In evolutionary biology, parasitism is a relationship between species, where one organism, the parasite, lives on or in another organism, the host, causing it some harm, is adapted structurally to this way of life. The entomologist E. O. Wilson has characterised parasites as "predators that eat prey in units of less than one". Parasites include protozoans such as the agents of malaria, sleeping sickness, amoebic dysentery. There are six major parasitic strategies of exploitation of animal hosts, namely parasitic castration, directly transmitted parasitism, trophically transmitted parasitism, vector-transmitted parasitism and micropredation. Like predation, parasitism is a type of consumer-resource interaction, but unlike predators, with the exception of parasitoids, are much smaller than their hosts, do not kill them, live in or on their hosts for an extended period. Parasites of animals are specialised, reproduce at a faster rate than their hosts. Classic examples include interactions between vertebrate hosts and tapeworms, the malaria-causing Plasmodium species, fleas.
Parasites reduce host fitness by general or specialised pathology, from parasitic castration to modification of host behaviour. Parasites increase their own fitness by exploiting hosts for resources necessary for their survival, in particular by feeding on them and by using intermediate hosts to assist in their transmission from one definitive host to another. Although parasitism is unambiguous, it is part of a spectrum of interactions between species, grading via parasitoidism into predation, through evolution into mutualism, in some fungi, shading into being saprophytic. People have known about parasites such as roundworms and tapeworms since ancient Egypt and Rome. In Early Modern times, Antonie van Leeuwenhoek observed Giardia lamblia in his microscope in 1681, while Francesco Redi described internal and external parasites including sheep liver fluke and ticks. Modern parasitology developed in the 19th century. In human culture, parasitism has negative connotations; these were exploited to satirical effect in Jonathan Swift's 1733 poem "On Poetry: A Rhapsody", comparing poets to hyperparasitical "vermin".
In fiction, Bram Stoker's 1897 Gothic horror novel Dracula and its many adaptations featured a blood-drinking parasite. Ridley Scott's 1979 film Alien was one of many works of science fiction to feature a terrifying parasitic alien species. First used in English in 1539, the word parasite comes from the Medieval French parasite, from the Latin parasitus, the latinisation of the Greek παράσιτος, "one who eats at the table of another" and that from παρά, "beside, by" + σῖτος, "wheat", hence "food"; the related term parasitism appears in English from 1611. Parasitism is a kind of symbiosis, a close and persistent long-term biological interaction between a parasite and its host. Unlike commensalism and mutualism, the parasitic relationship harms the host, either feeding on it or, as in the case of intestinal parasites, consuming some of its food; because parasites interact with other species, they can act as vectors of pathogens, causing disease. Predation is by definition not a symbiosis, as the interaction is brief, but the entomologist E. O. Wilson has characterised parasites as "predators that eat prey in units of less than one".
Within that scope are many possible strategies. Taxonomists classify parasites in a variety of overlapping schemes, based on their interactions with their hosts and on their life-cycles, which are sometimes complex. An obligate parasite depends on the host to complete its life cycle, while a facultative parasite does not. Parasite life-cycles involving only one host are called "direct". An endoparasite lives inside the host's body. Mesoparasites - like some copepods, for example - enter an opening in the host's body and remain embedded there; some parasites can be generalists, feeding on a wide range of hosts, but many parasites, the majority of protozoans and helminths that parasitise animals, are specialists and host-specific. An early basic, functional division of parasites distinguished macroparasites; these each had a mathematical model assigned in order to analyse the population movements of the host–parasite groupings. The microorganisms and viruses that can reproduce and complete their life cycle within the host are known as microparasites.
