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

Wildlife subsistence hunting is a major source of protein for tropical rural populations and a prominent conservation issue. The intrinsic rate of natural increase. (r_max) of populations is a key reproductive parameter in the most used assessments of hunting sustainability. However, 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. We conducted a 15‐year study in the Amazon in which we used reproductive data from the genitalia of 950 hunted female mammals. Genitalia were collected by local hunters. We examined tissue from these samples to estimate birthrates for wild populations of the 10 most hunted mammals. We compared our estimates with classic measures and considered the utility of the use of r_max in sustainability assessments. For woolly monkey (Lagothrix poeppigii) and tapir (Tapirus terrestris), wild birthrates were similar to those from captive populations, whereas birthrates for other ungulates and lowland‐paca (Cuniculus paca) were significantly lower than previous estimates. Conversely, for capuchin monkeys (Sapajus macrocephalus), agoutis (Dasyprocta sp.), and coatis (Nasua nasua), our calculated reproductive rates greatly exceeded often‐used values. Researchers could keep applying classic measures compatible with our estimates, but for other species previous estimates of r_max may not be appropriate. We suggest that data from local studies be used to set hunting quotas. Our maximum rates of population growth in the wild correlated with body weight, which suggests that our method is consistent and reliable. Integration of this method into community‐based wildlife management and the training of local hunters to record pregnancies in hunted animals could efficiently generate useful information of life histories of wild species and thus improve management of natural resources.     

Considering connections between Hollywood and biodiversity conservation

Cinema offers a substantial opportunity to share messages with a wide audience. However, there is little research or evidence about the potential benefits and risks of cinema for conservation. Given their global reach, cinematic representations could be important in raising awareness of conservation issues and species of concern, as well as encouraging greater audience engagement due to their heightened emotional impact on viewers. Yet there are also risks associated with increased exposure, including heightened visitor pressure to environmentally sensitive areas or changes to consumer demand for endangered species. Conservationists can better understand and engage with the film industry by studying the impact of movies on audience awareness and behavior, identifying measurable impacts on conservation outcomes, and engaging directly with the movie industry, for example, in an advisory capacity. This improved understanding and engagement can harness the industry's potential to enhance the positive impacts of movies featuring species, sites, and issues of conservation concern and to mitigate any negative effects. A robust evidence base for evaluating and planning these engagements, and for informing related policy and management decisions, needs to be built.     

Decrease in catalase activity of Folsomia candida fed a Bt rice diet

Here we report the effects of three Bt-rice varieties and their non-Bt conventional isolines on biological traits including survival, reproduction, and the activities of three antioxidant enzymes superoxide dismutase, catalase and peroxidase, in the Collembolan, Folsomia candida. The reproduction was significantly lower when fed Kemingdao and Huahui1 than those feeding on their non-GM near-isogenic varieties Xiushui and Minghui63 respectively, this can be explained by the differences of plant compositions depended on variety of rice. The catalase activity of F. candida was significantly lower when fed the Bt-rice variety Kemingdao compared to the near-isogenic non-Bt-rice variety Xiushui. This suggests that some Bt-rice varieties may impose environmental stress to collembolans. We emphasize that changes in activity of antioxidant enzymes of non-target organisms are important in understanding the ecological consequences for organisms inhabiting transgenic Bt-rice plantations.     

The veterinary drug ivermectin influences immune response in the yellow dung fly (Scathophaga stercoraria)

Phenoloxidase (PO) is a key enzyme involved in the immune response of insects. We show that egg-to-adult exposure to residues of 0.001, but not 0.0005 mg kg⁻¹ ivermectin elevated PO activity in yellow dung flies (Scathophaga stercoraria) developing in cattle dung. Fly fat content was unaffected by the treatments. Therefore, the response of PO was a direct effect of ivermectin and not an indirect one caused by an alteration in body ‘condition’. This supports the non-intuitive conclusion that flies surviving exposure to faecal residues may have enhanced immune function. To our knowledge, this is the first study to assess the effects on PO activity of insecticidal residues in livestock dung. The non-target effects of such residues are of wide interest, given the global use of veterinary products.     

Accumulation of anticoagulant rodenticides in a non-target insectivore, the European hedgehog (Erinaceus europaeus)

Studies on exposure of non-targets to anticoagulant rodenticides have largely focussed on predatory birds and mammals; insectivores have rarely been studied. We investigated the exposure of 120 European hedgehogs (Erinaceus europaeus) from throughout Britain to first- and second-generation anticoagulant rodenticides (FGARs and SGARs) using high performance liquid chromatography coupled with fluorescence detection (HPLC) and liquid-chromatography mass spectrometry (LCMS). The proportion of hedgehogs with liver SGAR concentrations detected by HPLC was 3-13% per compound, 23% overall. LCMS identified much higher prevalence for difenacoum and bromadiolone, mainly because of greater ability to detect low-level contamination. The overall proportion of hedgehogs with LCMS-detected residues was 57.5% (SGARs alone) and 66.7% (FGARs and SGARs combined); 27 (22.5%) hedgehogs contained >1 rodenticide. Exposure of insectivores and predators to anticoagulant rodenticides appears to be similar. The greater sensitivity of LCMS suggests that hitherto exposure of non-targets is likely to have been under-estimated using HPLC techniques.