Modern Predators Research Articles

Kscien’s List; A New Strategy to Discourage Predatory Journals and Publishers (Second Version)

Kscien’s list is currently the most up-to-date blacklist. The current study aims to add some additional properties to the first version of Kscien’s list in order to recognize predatory publications more appropriately. Kscien has developed two other independent lists besides the four previous ones under the titles “Conference list” and “Cumulative list”. The conference list includes the titles of predatory conferences that are independent or sponsored by a particular organization. After vanishing Beall’s list, Kscien’s list remained the only up-to-date list of predatory publications. Nonetheless, the predators' rapid evolution with several mutated strategies compelled Kscien Predatory List Committee to take some necessary actions to keep predatory publications under observation and better recognize them; the conference and cumulative lists would be a necessary option to shed light on modern predators.

Fast Detection of Snakes and Emotional Faces in the Macaque Amygdala.

Primate vision is reported to detect snakes and emotional faces faster than many other tested stimuli. Because the amygdala has been implicated in avoidance and emotional behaviors to biologically relevant stimuli and has neural connections with subcortical nuclei involved with vision, amygdalar neurons would be sensitive to snakes and emotional faces. In this study, neuronal activity in the amygdala was recorded from Japanese macaques (Macaca fuscata) during discrimination of eight categories of visual stimuli including snakes, monkey faces, human faces, carnivores, raptors, non-predators, monkey hands, and simple figures. Of 527 amygdalar neurons, 95 responded to one or more stimuli. Response characteristics of the amygdalar neurons indicated that they were more sensitive to the snakes and emotional faces than other stimuli. Response magnitudes and latencies of amygdalar neurons to snakes and monkey faces were stronger and faster than those to the other categories of stimuli, respectively. Furthermore, response magnitudes to the low pass-filtered snake images were larger than those to scrambled snake images. Finally, analyses of population activity of amygdalar neurons suggest that snakes and emotional faces were represented separately from the other stimuli during the 50–100 ms period from stimulus onset, and neutral faces during the 100–150 ms period. These response characteristics indicate that the amygdala processes fast and coarse visual information from emotional faces and snakes (but not other predators of primates) among the eight categories of the visual stimuli, and suggest that, like anthropoid primate visual systems, the amygdala has been shaped over evolutionary time to detect appearance of potentially threatening stimuli including both emotional faces and snakes, the first of the modern predators of primates.

Taphonomy of Small Predators multi-taxa accumulations: palaeoecological implications

Most small terrestrial vertebrate accumulations in archaeological and palaeontological sites result from predation but we are far from having an exhaustive knowledge of modern predators’ diet, ecological niches and bone modification patterns especially in North African sites. The few neotaphonomic referentials available result from taxon-specialized palaeontologists’ initiatives. A survey of the literature on North Africa predators shows that their prey diversity is high and not only include rodent and shrews but also amphibians, squamates, bats and insects. We performed here a pilot taphonomic study of a Moroccan Tyto alba nest pellets including the whole taxa consumed (birds, rodents, shrews, amphibians, insects). We analyzed bone representation, fragmentation and digestion for each taxa and then compared the results. We observe differences between the taxa but on the whole find higher modification levels for this assemblage compared to roost sites of barn owls from other sites. We used for the comparisons homologous bones like the femur and the humerus and also found differences between the taxa. For example, digestion was lower on amphibians and birds than on micromammals. We discuss here some methodological issues as well as archaeological and palaeoenviromental ones by comparison with the Pleisto-Holocene site of El Harhoura II (Morocco).

Body Size as a Driver of Scavenging in Theropod Dinosaurs.

Theropod dinosaurs dominated Earth's terrestrial ecosystem as a diverse group of predators for more than 160 million years, yet little is known about their foraging ecology. Maintaining a balanced energy budget presented a major challenge for therapods, which ranged from the chicken-sized Microraptor up to the whale-sized Giganotosaurus, in the face of intense competition and the demands of ontogenetic growth. Facultative scavenging, a behavior present in almost all modern predators, may have been important in supplementing energetically expensive lifestyles. By using agent-based models based on the allometric relationship between size and foraging behaviors, we show that theropods between 27 and 1,044 kg would have gained a significant energetic advantage over individuals at both the small and large extremes of theropod body mass through their scavenging efficiency. These results were robust to rate of competition, primary productivity, and detection distance. Our models demonstrate the potential importance of facultative scavenging in theropods and the role of body size in defining its prevalence in Mesozoic terrestrial systems.