Macroparasites are the multicellular organisms that reproduce and complete their life cycle outside of the host or on the host's body. Much of the thinking on types of parasitism has focussed on terrestrial animal parasites of animals, such as helminths; those in other environments and with other hosts have analogous strategies. For example, the snubnosed eel is a facultative endoparasite that opportunistically burrows into and eats sick and dying fish. Plant-eating insects such as scale insects and caterpillars resemble ectoparasites, attacking much larger plants; as female scale-insects cannot move, they are obligate parasites, permanently attached to their hosts. There are six major parasitic strategies, namely parasitic castration, directly transmitted parasitism, trophically transmitted parasitism, vector-transmitted parasitism, parasitoid
Fungivory or mycophagy is the process of organisms consuming fungi. Many different organisms have been recorded to gain their energy from consuming fungi, including birds, insects, amoebas, nematodes and other fungi; some of these, which only eat fungi, are called fungivores whereas others eat fungi as only part of their diet, being omnivores. Many mammals eat fungi, but only a few feed on fungi. At least 22 species of primate, including humans, colobines, lemurs, mangabeys and vervet monkeys are known to feed on fungi. Most of these species spend less than 5% of the time they spend feeding eating fungi, fungi therefore form only a small part of their diet; some species spend longer foraging for fungi, fungi account for a greater part of their diet. Fungi are comparatively rare in tropical rainforests compared to other food sources such as fruit and leaves and they are distributed more sparsely and appear unpredictably, making them a challenging source of food for Goeldi’s monkeys. Fungi are renowned for their poisons to deter animals from feeding on them: today humans die from eating poisonous fungi.
A natural consequence of this is the virtual absence of obligate vertebrate fungivores, with the diprotodont family Potoridae being the major exception. One of the few extant vertebrate fungivores is the northern flying squirrel, but it is believed that in the past there were numerous vertebrate fungivores and that toxin development lessened their number and forced these species to abandon fungi or diversify. Many terrestrial gastropod mollusks are known to feed on fungi, it is the case in several species of slugs from distinct families. Among them are the Philomycidae and Ariolimacidae, which feed on slime molds and mushrooms. Species of mushroom producing fungi used as food source by slugs include milk-caps, Lactarius spp. the oyster mushroom, Pleurotus ostreatus and the penny bun, Boletus edulis. Other species pertaining to different genera, such as Agaricus and Russula, are eaten by slugs. Slime molds used as food source by slugs include Stemonitis Symphytocarpus flaccidus; some slugs are selective towards certain parts or developmental stages of the fungi they eat, though this behavior varies greatly.
Depending on the species and other factors, slugs eat only fungi at specific stages of development. Moreover, in other cases, whole mushrooms can be eaten, without any trace of selectivity. In 2008, Euprenolepis procera a species of ant from the rainforests of South East Asia was found to harvest mushrooms from the rainforest. Witte & Maschwitz found that their diet consisted entirely of mushrooms, representing a undiscovered feeding strategy in ants. Several beetle families, including the Erotylidae and certain Tenebrionidae are specialists on fungi, though they may eat other foods occasionally. Other insects, scuttle flies, utilize fungi at their larval stage. Feeding on fungi is crucial for dead wood eaters as this is the only way to acquire nutrients not available in nutritionally scarce dead wood. Jays are believed to be the first birds. Canada jays, Siberian jays and Oregon jays have all been recorded to eat mushrooms, with the stomachs of Siberian jays containing fungi in the early winter.
The ascomycete, Phaeangium lefebvrei found in north Africa and the Middle East is eaten by migrating birds in winter and early spring be species of lark. Bedouin hunters have been reported to use P. lefebvrei as bait in traps to attract birds. Fungi are known to form an important part of the diet of the southern cassowary of Australia. Bracket fungi have been found in their droppings throughout the year, Simpson in the Australasian Mycological Newsletter suggested it is they eat species of Agaricales and Pezizales but these have not been found in their droppings since they disintegrate when they are eaten. Emus will eat immature Lycoperdon and Bovista fungi if presented to them as will brush turkeys if offered Mycena, suggesting that species of Megapodiidae may feed opportunistically on mushrooms. Mycoparasitism occurs when any fungus feeds on other fungi, a form of parasitism, our knowledge of it in natural environments is limited. Collybia grow on dead mushrooms; the fungal genus, Trichoderma produces enzymes such as chitinases which degrade the cell walls of other fungi.
