|
Adaptation Of Australian Animals To Cane Toads
Native to both South and Central America, Cane toads were introduced to Australia in the 1930s and have since become an invasive species and a threat to the continent's native predators and scavengers. The primary mechanism of impact cane toads have on Australian ecosystems is through poisoning of native species. The parotoid gland on either side of the head of a cane toad produces a secretion containing bufadienolides that is toxic to most animals. This chemical defence does not exist in any native Australian anuran. Consequently, many native animals that prey on anurans experienced significant population decline, immediately following the invasion of the toad species in Australia. Whilst the invasion of cane toads has had devastating impacts on the populations of native predators in many Australian ecosystems in which the species has spread, it is unlikely that cane toads are solely responsible for the extinction of any native species. Furthermore, many of the populations that in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southern subregion of a single continent called America. South America is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest. The continent generally includes twelve sovereign states: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela; two dependent territories: the Falkland Islands and South Georgia and the South Sandwich Islands; and one internal territory: French Guiana. In addition, the ABC islands of the Kingdom of the Netherlands, Ascension Island (dependency of Saint Helena, Ascension and Tristan da Cunha, a British Overseas Territory), Bouvet Island ( dependency of Norway), Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taste Aversion
Conditioned taste aversion occurs when an animal acquires an aversion to the taste of a food that was paired with aversive stimuli. The Garcia effect is that the aversion develops more strongly for stimuli that cause nausea than other stimuli. This is considered an adaptive trait or survival mechanism that enables the organism to avoid poisonous substances (e.g., poisonous berries) before they cause harm. The aversion reduces consuming the same substance (or something that tastes similar) in the future, thus avoiding poisoning. Studies on conditioned taste aversion that involved irradiating rats were conducted in the 1950s by Dr. John Garcia, leading to it sometimes being called the Garcia effect. Conditioned taste aversion can occur when sickness is merely coincidental to, and not caused by, the substance consumed. For example, a person who becomes very sick after consuming vodka-and-orange-juice cocktails may then become averse to the taste of orange juice, even though the si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corvidae
Corvidae is a cosmopolitan family of oscine passerine birds that contains the crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs, and nutcrackers. In colloquial English, they are known as the crow family or corvids. Currently, 133 species are included in this family. The genus ''Corvus'', including the crows, rooks, and ravens, makes up over a third of the entire family. Corvids (ravens) are the largest passerines. Corvids display remarkable intelligence for animals of their size, and are among the most intelligent birds thus far studied. Specifically, members of the family have demonstrated self-awareness in mirror tests (European magpies) and tool-making ability (e.g. crows and rooks), skills which until recently were thought to be possessed only by humans and a few other higher mammals. Their total brain-to-body mass ratio is equal to that of non-human great apes and cetaceans, and only slightly lower than that of humans.Birding in India and South AsiaCor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird Of Prey
Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predators have keen eyesight for detecting prey from a distance or during flight, strong feet with sharp talons for grasping or killing prey, and powerful, curved beaks for tearing off flesh. Although predatory birds primarily hunt live prey, many species (such as fish eagles, vultures and condors) also scavenge and eat carrion. Although the term "bird of prey" could theoretically be taken to include all birds that actively hunt and eat other animals, ornithologists typically use the narrower definition followed in this page, excluding both piscivorous predators such as storks, herons, gulls, skuas, penguins and kingfishers, as well as primarily insectivorous birds such as passerine birds (e.g. shrikes) and birds like nightjars and frogmouths. So ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marbled Frog
