Luiz Gustavo Rodrigues Oliveira-Santos

Integrating economic costs and biological traits into global conservation priorities for carnivores

Background Prioritization schemes usually highlight species-rich areas, where many species are at imminent risk of extinction. To be ecologically relevant these schemes should also include species biological traits into area-setting methods. Furthermore, in a world of limited funds for conservation, conservation action is constrained by land acquisition costs. Hence, including economic costs into conservation priorities can substantially improve their conservation cost-effectiveness. Methodology/Principal Findings We examined four global conservation scenarios for carnivores based on the joint mapping of economic costs and species biological traits. These scenarios identify the most cost-effective priority sets of ecoregions, indicating best investment opportunities for safeguarding every carnivore species, and also establish priority sets that can maximize species representation in areas harboring highly vulnerable species. We compared these results with a scenario that minimizes the total number of ecoregions required for conserving all species, irrespective of other factors. We found that cost-effective conservation investments should focus on 41 ecoregions highlighted in the scenario that consider simultaneously both ecoregion vulnerability and economic costs of land acquisition. Ecoregions included in priority sets under these criteria should yield best returns of investments since they harbor species with high extinction risk and have lower mean land cost. Conclusions/Significance Our study highlights ecoregions of particular importance for the conservation of the worlds carnivores defining global conservation priorities in analyses that encompass socioeconomic and life-history factors. We consider the identification of a comprehensive priority-set of areas as a first step towards an in-situ biodiversity maintenance strategy.

Activity pattern of Atlantic Forest small arboreal mammals as revealed by camera traps

Even though the great majority of the biomass and diversity of mammals in tropical forests inhabit the canopy (Eisenberg & Thorington 1973), most knowledge of this group is based on forest-floor samples (Lowman & Moffett 1993). Studies that include trapping efforts in the canopy are becoming increasingly common (Grelle 2003, Lambert et al . 2005, Malcolm 1995, Patton et al . 2000, Vieira & Monteiro-Filho 2003, Voss et al . 2001), but aspects on the ecology of arboreal small mammals still remain poorly understood. Many species of non-flying mammals co-occur in the canopy and, thus, are expected to use niche dimensions differently to permit coexistence (Cameron et al . 1979). Despite the difficulties of access to and in understanding the three-dimensional use of the arboreal strata by the different species (Emmons 1995), some studies have demonstrated that the differential use of the habitat (Cunha & Vieira 2002, Gentile & Fernandez 1999), of food items (Caceres et al . 2002, Santori et al . 1995) or both (Leite et al . 1996, Mauffrey & Catzeflis 2003), include strategies involved in the division of resources.

Abundance changes and activity flexibility of the oncilla, Leopardus tigrinus (Carnivora: Felidae), appear to reflect avoidance of conflict

We investigated the density and activity of the oncilla, Leopardus tigrinus (Schreber, 1775), a threatened small cat, in the Brazilian Atlantic Forest, using camera-trap data. We described differences in the activity of individuals occurring alone or in sympatry with larger cats. Oncilla presented low densities (7-13 ind./100 km²) and high flexibility in its activity. The oncillas were primarily nocturnal in the absence of other larger cat species - margay, ocelot and puma - but became more diurnal, with a cathemeral activity pattern, when the other cats were present. Oncilla is likely to be in a subordinate position in interactions with larger cats and changes its activity to decrease the chances for interspecific encounters. In this study, however, the presence of other cat species covaries with habitat changes (from coastal forest patches to dense evergreen forests). We also verified the highest oncilla relative abundance in an area with no sympatric larger cats, with abundance decreasing when it was in sympatry with margay, ocelot and puma. Our results, together with recent records of oncilla in other degraded landscapes of the Atlantic Forest of Brazil, provide evidence that oncillas may thrive even in harsh environments where other cats have already been extinct. This raise interesting conservation insights, as in the absence of other cats, L. tigrinus may assume a top predator role of these impoverished vertebrate communities.

