Influence of the landscape matrix on the abundance of arboreal primates in fragmented landscapes

Abstract

Composition of the landscape matrix of surrounding forest fragments is thought to be critically important to the survival of arboreal primates because it offers structures that help the animals move between fragments and other foraging sites. However, little is known about the composition of the matrix used by these animals. The aim of this study was to quantitatively assess the importance of the landscape matrix and its effects on primate abundance, using black howler monkeys (Alouatta pigra) living in a landscape fragmented by the expansion of agriculture and pastures for livestock in southeastern Mexico. In 2008, a complete census of the monkeys was carried out across the 2000-ha landscape matrix, and for every site where we observed monkeys, we recorded canopy height, tree basal area, food-source abundance, and distance to the nearest fragment. A total of 244 howler monkeys, distributed among 48 groups (including six solitary males) were counted in the matrix. Mean troop size was 5.6 ± 2.8 individuals, and the mode was three individuals. The highest number of troops and greatest howler monkey abundance were recorded in the isolated trees, the eucalyptus plantation, and orchards. A generalized linear model revealed that monkey abundance tended to be higher in matrix elements with higher canopy height, greater food availability, and closest to rainforest fragments. These results suggest that it is necessary to take into account the many elements of the landscape when drawing up conservation and habitat management plans, particularly in order to establish connectivity among the fragments and elements of the matrix with native trees.

The Howler Monkey as a Model for Exploring Host-Gut Microbiota Interactions in Primates

“…For example, as energy minimizers, howler monkeys are able to persist in a wide range of habitats, including highly fragmented or anthropogenically impacted areas (Strier 1992 ;Phillips and Abercrombie 2003 ;Bicca-Marques 2003 ;Behie and Pavelka 2005 ;Zunino et al 2007 ;Pozo-Montuy et al 2011 ;BonillaSanchez et al 2012 ), and can endure marked seasonal changes in availability of food items such as mature fruit by exploiting hard-to-digest foods such as mature leaves and unripe fruits (Arroyo-Rodriguez et al 2008 ), instead of dramatically increasing day range or time spent traveling [as observed in other atelines (Di Fiore et al 2011 )]. However, the role of the gut microbiota in allowing howlers to extract suffi cient energy and nutrients from a wide range of resources across seasons and habitats is not well studied, and many questions remain to be answered.…”

Anthropogenic Habitat Modification, Tourist Interactions and Crop-Raiding in Howler Monkeys

“…Primates with low ecological fl exibility, slow reproductive rates, and large home range requirements are the least fl exible in terms of responding to habitat change or destruction (Rylands and Keuroghlian 1988 ;Onderdonk and Chapman 2000 ;Fisher and Owens 2004 ;Michalski and Peres 2005 ;Cowlishaw et al 2009 ). Specifi cally, the atelines are particularly susceptible to anthropogenic disturbance because of their large body size, longevity, low reproductive rates, and dependency on a continuous canopy for locomotion (Di Fiore and Campbell 2007 ;Wiederholt et al 2010 ;Pozo-Montuy et al 2011 ).…”

Local vs landscape drivers of primate occupancy in a Brazilian fragmented region

“…Primate responses to habitat loss and fragmentation have been extensively studied (Mandujano et al 2006;Anderson et al 2007;Arroyo-Rodríguez and Dias 2010;Pozo-Montuy et al 2011). …”