Scavenging Habits Research Articles

Unknown scavenging habits of an elusive tropical Andean mammal

There is a significant gap in knowledge regarding the basic ecology of many mammal species that inhabit the Neotropical region. The mountain paca (Cuniculus taczanowskii) is an elusive Neotropical rodent, catalogued as “Near Threatened” by the IUCN and whose ecology is largely unknow. To better understand its dietary ecology, we first conducted a literature review on its diet, determining it as primarily herbivorous-frugivorous. However, through a field experiment using photo-trapping in the Madrigal del Podocarpus Reserve (southern Ecuador) to identify the vertebrate scavenger assemblage, we documented for the first time, an unexpected behaviour of this species consuming a significant amount of carrion. This unexpected finding challenges previous assumptions about the mountain paca's diet and raises important questions about its ecological role and the importance of carrion in ecosystems. Our study underscores the need to further explore carrion ecology and its significance in the understudied and biodiverse tropical Andes.

Characterization of intrapuparial development of Musca domestica (Diptera: Muscidae), under different temperatures in laboratory conditions.

Musca domestica (Linnaeus, 1758) (Diptera: Muscidae), popularly known as "housefly", is a highly synanthropic species, with economic, medical-sanitary, veterinary, and forensic importance. It is able to cause damage to health, transmit pathogenic agents, cause infection in domestic animals, and, in its immature stage, cause secondary myiasis. The scavenging habit of its immature stages makes these flies pioneers in colonizing both human and animal carcasses, from the initial stages of corpse decomposition to the final stages. Intrapuparial development studies of all stages of the biological cycle of these insects help estimate pupal age, being useful to forensic entomology to aid in determining the minimum postmortem interval (minPMI). This study describes, morphologically, the external structures of the pupae, under temperatures of 23, 27, and 30 ± 1 °C aiming to identify the characteristics that define their developmental stages and estimation of the pupae age of M. domestica. The whole experiment was carried out under laboratory conditions, with relative humidity 60 ± 10% and 12 hours of photoperiod. The process of pupariation and pupation including pre-pupae phases were observed; larvae pupae apolysis; early cryptocephalic pupae; late cryptocephalic pupae; phanerocephalic pupae; pharate adult, discriminated by eye color (transparent eyes, pink eyes, and red eyes); and the emergency of adults, which occurred in the intervals of 162-180; 138-144, and 96-102 hr, respectively, being described throughout the metamorphosis of the external morphological characteristics of the pupal stage of M. domestica.

The gut microbiome and metabolome of Himalayan Griffons (Gyps himalayensis): insights into the adaptation to carrion-feeding habits in avian scavengers

BackgroundHimalayan Griffons (Gyps himalayensis), large scavenging raptors widely distributed in Qinghai-Tibetan Plateau, have evolved a remarkable ability to feed on carcasses without suffering any adverse effects. The gut microbiome plays an important role in animal physiological and pathological processes, and has also been found to play a health protective role in the vulture adaptation to scavenging. However, the microbial taxonomic diversity (including nonculturable and culturable microbes), functions, and metabolites related to Himalayan Griffons have not been fully explored.MethodsIn the present study, the 28 fecal samples of the Himalayan Griffons and 8 carrion samples were collected and sequenced using high-throughput 16S rRNA gene sequencing methods to analyze the composition and functional structures of the microbiomes. Twelve fecal samples of the Himalayan Griffons were analyzed using untargeted Liquid Chromatography Mass Spectroscopy (LC–MS) to identify metabolites. We used different culture conditions to grow Himalayan Griffons gut microbes. Inhibitory effects of gut beneficial bacteria on 5 common pathogenic bacteria were also tested using the Oxford cup method.ResultsAccording to the results of the culture-independent method, a high abundance of four major phyla in Himalayan Griffons were identified, including Fusobacteria, Firmicutes, Bacteroidetes, and Proteobacteria. The most abundant genera were Fusobacterium, followed by Clostridium_sensu_stricto_1, Cetobacterium, Epulopiscium, and Bacteroides. The predicted primary functional categories of the Himalayan Griffons’ gut microbiome were associated with carbohydrate and amino acid metabolism, replication and repair, and membrane transport. LC–MS metabolomic analysis showed a total of 154 metabolites in all the fecal samples. Cultivation yielded 184 bacterial isolates with Escherichia coli, Enterococcus faecium, Enterococcus hirae, and Paeniclostridium sordellii as most common isolates. Moreover, 7 potential beneficial gut bacteria isolated showed certain inhibition to 5 common pathogenic bacteria.ConclusionsOur findings broaden and deepen the understanding of Himalayan Griffons’ gut microbiome, and highlighted the importance of gut microbiome-mediated adaptation to scavenging habits. In particular, our results highlighted the protective role of gut beneficial bacteria in the Himalayan Griffons against pathogenic bacteria that appear in rotten food resources.

