• A diversity of biogeographies in an extreme Amazonian wetland habitat

      Householder, Ethan; Janovec, John; Tobler, Mathias W.; Wittmann, Florian; Myster, Randall W. (John Wiley & Sons, Ltd, 2017)
      Amazonian wetlands are associated with lower species diversity relative to surrounding terra firme forests, as well as compositional turnover along strong hydro-edaphic gradients. Because species differ in their ecophysiological response to soil waterlogging, hydrological regime is likely a major determinant of the local diversity, species distribution and assemblage of plant communities in wetland habitats....
    • Do responsibly managed logging concessions adequately protect jaguars and other large and medium-sized mammals? Two case studies from Guatemala and Peru

      Tobler, Mathias W.; Garcia Anleu, Rony; Carrillo-Percastegui, Samia E.; Ponce Santizo, Gabriela; Polisar, John; Zuñiga Hartley, Alfonso; Goldstein, Isaac (2018)
      Large areas of tropical forest have been designated for timber production but logging practices vary widely. Reduced-impact logging is considered best practice and third-party certification aims to ensure that strict standards are met....
    • Effects of selective logging on large mammal populations in a remote indigenous territory in the northern Peruvian Amazon

      Mayor, Pedro; Pérez-Peña, Pedro; Bowler, Mark; Puertas, Pablo; Kirkland, Maire; Bodmer, Richard (2015)
      We examined the effects of selective timber logging carried out by local indigenous people in remote areas within indigenous territories on the mammal populations of the Yavari-Mirin River basin on the Peru-Brazil border. Recent findings show that habitat change in the study area is minimal, and any effect of logging activities on large mammal populations is highly likely to be the result of hunting associated with logging operations. We used hunting registers to estimate the monthly and yearly biomass extracted during timber operations and to calculate the catch per unit effort (CPUE) in subsistence hunting in the community of Esperanza 2 to 5 years before logging activities started and 4 to 7 years after logging began. We also used line transects and the distance method to estimate animal densities before and after logging. We found that 1389 hunted animals and 27,459 kg of mammal biomass were extracted per year from logging concessions. CPUE for ungulates declined; however, it increased for other mammal orders, such as rodents and primates, indicating a shift to alternative prey items. Although collared peccaries (Pecari tajacu) and tapirs (Tapirus terrestris) may also have declined in numbers, this shift may have been caused by a possibly natural population crash in white-lipped peccaries (Tayassu pecari) that coincided with the logging periods. We found no evidence that populations of primates were reduced by the logging activities. Because primates are sensitive to hunting, and their populations were of principal concern as logging commenced, this indicates that these forests remain of high conservation value. The unusual socioeconomic situation of these remote territories may mean that they are compatible with wildlife conservation in the Yavari-Mirin basin.
    • Habitat differentiation among three Nigeria–Cameroon chimpanzee (Pan troglodytes ellioti) populations

      Abwe, Ekwoge E.; Morgan, Bethan J.; Tchiengue, Barthelemy; Kentatchime, Fabrice; Doudja, Roger; Ketchen, Marcel E.; Teguia, Eric; Ambahe, Ruffin; Venditti, Dana M.; Mitchell, Matthew W.; et al. (2019)
      Ecological niche models (ENMs) are often used to predict species distribution patterns from datasets that describe abiotic and biotic factors at coarse spatial scales. Ground-truthing ENMs provide important information about how these factors relate to species-specific requirements at a scale that is biologically relevant for the species. Chimpanzees are territorial and have a predominantly frugivorous diet. The spatial and temporal variation in fruit availability for different chimpanzee populations is thus crucial, but rarely depicted in ENMs. The genetic and geographic distinction within Nigeria–Cameroon chimpanzee (Pan troglodytes ellioti) populations represents a unique opportunity to understand fine scale species-relevant ecological variation in relation to ENMs. In Cameroon, P. t. ellioti is composed of two genetically distinct populations that occupy different niches: rainforests in western Cameroon and forest–woodland–savanna mosaic (ecotone) in central Cameroon. We investigated habitat variation at three representative sites using chimpanzee-relevant environmental variables, including fruit availability, to assess how these variables distinguish these niches from one another. Contrary to the assumption of most ENM studies that intact forest is essential for the survival of chimpanzees, we hypothesized that the ecotone and human-modified habitats in Cameroon have sufficient resources to sustain large chimpanzee populations. Rainfall, and the diversity, density, and size of trees were higher at the rainforest. The ecotone had a higher density of terrestrial herbs and lianas. Fruit availability was higher at Ganga (ecotone) than at Bekob and Njuma. Seasonal variation in fruit availability was highest at Ganga, and periods of fruit scarcity were longer than at the rainforest sites. Introduced and secondary forest species linked with anthropogenic modification were common at Bekob, which reduced seasonality in fruit availability. Our findings highlight the value of incorporating fine scale species-relevant ecological data to create more realistic models, which have implications for local conservation planning efforts.
    • Hot monkey, cold reality: surveying rainforest canopy mammals using drone-mounted thermal infrared sensors