They are able to detect other fungi and grow towards them, they bind to the hyphae of other fungi using lectins on the host fungi as a receptor, forming an appressorium. Once this is formed, Trichoderma inject toxic enzymes into the host and peptaibol antibiotics, which create holes in the cell wall, allowing Trichoderma to grow inside of the host and feed. Trichoderma are able to digest sclerotia, durable structures which contain food reserves, important if they are to control pathogenic fungi in the long term. Trichoderma species have been recorded as protecting crops from Botrytis cinerea, Rhizoctonia solani, Alternaria solani, Glomerella graminicola, Phytophthora capsici, Magnaporthe grisea and Colletotrichum lindemuthianum.
A molluscivore is a carnivorous animal that specialises in feeding on molluscs such as gastropods, bivalves and cephalopods. Known molluscivores include numerous predatory molluscs, arthropods such as crabs and firefly larvae, vertebrates such as fish and mammals. Molluscivory is performed in a variety ways with some animals adapted to this method of feeding behaviour. A similar behaviour, describes the feeding of animals that consume hard-shelled or exoskeleton bearing organisms, such as corals, shelled molluscs, or crabs. Molluscivory is performed in several ways. In some cases, the mollusc prey are swallowed entire, including the shell, whereupon the prey is killed through suffocation and or exposure to digestive enzymes. Only cannibalistic sea slugs, snail-eating cone shells of the taxon Coninae, some sea anemones use this method. One method, used by vertebrate molluscivores, is to break the shell, either by exerting force on the shell until it breaks by biting the shell, like with oyster crackers and placodonts, or hammering at the shell, e.g. oystercatchers and crabs, or by dashing the mollusc on a rock.
Another method is to remove the shell from the prey. Molluscs are attached to their shell by strong muscular ligaments, making the shell's removal difficult. Molluscivorous birds, such as oystercatchers and the Everglades snail kite, insert their elongate beak into the shell to sever these attachment ligaments, facilitating removal of the prey; the carnivorous terrestrial pulmonate snail known as the "decollate snail" uses a similar method: it reaches into the opening of the prey's shell and bites through the muscles in the prey's neck, whereupon it begins devouring the fleshy parts of its victim. The walrus sucks meat out of bivalve molluscs by sealing its powerful lips to the organism and withdrawing its piston-like tongue into its mouth, creating a vacuum. Another method is used by many molluscs, themselves. Octopi and most molluscivoruous sea snails use their radula to drill a hole through the shell inject venom and digestive enzymes through the hole, whereupon the digested prey is sucked out through the hole.
The larvae of glowworms and fireflies are small enough to enter the shells of terrestrial snails and begin eating immediately. Whales: Sperm whales, pilot whales, Cuvier's beaked whale, Risso's dolphin and species in the genera Mesoplodon, Hyperoodon and the superfamily Physeteroidea are classified as molluscivores, eating squid. Pinnipeds: Elephant seals, Ross seals and South American fur seals are classed as molluscivores; the walrus eats benthic bivalve molluscs clams, for which it forages by grazing along the sea bottom and identifying prey with its sensitive vibrissae. The walrus sucks the meat out by sealing its powerful lips to the organism and withdrawing its piston-like tongue into its mouth, creating a vacuum; the walrus palate is uniquely vaulted, enabling effective suction. Several species of pufferfish and loaches are molluscivores; as many molluscs are protected by a shell, the feeding techniques applied amongst molluscivore fish are specialized and divided into two groups: "crushers" and "slurpers."
Pufferfish tend to be crushers and will use their beak-like teeth to break the shell in order to gain access to the meat inside. Loaches are specialized slurpers, will make use of their characteristically shaped snout in order to grab hold of suck out the animal living inside the shell; the black carp feeds by crushing large molluscs with pharyngeal teeth, extracting soft tissue, spitting out shell fragments. Four-year-old juveniles are capable of consuming 1–2 kg of molluscs per day; this bottom-dwelling molluscivore was purposely imported into the United States in the early 1970s for use as a food fish and as a biological control agent for snails—an intermediate host for a trematode parasite in fish reared on fish farms. Two snail-eating cichlids, Trematocranus placodon and Maravichromis anaphyrmis, have been tried as biological control agents of schistosomes in fish ponds in Africa. Redear sunfish and bluegill have been used to control quagga mussels in the lower Colorado River in the US.
