Density and Spatial Distribution of Buffy-tufted-ear Marmosets (Callithrix aurita) in a Continuous Atlantic Forest

Author(s)

Norris, Darren ^[1] ; Rocha-Mendes, Fabiana ^{[1, 2]} ; Marques, Renato ^[1] ; Nobre, Rodrigo de Almeida ^[1] ; Galetti, Mauro ^[1]

Affiliation

^[1] Univ Estadual Paulista UNESP, Dept Ecol, Lab Biol Conservacao, BR-13506900 Rio Claro, SP - Brazil

^[2] Inst Neotrop Pesquisa & Conservacao, BR-81531980 Curitiba, PR - Brazil

• Document type: Journal article
• Source: INTERNATIONAL JOURNAL OF PRIMATOLOGY; v. 32, n. 4, p. 811-829, AUG 2011.
• Web of Science Citations: 11

Abstract

The continued degradation of forest habitats and isolation of fragmented populations means that the conservation of endemic marmosets in the Brazilian Atlantic forest depends on human interventions including legal protection. Population monitoring is required to ensure effective management and appropriate allocation of conservation resources; however, deriving estimates of population metrics such as density within heterogeneous environments is challenging. We aimed to quantify the population density and spatial distribution of buffy-tufted-ear marmosets (Callithrix aurita) in the northern region of Serra-do-Mar State Park. We incorporated habitat suitability as quantified by a niche modeling algorithm (MAXENT) to refine density estimates obtained via distance methods. We used 6 environmental predictors to model the distribution of Callithrix aurita and used the resulting MAXENT niche model to identify environmental conditions that represent suitable habitat for this species. We used 877.7 km of line transect surveys and distance methods to derive estimates of 2.19 groups or 7.55 individuals/km(2) from direct observations (n = 40), providing an overall population estimate of 1892 (95% CI = 1155-3068) individuals in 250.7 km(2) of Atlantic forest. Our refined density estimate, obtained by combining distance methods and a niche model, yielded a result of 1386 individuals. Suitable habitat was not uniformly distributed across the study area and was most strongly associated with altitude and the type of vegetation cover. We provide a review of previous surveys and find this is the largest known population of Callithrix aurita. Our refinement of density estimates provides a simple and informative addition to the primatologist's toolbox. (AU)

• FAPESP's process: 01/14463-5 - Diagnosis of populations of birds and cynegetic mammals in the conservation units of the São Paulo Atlantic Rainforest
• Grantee: Mauro Galetti Rodrigues
• Support Opportunities: BIOTA-FAPESP Program - Regular Research Grants
• FAPESP's process: 07/03392-6 - Effects of the defaunation gradient on plant herbivory, seed predation and dispersal: the Atlantic Rainforest perspective
• Grantee: Mauro Galetti Rodrigues
• Support Opportunities: Research Projects - Thematic Grants