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Crepuscular Rays And Dead Trees At Mammoth Hot Springs.jpg
In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of daylight and of darkness, respectively. Some crepuscular animals may also be active by moonlight or during an overcast day. Matutinal animals are active only before sunrise, and vespertine only after sunset. A number of factors impact the time of day an animal is active. Predators hunt when their prey is available, and prey try to avoid the times when their principal predators are at large. The temperature at midday may be too high or at night too low. Some creatures may adjust their activities depending on local competition. Etymology and usage The word ''crepuscular'' derives from the Latin '' crepusculum'' ("twilight"). Its sense accordingly differs from diurnal and nocturnal behavior, which respectively peak during hours of daylight an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fox032118BW
Foxes are small to medium-sized, omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull, upright, triangular ears, a pointed, slightly upturned snout, and a long bushy tail (or ''brush''). Twelve species belong to the monophyletic "true foxes" group of genus ''Vulpes''. Approximately another 25 current or extinct species are always or sometimes called foxes; these foxes are either part of the paraphyletic group of the South American foxes, or of the outlying group, which consists of the bat-eared fox, gray fox, and island fox. Foxes live on every continent except Antarctica. The most common and widespread species of fox is the red fox (''Vulpes vulpes'') with about 47 recognized subspecies. The global distribution of foxes, together with their widespread reputation for cunning, has contributed to their prominence in popular culture and folklore in many societies around the world. The hunting of foxes with packs of hounds, long an es ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predation
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the host) and parasitoidism (which always does, eventually). It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators. Predators may actively search for or pursue prey or wait for it, often concealed. When prey is detected, the predator assesses whether to attack it. This may involve ambush or pursuit predation, sometimes after stalking the prey. If the attack is successful, the predator kills the prey, removes any inedible parts like the shell or spines, and eats it. Predators are adapted and often highly specialized for hunting, with acute senses such as vision, hearing, or smell. Many predatory animals, both vertebrate an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Phase
Concerning the lunar month of ~29.53 days as viewed from Earth, the lunar phase or Moon phase is the shape of the Moon's directly sunlit portion, which can be expressed quantitatively using areas or angles, or described qualitatively using the terminology of the 4 major phases: new moon, first quarter, full moon, last quarter and 4 minor phases: waxing crescent, waxing gibbous, waning gibbous, and waning crescent. The lunar phases gradually change over a synodic month (~29.53 days) as the Moon's orbital positions around Earth and Earth around the Sun shift. The visible side of the Moon is variously sunlit, depending on the position of the Moon in its orbit. Thus, this face's sunlit portion can vary from 0% (at new moon) to 100% (at full moon). Each of the 4 major lunar phases (see below) is ~7.4 days, with +/− 19 hours in variation (6.58–8.24 days) due to the elliptical shape of the Moon's orbit. Phases of the Moon There are four ''principal'' (primary/major) lunar phases: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walnut Twig Beetle
''Pityophthorus juglandis'', also known as the walnut twig beetle for feeding on several different species of walnut trees, ''Juglans'', is one of only a few species in the genus ''Pityophthorus'' that is associated with hardwoods and the only one associated with feeding on walnut trees. Description ''Pityophthorus juglandis'' can easily be distinguished from other members of its genus. Curtis Utley, a researcher at Colorado State University, elaborates on these differences stating, "Among these differences there are the 4 to 6 concentric rows of asperities on the prothorax, usually broken and overlapping at the median line. The declivity at the end of the wing covers is steep, very shallowlbisulcate and at the apex it is generally flattened with small granules." The walnut twig beetles' small size is common for its genus. Adult beetles average between 1.5 and 1.9 millimeters in length. Although little is known about the life-cycle of the walnut twig beetle, during experimentatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Hindu
''The Hindu'' is an Indian English-language daily newspaper owned by The Hindu Group, headquartered in Chennai, Tamil Nadu. It began as a weekly in 1878 and became a daily in 1889. It is one of the Indian newspapers of record and the second most circulated English-language newspaper in India, after '' The Times of India''. , ''The Hindu'' is published from 21 locations across 11 states of India. ''The Hindu'' has been a family-owned newspaper since 1905, when it was purchased by S. Kasturi Ranga Iyengar from the original founders. It is now jointly owned by Iyengar's descendants, referred to as the "Kasturi family", who serve as the directors of the holding company. The current chairperson of the group is Malini Parthasarathy, a great-granddaughter of Iyengar. Except for a period of about two years, when Siddharth Varadarajan, S. Varadarajan held the editorship of the newspaper, the editorial positions of the paper were always held by members of the family or held under t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galapagos Hawk
The Galápagos hawk (''Buteo galapagoensis'') is a large hawk endemic to most of the Galápagos Islands. Description The Galapágos hawk is similar in size to the red-tailed hawk (''Buteo jamaicensis'') and the Swainson's hawk (''Buteo swainsoni'') of North America, but the size is variable across the islands as is recorded for many animals native to the Galapágos. They appear to be somewhat more heavily built than those well-known mainland species, and going on average weights, this species is the second heaviest ''Buteo'' in the Americas, behind only the ferruginous hawk. The Galapágos hawk can range from in length from beak to tail with a wingspan of .Del Hoyo, J., & Elliot, A. I SARGATAL, J. eds. 1994. ''Handbook of the birds of the World. Vol. 2. New World Vultures to Guineafowl''. Lynx Edicions, Barcelona. The smallest hawk sizes recorded are on Marchena Island, where males average and females average . Intermediate in size are the hawks of Santiago Island, on whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Cruz Island (Galápagos)
