Academic literature on the topic 'Animal necrophagy'

Temporary aquatic habitats are contingent on the allochthonous inputs of plant and animal detritus, whose quality and availability can significantly affect the species developing in these habitats. Although animal detritus (i.e., invertebrate carcasses) is a high-quality food, it is an unpredictable and variable resource. On the contrary, conspecific individuals (dead or alive) are a nutritionally high-quality food source that is always available. In this context, conspecifics consumption, by cannibalism or necrophagy, can be a good strategy to overcome nutrient limitation and allow individual maintenance and development. Here, we tested this hypothesis by using the tiger mosquito Aedes albopictus. By carrying out laboratory and semi-field experiments, we first estimated the relative rate of cannibalism and necrophagy, under different larval densities. Then, we analyzed the effects of cannibalism and necrophagy on larval survival and adult yield. Consistent with our hypothesis, we found that cannibalism and necrophagy occurred under all experimental conditions, and that conspecific consumption had positive effects on individual development, as it significantly increased the rate of adult emergence and larval survival. Interestingly, about 50% of the initial cohort was consumed by conspecifics, suggesting that cannibalism and necrophagy can drive an important resources loop in temporary aquatic habitats.

The life cycle, infectivity and clinical effects of Capillaria hepatica, a nematode parasite of the liver of Mus musculus, were investigated as a prelude to assessment of the potential of the organism to suppress populations of this economic pest. Eggs of the parasite are deposited in the liver of the host and are not released during the life of that animal. C. hepatica was not transmitted by a trans-seminal, trans- placental or trans-mammary route. A high rate of transmission of C. hepatica (prevalence 71.7% at 145 days) occurred in an enclosed breeding colony of BALB/c mice after the founders of the colony were fed infected mouse liver. After ingestion of infected liver by mice, the majority of eggs were released unembryonated to the environment, via the faeces, within 40 h. Eggs have specific temperature, moisture and oxygen requirements for embryonation. We postulate that transmission of C. hepatica is dependent principally upon cannibalism and/or necrophagy for release of eggs, upon the mouse burrow and the host population density for embryonation and survival of eggs, and upon grooming behaviour within the burrow for ingestion of embryonated eggs. C. hepatica established, and produced clinical signs, in 11 strains of laboratory mice and in wild mice. Hepatomegaly and splenomegaly were characteristic features of infection, and death occurred in some animals. The slight variation in susceptibility to infection among genetically diverse mice suggests that mice may not have the genetic flexibility to rapidly develop resistance to C. hepatica. The parasite has been recorded only in M. rnusculus, Rattus norvegicus and R. rattus in urban areas in Australia. However, native murids Rattus fuscipes and Pseudomys australis, and a marsupial Trichosurus vulpecula, are susceptible to experimental infection. Suspected C. hepatica infection has been found only in native murids near Atherton, Qld. The absence of this conspicuous infection in free-ranging native mammals elsewhere in Australia suggests that they do not come into contact with embryonated eggs of C. hepatica, a situation compatible with the postulated transmission cycle. The life cycle of C. hepatica appears unique among helminth parasites of mammals, in that transmission and hence survival of the parasite is dependent upon death of the definitive host. This parasite may have the potential to suppress mouse population density.

Scavengers can provide ecosystem services to people by removal of dead animals that could become sources of disease. From such point of view, it seems appropriate to evaluate these benefits in Azerbaijan in quantitative terms. To this end, in 2013, an extensive monitoring was organized in the Turyanchay Reserve, which covers six regions and neighboring territories (the total population here is 640 thousand people). A high level of animal mortality in the Turyanchay Reserve is supported by the concentration of 24 species of wild mammals and 700 thousand domestic animals in the surrounding environment. The difficult terrain area is another factor leading to the death of animals. Animals grazing on hillsides often break down and die. The bodies of domestic and wild animals killed by wolves also often remain lying on this territory. In addition, vehicles traveling along the Agdash-Gabala highway cause the death of many domestic and wild animals. During the two months of the study (from June to July), 62 dead animals were found. Ten kinds of diseases were identified in 38 undecomposed bodies of these animals. Scavengers eat animal bodies in one-three days (without bones), preventing them from becoming a source of infection. The role of necrophages in minimizing of epizootic cases and improving sanitary conditions is important for ecosystems, because the blood of most animals is a carrier of diseases and most of the parasites present in it are common to both humans and animals. Scavengers can be used by veterinary organizations as indicators to simplify the identification of animal bodies and the subsequent disposal of their remains.

