An injured pachypleurosaur (Diapsida: Sauropterygia) from the Middle Triassic Luoping Biota indicating predation pressure in the Mesozoic

The Middle Triassic Luoping Biota in south-west China represents the inception of modern marine ecosystems, with abundant and diverse arthropods, fishes and marine reptiles, indicating recovery from the Permian–Triassic mass extinction. Here we report a new specimen of the predatory marine reptile Diandongosaurus, based on a nearly complete skeleton. The specimen is larger than most other known pachypleurosaurs, and the body shape, caniniform teeth, clavicle with anterior process, and flat distal end of the anterior caudal ribs show its affinities with Diandongosaurus acutidentatus, while the new specimen is approximately three times larger than the holotype. The morphological characters indicate that the new specimen is an adult of D. acutidentatus, allowing for ontogenetic variation. The fang-like teeth and large body size confirm it was a predator, but the amputated hind limb on the right side indicate itself had been predated by an unknown hunter. Predation on such a large predator reveals that predation pressure in the early Mesozoic was intensive, a possible early hint of the Mesozoic Marine Revolution.

Comments on a small sabretooth cat in the Abismo Ponta de Flecha Cave, Vale do Ribeira, southeastern Brazil

The Vale do Ribeira, located in southeastern Brazil, is known for many caves with osteological material, including several extinct species. The saber-tooth cat Smilodon populator was a large predator that inhabited the Pleistocene and Holocene of South America. A specimen found in the Abismo Ponta de Flecha Cave based on small bones (metacarpals and phalanges) is commented here. The metacarpals have morphological characteristics of S. populator, but are smaller than that of S. fatalis and Panthera onca and larger than that of S. gracilis. The specimen is among the smallest ever found and is comparable in size to an adult lion.

Human Decision-Making as a Key Factor in the Risk of Wolf–Dog Interactions during Outdoor Activities

As a result of species protection in Poland, wolves now appear in places that are attractive for human recreation, increasing their exposure to dogs. This creates a risk of spontaneous direct interactions between these two canine species. Aggressive interactions between the gray wolf and the domestic dog lead to human–large predator conflicts. This study examined wolf–dog interactions using data collected in an online questionnaire and included questions related to factors that might influence the likelihood of interactions between these canines. One of the most important factors affecting the likelihood of interaction between a dog and a wolf was the distance between the dog and the human. The number of wolves was also important—the more wolves, the more likely they were to interact with dogs. The risk of interaction also significantly increases with decreasing distance to human settlements. There were also statistical differences in terms of the type of outdoor activity being engaged in. Hunting was seven times more likely to result in a wolf–dog interaction than normal walk. We postulate that the choices made by the human (dog control and type of recreation) caring for the dog are an important factor that can reduce the risk of direct contact between dogs and wolves.

An alternating active-dormitive strategy enables disadvantaged prey to outcompete the perennially active prey through Parrondo’s paradox

Background Dormancy is widespread in nature, but while it can be an effective adaptive strategy in fluctuating environments, the dormant forms are costly due to the inability to breed and the relatively high energy consumption. We explore mathematical models of predator-prey systems, in order to assess whether dormancy can be an effective adaptive strategy to outcompete perennially active (PA) prey, even when both forms of the dormitive prey (active and dormant) are individually disadvantaged. Results We develop a dynamic population model by introducing an additional dormitive prey population to the existing predator-prey model which can be active (active form) and enter dormancy (dormant form). In this model, both forms of the dormitive prey are individually at a disadvantage compared to the PA prey and thus would go extinct due to their low growth rate, energy waste on the production of dormant prey, and the inability of the latter to grow autonomously. However, the dormitive prey can paradoxically outcompete the PA prey with superior traits and even cause its extinction by alternating between the two losing strategies. We observed higher fitness of the dormitive prey in rich environments because a large predator population in a rich environment cannot be supported by the prey without adopting an evasive strategy, that is, dormancy. In such environments, populations experience large-scale fluctuations, which can be survived by dormitive but not by PA prey. Conclusion We show that dormancy can be an effective adaptive strategy to outcompete superior prey, recapitulating the game-theoretic Parrondo’s paradox, where two losing strategies combine to achieve a winning outcome. We suggest that the species with the ability to switch between the active and dormant forms can dominate communities via competitive exclusion.