Leftover prey remains: a new taphonomic mode from the Late Miocene Cerro Azul Formation of Central Argentina

The Cerro Azul Formation (La Pampa Province, Argentina) comprises a rich vertebrate fauna of small mammals dominated by notoungulates and rodents. The fauna pertains to the Late Miocene specifically to the Huayquerian Stage/Age. Taphonomic analysis of micro-mammals from Estancia Re locality evidenced that the faunal assemblage was accumulated by the activity of a predator. This assemblage was compared with others from the Cerro Azul Formation in Telen and Caleufu localities (La Pampa Province), previously interpreted as products of predator activities. These microfossil accumulations differ from assemblages attributed to pellets and faeces produced by modern predators (nocturnal and diurnal bird raptors and carnivore mammals). However, due to their anatomical representation, degree of bone breakage and presence of tooth marks, they are interpreted as accumulations of uneaten prey remains discarded by the predator. The predator involved could not be determined with certainty, although the presence of tooth marks in some skeletal remains and the presence of coprolites in Telen and Caleufu suggest that it could be a carnivore mammal. Similarities in the accumulation mechanism, patterns of preservation and sedimentary contexts in the three assemblages support the recognition of a new taphonomic mode, termed ‘leftover prey remains’.

A Carapace-Like Bony ‘Body Tube’ in an Early Triassic Marine Reptile and the Onset of Marine Tetrapod Predation

Parahupehsuchus longus is a new species of marine reptile from the Lower Triassic of Yuan’an County, Hubei Province, China. It is unique among vertebrates for having a body wall that is completely surrounded by a bony tube, about 50 cm long and 6.5 cm deep, comprising overlapping ribs and gastralia. This tube and bony ossicles on the back are best interpreted as anti-predatory features, suggesting that there was predation pressure upon marine tetrapods in the Early Triassic. There is at least one sauropterygian that is sufficiently large to feed on Parahupehsuchus in the Nanzhang-Yuan’an fauna, together with six more species of potential prey marine reptiles with various degrees of body protection. Modern predators of marine tetrapods belong to the highest trophic levels in the marine ecosystem but such predators did not always exist through geologic time. The indication of marine-tetrapod feeding in the Nanzhang-Yuan’an fauna suggests that such a trophic level emerged for the first time in the Early Triassic. The recovery from the end-Permian extinction probably proceeded faster than traditionally thought for marine predators. Parahupehsuchus has superficially turtle-like features, namely expanded ribs without intercostal space, very short transverse processes, and a dorsal outgrowth from the neural spine. However, these features are structurally different from their turtle counterparts. Phylogeny suggests that they are convergent with the condition in turtles, which has a fundamentally different body plan that involves the folding of the body wall. Expanded ribs without intercostal space evolved at least twice and probably even more among reptiles.

Feeding behaviour and bone utilization by theropod dinosaurs

Examples of bone exploitation by carnivorous theropod dinosaurs are relatively rare, representing an apparent waste of both mineral and energetic resources. A review of the known incidences and possible ecological implications of theropod bone use concludes that there is currently no definitive evidence supporting the regular deliberate ingestion of bone by these predators. However, further investigation is required as the small bones of juvenile dinosaurs missing from the fossil record may be absent as a result of theropods preferentially hunting and consuming juveniles. We discuss implications for both hunting and feeding in theropods based on the existing data. We conclude that, like modern predators, theropods preferentially hunted and ate juvenile animals leading to the absence of small, and especially young, dinosaurs in the fossil record. The traditional view of large theropods hunting the adults of large or giant dinosaur species is therefore considered unlikely and such events rare. square Behaviour, carnivory, palaeoecology, predation, resource utilization.

First report of sublethal breakage-induced predation on Devonian bivalves

Here we report on the frequency, shape, and position of sublethal, predatory-induced breakage on shells of the common pterineid bivalve genus Ptychopteria from the Middle Devonian of New York. Twenty-six of the 115 well-preserved shells of Ptychopteria examined displayed evidence of at least one repair scar. The capacity to retract the vulnerable mantle deep within the shell and squeeze the valve margins together tightly to seal the shell enabled Ptychopteria to sustain marginal shell damage that was often severe. Repair scars resemble traces made by modern shell-breaking predators, especially decapod arthropods. Stereotyped positioning of the repair scars on the posterior portion of the valve also suggests active selection of an attack site by unknown shell-breaking predators. The relatively high repair frequency for Ptychopteria supports a growing body of evidence that suggests predation pressure intensified in the middle Paleozoic.

