Mammalian Biology 80 (2015) 431–439 Contents lists available at ScienceDirect Mammalian Biology jou rnal homepage: www.elsevier.com/locate/mambio Original Investigation The home range and multi-scale habitat selection of the threatened maned three-toed sloth (Bradypus torquatus) a b,∗ c c Nereyda Falconi , Emerson M. Vieira , Julio Baumgarten , Deborah Faria , c Gastón Andrés Fernandez Giné a Universidade Estadual de Santa Cruz (UESC), Departamento de Ciências Biológicas, Programa de Pós-graduac¸ ão em Ecologia e Conservac¸ ão da Biodiversidade, Rodovia Ilhéus Itabuna, Km 16, CEP 45650-000, Ilhéus, Bahia, Brazil b Laboratório de Ecologia de Vertebrados, Departamento de Ecologia, Instituto de Ciências Biológicas, Universidade de Brasília, Campus Darcy Ribeiro, C.P. 04457, Brasília, DF 70910-900, Brazil c Universidade Estadual de Santa Cruz (UESC), Departamento de Ciências Biológicas, Laboratório de Ecologia Aplicada à Conservac¸ ão, Rodovia Ilhéus Itabuna, Km 16, CEP 45650-000, Ilhéus, Bahia, Brazil a r t i c l e i n f o a b s t r a c t Article history: Habitat selection is a scale-dependent process of paramount importance to the understanding of how Received 30 July 2014 species deal with environmental variation. This process has practical implications for wildlife conserva- Accepted 30 January 2015 tion, aiding in the identification of key resources for animals and in the definition of scales relevant to Handled by Francesco Ferretti the proposal of practical conservation actions. In this study, we investigated in different spatial scales the Available online 7 February 2015 habitat selection of the maned three-toed sloth (Bradypus torquatus), a threatened and endemic arboreal folivore of the Atlantic rainforest (vulnerable, sensu IUCN). We radio-tracked and monitored seven sloths Keywords: for 18 months in landscapes of Southern Bahia, Brazil, the current core region of the species’ distribution. Atlantic forest The average values of the home-range estimates were low, but varied considerably among individuals Habitat use Radiotelemetry regardless of the estimator (from 0.95 to 27.8 ha, MCP method, and from 0.39 to 21.52 ha, fixed kernel Forest structure method). At the landscape scale, the maned sloths preferred early secondary forest and shade cacao Shaded cocoa plantation plantations, avoided open areas, and occupied late secondary forest as expected compared to its avail- ability. At the home range scale, however, the sloths did not show preference for any forest category, though, again, avoided open areas. At smaller spatial scales, the sloths were highly selective towards forest patches characterized by complex vegetation structures (i.e., areas with a high density of trees, closed and dense canopies), and selected large trees with lianas and bromeliads and also with connected crowns. The high selectivity observed at finer scales appeared to be the result of limited spatial percep- tion and experience due to the species’ characteristic slow mobility. Our results support the notion that maned sloths can effectively occupy (and even select for) disturbed forested habitats. However, we do not know whether sloth populations are viable in landscapes containing only disturbed habitats or low proportions of undisturbed habitats. © 2015 Deutsche Gesellschaft für Säugetierkunde. Published by Elsevier GmbH. All rights reserved. Introduction of habitat selection affect species distribution and abundance (Saavedra-Rodríguez et al., 2012) and are often scale dependent Habitat loss, disturbance, and fragmentation are synergistic pro- (Kelt et al., 1999; Morin et al., 2005; Finlayson et al., 2007). Due cesses that account for the current and unprecedented rates of to the fact that ecosystem processes encompass different spatial species loss on a global scale (Fischer and Lindenmayer, 2007). scales, the understanding of the effects of scale-dependent vari- Due to the fact that extinction proneness is closely linked with a ation in habitat and resource quality is highly relevant for the species’ capacity to utilize and thrive in disturbed, anthropogenic effective conservation of any species (Milne et al., 1989). habitats, species-specific information on habitat use and selection The evaluation of habitat-use patterns is particularly needed for is of paramount importance for conservation purposes. Patterns the establishment of adequate strategies for the conservation of rare, threatened, and highly-specialized species (Croak et al., 2013), such as the maned three-toed sloth (or simply maned sloth) Brady- ∗ pus torquatus (Mammalia, Bradypodidae). It is an arboreal folivore Corresponding author. Tel.: +55 61 31072998; fax: +55 61 31072904. E-mail address: [email protected] (E.M. Vieira). endemic to the Brazilian Atlantic forest whose populations are http://dx.doi.org/10.1016/j.mambio.2015.01.009 1616-5047/© 2015 Deutsche Gesellschaft für Säugetierkunde. Published by Elsevier GmbH. All rights reserved. 