Biomechanical Skull Study of the Aetosaur Neoaetosauroides engaeus Using Finite Element Analysis

Aetosaurs are quadrupedal archosaurs that had a worldwide distribution during the Late Triassic. They had small heads relative to their body size and a long tail, and they are characterized by a dorsal and ventral carapace formed by ornamented and articulated osteoderms. Although aetosaurs historically have been considered the only herbivorous among the early pseudosuchian archosaurs, few analyses quantitatively assess their feeding habits, and some authors have proposed omnivorous and/or scavenging habits for the group. Neoaetosauroides engaeus is an aetosaur from the Late Triassic of the Los Colorados Formation, La Rioja, Argentina. N. engaeus is known from three relatively well-preserved skulls, making it an excellent taxon to study the feeding ecology. We applied the Finite Element Method to estimate bite force and to evaluate the structural response of the skull at different positions during food processing. Our results show that the skull of N. engaeus generated a bite force of 3.6 kN, a magnitude comparable with the measurement made in Alligator mississippiensis, and could resist lateral and longitudinal forces during feeding. This indicates that N. engaeus was capable of hunting of small living prey (e.g., cynodonts) with its jaws, and/or dragging carcasses of larger sizes (e.g., dicynodonts). These results bring new evidence that supports possible zoophagy or omnivory for N. engaeus, thus expanding the potential ecological roles of aetosaurs.

Foraging strategies in four deep-sea benthic species

The feeding behaviour of deep-sea animals is largely understudied despite being of relevance to assess changes in ecosystems functioning in the face of anthropogenic impacts and climate regime shifts. Here, time-lapse videography in dark, cold-water, flow-through laboratory settings was used to study the behaviours of a gastropod (Buccinum scalariforme) and three sea stars (Ceramaster granularis, Hippasteria phrygiana, Henricia lisa) from the bathyal Northwest Atlantic, to build knowledge on their foraging strategies (i.e. food search, assessment and handling). In all species tested, the presence/absence of a palatable food source modulated the speed and directionality of movements. Approach paths were erratic in the absence of palatable food and targeted in its presence: B. scalariforme, C. granularis and H. phrygiana, moved in straight line to the food, while H. lisa moved either in straight line or counterclockwise loop. The four species traveled at mean speeds of 2.9, 0.2, 0.7, and 0.6 cm min−1, respectively. At the finer scale, unprecedented pulses in displacement speed were detected, varying in amplitude and frequency depending on the food item. The results also support more generalist diets and broader scavenging habits in deep-sea sea gastropods and sea stars than assumed from previous studies and knowledge of shallower-water counterparts. Depth-related food limitation may drive greater flexibility in foraging strategies and acceptable food items.