Cranial performance in the Komodo dragon (Varanus komodoensis) as revealed by high‐resolution 3‐D finite element analysis

The Komodo dragon (Varanus komodoensis) displays a unique hold and pull-feeding technique. Its delicate 'space-frame' skull morphology differs greatly from that apparent in most living large prey specialists and is suggestive of a high degree of optimization, wherein use of materials is minimized. Here, using high-resolution finite element modelling based on dissection and in vivo bite and pull data, we present results detailing the mechanical performance of the giant lizard's skull. Unlike most modern predators, V. komodoensis applies minimal input from the jaw muscles when butchering prey. Instead it uses series of actions controlled by postcranial muscles. A particularly interesting feature of the performance of the skull is that it reveals considerably lower overall stress when these additional extrinsic forces are added to those of the jaw adductors. This remarkable reduction in stress in response to additional force is facilitated by both internal and external bone anatomy. Functional correlations obtained from these analyses also provide a solid basis for the interpretation of feeding ecology in extinct species, including dinosaurs and sabre-tooth cats, with which V. komodoensis shares various cranial and dental characteristics.

Climate Change and Invasibility of the Antarctic Benthos

Benthic communities living in shallow-shelf habitats in Antarctica (<100-m depth) are archaic in structure and function compared to shallow-water communities elsewhere. Modern predators, including fast-moving, durophagous (skeleton-crushing) bony fish, sharks, and crabs, are rare or absent; slow-moving invertebrates are generally the top predators; and epifaunal suspension feeders dominate many soft-substratum communities. Cooling temperatures beginning in the late Eocene excluded durophagous predators, ultimately resulting in the endemic living fauna and its unique food-web structure. Although the Southern Ocean is oceanographically isolated, the barriers to biological invasion are primarily physiological rather than geographic. Cold temperatures impose limits to performance that exclude modern predators. Global warming is now removing those physiological barriers, and crabs are reinvading Antarctica. As sea temperatures continue to rise, the invasion of durophagous predators will modernize the shelf benthos and erode the indigenous character of marine life in Antarctica.

Microwear on Canines and Killing Behavior in Large Carnivores: Saber Function in Smilodon fatalis

Canids and hyaenids display a high density of features of microwear on canine teeth that reflect their similarity in killing strategy. However, hyaenids tend to have a higher percentage of short and wide features (pits) because of the high percentage of bone in their diet. Canines of felids display relatively fewer features than canids and hyaenids, which suggest that felids apprehend prey by delivering deep, strong bites that result in less abrasion of the canines. I suggest that canids rely more heavily on their canines and incisors for feeding than do felids. Smilodon fatalis, a large saber-tooth cat from the Pleistocene of North America, is similar to living felids in having relatively few features of canines, but differs from cheetahs (Acinonyx jubatus) and African lions (Panthern leo) in having relatively more pits. S. fatalis showed no consistent similarity in features of microwear on canine teeth to six large carnivores (leopard, Panthera pardus; cheetah; African lion; spotted hyaena, Crocuta crocuta; African wild dog, Lycaon pictus; gray wolf, Canis lupus), which suggests that its killing behavior and possibly dietary preference differed from modern predators. S. fatalis may have avoided contact with bone during killing and feeding encounters, which caused fewer features to form on the upper canines.

Evolution of nocturnality in bats: Potential competitors and predators during their early history

Despite their taxonomic and ecological diversity, modern bats (Order Chiroptera) are almost exclusively nocturnal. This behaviour is too ubiquitous to be explained by common patterns of temporal variation in availability of their diverse food sources or by the risk of hyperthermia when flying during the day. Other explanations for bat nocturnality include competition and increased predation risk from birds during the day. In the early and mid Eocene, the known bat fauna consisted of several insectivorous species of sizes similar to those of the modern European assemblage. This fauna was contemporaneous with several species of predatory birds, including owls (Strigiformes), hawks (Accipitridae), falcons (Falconidae) and rollers (Coraciiformes), which were the same size as modern predators on bats. Predation risk could therefore have been a significant factor preventing the early bats from becoming diurnal. Competition from aerial insectivorous birds, however, was less likely to have been significant for bats during the early Eocene, since very few such groups, mainly small Aegialornithidae, were present, with most of the major groups of aerial insectivores evolving later.

Overlapping Species "Choice" by Italian Upper Pleistocene Predators

Overlapping Species "Choice" by Italian Upper Pleistocene Predators