Howler Monkey Positional Behavior

Abstract

This chapter reviews the positional behavior and grasping tail use in Alouatta with the specifi c goal of exploring behavioral diversity among members of this genus. Despite long-term studies, data on positional behavior derive mainly from fi ve species ( Alouatta arctoidea , A. macconnelli , A. seniculus , A. palliata , A. caraya ) and indicate consistent patterns. A diagonal gait, a deliberate quadrupedal walk along single branches, clambering on multiple branches, and vertical climbing are the major locomotor modes, accompanied by varying rates of tailassisted suspensory locomotion. These modes occur more frequently on small and medium branches of mainly horizontal inclination. Regarding feeding postures, above branch sitting is dominant, with below branch tail-limb assisted postures variably representing one third of the postural repertoire. Postural behavior mainly takes place on small branches of horizontal and oblique inclinations in tree peripheries. Data on tail use derive from only three species ( A. macconnelli , A. seniculus , A. palliata ) and consistently indicate that tail-supported behaviors occur more frequently in the context of feeding. Tail-assisted postures appear to increase access to food resources, providing stability and freeing the hands when procuring and processing food items. In addition, the tail is frequently recruited during travel and the context in which it is used depends on both locomotor mode and substrate size. Despite some underlying differences, this positional profi le provides evidence that Alouatta evolved into specifi c adaptive strategies related to social and ecological factors enabling it to exploit multiple habitats throughout central and southern America.Resumen Este capítulo revisa el comportamiento posicional y el uso de la cola en Alouatta , con el objetivo específi co explorar la diversidad conductual en los miembros del género. A pesar de existir estudios de largo plazo, los datos del comportamiento posicional derivan mayormente de 5 especies ( Alouatta arctoidea ,

The vertical stratification of potential bridge vectors of mosquito-borne viruses in a central Amazonian forest bordering Manaus, Brazil

“…chloropterus have previously been collected at higher heights than sampled in this study 25 , 31 and may, therefore, provide a route of arbovirus transmission between humans and monkeys active higher in the forest canopy. Of the monkeys present at the Ducke reserve, Ateles paniscus 86 , 87 and Alouatta species 86 , 88 are most frequently encountered above 20 m but seldom occur at forest edges. Both Chiropotes 86 and Pithecia species 86 , 89 often occur above 15 m, but the latter also occurs below 15 m and is more likely to enter edge habitats.…”

Drivers of jaguar (Panthera onca) and puma (Puma concolor) predation on endangered primates within a transformed landscape in southern Mexico

“…This agrees with reports that forest transformation may intensify predation on canopy dwelling primates by facilitating access to prey (Irwin et al, 2009), due to a lack of large trees and especially in areas close to the forest edge, where the presence of other mammals can be lower (Slater et al, 2023). Additionally, changes in the environment and habitat structure (e.g., microclimate and large tree availability) may also force both spider and howler monkeys to seek resources such as water on the ground (Delgado‐Martínez et al, 2021; Youlatos & Guillot, 2015), or to cross through open areas to reach disconnected forest fragments (Campbell et al, 2005; Martínez‐Mota et al, 2007), which potentially explains the high levels of primate consumption at our study site.…”

Sexual dimorphism and growth inAlouatta palliatabased on 20+ years of field data

“…In locomotory behavior, all three genera can be described as quadrupeds that walk above branches and frequently climb (DuMond, 1968;Fontaine, 1990;Gebo, 1992;Youlatos and Guillot, 2015). Alouatta uses bridging and suspensory behaviors more than Cebus, with assistance from its prehensile tail (Gebo, 1992;Youlatos and Guillot, 2015). Garber and Rehg (1999) review several works that, in combination, demonstrate that the tail of Alouatta is anatomically a specialized locomotory and sensory organ.…”