432 N. Falconi et al. / Mammalian Biology 80 (2015) 431–439 currently listed as vulnerable due to habitat loss and fragmentation forest fragments, and 16% early secondary forests (Faria et al., 2007). (Machado et al., 2008; IUCN, 2014). This species inhabits isolated Shaded cacao plantations cover 6% of the landscape, the majority of areas of central-northeastern to central portion of the Atlantic for- which are quite small (median patch size: 2.73 ha) and immersed in est, from Rio de Janeiro to Southern Sergipe, along the coast of Brazil a forest-dominated landscape (Faria et al., 2007). Open areas make (Hirsch and Chiarello, 2011). The region of Southern Bahia main- up the remaining ∼27% of the landscape. Therefore, forested areas, tains the largest and most genetically diverse population of this including shaded cacao plantations, make up the bulk of the avail- species (Lara-Ruiz and Chiarello, 2005; Hirsch and Chiarello, 2011), able habitat in the region. These plantations are the result of specific and thus represents a key location where conservation actions management interventions that vary according to region. Previous should be focused. studies that compared native forests with shaded plantations in Our current limited knowledge on the space use of the maned the Una region of Southern Bahia indicated that these latter form sloths shows wide variation in individual home range estimates, a distinct forest category, characterized by decreasing densities of varying from 0.44 to 29.33 ha in the Southern Bahia state in North- woody lianas and foliage within the superior forest strata (Faria, eastern Brazil (Cassano et al., 2011), 0.8 to 10.8 ha in the Espírito 2002). In particular, the shaded cacao plantations of Rebio-Una and Santo state (Chiarello, 1998; Chiarello et al., 2004), and 4.7 to 16.2 ha its neighboring farms commonly show higher structural complex- in the Rio de Janeiro state (Pinder, 1997). Such variation may be ity and greater density of native trees compared to the shaded cacao attributed not only to differences in the methodologies of previous plantations of other regions of Southern Bahia, this mainly due to studies, but also to distinct individual needs and to specific features the Rebio-Una’s laws and conservation goals. that characterize distinct forest types (Chiarello, 2008), as well as the landscape contexts of each study area. Sloth capture and radiotracking The available information on the habitat selection of maned sloths comes from one adult sloth and two juveniles from a sin- We captured seven maned sloths between May 2011 and March gle plantation in Southern Bahia (Cassano et al., 2011). This study 2012 (Table 1). The sloths were physically immobilized following suggested that sloths use mature forests and that they may pre- a technique used in previous studies (Chiarello, 1998; Chiarello fer shaded cacao plantations and avoids pastures, swamps, or early et al., 2004; Cassano et al., 2011), and each sloth was fitted with a secondary forests (Cassano et al., 2011). ball-chain collar attached to a VHF radiotransmitter (Biotrack Ltd.; Given the scarcity of data on the home range and habitat selec- Model TW3SM) weighing 30 g (<1% of the weight of the animals). tion of maned sloths and their necessity for conservation purposes, Four maned sloths were captured inside the forest and released we evaluated patterns of maned sloths’ habitat use at different back into the same tree where they had been captured. The other scales within the landscape of Southern Bahia. More specifically, three animals were captured after being sighted by local people or we aimed to (i) estimate the home range size of maned sloths in park rangers on the roads of the Rebio-Una near high hunting pres- Southern Bahia, (ii) investigate the species’ habitat selection and its sure areas. We translocated these sloths into more protected areas level of congruence across four different spatial scales (landscape, within the Rebio-Una. Except for one individual whose radio signal home range, forest patch, and tree levels), and (iii) identify features was lost at the end of the study, we recaptured the remaining six connected to habitat preference or avoidance in each spatial scale. sloths and removed the radio collars without injury. We followed Sloths are slow-moving and low-metabolism animals whose the recommended procedures of the American Society of Mam- physiological and locomotion constraints do not allow for leap- malogists (Sikes and Gannon, 2011) in the capture, handling, and ing between trees to cross canopy discontinuities, which results tagging