Space use by giant otter groups in the Brazilian Pantanal

Abstract Giant otters (Pteronura brasiliensis) live in groups that seem to abandon their territories during the flooding season. We studied the spatial ecology of giant otter groups during dry and wet seasons in the Vermelho and Miranda rivers in the Brazilian Pantanal. We monitored visually or by radiotelemetry 10 giant otter groups monthly from June 2009 to June 2011.We estimated home-range size for all groups with the following methods: linear river length, considering the extreme locations of each group, and fixed kernel. For the radiotracked groups, we also used the k-LoCoh method. Spatial fidelity and habitat selection of giant otter groups were analyzed seasonally. On the basis of k-LoCoh (98%) method, home-range sizes during the wet season (3.6–7.9 km2) were 4 to 59 times larger than during the dry season (0.1–2.3 km2). Home-range fidelity between seasons varied among giant otter groups from 0% to 87%, and 2 radiotagged groups shifted to flooded areas during the wet seasons. Giant otter groups were selective in relation to the composition of the landscape available during the dry seasons, when the river was used more intensively than other landscape features. However, they seemed to be less selective in positioning activity ranges during the wet season. During this season, giant otters were frequently observed fishing in the areas adjacent to the river, such as flooded forest, grassland, and swamps. Resumo Ariranhas (Pteronura brasiliensis) vivem em grupos, que parecem abandonar seus territórios durante a estação de inundação. Nós estudamos a ecologia espacial de grupos de ariranhas durante as estações seca e chuvosa nos rios Vermelho e Miranda no Pantanal brasileiro. Nós monitoramos visualmente ou por rádio telemetria 10 grupos de ariranhas mensalmente entre junho de 2009 e junho de 2011. Nós estimamos o tamanho da área de vida de todos os grupos através dos seguintes métodos: 1) comprimento linear do rio, considerando as localizações extremas de cada grupo, e 2) kernel fixo. Para os grupos monitorados com telemetria nós também usamos o método 3) k-LoCoh. Fidelidade espacial e seleção de habitat dos grupos de ariranhas foi analisada sazonalmente. Baseado no método de k-LoCoh (98%), os tamanhos das áreas de vidas durante a estação chuvosa (3.6 −7.9 km2) foram 4 a 59 vezes maiores do que durante as estações secas (0.1–2.3 km2). Fidelidade de área de vida entre estações variou de 0% to 87% entre os grupos de ariranhas e dois grupos monitorados com rádio telemetria dispersaram para áreas inundadas durante as estações chuvosas. Grupos de ariranhas foram seletivos em relação à composição da paisagem durante as estações secas, quando o rio foi mais intensamente utilizado em relação a outras características da paisagem. No entanto, eles pareceram ser menos seletivos no posicionamento de suas atividades durante as estações chuvosas. Durante essa estação, ariranhas foram freqüentemente observadas pescando em áreas adjacentes ao rio, como florestas inundadas, campos e brejos.

Ecology of the ocelot (Leopardus pardalis) in the Atlantic Forest of Southern Brazil

The ocelot Leopardus pardalis is a medium-sized Neotropical spotted cat with a wide geographic range. The present study was conducted in a reserve in an Atlantic Forest area in southern Brazil, and provided information on ocelot ecology through photographic records. Density estimated by the half of the mean maximum distance moved method resulted in 0.04 ocelots per km2. The minimum home range sizes were obtained by the minimum convex polygon method and were in agreement with other studies for the males recorded. Our female’s home range size was smaller than ranges reported elsewhere. The nocturnal pattern recorded is probably related with prey activity, since it is suggested that ocelots adjust their movements to the probabilities of encountering local prey, or with an evolutionary factor, aiming to avoid competition/predation with larger cats. The low density observed could be a consequence of the conditions of the study area, small and isolated, which indicates the necessity for larger reserves and mechanisms to connect isolated populations.

Landscape features lead to shifts in communities of medium- to large-bodied mammals in subtropical Atlantic Forest

Defaunation is a key ecological issue that has only recently been given sufficient attention. As predicted, evidence so far indicates loss of larger species followed by medium-sized species, leading to cascading effects that propagate throughout entire communities and ecosystems. The Atlantic Forest is among the most important global biodiversity hotspots. These regions have historically been impacted by habitat loss and fragmentation, resulting in landscape changes and negative impacts upon animal communities. This study evaluates community characteristics of medium- and large-sized mammals in subtropical Atlantic Forest, southern Brazil. We gathered data on mammal occurrence using 108 cameras traps located across 8 protected areas. We then tested whether landscape differences impact mammal richness, composition, and community complexity. Specifically, we used a regression tree to evaluate compositional differences as a function of landscape configuration. We analyzed data for 26 species in total, with the number of species per area ranging from 9 to 17. Changes in mammal composition at the landscape scale were most strongly associated with human occupation. Areas with strong human occupation had low species richness, with a predominance of medium-sized omnivores and insectivores species; these conditions led to high defaunation indices. Community complexity was greater in areas with low human occupation, where carnivores (Felidae) were more abundant. Differences in species composition were also linked to altitudinal bands and the ratio of period of time with protected status versus history of land exploitation in a particular area. Analysis of functional groups indicated that intense human occupation had negative effects on larger species, a process that may have impending consequences. Despite defaunation being a serious ecological issue, we assert that taking prompt action may limit or potentially reverse effects of defaunation before the most dramatic changes take place.