High prevalence, intensity, and genetic diversity of Trichinella spp. in wolverine (Gulo gulo) from Yukon, Canada

BackgroundSpecies of Trichinella are globally important foodborne parasites infecting a number of domestic and wild vertebrates, including humans. Free-ranging carnivores can act as sentinel species for detection of Trichinella spp. Knowledge of the epidemiology of these parasites may help prevent Trichinella spp. infections in northern Canadian animals and people. Previous research on Trichinella spp. in wildlife from Yukon did not identify risk factors associated with infection, or the diversity and identity of species of Trichinella in regional circulation, based on geographically extensive sampling with large sample sizes.MethodsIn a cross-sectional study, we determined the prevalence, infection intensity, risk factors, and species or genotypes of Trichinella in wolverine (Gulo gulo) in two regions of Yukon, Canada, from 2013–2017. A double separatory funnel digestion method followed by mutiplex PCR and PCR-RFLP were used to recover and identify species of Trichinella, respectively.ResultsWe found larvae of Trichinella in the tongues of 78% (95% CI 73–82) of 338 wolverine sampled. The odds of adult (≥ 2 years) and yearling (1 year) wolverine being Trichinella spp.-positive were four and two times higher, respectively, compared to juveniles (<1 year). The odds of Trichinella spp. presence were three times higher in wolverine from southeast than northwest Yukon. The mean intensity of infection was 22.6 ± 39 (SD, range 0.1–295) larvae per gram. Trichinella T6 was the predominant genotype (76%), followed by T. nativa (8%); mixed infections with Trichinella T6 and T. nativa (12%) were observed. In addition, T. spiralis was detected in one wolverine. Out of 22 isolates initially identified as T. nativa in multiplex PCR, 14 were analyzed by PCR-RFLP to distinguish them from T. chanchalensis, a recently discovered cryptic species, which cannot be distinguished from the T. nativa on multiplex PCR. Ten isolates were identified either as T. chanchalensis alone (n = 7), or mixed infection with T. chanchalensis and T. nativa (n = 2) or T. chanchalensis and Trichinella T6 (n = 1)].ConclusionsWolverine hosted high prevalence, high larval intensity, and multiple species of Trichinella, likely due to their scavenging habits, apex position in the food chain, and wide home range. Wolverine (especially adult males) should be considered as a sentinel species for surveys for Trichinella spp. across their distributional range.Graphical

Lead contamination in tissues of large avian scavengers in south-central Europe.

Lead poisoning from spent ammunition is known to affect many avian species. Birds of prey ingest lead when feeding on game shot with lead gunshot or bullets. Raptors with scavenging habits are particularly vulnerable to ingesting lead in areas with intensive hunting and are good indicators of the risk of poisoning from lead ammunition. To assess how much facultative and obligate avian scavengers suffer lead contamination in south-central Europe, between 2005 and 2019 we collected and analysed 595 tissue samples from 252 carcasses of 4 species (golden eagle, bearded vulture, griffon vulture, cinereous vulture). Lead concentrations in organs showed a similar pattern across species with long and small bones revealing the highest median values (5.56 and 6.8mg/kg w.w., respectively), the brain the lowest (0.12), and the liver and kidney the intermediate (0.47 and 0.284). Overall, 111 individuals (44.0%) had lead concentrations above background thresholds in at least one tissue (i.e. >2mg/kg w.w. in soft tissues, >8.33 in bone) and 66 (26.2%) had values indicating clinical poisoning (>6mg/kg w.w. in liver, >4 in kidney, >16.6 in bone). Tissue lead concentrations and incidence of clinical and sub-clinical poisoning were higher in golden eagles and griffon vultures than in bearded and cinereous vultures, likely due to different feeding habits. In all species we found a rapid increase in lead values with age, but differences between age classes were significant only in the golden eagle. Birds with lead fragments in their digestive tract, as detected by X-rays, had higher median lead concentrations, suggesting that hunting ammunition is the main source of lead poisoning. Our results imply that lead impacts the demography of these long-lived species with delayed sexual maturity and low reproduction rate. A rapid transition towards lead-free bullets and gunshot is therefore required across Europe.