Cannibalism has been documented as a possible disease transmission route in several species, including humans. However, the dynamics resulting from this type of disease transmission are not well understood. Using a theoretical model, we explore how cannibalism (i.e. killing and consumption of dead conspecifics) and intraspecific necrophagy (i.e. consumption of dead conspecifics) affect host–pathogen dynamics. We show that group cannibalism, i.e. shared consumption of victims, is a necessary condition for disease spread by cannibalism in the absence of alternative transmission modes. Thus, endemic diseases transmitted predominantly by cannibalism are likely to be rare, except in social organisms that share conspecific prey. These results are consistent with a review of the literature showing that diseases transmitted by cannibalism are infrequent in animals, even though both cannibalism and trophic transmission are very common.

Seacoasts, especially the tidewide zone, are the place of concentration for many species of animals and birds that migrate here in order to find food, which is presented in the form of sea ejections of the marine mammals’ corpses or fallen terrestrial animals here. Taking into account the environmental significance of the transmission mechanisms of Trichinella through necrophagy, it is important to know how long Trichinella larvae are able to be viable in the corpses of dead animals in the tidewide zones, i.e. in zones that are exposed to sea water. The purpose of this study was to determine the time period of preserving the viability of musculaire Trichinella when they were in sea water. The experiment was performed on a model – a guinea pig carcass, which was kept in different environment at different temperature conditions. It was found out that Trichinella larvae in the muscles of guinea pigs remained viable in sea water (experimental group) during 73 days at room temperature. In fresh water (control group) they remained viable during 23 days. Under the conditions of a domestic refrigerator, Trichinella larvae remained viable during 113 days in the experimental group, while in the control group they lived no more than 33 days from the moment of setting the experiment. The results of the bioassay tests performed on Syrian hamsters turned out to be positive in all the cases; all the animals were infected with different infection intensity

The oribatid mite genus Protoribates Berlese (Haplozetidae) is reviewed for North America and the genus diagnosis is revised to account for the North American species, Protoribates robustior (Jacot, 1937) is redescribed and newly reported from western North America and a new species from Alberta is described. Protoribates haughlandae sp. n. is bisexual, heterotridactylous, and lives primarily in the peat soils of fens and bogs. Protoribates robustior is all-female, monodactylous, and occurs primarily in dry forests or in dry, treeless sites dominated by grasses, sedges, and shrubs. Both species feed on fungal hyphae and spores, but P. haughlandae also is an opportunistic predator and/or necrophage of small arthropods and P. robustior gut contents often include material that resembles plant cell walls. Examination of type specimens confirms that Protoribates prionotus (Woolley, 1968) is a junior synonym of the widespread Protoribates lophotrichus (Berlese, 1904). A key to differentiate Lagenobates from Protoribates and to identify the 7 species of the latter that are known or reported from North America is provided.

Abstract The role of the robin, Erithacus rubecula Linnaeus, 1758 as a consort of autotrophic consortia is considered. It has been found that representatives of 9 higher taxa of animals (Mammalia, Aves, Gastropoda, Insecta, Arachnida, Acarina, Malacostraca, Diplopoda, Clitellata) have trophic and topical links with the robin. At the same time, the robin is a consort of determinants of autotrophic consortia, which core is represented mostly by dominating species of deciduous trees (Quercus robur Linnaeus, 1753 (24.6 %), Tilia cordata Miller, 1768 (17.5 %), Acer platanoides Linnaeus, 1753 (22.8 %), Acer campestre Linnaeus, 1753), and also by sedges (Carex sp.) and grasses (Poaceae). The robin also belongs to the concentre of the second and higher orders as a component of forest biogeocenoses and forms a complex trophic system. In the diet of its nestlings, there have been found 717 objects from 32 invertebrate taxa, belonging to the phylums Arthropoda (99.2 %, 31 species) and Annelida (0.8 %, 1 species). The phylum Arthropoda was represented by the most numerous class Insecta (76.9 %), in which 10 orders (Lepidoptera (46.8 %) dominates) and 20 families were recorded, and also by the classes Arachnida (15.0 %), Malacostraca (5.3 %) and Diplopoda (1.9 %). The invertebrate species composition was dominated by representatives of a trophic group of zoophages (14 species; 43.8 %); the portion of phytophages (7 species; 21.9 %), saprophages (18.7 %), and necrophages (15.6 %) was the less. The highest number of food items was represented by phytophages (N = 717; 51 %), followed by zoophages (34 %), saprophages (12 %), and necrophages (3 %). The difference among study areas according to the number of food items and the number of species in the robin nestling diet is shown. In NNP “HF”, the highest number of food items was represented by phytophages - 47 % (N = 443), whereas zoophages were the most species-rich group (43.3 %, 13 species). In NNP “H”, phytophages also prevailed in food items - 62.3 % (N = 164), but the number of phyto-, zoo- and saprophage species was equal (30.8 %, 13 species). In the forest park, zoophages were more frequent - 45.5 % (N = 110), but phytophages were the most species-rich (42.9 %).