Armadilhas de dossel: uma técnica para amostrar formigas no estrato vertical de florestas

Our knowledge of tropical ant fauna is mainly based on samples collected in forest understory or in the soil. In this study, we describe a low-cost trap which is easy to produce and install to sample arboreal ants in forest vertical strata. We also present empirical evidences of the usefulness and effectiveness of such trap providing an example from results obtained in Pantanal forest patches.

Forest cover influences occurrence of mammalian carnivores within Brazilian Atlantic Forest

Habitat fragmentation reduces biodiversity and affects ecological processes that are fundamental for maintaining ecosystem services. We investigated how landscape structure—percent forest cover, patch density, percent cover by edge, perimeter-area ratio, and spatial heterogeneity—affects the diversity of mammalian carnivores at multiple extents within 22 Atlantic Forest landscapes. We hypothesized that 1) species richness of carnivores is positively related to forest cover; and 2) the occurrence of species will vary according to its sensitivity to forest loss and its preference for forest or open areas. Species richness, composition, and occurrence of mammalian carnivores were correlated with several landscape structure metrics. Due to a high correlation among the metrics, we adopted forest cover as the principal predictor variable. We compared a forest cover model to a null model using Akaike Information Criterion (AICc), and evaluated other fragmentation metrics using a redundancy analysis. Carnivore species richness was positively related to forest cover and negatively associated with other fragmentation metrics. However, the responses to landscape structure differed among species, possibly due to their differences in habitat use. Landscape configuration is an important factor influencing carnivore species composition. Forest cover can explain some, but not all, carnivore species occurrence. Our results reinforce the protection of forests as fundamental to the conservation of carnivore species and the ecological processes in which they participate.

Disentangling the effects of habitat, food, and intraspecific competition on resource selection by the spiny rat, Thrichomys fosteri

Animals make directional movements toward resources to satisfy nutritional, reproductive, and protection needs. We evaluated resource selection by the spiny rat (Thrichomys fosteri) in a heterogeneous habitat, disentangling the relative importance of habitat structure, escape cover, food availability, and intraspecific competition. The last 2 variables were estimated directly by explicitly incorporating their spatiotemporal variation in the model. We radiotracked 15 males and 5 females for a median of 10 days per month for 17 months. Used and available resources were estimated at the home-range scale by intersecting the radiotracking locations (used) and random points (available) with resource maps that were either temporally static (measured only once; palm density and bromeliad cover) or dynamic (with temporal variation; arthropod biomass and conspecific abundance). We performed a resource selection function analysis using conditional logistic regression stratified by each individual location. Within their home ranges, spiny rats selected areas with high bromeliad cover and arthropod biomass. There was a negative interaction between conspecific abundance and arthropod biomass. We showed that resource selection by individuals takes into account multiple resources that vary in space and time. Individuals tended to select areas with high escape cover and high food availability balanced by low intraspecific competition.

Suitable animal movement indexes or just geometric correlations? A comment on Püttker et al. 2012

Abstract We investigate the potential flaws of estimating animal home range using indexes based on distance between captures as proposed by Püttker et al. (2012, Journal of Mammalogy 93:115–123). Through simulated capture distributions we demonstrated that distance indexes are inherently correlated with home-range estimates derived from the same data set. We also arrived at a similar conclusion using a real capture data set from the spiny rat (Thrichomys pachyurus). However, distance indexes were not correlated to home range based on radiotelemetry for the same individuals of T. pachyurus. Our results strongly support that the conclusions presented by Püttker et al. (2012) were due to statistical dependence between correlated measures and that these indexes might not represent the biological phenomenon of interest—the home range. Resumo Nós investigamos as potenciais falhas em estimar a área de vida de animais utilizando índices baseados na distância entre capturas propostos por Puttker et al. (2012, Journal of Mammalogy 93:115–123). Através de distribuições espaciais de capturas simuladas, demonstramos que índices de distância estão inerentemente correlacionados com as estimativas de área de vida produzidas pelo mesmo conjunto de capturas simuladas. Nós também obtivemos resultados similares usando um conjunto real de dados de captura-marcação-recaptura de punarés (Thrichomys pachyurus). No entanto, os índices de distância entre capturas não foram correlacionados com as áreas de vidas estimadas usando informações providas por radiotelemetria para os mesmos indivíduos de T. pachyurus. Nossos resultados sugerem fortemente que as conclusões apresentadas por Puttker et al. (2012) foram devido a dependência estatística entre duas estimativas inerentemente correlacionadas, e que índices de distância entre capturas podem não representar o fenômeno biológico de interesse—a área de vida.