Cranial evolution in the extinct Rodrigues Island owl Otus murivorus (Strigidae), associated with unexpected ecological adaptations

Island birds that were victims of anthropic extinctions were often more specialist species, having evolved their most distinctive features in isolation, making the study of fossil insular birds most interesting. Here we studied a fossil cranium of the ‘giant’ extinct scops owl Otus murivorus from Rodrigues Island (Mascarene Islands, southwestern Indian Ocean), to determine any potential unique characters. The fossil and extant strigids were imaged through X-ray microtomography, providing 3D views of external and internal (endocast, inner ear) cranial structures. Geometric morphometrics and analyses of traditional measurements yielded new information about the Rodrigues owl’s evolution and ecology. Otus murivorus exhibits a 2-tier “lag behind” phenomenon for cranium and brain evolution, both being proportionately small relative to increased body size. It also had a much more developed olfactory bulb than congeners, indicating an unexpectedly developed olfactory sense, suggesting a partial food scavenging habit. In addition, O. murivorus had the eyes placed more laterally than O. sunia, the species from which it was derived, probably a side effect of a small brain; rather terrestrial habits; probably relatively fearless behavior; and a less vertical posture (head less upright) than other owls (this in part an allometric effect of size increase). These evolutionary features, added to gigantism and wing reduction, make the extinct Rodrigues owl’s evolution remarkable, and with multiple causes.

Do roadkill aggregations of wild and domestic mammals overlap?

Domestic animals are involved in a large number of traffic accidents and they represent danger to humans due to their size. Despite this, few studies consider domestic animals. That is why we evaluate mammals’ roadkill aggregations in order to locate them and to determine if wild and domestic mammals’ roadkills overlap. In addition, we investigate the influence of the landscape on the location of the aggregations. This study was carried out on the BR-050 highway, an area of Cerrado biome, in Southeastern Brazil. The monitoring was executed from April 2012 to March 2013, by car, at an average speed of 60 km/h, with two observers looking for roadkills on the highway. We found 482 mammals’ roadkills, including 260 (54 %) wild mammals, 164 (34 %) domestic and 58 (12.0 %) undetermined specimens. Of the 21 recorded mammal species, five were domestic. The wild mammals’ roadkill rate was 0.03 (± 0.02) individuals/km/day and the domestic roadkill rate was 0.02 (± 0.01). We detected roadkill aggregations for wild and domestic mammals. Roadkill hotspots of domestic mammals and wild mammals did not overlap. The variables that had the highest influence on wild mammals’ roadkill probability were: agriculture and silviculture cover as positive effects and distance to the nearest river, to the urban perimeter and to a natural fragment as negative effects. For domestic mammals these variables were: area of the smallest fragment and distance to a natural fragment as positive effects and silviculture cover as a negative effect. The explanation for the wild and domestic mammals’ roadkill hotspot non overlapping seems to be the effect of each variable in determining the roadkill hotspot since their effect is different for wild and domestic mammals. On the other hand, this non overlapping can be a result of domestic mammals’ scavenging habits. We propose different kinds of mitigation measures in order to reduce domestic and wild mammals’ roadkill.

EFFECTS OF THE DUMPSITE ON RUNYARARO WEST AND VICTORIA RANCH RESIDENTS MASVINGO CITY, ZIMBABWE

Poor waste management practices are a major challenge in most developing countries like Zimbabwe. A number of reasons which include financial constraints, lack of skilled personnel, lack of interest by the general public to practice good waste management practices and increase in population due to rapid urbanization have led to some residential suburbs being commissioned near dumpsites. Developing countries use varying methods for waste disposal however according to literature most are below the recommended international standards hence this poses a huge danger to the environment and humans living close to the sites of disposal. The study has revealed that people living close to the dumpsite like the Victoria Ranch residents in Masvingo are greatly affected in a number of ways. These mainly include incidences of dysentery cases, high prevalent of rats, mosquitoes in wet seasons, flies in summer, permanent bad odors that prevail throughout the year and bad scavenging habits being practiced by some of their children. As with many disposal sites in developing countries no international practices are being followed so as to promote a healthy living environment to the Victoria Ranch residents and Runyararo West residents. Various reasons were stated by the responsible local authorities for the utilization of an expired dumpsite. However, there is need for the Government to cooperate with the local authorities in waste management practices so as to provide a healthy living environment to every citizen regardless of their location Article visualizations:

Antennular Morphology and Contribution of Aesthetascs in the Detection of Food-related Compounds in the Shrimp Palaemon adspersus Rathke, 1837 (Decapoda: Palaemonidae).

Shrimp are an essential ecological component of marine ecosystems, and have commercial importance for human consumption and aquaculture. Like other decapod crustaceans, shrimp rely on chemical senses to detect and localize food resources by means of chemosensilla that are located mainly on the cephalothoracic appendages. Using the shrimp Palaemon adspersus, a model organism with omnivorous feeding behavior, we aimed to provide comparative information on the role of aesthetascs, antennular sensilla, and flicking behavior in food detection. To this end, we examined i) the morphology of antennular sensilla by field emission scanning electron microscopy, ii) the shrimp's sensitivity to a number of food-related compounds (amino acids and sugars) by means of whole-animal bioassays, and iii) the contribution of the aesthetasc sensilla to food detection. Our results showed that, aside from the aesthetascs, only three other main morphotypes of setae with chemoreceptive features were present in the antennules, thus accounting for relatively simple sensillar equipment. Nevertheless, we found broad-spectrum sensitivity of the shrimp to a number of amino acids (i.e., isoleucine, leucine, methionine, phenylalanine, glycine, tryptophan, cysteine, and tyrosine) and carbohydrates (trehalose, maltose, cellobiose, and fructose) that was consistent with the omnivorous or scavenging habits of the animal. Although aesthetasc ablation attenuated flicking behavior in a chemical stimulus-independent manner, success in detection and short-range localization of food did not rely on the presence of aesthetasc sensilla. This finding confirms the existence of a non-aesthetasc alternative pathway for feeding, with functional redundancy in simple generalist feeder models such as shrimp.

The Feeding Habits of Mesosauridae

Mesosauridae comprises the oldest known aquatic amniotes which lived in Gondwana during the Early Permian. Previous work in the Uruguayan mesosaur-bearing Mangrullo Formation suggested that mesosaurids lived in an inland water body, inferred as moderately hypersaline, with exceptional preservational conditions that justified describing these strata as a Fossil-Lagerstatte. Exquisitely preserved articulated mesosaur skeletons, including gastric content and associated coprolites, from the Brazilian Irati Formation in the State of Goias (central-western Brazil) indicate excellent conditions of preservation, extending the Konservat-Lagerstatte designation to both units in the Parana Basin. The near-absence of more resistant fossil remains, like actinopterygian and temnospondyl bones, demonstrates the faunistic poverty of the mesosaur-bearing “salty sea”. Our studies of the alimentary habits of mesosaurids through the use of stereoscopic microscopy, light and electronic microscopy, and X-ray diffractometry suggest that the diet of mesosaurids was predominantly composed of pygocephalomorph crustaceans (possibly not exceeding 20 mm in length). However, the presence of bones and bone fragments of small mesosaurs in the gastric content, cololites, coprolites, and possible regurgitalites may also indicate cannibalistic and/or scavenging habits. Cannibalism is relatively common among vertebrates, particularly during conditions of environmental stress, like food shortage. Likewise, the apparent abundance of pygocephalomorph crustacean fossils in the Irati and Mangrullo Formations, outside and within the studied gastric, cololite, and coprolite contents, might have to do with environmental stress possibly caused by volcanic activity, in particular ash spread into the basin during the Early Permian. In this context, casual necrophagy on the dead bodies of small mesosaurs and large pygocephalomorphs might have been an alternative alimentary behavior adopted for survival in mesosaurs.

