Biotropica最新文献

Streams and rivers are ubiquitous in tropical forests and can act as barriers for animal movement. This role as barriers can be modulated by connecting features like fallen logs. While logs are commonly observed across rivers, their role as natural bridges has rarely been highlighted. We used motion-activated cameras to characterize how mammals and terrestrial birds use logs across rivers and streams in the Osa peninsula, southern Costa Rica. We investigated factors that influence the frequency and probability of crossing and analyzed interactions like temporal avoidance/attraction or communication. We detected 20 terrestrial mammal species; on most detections (80%) animals used logs to get across the river. Crossing probability depended mostly on the species: species adapted to climbing like tamanduas (Tamandua mexicana), coatis (Nasua narica), and common opossums (Didelphis marsupialis) were more likely to cross than strictly terrestrial species like agoutis (Dasyprocta punctata) and pacas (Cuniculus paca). Animals also crossed logs that were wider, longer, and higher above the water. The diversity of species that used logs suggests they could be important drivers of movement, defining routes across the forest. We found evidence of temporal attraction between coatis, skunks (Conepatus semistriatus), and opossums, probably influenced by scent-marking, observed for 6 of 20 species, suggesting logs also act as inter and intra-specific communication sites. Our results provide evidence of the potential importance of logs and branches and suggest they could be critical features that influence daily movements and long-term space use of many terrestrial vertebrate species in tropical forests.

Mendonça, L. R., J. A. R. Azevedo, M. Gordo, and F. P. Werneck. 2025. “Racing Amidst Change: Urbanization and Climate Alter Functional Traits and Distribution of an Amazonian Parthenogenetic Lizard.” Biotropica 57, no. 5: e70077.

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Tropical rainforests are biodiversity hotspots, where the seeds of 60%–90% of trees are dispersed by animals, yet movement data needed to understand the behaviors and habitat selection of tropical frugivores remain scarce. We GPS-tracked four great blue turacos (Corythaeola cristata) in the Dja Faunal Reserve of southern Cameroon and predicted spatial patterns of seed dispersal within each bird's home range, which covered up to 2.33 km². Using integrated Step Selection Analyses, we related turaco movements to LiDAR-derived measurements of 3D vegetation structure and habitat type. One individual preferred areas of tall canopy height, whereas one preferred intermediate canopy height and avoided swamps and areas of greater vertical vegetation complexity. Seed dispersal patterns for the two turacos with the largest home ranges were predicted to be more diffuse, with local maxima almost an order of magnitude smaller than those with smaller home ranges. Although the great blue turaco is a common bird species throughout central African forests, this is the first study to characterize the species' movement ecology using telemetry. The observed individual variation in movement and habitat use underscores the need to track a broader range of species in central African landscapes, which are increasingly threatened by hunting, logging, habitat loss, and climate change.

Protected Areas (PAs) are a primary mechanism to mitigate habitat loss, deforestation, and land-use change. In Southern Brazil's Atlantic Forest, agricultural expansion has fragmented the Mixed Ombrophilous Forest and Subtropical Highland Grasslands, ecosystems with limited formal protection. Using the MapBiomas land use and cover time series (1985–2021), we quantitatively assessed changes inside and outside (500, 3000, and 10,000 m buffer zones) three federal PAs established in 2005. Our analysis revealed a contrast in conservation outcomes. Forest formations were effectively conserved within PAs, with losses of only −1.82% and −1.40% over 36 years in Araucárias National Park and Mata Preta Ecological Station, respectively. In contrast, the Subtropical Highland Grasslands ecosystem suffered a −31.08% loss inside the Campos de Palmas Wildlife Refuge, a PA specifically designated for their protection. Notably, this internal grassland loss exceeded a −30.28% loss in the broader 10,000 m buffer zone. Buffer zones consistently exhibited higher conversion rates and did not provide an effective conservation gradient, resembling the wider unprotected landscape. Although the PAs successfully stabilized forest cover post-establishment, they failed to curb the conversion of grasslands to agriculture and silviculture. Our findings demonstrate that PA effectiveness is ecosystem-dependent and underscore the urgent need for targeted conservation strategies, including active management and policy reform, to prevent the collapse of the threatened Subtropical Highland Grasslands.

Humans have inhabited Bornean tropical forests for at least 45,000 years, yet the impact of that long-term presence is poorly understood. Borneo's extensive archaeological record and high biodiversity offer a unique laboratory to examine patterns of site selection and the effects of human activity on tropical forest ecosystems. This paper establishes a synthetic literature-based data set of 73 archaeological sites, 47 with radiocarbon or radiometric records dating during the last 6 ka BP. Palaeoclimate, current climate, soil, and terrain variables of these 47 sites are compared against a set of simulated random locations across Borneo. We also consider spatial proximity as a factor influencing human settlement, clustering sites based on location and examining the timing and duration of habitation of sites within the clusters. Finally, we compare the 47 site records against the HYDE-3.2 land-use model to assess correspondence. Our results suggest that during the last 6000 years BP, Bornean human settlements tended to be located in the forests at lower elevations, near coasts and river networks, in higher temperatures and lower precipitation. Comparative sedimentary analysis also suggests preferential use of locations exhibiting lower clay and higher sand content. This combination of conditions likely improved food production and resource supply. Our study highlights the value of integrating archaeological data with global historical land-use and climate models to uncover long-term human–environment interactions. By establishing a cross-site environmental baseline, these findings provide insights into past human settlement patterns and likely human legacies in Borneo's tropical forests.