Jellyfish blooms are common in many oceans, and anthropogenic changes appear to have increased their magnitude in some regions. Although mass falls of jellyfish carcasses have been observed recently at the deep seafloor, the dense necrophage aggregations and rapid consumption rates typical for vertebrate carrion have not been documented. This has led to a paradigm of limited energy transfer to higher trophic levels at jelly falls relative to vertebrate organic falls. We show from baited camera deployments in the Norwegian deep sea that dense aggregations of deep-sea scavengers (more than 1000 animals at peak densities) can rapidly form at jellyfish baits and consume entire jellyfish carcasses in 2.5 h. We also show that scavenging rates on jellyfish are not significantly different from fish carrion of similar mass, and reveal that scavenging communities typical for the NE Atlantic bathyal zone, including the Atlantic hagfish, galatheid crabs, decapod shrimp and lyssianasid amphipods, consume both types of carcasses. These rapid jellyfish carrion consumption rates suggest that the contribution of gelatinous material to organic fluxes may be seriously underestimated in some regions, because jelly falls may disappear much more rapidly than previously thought. Our results also demonstrate that the energy contained in gelatinous carrion can be efficiently incorporated into large numbers of deep-sea scavengers and food webs, lessening the expected impacts (e.g. smothering of the seafloor) of enhanced jellyfish production on deep-sea ecosystems and pelagic–benthic coupling.

[Truncated abstract] One of the standard ways of assessing time since death is from the stages of decomposition of the body. It is well known that the rate of decomposition is affected by environmental factors such as temperature and humidity. Another factor that can affect decompositional rates is the presence of breaches in the protective barrier of the skin, whether arising from antemortem injury or postmortem damage, including that occurring from animal necrophagy. Scavengers have the potential to affect decomposition by breaching the skin allowing access to associated insect material, feeding on the maggot masses, or by consumption of the carcass itself. Each locality will have its own set of features determining the rate of decomposition of the body, and variation may occur within localities based on the seasons. Such variation implies the need for local calibration of time since death against degree of decomposition and to establish the magnitude of interseasonal variation. When the localities are outdoors, the influence of potential scavengers, and the factors affecting their activity need also to be taken into account. This study investigates the interaction of environmental factors and animal scavenging on the rate of decomposition of pig (Sus scrofa) carcasses at four south-west Western Australia sites; Jandakot, Shenton Park, Perup Forest, and Watheroo National Park. Jandakot and Shenton Park are both close to the Perth metropolitan area and the western coast while Perup Forest is southern and inland and Watheroo is northern and inland. ... The most common insectivore feeding in relation to the carcasses was the Willie Wagtail (Rhipidura leucophrys) which was associated with the carcasses in all seasons and all locations except for Perup Forest. The breeding cycle appeared to have a marked influence on the intensity of scavenging by several species. The effect of season on decompositional rates was greatly reduced in carcasses that were exposed to scavenging. It took no additional time for carcasses to achieve skeletonization in winter than in the other seasons in the presence of scavenging. Scavenging had no significant impact on the rate of breakdown of carcasses in summer, when decompositional rates were greatest and scavenging at a minimum. v In Western Australia, it is not uncommon for bodies to remain undiscovered in bush environments for lengthy periods of time due to the low human population density. This study shows conclusively that it is not sufficient simply to consider the accumulated degree day (ADD) when estimating time since death by the degree of decomposition of the body. Attention must also be given to local wildlife assemblages and variations in their activities with the seasons. The implications of this research are in the determination of time of death. If the effects of scavengers accelerate decomposition this must be taken into account when any calculation since time of death is determined. The marked variations between sites in the rates of decomposition of carcasses exposed to natural animal scavenging in this study highlights the need for local calibration of time since death to decompositional stages for all locales. The techniques devised in this study are straight forward and easily conducted yet are informative and essential in determining time since death for bodies which have been exposed to animal scavenging.