Artefactual incised wounds due to postmortem predation by the Sri Lankan water monitor (kabaragoya)

Monitor lizards are large reptilian animals mostly seen around water based habitats. Sri Lanka has an endemic water monitor lizard called the kabaragoya (Varanus salvator salvator) which is perhaps the most common large animal scavenger in the country. Scavenging by the kabaragoya can result in postmortem incised injuries which are caused by their sharp pointed claws as they grip or crawl over a dead body. The author presents four cases where these claw marks raised significant medicolegal issues. In one case of a young female they mimicked defense injuries that might be seen in a person that was killed with heavy sharp weapon trauma to the head. In another case, claw marks on the face raised homicidal allegations in an immersion death following intoxication. In a case of suicidal drowning these injuries simulated self-inflicted cuts. The fourth case shows how claw marks complicated the investigation of a dismembered upper limb. Kabaragoya claw marks are mostly seen in decomposed and macerated bodies recovered from water. Injuries are mostly superficial and limited to skin and soft tissues. Bony injuries are not seen. Awareness of the creature's scavenging habits and careful analysis of the appearance and distribution of the injuries is essential to differentiate claw marks from sharp weapon trauma.

Reconstructing the diet of a 505-million-year-old arthropod: Sidneyia inexpectans from the Burgess Shale fauna

The feeding ecology of the 505-million-year-old arthropod Sidneyia inexpectans from the middle Cambrian (Series 3, Stage 5) Burgess Shale fauna (British Columbia, Canada) is revealed by three lines of evidence: the structure of its digestive system, the fossilized contents of its gut and the functional anatomy of its appendages. The digestive tract of Sidneyia is straight, tubular and relatively narrow in the trunk region. It is enlarged into a pear-shaped area in the cephalic region and stretches notably to form a large pocket in the abdomen. The mouth is ventral, posteriorly directed and leads to the midgut via a short tubular structure interpreted as the oesophagus. Anteriorly, three pairs of glands with internal, branching tubular structures open into the digestive tract. These glands have equivalents in various Cambrian arthropod taxa (e.g. naraoiids) and modern arthropods. Their primary function was most likely to digest and assimilate food. The abdominal pocket of Sidneyia concentrates undigested skeletal elements and various residues. It is interpreted here as the functional analogue of the stercoral pocket of some extant terrestrial arachnids (e.g. Araneae, Solifugae), whose primary function is to store food residuals and excretory material until defecation. Analysis of the gut contents indicates that Sidneyia fed largely on small ptychopariid trilobites, brachiopods, possibly agnostids, worms and other undetermined animals. Sidneyia was primarily a durophagous carnivore with predatory and/or scavenging habits, feeding on small invertebrates that lived at the water-sediment interface. There is no evidence for selective feeding. Its food items (e.g. living prey or dead material) were grasped and manipulated ventrally by its anterior appendages, then macerated into ingestible fragments and conveyed to the mouth via the converging action of strong molar-like gnathobases. Digestion probably took place within the anterior midgut via enzymes secreted in the glands. Residues were transported through the digestive tract into the abdominal pocket. The storage of faeces suggests infrequent feeding. The early diagenetic three-dimensional preservation of the digestive glands and abdominal pocket may be due to the capacity of Sidneyia to store Phosphorus and Calcium (e.g. spherites) in its digestive tissues during life as do, for example, modern horseshoe crabs.