The common name of some fish reflects their molluscivorous feeding, for example, the "snail-crusher hap", ""red rock sheller", "Rusinga oral sheller" and "rainbow sheller". The redear sunfish is known as the "shellcracker". Gray's monitor is well known for its diet, which consists of ripe fruit. Monitors are carnivorous animals, which makes the Gray's monitor somewhat of an exception amongst the varanid family; the prehistoric placodont reptiles is an extinct taxon of marine animals that superficially resembled lizards and turtles, most of whose dentition of peg-like incisors and enormous, molar-like teeth allowed them to prey on molluscs and brachiopods by plucking their prey off of the substrate, crushing the shells. Among birds, the eponymous shorebirds known as oystercatchers are renowned for feeding upon bivalves. At least one bird of prey is primarily a molluscivore—the snail kite, Rostrhamus sociabilis; the limpkin is a small rail-like bird that feeds entirely on apple snails. Other birds that will eat molluscs include mergansers, coots, d
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals have mouthparts adapted to rasping or grinding. Horses and other herbivores have wide flat teeth that are adapted to grinding grass, tree bark, other tough plant material. A large percentage of herbivores have mutualistic gut flora that help them digest plant matter, more difficult to digest than animal prey; this flora is made up of cellulose-digesting bacteria. Herbivore is the anglicized form of a modern Latin coinage, cited in Charles Lyell's 1830 Principles of Geology. Richard Owen employed the anglicized term in an 1854 work on fossil skeletons. Herbivora is derived from the Latin herba meaning a small plant or herb, vora, from vorare, to eat or devour. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants and photosynthesizing bacteria.
More organisms that feed on autotrophs in general are known as primary consumers. Herbivory is limited to animals that eat plants. Fungi and protists that feed on living plants are termed plant pathogens, while fungi and microbes that feed on dead plants are described as saprotrophs. Flowering plants that obtain nutrition from other living plants are termed parasitic plants. There is, however, no single exclusive and definitive ecological classification of consumption patterns. In zoology, an herbivore is an animal, adapted to eat plant matter. Our understanding of herbivory in geological time comes from three sources: fossilized plants, which may preserve evidence of defence, or herbivory-related damage. Although herbivory was long thought to be a Mesozoic phenomenon, fossils have shown that within less than 20 million years after the first land plants evolved, plants were being consumed by arthropods. Insects fed on the spores of early Devonian plants, the Rhynie chert provides evidence that organisms fed on plants using a "pierce and suck" technique.
During the next 75 million years, plants evolved a range of more complex organs, such as roots and seeds. There is no evidence of any organism being fed upon until the middle-late Mississippian, 330.9 million years ago. There was a gap of 50 to 100 million years between the time each organ evolved and the time organisms evolved to feed upon them. Further than their arthropod status, the identity of these early herbivores is uncertain. Hole feeding and skeletonisation are recorded in the early Permian, with surface fluid feeding evolving by the end of that period. Herbivory among four-limbed terrestrial vertebrates, the tetrapods developed in the Late Carboniferous. Early tetrapods were large amphibious piscivores. While amphibians continued to feed on fish and insects, some reptiles began exploring two new food types and plants; the entire dinosaur order ornithischia was composed with herbivores dinosaurs. Carnivory was a natural transition from insectivory for medium and large tetrapods, requiring minimal adaptation.