      Kays, Roland; Sheppard, James; Mclean, Kevin; Welch, Charlie; Paunescu, Cris; Wang, Victor; Kravit, Greg; Crofoot, Meg (2018)
      Animals of the rainforest canopies are often endangered by deforestation or hunting but are difficult to survey and study because of the inaccessibility of the treetops, combined with the visual camouflage of many species. Drone-based thermal sensors have the potential to overcome these hurdles by rapidly scanning large forested areas from above, detecting and mapping wildlife based on the contrast between their warm body temperatures and the cool tree canopies....
    • Mapping open space in an old-growth, secondary-growth, and selectively-logged tropical rainforest using discrete return LIDAR

      Jung, Jinha; Pekin, Burak K.; Pijanowski, Bryan C. (2013)
      Light detection and ranging (LIDAR) is a valuable tool for mapping vegetation structure in dense forests. Although several LIDAR-derived metrics have been proposed for characterizing vertical forest structure in previous studies, none of these metrics explicitly measure open space, or vertical gaps, under a forest canopy. We develop new LIDAR metrics that characterize vertical gaps within a forest for use in forestry and forest management applications....
    • Phenotypic variability along a climatic gradient in a perennial afrotropical rainforest understorey herb

      Ley, Alexandra C.; Herzog, Patrick; Lachmuth, Susanne; Abwe, Abwe E.; Christian, Mbella F.; Sesink Clee, Paul R.; Abwe, Ekwoge E.; Morgan, Bethan J.; Gonder, Mary K. (2018)
      Plants evolved in response to climatic conditions, which shaped their geographic distribution, functional traits and genetic composition. In the face of climatic changes, plants have to react by either genetic adaptation, phenotypic plasticity or geographic range shift....
    • The Giant Otter: Giants of the Amazon

      Groenendijk, Jessica (White OwlBarnsley, UK, 2019)
      The aptly named giant otter is exceptionally well adapted to life in rivers, lakes and wetlands in tropical South America. Known in Spanish as lobo del rio or 'river wolf', it can be as long as a human is tall, and is the most social of the world's thirteen otter species. Each individual is identifiable from birth by its pale throat pattern, as unique as your fingerprint. Giant otters are top carnivores of the Amazon rainforest and have little to fear… except man.There are many reasons why scientists and tourists alike are fascinated by this charismatic species. Spend a day in the life of a close-knit giant otter family and you’ll realise why. Learn about their diet and hunting techniques, marking and denning behaviour, and breeding and cub-rearing strategies, including shared care of the youngest members. Become familiar with the complex life histories of individual otters over their 15-year lifespans. And accompany a young disperser during the trials and tribulations of a year spent looking for a mate and a home of its own.Although giant otters have few natural enemies, they became the target of the international pelt trade in the 1940s, and by the early 1970s had been hunted to the brink of extinction. Today, illegal hunting is a minor hazard. So why is the giant otter still endangered? Find out about current threats to the species and discover how a variety of conservation actions are benefiting the otters over the last decades. Then be a part of the solution by acting on the steps we can all take to help further giant otter conservation.