Fruit availability drives the distribution of a folivorous–frugivorous primate within a large forest remnant

Abstract

Understanding the ecological factors that influence the presence, abundance, and distribution of species within their habitats is critical for ensuring their long-term conservation. In the case of primary consumers, such as most primates, the availability and richness of plant foods are considered key drivers of population density at these variables influence the spatial distribution of social units within a finer, habitat patch level scale. We tested the hypothesis that the spatiotemporal availability and richness of plant foods, drive the spatial distribution of brown howler monkeys (Alouatta guariba clamitans) at a fine spatial scale. We established five line transects (2.6-4.3 km long) to census the population of brown howlers in Morro São Pedro, a 1,200 ha Atlantic forest remnant in southern Brazil, every 2 weeks from January to June 2015. We used data from tree inventories performed in sighting and control plots, and phenological surveys of 17 top food tree species to estimate bi-weekly food availability. We recorded a total of 95 sightings. The number of sightings per sampling period ranged from 2 to 12. The availability of fruit (ripe and unripe) was higher in sighting than in control plots, whereas leaf availability and the richness of food tree species was similar. We conclude that the spatial distribution of fruiting trees and the availability of fruit drive the pattern of habitat use, and spacing of brown howler groups in Morro São Pedro.

Howler monkey tolerance to habitat shrinking: Lifetime warranty or death sentence?

“…Therefore, restoring and reconnecting small habitat patches to promote metapopulation functioning can increase the odds of the persistence of a species in highly fragmented landscapes (Bonilla‐Sánchez et al, ; Boyle & Smith, ; Chapman et al, ; Cristóbal‐Azkarate & Arroyo‐Rodríguez, ; Galán‐Acedo et al, ; Mandujano et al, ; Marsh et al, ; Oklander et al, ; Silva & Bicca‐Marques, ). It is also critical to highlight that primates sometimes represent the largest remaining frugivores of the original fauna in these fragmented landscapes (Camaratta, Chaves, & Bicca‐Marques, ), playing important roles as seed dispersers and promoters of forest regeneration (Bufalo, Galetti, & Culot, ; Chaves, Bicca‐Marques, & Chapman, ).…”

Identifying hotspots of woody plant diversity and their relevance with home ranges of the critically endangered gibbon (Nomascus hainanus) across forest landscapes within a tropical nature reserve

“…Consequently, there is a growing interest in developing a more comprehensive approach to assess the effectiveness of hotspots, yet there remains a gap in knowledge concerning hotspots in relation to the conservation of rare and endangered species (Rutledge et al, 2001;Zhao et al, 2016). The spatial patterns of plant species composition and diversity distribution within habitats can influence primate population size and distribution (Camaratta et al, 2017;Souza-Alves et al, 2021). On one hand, since food constitutes the most fundamental and crucial survival resource for animals, Hainan gibbon predominantly rely on plants for sustenance, and the adequacy of their food supply directly influences their survival, reproduction, and population dynamics (Wang et al, 2022).…”

Quantity and quality of seed dispersal by a large arboreal frugivore in small and large Atlantic forest fragments

“…Given that we monitored each study group once every two months, it is likely that even a higher proportion of the tree species from this syndrome that are found in their forest fragments benefit from the seed dispersal promoted by the eclectic fruit-feeding howlers [ 27 , 28 , 31 ]. The fact that howler monkeys are the last large remnant arboreal frugivores of the original fauna [ 51 ] that are capable of ingesting and dispersing large seeds (at least, up to 23 mm as those of “bacupari” Garcinia gardneriana ) in this region further highlights the importance of these dispersers in the region.…”