In contrast, a complex set of adaptations was necessary for feeding on fibrous plant materials. Arthropods evolved herbivory in four phases, changing their approach to it in response to changing plant communities. Tetrapod herbivores made their first appearance in the fossil record of their jaws near the Permio-Carboniferous boundary 300 million years ago; the earliest evidence of their herbivory has been attributed to dental occlusion, the process in which teeth from the upper jaw come in contact with teeth in the lower jaw is present. The evolution of dental occlusion led to a drastic increase in plant food processing and provides evidence about feeding strategies based on tooth wear patterns. Examination of phylogenetic frameworks of tooth and jaw morphologes has revealed that dental occlusion developed independently in several lineages tetrapod herbivores; this suggests that evolution and spread occurred within various lineages. Herbivores form an important link in the food chain because they consume plants in order to digest the carbohydrates photosynthetically produced by a plant.
Carnivores in turn consume herbivores for the same reason, while omnivores can obtain their nutrients from either plants or animals. Due to a herbivore's ability to survive on tough and fibrous plant matter, they are termed the primary consumers in the food cycle. Herbivory and omnivory can be regarded as special cases of Consumer-Resource Systems. Herbivores come in all sizes in the animal kingdom, they include aquatic and non-aquatic vertebrates. They can be large, like an elephant. Many herbivores found living in close proximity to humans, such as rodents, cows and camels. Two herbivore feeding strategies are browsing. For a terrestrial mammal to be called a grazer, at least 90% of the forage has to be grass, for a browser at least 90% tree leaves and/or twigs. An intermediate feeding strategy is called "mixed-feeding". In their daily need to take up energy from forage, herbivores of different body mass may be selective in choosing their food. "Selective" means that herbivores may choose their forage source depending on, e.g. season or food avail
Hematophagy is the practice by certain animals of feeding on blood. Since blood is a fluid tissue rich in nutritious proteins and lipids that can be taken without great effort, hematophagy has evolved as a preferred form of feeding for many small animals, such as worms and arthropods; some intestinal nematodes, such as Ancylostomids, feed on blood extracted from the capillaries of the gut, about 75 percent of all species of leeches, a free-living worm, are hematophagous. Some fish, such as lampreys and candirus, mammals the vampire bats, birds, such as the vampire finches, hood mockingbirds, the Tristan thrush, oxpeckers practise hematophagy; these hematophagous animals have mouth parts and chemical agents for penetrating vascular structures in the skin of hosts of mammals and fish. This type of feeding is known as phlebotomy. Once phlebotomy is performed, blood is acquired either by sucking action directly from the veins or capillaries, from a pool of escaped blood, or by lapping. To overcome natural hemostasis, vasoconstriction and pain sensation in the host, hematophagous animals have evolved hembiochemical solutions, in their saliva for instance, that they pre-inject—and anesthesia and capillary dilation have evolved in some hematophagous species.
Scientists have developed anticoagulant medicines from studying substances in the saliva of several hematophagous species, such as leeches. Hematophagy is classified as either facultative. Obligatory hematophagous animals cannot survive on any other food. Examples include Rhodnius prolixus, a South American assassin bug, Cimex lectularius, the human bed bug. Facultative hematophages, acquire at least some portion of their nutrition from non-blood sources in at least one of the sexually mature forms. Examples of this include many mosquito species, such as Aedes aegypti, whose males feed on pollen and fruit juice while the females survive by feeding on mammalian blood. In anautogenous species, the female can survive without blood, but must consume blood in order to produce eggs; as a feeding practice, hematophagy has evolved independently in a number of arthropod, annelid and mammalian taxa. For example, Diptera have eleven families with hematophagous habits. About 14,000 species of arthropods are hematophagous including some genera that were not thought to be, such as moths of the genus Calyptra.
Several complementary biological adaptations for locating the hosts have evolved, such as special physical or chemical detectors for sweat components, CO2, light, etc. The phlebotomic action opens a channel for contamination of the host species with bacteria and blood-borne parasites contained in the hematophagous organism. Thus, many animal and human infectious diseases are transmitted by hematophagous species, such as the bubonic plague, Chagas disease, dengue fever, eastern equine encephalitis, leishmaniasis, Lyme disease, rabies, sleeping sickness, St. Louis encephalitis, typhus, Rocky Mountain spotted fever, West Nile fever, Zika fever, many others. Insects and arachnids of medical importance for being hematophagous, at least in some species, include the sandfly, tsetse fly, assassin bug, tick, mite and flea. Hematophagous organisms have been used by physicians for beneficial purposes; some doctors now use leeches to prevent the clotting of blood on some wounds following surgery or trauma.
