• Assessment of mammal reproduction for hunting sustainability through community-based sampling of species in the wild

      Mayor, Pedro; El Bizri Hani; Bodmer Richard E.; Bowler, Mark (2017)
      ...researchers face severe difficulties in obtaining reproductive data in the wild, so these assessments often rely on classic reproductive rates calculated mostly from studies of captive animals conducted 30 years ago. The result is a flaw in almost 50% of studies, which hampers management decision making....
    • 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.
    • Refining reproductive parameters for modelling sustainability and extinction in hunted primate populations in the Amazon

      Bowler, Mark; Anderson, Matthew J.; Montes, Daniel; Pérez, Pedro; Mayor, Pedro; Fenton, Brock; Fenton, Brock (2014)
      Primates are frequently hunted in Amazonia. Assessing the sustainability of hunting is essential to conservation planning. The most-used sustainability model, the ‘Production Model’, and more recent spatial models, rely on basic reproductive parameters for accuracy. These parameters are often crudely estimated. To date, parameters used for the Amazon’s most-hunted primate, the woolly monkey (Lagothrix spp.), come from captive populations in the 1960s, when captive births were rare. Furthermore, woolly monkeys have since been split into five species. We provide reproductive parameters calculated by examining the reproductive organs of female Poeppig’s woolly monkeys (Lagothrix poeppigii), collected by hunters as part of their normal subsistence activity. Production was 0.48–0.54 young per female per year, and an interbirth interval of 22.3 to 25.2 months, similar to parameters from captive populations. However, breeding was seasonal, which imposes limits on the maximum reproductive rate attainable. We recommend the use of spatial models over the Production Model, since they are less sensitive to error in estimated reproductive rates. Further refinements to reproductive parameters are needed for most primate taxa. Methods like ours verify the suitability of captive reproductive rates for sustainability analysis and population modelling for populations under differing conditions of hunting pressure and seasonality. Without such research, population modelling is based largely on guesswork.