Type: PhD thesis
Publication date: 23/02/2017

Namesort descending Role
Sérgio Lucena Mendes Advisor *

Examining board:

Namesort descending Role
Adriano Pereira Paglia External Examiner *
Carlos Eduardo de Viveiros Grelle External Alternate *
Karen Barbara Strier Internal Examiner *
Sérgio Lucena Mendes Advisor *
Taissa Rodrigues Marques da Silva Internal Alternate *
Yuri Luiz Reis Leite Internal Examiner *

In a world of highly fragmented natural landscapes, it is convenient to identify different
types of animal movement behavior and how they contribute to the understanding of
dispersal processes and species distribution. Regional demand for agricultural products
creates new patterns of land use and influences deforestation rates, changing the
connectivity between habitats and therefore the degree to which animal populations are
isolated or can maintain gene flow, and influencing the persistence of species in the
landscape. In this context, this thesis addressed hypotheses about how habitat features
affect the distribution and movement of the northern muriqui, an endemic, critically
endangered primate, in an Atlantic Forest region, a hotspot of biodiversity. Using fieldcollected
data, graph theory and individual-based spatially explicit models, we were
able to analyze the muriqui’s population response to landscape variables, make
inferences about the distribution of social groups, animal movement and population
growth, and suggest conservation strategies that can be implemented in the region. We
found that from 1970 to 2008, forest cover increased almost three-fold. The number of
forest patches is diminished but the size increased, a reflection of the natural
regeneration that connected some of the previously isolated patches. We found that
patch size, connectivity and forest growth influence the distribution of muriquis, and
their persistence in the landscape was probably ensured by forest regeneration and their
ability to explore secondary forests. Empirical data showed that isolated forest patches
produced a complete change of the typical behavior of muriquis, a primate with femalebiased
dispersal pattern. At least five females stayed in their natal group and became
sexually active and reproductive, while others left the group and became solitary. Forest
patches functionally connected preserved that typical behavior, with dispersal of
females from one group into another. Other than the expected female dispersal, we also
recorded a fission of one group into two different social groups, in which the smallest
one migrated to another fragment by crossing a road and an eucalyptus plantation. We
developed the MPSG model (Muriqui Population Spread and Growth), which simulates
movement behavior across the landscape by using population dynamics outputs as a
trigger to regulate the events of migration. The simulation resulted in an average
population increase of 2.4-fold in 50 years, with female migration playing an important
role in that growth. More than 60% of females will probably have no success in finding
a mating partner because their dispersal will lead to empty patches. We found that, for
species with dispersal process such as the muriquis, connectivity may be as important as
(or even more important than) habitat size. For conservation purposes, we proposed to
improve the connectivity between patches, to establish a protected corridor of
biodiversity, and the translocation of young females to other groups within the
landscape. This study shows the importance of historical landscape analyses to
understand potential population recovery of endangered species. Models that estimate
the spatial behavior of populations in the landscape using spatial and population
information can be a powerful tool to understand how past landscape features shaped
present species distribution and to project the future persistence of this species.
Key words: Brachyteles hypoxanthus; habitat connectivity; landscape heterogeneity; forest
regeneration; female-biased dispersal; agent-based model

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