The anticoagulants in the laboratory-raised leeches' saliva keeps fresh blood flowing to the site of an injury preventing infection and increasing chances of full recovery. In a recent study a genetically engineered drug called desmoteplase based on the saliva of Desmodus rotundus was shown to improve recovery in stroke patients. Many human societies drink blood or use it to manufacture foodstuffs and delicacies. Cow blood mixed with milk, for example, is a mainstay food of the African Maasai. Marco Polo reported. Many places around the world eat blood sausage; some societies, such as the Moche, had ritual hematophagy, as well as the Scythians, a nomadic people of Russia, who drank the blood of the first enemy they killed in battle. Some religious rituals and symbols mirror hematophagy, such as in the transubstantiation of wine as the blood of Jesus Christ during Christian eucharist. Psychiatric cases of patients performing hematophagy exist. Sucking or licking one's own blood from a wound is a common human behavior, in small enough quantities is not considered taboo.
Human vampirism has been a persistent object of literary and cultural attention. Chupacabra Consumer-resource systems Natural reservoir Tick-borne disease Transmission Zoonosis Scharfetter C, Hagenbuchner K. "Blutdurst als Symptom. Ein seltsamer Fall von Bluttrinken". Psychiatr Neurol. Basel. 154: 288–310. Ciprandi A, Horn F, Termignoni C. "Saliva of hematophagous animals: source of new anticoagulants". Rev. Bras
Scavengers are animals that consume dead organisms that have died from causes other than predation. While scavenging refers to carnivores feeding on carrion, it is a herbivorous feeding behavior. Scavengers play an important role in the ecosystem by consuming dead plant material. Decomposers and detritivores complete this process, by consuming the remains left by scavengers. Scavengers aid in overcoming fluctuations of food resources in the environment; the process and rate of scavenging is affected by both biotic and abiotic factors, such as carcass size, habitat and seasons. Scavenger is an alteration of scavager, from Middle English skawager meaning "customs collector", from skawage meaning "customs", from Old North French escauwage meaning "inspection", from schauwer meaning "to inspect", of Germanic origin. Obligate scavenging is rare among vertebrates, due to the difficulty of finding enough carrion without expending too much energy. In vertebrates, only vultures and some pterosaurs are obligate scavengers, as terrestrial soaring flyers are the only animals able to find enough carrion.
Well-known invertebrate scavengers of animal material include burying beetles and blowflies, which are obligate scavengers, yellowjackets. Most scavenging animals are facultative scavengers that gain most of their food through other methods predation. Many large carnivores that hunt such as hyenas and jackals, but animals thought of as scavengers, such as African lions and wolves will scavenge if given the chance, they may use their size and ferocity to intimidate the original hunters. All scavengers above insect size are predators and will hunt if not enough carrion is available, as few ecosystems provide enough dead animals year-round to keep its scavengers fed on that alone. Scavenging wild dogs and crows exploit roadkill. Scavengers of dead plant material include termites that build nests in grasslands and collect dead plant material for consumption within the nest; the interaction between scavenging animals and humans is seen today most in suburban settings with animals such as opossums and raccoons.
In some African towns and villages, scavenging from hyenas is common. In the prehistoric eras, the species Tyrannosaurus rex may have been an apex predator, preying upon hadrosaurs and juvenile sauropods, although some experts have suggested the dinosaur was a scavenger; the debate about whether Tyrannosaurus was an apex predator or scavenger was among the longest ongoing feuds in paleontology. Recent research shows that while an adult Tyrannosaurus rex would energetically gain little though scavenging, smaller theropods of 500 kg may have gained levels similar to that of hyenas, though not enough for them to rely on scavenging. There are an info that Otodus megalodon, Ceratosaurus and some more prehistoric animals were scavengers. Animals which consume feces, such as dung beetles, are referred to as coprovores. Animals that collect small particles of dead organic material of both animal and plant origin are referred to as detritivores. Scavengers play a fundamental role in the environment through the removal of decaying organisms, serving as a natural sanitation service.