Mesocarnivore community structuring in the presence of Africa's apex predator

Apex predator reintroductions have proliferated across southern Africa, yet their ecological effects and proposed umbrella benefits of associated management lack empirical evaluations. Despite a rich theory on top-down ecosystem regulation via mesopredator suppression, a knowledge gap exists relating to the influence of lions ( Panthera leo ) over Africa's diverse mesocarnivore (less than 20 kg) communities. We investigate how geographical variation in mesocarnivore community richness and occupancy across South African reserves is associated with the presence of lions. An interesting duality emerged: lion reserves held more mesocarnivore-rich communities, yet mesocarnivore occupancy rates and evenness-weighted diversity were lower in the presence of lions. Human population density in the reserve surroundings had a similarly ubiquitous negative effect on mesocarnivore occupancy. The positive association between species richness and lion presence corroborated the umbrella species concept but translated into small differences in community size. Distributional contractions of mesocarnivore species within lion reserves, and potentially corresponding numerical reductions, suggest within-community mesopredator suppression by lions, probably as a result of lethal encounters and responses to a landscape of fear. Our findings offer empirical support for the theoretical understanding of processes underpinning carnivore community assembly and are of conservation relevance under current large-predator orientated management and conservation paradigms.

KERAGAMAN JENIS DAN PERILAKU PEMANGSA PREDATOR YANG BERASOSIASI DENGAN HAMA KEPIK PENGISAP BUAH KAKAOHelopeltis spp. PADA TANAMAN KAKAO

Helopeltis spp. is one of the pests that attack cocoa fruit and can lead to decreased quality and quantity of fruit. Efforts to control that can be done is the utilization of natural enemy one of them is a predator. The large predator populations in the cocoa ecosystem will decrease the pest population of Helopeltisspp. the aim of this study was to know the predator species of pests associated with Helopeltisspp pests and predatory behavior. This research was conducted in Ende Sub-district in 6 villages and Laboratory of Agricultural Faculty of Flores University from March to May 2017. The method used was observation in the field by taking predator samples and observed their morphology and testing of predatory behavior. The variables observed were predators and behavioral diversity and predator predation time. The results obtained 3 species of predators namely Oecophyllasmaragdina, Gasteracanthacancriformis, and Leucaugevenusta. The diversity of predator types associated with Helopeltis spp. all of which are low in Randorama village of 0.29; Randotonda village 0.31; village Ndetundora I 0.26; village Ndetundora II 0.16; village Ndetundora III 0.18; and Embutheru village 0.23. Predator behavior of each predator differs from the predation time of Oecophyllasmaragdina 47 min/ tail, Gasteracanthacancriformis 1 hour 51 min/tail and Leucaugevenusta 1 hour 29 min/ head.

Diet ecology of tigers and leopards in Chhattisgarh, central India

Wild prey base is a potential regulatory parameter that supports successful propagation and secured long term survival of large predators in their natural habitats. Therefore, low wild prey availability with higher available livestock in or around forest areas often catalyzes livestock depredation by predators that eventually leads to adverse situations to conservation initiatives. Thus understanding the diet ecology of large predators is significant for their conservation in the areas with low prey base. The present study reports the diet ecology of tiger and leopard in Udanti Sitanadi Tiger Reserve and Bhoramdeo Wildlife Sanctuary, in central India to know the effect of wild prey availability on prey predator relationship. We walked line transects to estimate prey abundance in the study areas where we found langur and rhesus macaque to be the most abundant species. Scat analysis showed that despite the scarcity of large and medium ungulates, tiger used wild ungulates including chital and wild pig along with high livestock utilization (39%). Leopards highly used langur (43–50 %) as a prime prey species but were observed to exploit livestock as prey (7–9 %) in both the study areas. Scarcity of wild ungulates and continuous livestock predation by tiger and leopard eventually indicated that the study areas were unable to sustain healthy large predator populations. Developing some strong protection framework and careful implementation of the ungulate augmentation can bring a fruitful result to hold viable populations of tiger and leopard and secure their long term survival in the present study areas in central India, Chhattisgarh.

Wildlife Management, Species Injustice and Ecocide in the Anthropocene

Norway has been signatory to the Council of Europe’s Convention on the Conservation of European Wildlife and Natural Habitats (1979) (otherwise known as the “Bern Convention”) since 1986. Nevertheless, every year, Norwegian authorities authorize the killing of brown bears, lynx, wolves and wolverines, which are listed as strictly protected fauna species by the Bern Convention. Norway has a responsibility to protect these species and has several times been brought to court by nongovernmental organizations (NGOs) for failure to satisfy their duties under this international legal instrument. This article discusses Norway’s large predator policy and its compliance with the Bern Convention through an analysis of court decisions and judicial reasoning from the perspective of species justice for nonhumans.