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Hibernators
Hibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It most commonly occurs during winter months. Although traditionally reserved for "deep" hibernators such as rodents, the term has been redefined to include animals such as bears and is now applied based on active metabolic suppression rather than any absolute decline in body temperature. Many experts believe that the processes of daily torpor and hibernation form a continuum and utilise similar mechanisms. The equivalent during the summer months is aestivation. Hibernation functions to conserve energy when sufficient food is not available. To achieve this energy saving, an endothermic animal decreases its metabolic rate and thereby its body temperature. Hibernation may last days, weeks, or months—depending on the species, ambient temperature, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Black Bear
The American black bear (''Ursus americanus''), also called simply a black bear or sometimes a baribal, is a medium-sized bear endemic to North America. It is the continent's smallest and most widely distributed bear species. American black bears are omnivores, with their diets varying greatly depending on season and location. They typically live in largely forested areas, but will leave forests in search of food, and are sometimes attracted to human communities due to the immediate availability of food. The International Union for Conservation of Nature (IUCN) lists the American black bear as a least-concern species, due to its widespread distribution and a large population estimated to be twice that of all other bear species combined. Along with the brown bear (''Ursus arctos''), it is one of only two modern bear species not considered by the IUCN to be globally threatened with extinction. Taxonomy and evolution Despite living in North America, American black bears are not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterothermy
Heterothermy or heterothermia (from Greek ἕτερος ''heteros'' "other" and θέρμη ''thermē'' "heat") is a physiological term for animals that vary between self-regulating their body temperature, and allowing the surrounding environment to affect it. In other words, they exhibit characteristics of both poikilothermy and homeothermy. Definition Heterothermic animals are those that can switch between poikilothermic and homeothermic strategies. These changes in strategies typically occur on a daily basis or on an annual basis. More often than not, it is used as a way to dissociate the fluctuating metabolic rates seen in some small mammals and birds (e.g. bats and hummingbirds), from those of traditional cold blooded animals. In many bat species, body temperature and metabolic rate are elevated only during activity. When at rest, these animals reduce their metabolisms drastically, which results in their body temperature dropping to that of the surrounding environment. This ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eptesicus Nilssonii Hibernating
''Eptesicus'' is a genus of bats, commonly called house bats or serotine bats, in the family Vespertilionidae. The genus name is likely derived from the Greek words ''ptetikos'' 'able to fly' or ''petomai'' 'house flier', although this is not certain. Species 28 species have been identified within the genus. Of these, 19 are from South America. These species are grouped into two subgenera In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...: ''Eptesicus'' and ''Histiotus''. References Bat genera Taxa named by Constantine Samuel Rafinesque {{Vespertilionidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seed Dormancy
Seed dormancy is an evolutionary adaptation that prevents seeds from germinating during unsuitable ecological conditions that would typically lead to a low probability of seedling survival. Dormant seeds do not germinate in a specified period of time under a combination of environmental factors that are normally conducive to the germination of non-dormant seeds. An important function of seed dormancy is delayed germination, which allows dispersal and prevents simultaneous germination of all seeds. The staggering of germination safeguards some seeds and seedlings from suffering damage or death from short periods of bad weather or from transient herbivores; it also allows some seeds to germinate when competition from other plants for light and water might be less intense. Another form of delayed seed germination is seed quiescence, which is different from true seed dormancy and occurs when a seed fails to germinate because the external environmental conditions are too dry or warm or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White-tailed Prairie Dog
The white-tailed prairie dog (''Cynomys leucurus'') is found in western Wyoming and western Colorado with small areas in eastern Utah and southern Montana. The largest populations are in Wyoming where they are known colloquially as "chiselers". This prairie dog species lives at an elevation between 5,000 and 10,000 feet, generally a higher elevation than other prairie dog species. Its predators include black-footed ferrets, badgers, and golden eagles. Description The white-tailed prairie dog is tan-brown in color, with large eyes and a dark patch on their cheeks above and below each eye. This prairie dog species weighs between 28 - 53oz (800 - 1500g), while having a length between 12 - 16in (315 - 399mm). Behavior White-tailed prairie dogs display Interspecific competition with the Wyoming ground squirrel. When the squirrel enters the territory of the prairie dog, the white-tailed prairie dog chases the squirrel. Rarely does the prairie dog capture and kill the squirrel, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prairie Dog
Prairie dogs (genus ''Cynomys'') are herbivorous burrowing ground squirrels native to the grasslands of North America. Within the genus are five species: black-tailed, white-tailed, Gunnison's, Utah, and Mexican prairie dogs. In Mexico, prairie dogs are found primarily in the northern states, which lie at the southern end of the Great Plains: northeastern Sonora, north and northeastern Chihuahua, northern Coahuila, northern Nuevo León, and northern Tamaulipas. In the United States, they range primarily to the west of the Mississippi River, though they have also been introduced in a few eastern locales. They are also found in the Canadian Prairies. Despite the name, they are not actually canines; prairie dogs, along with the marmots, chipmunks, and several other basal genera belong to the ground squirrels (tribe ''Marmotini''), part of the larger squirrel family (''Sciuridae''). Prairie dogs are considered a keystone species with their mounds often being used by other s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Ground Squirrel