While microscopic and invertebrate decomposers break down dead organisms into simple organic matter which are used by nearby autotrophs, scavengers help conserve energy and nutrients obtained from carrion within the upper trophic levels, are able to disperse the energy and nutrients farther away from the site of the carrion than decomposers. Scavenging unites animals which would not come into contact, results in the formation of structured and complex communities which engage in nonrandom interactions. Scavenging communities function in the redistribution of energy obtained from carcasses and reducing diseases associated with decomposition. Oftentimes, scavenger communities differ in consistency due to carcass size and carcass types, as well as by seasonal effects as consequence of differing invertebrate and microbial activity. Competition for carrion results in the inclusion or exclusion of certain scavengers from access to carrion, shaping the scavenger community; when carrion decomposes at a slower rate during cooler seasons, competitions between scavengers decrease, while the number of scavenger species present increases.
Alterations in scavenging communities may result in drastic changes to the scavenging community in general, reduce ecosystem services and have detrimental effects on animal and humans. The reintroduction of gray wolves into Yellowstone National Park in the United States caused drastic changes to the prevalent scavenging community, resulting in the provision of carrion to many mammalian and avian species; the reduction of vulture species in India lead to the increase of opportunistic species such as feral dogs and rats. The presence of both species at carcasses resulted in the increase of diseases such as rabies and bubonic plague in wildlife and livestock, as feral dogs and rats are transmitters of such diseases. Furthermore, the decline of vulture populations in India has been linked to the increased rates of anthrax in humans due to the handling and ingestion of infected livestock carcasses. An increase of disease transmission has been observed in mammalian scavengers in Kenya due to the decrease in vulture populations in the ar
Armadillidiidae is a family of woodlice, a terrestrial crustacean group in the order Isopoda. Unlike members of other woodlouse families, members of this family can roll into a ball, an ability they share with the outwardly similar but unrelated pill millipedes and other animals; this ability gives woodlice in this family their common names of pill bugs, roly polies, doodle bugs. The best known species in the family is the common pill bug. Pill bugs instead were introduced from Europe. Pill bugs in the family Armadillidiidae are able to form their bodies into a ball shape, in a process known as conglobation; this behaviour is shared with pill millipedes and cuckoo wasps. It may be triggered by stimuli such as vibrations or pressure, is a key defense against predation; the diet of pill bugs is made up of decaying or decomposed plant matter such as leaves, to a lesser extent, wood fibers. Pill bugs will eat living plants in wet conditions, sometimes consuming leaves, shoots, roots and fruits. Pill bugs can be serious pests in certain agricultural systems in areas that are prone to heavy rains and flood conditions.
Pill bugs will feed on numerous crop plants including corn, squash, melon, beet, potato, spinach and strawberry, with potential for significant yield loss in strawberry in particular. Some species of pill bugs feces, they will eat shed snakeskin and dead bugs, if necessary. Pill bugs contribute to their ecosystem as decomposers, they are capable of taking in heavy metals such as copper, zinc and cadmium and crystallize these out as spherical deposits in the midgut. In this way, they temporarily remove many of the toxic metal ions from the soil although the toxic metals are returned to the soil when they die, they provide a food source for birds, spiders and centipedes. The family Armadillidiidae is differentiated from other woodlouse families by the two-segmented nature of the antennal flagellum, by the form of the uropods, by the ability to roll into a ball. Within the family Armadillidiidae, 15 genera are recognized: Data related to Armadillidiidae at Wikispecies Regional maps for the most common American names for this isopod can be found in the results for question 74 of the Harvard Dialect Survey