Predators, Prey and Habitat Structure: Can Key Conservation Areas and Early Signs of Population Collapse Be Detected in Neotropical Forests?

• Published in: PloS one Vol. 11; no. 11; p. e0165362
• Main Authors: de Thoisy, Benoit, Fayad, Ibrahim, Clément, Luc, Barrioz, Sébastien, Poirier, Eddy, Gond, Valéry
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 09.11.2016; Public Library of Science (PLoS)
• Subjects: Air traffic control; Animal behavior; Animals; Biodiversity; Biology and Life Sciences; Biomass; Birds; Birds - physiology; Canopies; Capture-recapture studies; Collapse; Conservation; Conservation areas; Conservation of Natural Resources - methods; Conservation status; Data acquisition; Deforestation; Density; Disturbance; Ecological models; Ecology; Ecology and Environmental Sciences; Ecology, environment; Ecosystem; Ecosystems; Environmental conditions; Environmental Engineering; Environmental Sciences; Food Chain; Forest biomass; Forests; French Guiana; Geography; Habitats; Human populations; Humans; Identification methods; Image acquisition; Lidar; Life Sciences; Modelling; Models, Theoretical; Monitoring; Neural networks; Optical radar; Panthera - physiology; Panthera onca; Population; Population decline; Population Density; Population Dynamics; Predators; Predatory Behavior - physiology; Prey; Protection and preservation; Radar; Radar data; Radar imaging; Remote sensing; Rodentia - physiology; Rodents; Science; Terrestrial environments; Tropical Climate; Tropical forests; Ungulates; South America; Guyana; Suriname; French Guiana; France; FORET; predation; remote sensing; HAUTEUR; TELEDETECTION; monitoring; forests; ESTIMATION; spatial modelling; assessment; MODELISATION SPATIALE; SURVEILLANCE; lidar; ZONE D'ENVIRONNEMENT PROTEGE; height
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0165362

Tropical forests with a low human population and absence of large-scale deforestation provide unique opportunities to study successful conservation strategies, which should be based on adequate monitoring tools. This study explored the conservation status of a large predator, the jaguar, considered an indicator of the maintenance of how well ecological processes are maintained. We implemented an original integrative approach, exploring successive ecosystem status proxies, from habitats and responses to threats of predators and their prey, to canopy structure and forest biomass. Niche modeling allowed identification of more suitable habitats, significantly related to canopy height and forest biomass. Capture/recapture methods showed that jaguar density was higher in habitats identified as more suitable by the niche model. Surveys of ungulates, large rodents and birds also showed higher density where jaguars were more abundant. Although jaguar density does not allow early detection of overall vertebrate community collapse, a decrease in the abundance of large terrestrial birds was noted as good first evidence of disturbance. The most promising tool comes from easily acquired LiDAR data and radar images: a decrease in canopy roughness was closely associated with the disturbance of forests and associated decreasing vertebrate biomass. This mixed approach, focusing on an apex predator, ecological modeling and remote-sensing information, not only helps detect early population declines in large mammals, but is also useful to discuss the relevance of large predators as indicators and the efficiency of conservation measures. It can also be easily extrapolated and adapted in a timely manner, since important open-source data are increasingly available and relevant for large-scale and real-time monitoring of biodiversity.