The Caatinga is a semi-arid domain, characterized by reduced humidity and high rates of anthropogenic impact. In addition to the low availability of water, carnivorous mammals are still exposed to a number of threats related to landscape modifications.We used data from camera traps and occupancy models to investigate the habitat use by carnivores in an area of Caatinga in northeastern Brazil. We found a negative correlation between the distance from wind farms and the occupancy probability of the jaguar, and a positive correlation with the occupancy probability of the jaguarundi. Puma and jaguarundi occupied primarily sites near watercourses, whereas the occupancy of the crab-eating fox was correlated positively with the presence of poachers. The ocelot was detected more frequently at sites distant from human settlements, whereas the jaguar was detected more often in areas far from wind farms.We found a negative correlation between the distance of water and the detection of the ocelot. The detection of the crab-eating fox was influenced positively by the detection of cattle. In addition to the negative influence of some anthropic activities, our results indicate that water is a very important resource for species, and the few permanent sources of this resource available in the area must be preserved. The replication of our research in other systems, worldwide, that are experiencing similar pressures, should permit a systematic evaluation of the management and conservation strategies needed to rebuild or maintain populations, restore ecosystems, and support conservation policies in human-altered landscapes.Abstract in Portuguese is available with online material. K E Y W O R D Sbiodiversity, habitat use, human activities, semi-arid environment, wind farm S U PP O RTI N G I N FO R M ATI O NAdditional supporting information may be found online in the Supporting Information section at the end of the article.
Phytophagous insects choose their feeding resources according to their own requirements, but their feeding preferences in the semiarid Caatinga have rarely been studied. Flowering trees leads to a greater diversity of flower visitors and their predators in the host plant, but little is known about why the diversity of phytophagous insects not associated with flowers is also increased. The purpose of this study was to evaluate the diversity of sap-sucking, wood-boring and leaf-chewing insects associated with leaf chlorophyll content in flowering and non-flowering plants of Poincianella pyramidalis, an endemic tree of Caatinga. We used a leaf chlorophyll index (LCI) as a surrogate for resource quality, and an entomological umbrella to collect phytophagous insects. We show that trees which bloomed demonstrated higher chlorophyll content, greater abundance and a significant difference in the composition of phytophagous insect species when compared to non-flowering trees (p < 0.05). The results suggest that not only the presence of flowers themselves, but also the higher nutritional quality of leaf tissue, can explain the differences in species diversity and abundance of phytophagous insects. Exceptional flowering trees in the Caatinga area studied may thus act as spots of high quality resources, favouring changes in the diversity of insects in this environment.
The spatiotemporal distribution of a predator within an environment tends to be synchronized with that of its prey, to maximize the efficiency of its hunting behavior. However, small predators may also be obliged to avoid potentially agonistic encounters with larger predators due to interspecific competition and intraguild predation. We used occupancy models and indices of temporal overlap to evaluate whether the occurrence of prey species, ocelots (Leopardus pardalis) and top predators (puma Puma concolor and jaguar Panthera onca) influenced the habitat use and activity patterns of the northern tiger cat (Leopardus tigrinus) and jaguarundi (Herpailurus yagouaroundi) in a region of the semi‐arid Caatinga biome in Bahia, northeastern Brazil. The occurrence of prey had a positive influence on the use of habitat by the small felids. The northern tiger cat was nocturnal‐crepuscular and presented a high degree of temporal overlap with Spix's cavy (Galea spixii) and the rock cavy (Kerodon rupestris). The jaguarundi was diurnal, by contrast and overlapped temporally with the agouti (Dasyprocta nigriclunis). The occurrence of the ocelot did not influence the habitat or daily activity pattern of the jaguarundi, but presented a high degree of temporal overlap with the northern tiger cat, which adopted a strategy of spatial segregation to avoid direct contact with this dominant competitor. The top predators did not influence the spatiotemporal distribution of the small felids, indicating that their niches are segregated by dietary parameters related to differences in body size. Our results indicate that the availability of prey has a more profound influence on the spatiotemporal ecology of the small felids than the occurrence of the top predators, although the presence of the northern tiger cat appeared to be correlated negatively with that of the ocelot. We believe that environmental factors, such as the conservation status, size and isolation of native habitats, may have a fundamental influence on the strategies adopted by the northern tiger cat to mediate its coexistence with the ocelot.
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