Paleoecology of the mammalian predator guild of Southern Patagonia during the latest Pleistocene: Ecomorphology, stable isotopes, and taphonomy

During the late Pleistocene, Patagonia had a rich fauna of large mammals including some megamammals such as ground sloths (Mylodon darwini), horse (Hippidion saldiasi), and camelids (e.g., Lama guanicoe). The carnivore guild was represented by several extinct taxa such as the sabretooth cat (Smilodon), the Patagonian Panther (Panthera onca mesembrina), a short-faced bear (Arctotherium tarijense) and a large fox (Dusicyon avus), but also by the extant puma (Puma concolor). In order to reconstruct the relationships within the predator guild and between these carnivores and their potential prey, body size, prey size and diet habits of each predator were estimated. These results are complemented with stable isotopic analyses and taphonomic information. Results indicate that the guild was composed of three felids that were large hypercarnivores, two of which (Smilodon, P. onca) could prey on most large mammals. Morphology suggests that the short-faced bear was mainly an omnivore that may have scavenged and occasionally hunted medium-large mammals like camelids and horses. D. avus was slightly larger and more carnivorous than the living culpeo fox (Lycalopex culpaeus), and preyed mostly on small mammals (rodents) but occasionally on camelids. Stable isotopes (δ13C and δ15N) are congruent with these interpretations, although they indicate that Arctotherium and D. avus were highly carnivorous. This could be explained by scavenging habits. Stable isotopes also indicate that P. o. mesembrina ate larger proportions of Hippidion and Lama gracilis. Taphonomic studies showed that P. o. mesembrina gnawed bones of Mylodon, Hippidion and camelids, a result that suggests that these taxa were common prey, and agrees with the ecomorphological and stable isotope interpretations. The diversity of potential prey is lower than that observed in lower latitudes (e.g., Pampean Region) while the number of predators is similar, a relationship that could be explained by the high latitude where these mammals lived.

New Insights into the Skull of Istiodactylus latidens (Ornithocheiroidea, Pterodactyloidea)

The skull of the Cretaceous pterosaur Istiodactylus latidens, a historically important species best known for its broad muzzle of interlocking, lancet-shaped teeth, is almost completely known from the broken remains of several individuals, but the length of its jaws remains elusive. Estimates of I. latidens jaw length have been exclusively based on the incomplete skull of NHMUK R3877 and, perhaps erroneously, reconstructed by assuming continuation of its broken skull pieces as preserved in situ. Here, an overlooked jaw fragment of NHMUK R3877 is redescribed and used to revise the skull reconstruction of I. latidens. The new reconstruction suggests a much shorter skull than previously supposed, along with a relatively tall orbital region and proportionally slender maxilla, a feature documented in the early 20th century but ignored by all skull reconstructions of this species. These features indicate that the skull of I. latidens is particularly distinctive amongst istiodactylids and suggests greater disparity between I. latidens and I. sinensis than previously appreciated. A cladistic analysis of istiodactylid pterosaurs incorporating new predicted I. latidens skull metrics suggests Istiodactylidae is constrained to five species (Liaoxipterus brachyognathus, Lonchengpterus zhoai, Nurhachius ignaciobritoi, Istiodactylus latidens and Istiodactylus sinensis) defined by their distinctive dentition, but excludes the putative istiodactylids Haopterus gracilis and Hongshanopterus lacustris. Istiodactylus latidens, I. sinensis and Li. brachyognathus form an unresolved clade of derived istiodactylids, and the similarity of comparable remains of I. sinensis and Li. brachyognathus suggest further work into their taxonomy and classification is required. The new skull model of I. latidens agrees with the scavenging habits proposed for these pterosaurs, with much of their cranial anatomy converging on that of habitually scavenging birds.

RAVENS AND CROWS IN IRON AGE AND ROMAN BRITAIN

SummaryThe raven and crow skeletons from Danebury are re‐examined, taking into account their taphonomy, their context and the associated finds. Raven and crow burials from other Iron Age and Roman sites are surveyed, again with a discussion of their context and associated finds where these could be ascertained. Taken together, the evidence makes it clear that most if not all were deliberate burials, often at the base of pits. We demonstrate how interpretations of such burials have changed, with zooarchaeologists initially proposing functional explanations and archaeologists readier to accept that the burials were deliberate. We go on to argue that the unique character of ravens and crows, including their tolerance of humans, their scavenging habits, and their voice, led to their playing an important role in Iron Age and Roman rites and beliefs.

