Pitheciids in fragmented habitats: Land cover change and its implications for conservation

Abstract

Pitheciids (Cacajao, Callicebus, Chiropotes, and Pithecia) have experienced habitat loss and fragmentation across their geographic range in South America. Some populations living in habitat fragments live in smaller groups, travel shorter distances, and consume items that are not regularly found in the diets of populations living in continuous habitat; however, these patterns are not consistent across species. I used the IUCN Red List of Threatened Species to delineate the geographic range and conservation status of 43 pitheciid species. I calculated the amount of modified land cover within the range of each species, as well as the extent to which the remaining habitat exists in small fragments and the amount of forest lost from 2000 to 2012. Mean forest fragment size ranged from 12 to 12,027 ha, and mean forest loss from 2000 to 2012 ranged from 10.7% for Chiropotes to 0.9% for Pithecia. Critically Endangered and Endangered species represented 20.9% of the pitheciid species, and 46.5% of these species had population trends documented as decreasing. Total modified land cover was greatest for Callicebus species (18.0% of geographic range), followed by Chiropotes (13.8%), Pithecia (4.4%), and Cacajao (1.1%). Species of greater conservation concern had smaller geographic ranges, and a greater percentage of their range consisting of modified land cover than species of lower conservation concern. Species of greater conservation concern also had a greater percentage of forest lost from 2000 to 2012 and a smaller percentage of the remaining forest being protected. Most studies of pitheciids in fragments have concentrated on census data; the behavior of pitheciids in fragments has been examined for only 9 of the 43 species. Increased data on the responses of pitheciid species to forest loss and fragmentation are necessary in order to address pitheciid conservation, especially in areas undergoing severe habitat loss.

Geographic comparison of plant genera used in frugivory among the pitheciids Cacajao, Callicebus, Chiropotes, and Pithecia

“…Pitheciid genera consume fruit from a large number of plant genera, which is to be expected given the large geographic ranges of the four genera [Boyle, ], the diversity of habitats found within these ranges [Silva Júnior et al, ], and the morphological adaptations that allow pitheciids to consume ripe and unripe fruit parts [Kinzey, ; Norconk et al, ]. We found that 1) Chiropotes and Pithecia fruit lists were the most similar to each other and Callicebus fruit lists were the least similar to the fruit lists of the other genera; 2) overall, and for Callicebus and Chiropotes , fruit lists from locations in close proximity had greater similarities than lists from study sites that were further apart; and 3) fruit lists from forest fragments and continuous forest did not differ in the number of fruit genera used by the pitheciids.…”

“…The geographic distribution of the pitheciids covers 600 million ha in 10 South American countries [Boyle, ; IUCN, ]. Among pitheciids, Cacajao has the smallest total geographic range and Callicebus the largest, and the range of Callicebus extends beyond that of other pitheciids in approximately 25% of its geographic range (i.e., southern Bolivia, Paraguay, southwestern Brazil, Atlantic Forest of Brazil) [Boyle, ; IUCN, ].…”

“…The geographic distribution of the pitheciids covers 600 million ha in 10 South American countries [Boyle, ; IUCN, ]. Among pitheciids, Cacajao has the smallest total geographic range and Callicebus the largest, and the range of Callicebus extends beyond that of other pitheciids in approximately 25% of its geographic range (i.e., southern Bolivia, Paraguay, southwestern Brazil, Atlantic Forest of Brazil) [Boyle, ; IUCN, ]. Pitheciid distribution can be divided into five geographic regions—Guiana Shield, Western Amazon, Central Amazon, Eastern Amazon, and Atlantic Forest—corresponding to the canonical divisions of Neotropical biogeography [Ribeiro et al, ;].…”

“…Within the geographic range of the pitheciids, 5% of the forest was lost from 2000 to 2012, and the greatest extent of deforestation occurred in the southern portion of the Central Amazon, the Eastern Amazon, Paraguayan Chaco, and western portion of the Western Amazon [Boyle, ]. In addition, approximately 88–92% of the original Atlantic Forest has been deforested, and much of the remaining forest consists of fragments <250 ha [Myers et al, ; Ribeiro et al, ].…”

An annotated checklist of the mammals of Paraguay

“…The taxonomy of Neotropical primates has changed considerably in the past few years, reflecting current research efforts focusing on the group across the South American continent. Although Paraguayan specimens have been used in regional studies including morphology (Arístide et al 2014), genetics (Matayoshi et al 1986;Mudry et al 1987;Pargament and Slavutsky 1987;Martínez et al 2004;Mudry et al 2007;Casado et al 2010), phylogenetics and phylogeography (Hoyos et al 2016), ecology (Boyle 2014) and zoonosis (Díaz et al 2007), little research has been done on this group within Paraguay; the few works available focus on rare or uncommon species such as Mico melanurus (Stallings and Mittermeier 1983), Aotus azarae , and on the more common Alouatta caraya (Giordano and Ballard 2010). Conservation status of primates in Paraguay was assessed by Stallings (1985) and Rumiz and Stallings (1989) and has not been revised since.…”