106) mentioned that specimens from Sevilla Island, western Panama, collected by J. H. Batty were “manifestly” A. p. palliata. Hall (1981), on the other hand, lists Sevilla Island, and Puerto Cortez, Costa Rica, as marginal records for A. p. aequatorialis. Lawrence (1933) comments that many individuals from Panama are intermediate. Based on mitochondrial DNA analyses, Cortés-Ortiz et al. (2003) reported two clades separating A. p. palliata/A. p. coibensis/ A. p. mexicana from A. p. trabeata/A. p aequatorialis, and mentioned that these two clades were divided around the Sona Peninsula in western Panama (Cortés-Ortiz et al. 2003). Consistent with this view, recent analyses of individuals from Limones in Punta Burica Panama (Cortés-Ortiz unpubl.) show that their mitochondrial DNA haplotypes cluster with those from A. p. palliata from Costa Rica. To the north, A. p. palliata extends through Costa Rica, Nicaragua and Honduras reaching the south margin of Rio Dulce in southern Guatemala, where it may be sympatric with A. pigra (Curdts 1993, Baumgarten and Williamson 2007). It is not known to currently occur in El Salvador (Burt and Stirton 1961), but it is likely that it occurred there in the past (Daugherty 1972).

Alouatta palliata mexicana
The distribution of A. p. mexicana ranges from southern Veracruz state in Mexico extending southeast to northeastern Oaxaca (Ortiz-Martínez et al. 2008), western Tabasco, and northern Chiapas (see Serio-Silva et al. 2006). In Tabasco A. p. mexicana is sympatric with A. pigra (Smith 1970) and hybridization has been confirmed in that region (Cortés-Ortiz et al. 2007, 2015b). Serio-Silva et al. (2006) reported the presence of A. p. mexicana in Campeche, Mexico, based on the observation of individuals with atypical white hairs on the flanks of their bodies. Cortés-Ortiz et al. (in prep.) have analysed mitochondrial and nuclear DNA from individuals in Campeche with similar coloration patterns and concluded that they are A. pigra, and not A. palliata or hybrid individuals. The reason for the presence of white hairs in the pelage of A. pigra individuals remains unclear. Although several published maps include the range of this subspecies extending into the highlands of Chiapas and north-central Guatemala, a study by A. Cuarón (unpublished) revealed that its range is restricted to western Chiapas, central and western Tabasco, southern Veracruz, and northeastern Oaxaca. Baumgarten and Williamson (2007) argued that A. palliata could have occurred on the Pacific side of the highland massif of northern Central America. There are historical records that suggest the presence of A. palliata (putatively A. p. mexicana) in this region in Mexico (Estrada and Coates-Estrada 1984) and Guatemala (Handley 1950), but no current populations are reported.

Alouatta palliata aequatorialis
Alouatta palliata aequatorialis occurs in eastern Panama extending through the Serranía del Darién (Anthony 1916, Lawrence 1933) to western Colombia, Ecuador and into the Tumbes region of northwestern Peru (Aquino and Encarnación 1994; Encarnación and Cook 1998; Tirira 2001, 2007). In northern Colombia A. p. aequatorialis is sympatric with A. seniculus in the left banks of the Peye and Atrato rivers in the department of Chocó and perhaps east of the Atrato River, south to the río Sinú (Zuñiga Leal and Defler 2013).

Alouatta palliata coibensis
This howler monkey is known only from Coiba Island and neighbouring Jicarón Island, off the Pacific coast of Panama (Milton and Mittermeier 1977, Méndez-Carvajal 2012).

Alouatta palliata trabeata
This subspecies is endemic to the Azuero Peninsula, Panama (Froehlich and Froehlich 1987, Rowe 2000, Mendes-Carvajal 2005).