Santa Cruz Island () is one of the Galápagos Islands with an area of and a maximum altitude of . Situated in the center of the archipelago, Santa Cruz is the second largest island after Isabela. Its capital is Puerto Ayora, the most populated urban centre in the islands. On Santa Cruz, there are some small villages, whose inhabitants work in agriculture and cattle raising. The island is an oval-shaped, long and wide shield volcano. Its summit contains a shallow caldera that has been largely buried by youthful pit craters and cinder cones with well-preserved craters. The most recent eruptions may have occurred only a few thousand years ago with the effusion of sparsely vegetated lava flows from vents on the north flank and along the summit fissure. A gigantic lava tube measuring over long is a tourist attraction on the island. As a testimony to its volcanic history there are two big holes formed by the collapse of a magma chamber: Los Gemelos, or "The Twins". Named after ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galápagos Islands
The Galápagos Islands (Spanish: , , ) are an archipelago of volcanic islands. They are distributed on each side of the equator in the Pacific Ocean, surrounding the centre of the Western Hemisphere, and are part of the Republic of Ecuador. Located west of continental Ecuador, the islands are known for their large number of endemic species that were studied by Charles Darwin during the second voyage of HMS ''Beagle''. His observations and collections contributed to the inception of Darwin's theory of evolution by means of natural selection. The Galápagos Islands and their surrounding waters form the Galápagos Province of Ecuador, the Galápagos National Park, and the Galápagos Marine Reserve. The principal language on the islands is Spanish. The islands have a population of slightly over 25,000. The first recorded visit to the islands happened by chance in 1535, when Fray Tomás de Berlanga, the Bishop of Panamá, was surprised to find this undiscovered land on a vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short-eared Owl
The short-eared owl (''Asio flammeus'') is a widespread grassland species in the family Strigidae. Owls belonging to genus ''Asio'' are known as the eared owls, as they have tufts of feathers resembling mammalian ears. These "ear" tufts may or may not be visible. The short-eared owl will display its tufts when in a defensive pose, although its very short tufts are usually not visible. The short-eared owl is found in open country and grasslands. Taxonomy The short-eared owl was formally described in 1763 by the Lutheran bishop Erik Pontoppidan under the binomial name ''Strix flammea''. The specific epithet is from the Latin ''flammeus'' meaning "flammulated" or "flame-coloured". This owl is now placed with seven other species in the genus ''Asio'' that was introduced by the French zoologist Mathurin Jacques Brisson in 1760. Eleven subspecies are recognised: * ''A. f. flammeus'' – ( Pontoppidan, 1763): the nominate subspecies, found in North America, Europe, North Africa and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foraging
Foraging is searching for wild food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce. Foraging theory is a branch of behavioral ecology that studies the foraging behavior of animals in response to the environment where the animal lives. Behavioral ecologists use economic models and categories to understand foraging; many of these models are a type of optimal model. Thus foraging theory is discussed in terms of optimizing a payoff from a foraging decision. The payoff for many of these models is the amount of energy an animal receives per unit time, more specifically, the highest ratio of energetic gain to cost while foraging. Foraging theory predicts that the decisions that maximize energy per unit time and thus deliver the highest payoff will be selected for and persist. Key words used to describe foraging behavior include ''resources'', the elements necessary for survival and reproduction which have a l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptation
In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is a phenotypic trait or adaptive trait, with a functional role in each individual organism, that is maintained and has evolved through natural selection. Historically, adaptation has been described from the time of the ancient Greek philosophers such as Empedocles and Aristotle. In 18th and 19th century natural theology, adaptation was taken as evidence for the existence of a deity. Charles Darwin proposed instead that it was explained by natural selection. Adaptation is related to biological fitness, which governs the rate of evolution as measured by change in allele frequencies. Often, two or more species co-adapt and co-evolve as they develop adaptations that interlock with those of the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antipredator Adaptation
Anti-predator adaptations are mechanisms developed through evolution that assist prey organisms in their constant struggle against predators. Throughout the animal kingdom, adaptations have evolved for every stage of this struggle, namely by avoiding detection, warding off attack, fighting back, or escaping when caught. The first line of defence consists in avoiding detection, through mechanisms such as camouflage, masquerade, apostatic selection, living underground, or nocturnality. Alternatively, prey animals may ward off attack, whether by advertising the presence of strong defences in aposematism, by mimicking animals which do possess such defences, by startling the attacker, by signalling to the predator that pursuit is not worthwhile, by distraction, by using defensive structures such as spines, and by living in a group. Members of groups are at reduced risk of predation, despite the increased conspicuousness of a group, through improved vigilance, predator confusio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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