The Arctic ground squirrel (''Urocitellus parryii'') (Inuktitut: ''ᓯᒃᓯᒃ, siksik'') is a species of ground squirrel native to the Arctic and Subarctic of North America and Asia. People in Alaska, particularly around the Aleutians, refer to them as "parka" squirrels, most likely because their pelt is good for the ruff on parkas and for clothing. Taxonomy Subspecies listed alphabetically. *''U. p. ablusus'' Osgood, 1903 *''U. p. kennicottii'' Ross, 1861 – Barrow ground squirrel (northern Alaska, northern Yukon, and northern Northwest Territories) *''U. p. kodiacensis'' Ross, 1861 *''U. p. leucostictus'' Brandt, 1844 *''U. p. lyratus'' Hall and Gilmore, 1932 *''U. p. nebulicola'' Osgood, 1903 *''U. p. osgoodi'' Merriam, 1900 *''U. p. parryii'' Richardson, 1825 *''U. p. plesius'' Osgood, 1900 *''U. p. stejnegeri'' J. A. Allen, 1903 Description The Arctic ground squirrel has a beige and tan coat with a white-spotted back. This squirrel has a short face, small ears, a dark tai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sleep Debt
Sleep debt or sleep deficit is the cumulative effect of not getting enough sleep. A large sleep debt may lead to mental or physical fatigue, and can adversely affect one's mood, energy and ability to think clearly. There are two kinds of sleep debt: result of partial sleep deprivation, and of total sleep deprivation. Partial sleep deprivation occurs when a person or a lab animal sleeps too little for several days or weeks. Total sleep deprivation, on the other hand, occurs when the subject is being kept awake for at least 24 hours. There is debate in the scientific community over the specifics of sleep debt (see ), and it is not considered to be a disorder. Physiological effects of sleep debt Chronic sleep debt has a substantial health impact on the human body, specifically on metabolic and endocrine functions. A study published in ''The Lancet'' investigated the physiological effects of sleep debt by assessing the sympathovagal balance (an indicator of the sympathetic nerv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupials
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a pouch. Marsupials include opossums, Tasmanian devils, kangaroos, koalas, wombats, wallabies, bandicoots, and the extinct thylacine. Marsupials represent the clade originating from the last common ancestor of extant metatherians, the group containing all mammals more closely related to marsupials than to placentals. They give birth to relatively undeveloped young that often reside in a pouch located on their mothers' abdomen for a certain amount of time. Close to 70% of the 334 extant species occur on the Australian continent (the mainland, Tasmania, New Guinea and nearby islands). The remaining 30% are found in the Americas—primarily in South America, thirteen in Central America, and one species, the Virginia opossum, in North America, nor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotremes
Monotremes () are prototherian mammals of the order Monotremata. They are one of the three groups of living mammals, along with placentals (Eutheria), and marsupials (Metatheria). Monotremes are typified by structural differences in their brains, jaws, digestive tract, reproductive tract, and other body parts, compared to the more common mammalian types. In addition, they lay eggs rather than bearing live young, but, like all mammals, the female monotremes nurse their young with milk. Monotremes have been considered members of Australosphenida, a clade that contains extinct mammals from the Jurassic and Cretaceous of Madagascar, South America, and Australia, though this is disputed. The only surviving examples of monotremes are all indigenous to Australia and New Guinea, although there is evidence that they were once more widespread, as ''Monotrematum'' is known from the Paleocene of South America. The extant monotreme species are the platypus and four species of echidnas. There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insectivores
A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores were amphibians. When they evolved 400 million years ago, the first amphibians were piscivores, with numerous sharp conical teeth, much like a modern crocodile. The same tooth arrangement is however also suited for eating animals with exoskeletons, thus the ability to eat insects is an extension of piscivory. At one time, insectivorous mammals were scientifically classified in an order called Insectivora. This order is now abandoned, as not all insectivorous mammals are closely related. Most of the Insectivora taxa have been reclassified; those that have not yet been reclassified and found to be truly related to each other remain in the order Eulipotyphla. Although individually small, insects exist in enormous numbers. Insects make ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Hedgehog
The European hedgehog (''Erinaceus europaeus''), also known as the West European hedgehog or common hedgehog, is a hedgehog species native to Europe from Iberia and Italy northwards into Scandinavia and westwards into the British Isles.Harris, S. & Yalden, D.W. (2008). ''Mammals of the British Isles: Handbook, 4th Edition.'' The Mammal Society, Southampton. It is a generally common and widely distributed species that can survive across a wide range of habitat types. It is a well-known species, and a favourite in European gardens, both for its endearing appearance and its preference for eating a range of garden pests. While populations are currently stable across much of its range, it is declining severely in Great Britain where it is now Red Listed (classified as near to extinction). Outside its native range, the species was introduced to New Zealand during the late-19th and early-20th centuries. Description The European hedgehog has a generalised body structure with unspeciali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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