Crinoids for lunch? An unexpected biotic interaction from the Upper Ordovician of Scotland

Specimens of the polyplacophoran mollusk ‘ Helminthochiton ’ thraivensis Reed from the Upper Ordovician of southwest Scotland provide rare examples of complete valve series preserved in near life position, albeit as external molds. Application of high-resolution X-ray microtomography to one such specimen has revealed the exceptional preservation of its last meal, which included elements of a crinoid column, in its intestine. The interaction was either predatory or scavenging; extant chitons are not known to be crinoidivorous. This is the earliest direct record of predation or scavenging on crinoids in the fossil record. It is also the first indication that the broad axial canal of primitive crinoids may have contained nutritious tissues. The predatory or scavenging habit of H. thraivensis is consistent with its inferred phylogenetic position as a stem-group aplacophoran and provides new data suggesting an origin of carnivory early in the evolution of this clade.

Chronic wasting disease (CWD) susceptibility of several North American rodents that are sympatric with cervid CWD epidemics.

Chronic wasting disease (CWD) is a highly contagious always fatal neurodegenerative disease that is currently known to naturally infect only species of the deer family, Cervidae. CWD epidemics are occurring in free-ranging cervids at several locations in North America, and other wildlife species are certainly being exposed to infectious material. To assess the potential for transmission, we intracerebrally inoculated four species of epidemic-sympatric rodents with CWD. Transmission was efficient in all species; the onset of disease was faster in the two vole species than the two Peromyscus spp. The results for inocula prepared from CWD-positive deer with or without CWD-resistant genotypes were similar. Survival times were substantially shortened upon second passage, demonstrating adaptation. Unlike all other known prion protein sequences for cricetid rodents that possess asparagine at position 170, our red-backed voles expressed serine and refute previous suggestions that a serine in this position substantially reduces susceptibility to CWD. Given the scavenging habits of these rodent species, the apparent persistence of CWD prions in the environment, and the inevitable exposure of these rodents to CWD prions, our intracerebral challenge results indicate that further investigation of the possibility of natural transmission is warranted.

Community structure and food web based on stable isotopes ( δ15N and δ13C) analysis of a North Eastern Atlantic maerl bed

Maerl beds are highly biodiverse biogenic substrata that have been receiving increasing attention in the last decade. Although maerl beds represent important nursery areas for commercial fishes and molluscs, little is known on the trophic web of their communities. Community structure parameters of maerl bed of the Bay of Brest (species richness, abundance, biomass and dominating species) were studied in parallel with the carbon and nitrogen isotopic composition of their main benthic species (macrofaunal, and megafaunal organisms) in order to assess the trophic levels and differences in the potential food sources of maerl inhabitants. The major potential sources of energy were identified to originate either from epiphytic macroalgae and microphytobenthos both growing on maerl thalli, together with sedimenting (sedimentary) particulate organic matter (POM) originating from the water column. The majority of the macro- and megafaunal organisms investigated were filter feeders, selective-deposit feeders and predators/scavengers. Filter feeders fall into three different groups representing different trophic pathways (i) sponges feeding directly on POM (water column filter feeders I), (ii) ascidians and holothurians feeding on POM and probably captured pelagic preys (water column filter feeders II), and (iii) filter feeding molluscs and crustaceans were hypothesised to feed on microphytobenthos or on decaying sedimented POM (Interface filter feeders). Selective deposit feeders were also divided into two subgroups. Carnivores were also distinguished between those with scavenging habits and true predators. Coupling of the trophic levels observed with the community biomass structure revealed that most of the benthic biomass derives its food from detritic sedimented POM and/or microphytobenthos, with interface filter feeders (23% of the biomass), selective deposit feeders (12%). Carnivores made up to 14% of the total biomass. Generally stable isotopes ratio mean values overlap and cover a large range within feeding types, indicating a strong overlap in food sources and a high degree of complexity of the food web presumably due to the diversity of the potential food sources.