The marbled frog or marbled marsh frog (''Limnodynastes convexiusculus'') is a species of ground-dwelling frog native to northern and north-eastern Australia, and southern New Guinea in both Indonesia and Papua New Guinea. It is not to be confused with the spotted grass frog The spotted grass frog or spotted marsh frog (''Limnodynastes tasmaniensis'') is a terrestrial frog native to Australia. It is distributed throughout all of New South Wales and Victoria, eastern South Australia, the majority of Queensland, and ... (''Limnodynastes tasmaniensis''), which was also formerly known as the "marbled frog" in South Australia.Waite, Edgar R. (1929): ''The reptiles and amphibians of South Australia.'' Facsimile Edition, issued to commemorate the Second World Congress of Herpetology, Adelaide,South Australia, by the Society for the Study of Amphibians and Reptiles. 1993. Description Adult marbled frogs reach about 4.5 centimetres (1.8 in) in length, sometimes larger. Toes ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some insects, fish, amphibians, mollusks, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis, which is often accompanied by a change of nutrition source or behavior. Animals can be divided into species that undergo complete metamorphosis (" holometaboly"), incomplete metamorphosis ("hemimetaboly"), or no metamorphosis (" ametaboly"). Scientific usage of the term is technically precise, and it is not applied to general aspects of cell growth, including rapid growth spurts. Generally organisms with a larva stage undergo metamorphosis, and during metamorphosis the organism loses larval characteristics. References to "metamorphosis" in mammals are imprecise and only colloquial, but historically idealist ideas of transformation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ontogeny
Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the study of the entirety of an organism's lifespan. Ontogeny is the developmental history of an organism within its own lifetime, as distinct from phylogeny, which refers to the evolutionary history of a species. Another way to think of ontogeny is that it is the process of an organism going through all of the developmental stages over its lifetime. The developmental history includes all the developmental events that occur during the existence of an organism, beginning with the changes in the egg at the time of fertilization and events from the time of birth or hatching and afterward (i.e., growth, remolding of body shape, development of secondary sexual characteristics, etc.). While developmental (i.e., ontogenetic) processes can influence sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mogurnda
''Mogurnda'' is a genus of freshwater fishes in the family Eleotridae native to eastern and northern Australia and New Guinea. Several species are endemic to Lake Kutubu in Papua New Guinea. Species The currently recognized species in this genus are: * '' Mogurnda adspersa'' Castelnau, 1878 ( outhernpurple-spotted gudgeon) * '' Mogurnda aiwasoensis'' G. R. Allen & Renyaan, 1996 * '' Mogurnda arguni'' G. R. Allen & Hadiaty, 2014 Allen, G.R. & Hadiaty, R.K. (2014): Two new species of freshwater gudgeons (Eleotridae: Mogurnda) from the Arguni Bay Region of West Papua, Indonesia. ''aqua, International Journal of Ichthyology, 20 (2): 97-110.'' * '' Mogurnda aurifodinae'' Whitley, 1938 (northern mogurnda) * '' Mogurnda cingulata'' G. R. Allen & Hoese, 1991 (banded mogurnda) * ''Mogurnda clivicola'' G. R. Allen & A. P. Jenkins, 1999 (Flinders Ranges mogurnda) * ''Mogurnda furva'' G. R. Allen & Hoese, 1986 (black mogurnda) * '' Mogurnda kaifayama'' G. R. Allen & A. P. Jenkins, 1999 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barramundi
The barramundi (''Lates calcarifer'') or Asian sea bass, is a species of catadromous fish in the family Latidae of the order Perciformes. The species is widely distributed in the Indo-West Pacific, spanning the waters of the Middle East, South Asia, Southeast Asia, East Asia, and Oceania. Origin of name Barramundi is a loanword from an Australian Aboriginal language of the Rockhampton area in Queensland meaning "large-scaled river fish". Originally, the name barramundi referred to ''Scleropages leichardti'' and ''Scleropages jardinii''. However, the name was appropriated for marketing reasons during the 1980s, a decision that has aided in raising the profile of this fish significantly. ''L. calcarifer'' is broadly referred to as Asian seabass by the international scientific community, but is also known as Australian seabass. Description This species has an elongated body form with a large, slightly oblique mouth and an upper jaw extending behind the eye. The lower edge of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tadpole
A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found in adult amphibians such as a lateral line, gills and swimming tails. As they undergo metamorphosis, they start to develop functional lungs for breathing air, and the diet of tadpoles changes drastically. A few amphibians, such as some members of the frog family Brevicipitidae, undergo direct development i.e., they do not undergo a free-living larval stage as tadpoles instead emerging from eggs as fully formed "froglet" miniatures of the adult morphology. Some other species hatch into tadpoles underneath the skin of the female adult or are kept in a pouch until after metamorphosis. Having no hard skeletons, it might be expected that tadpole fossils would not exist. However, traces of biofilms have been preserved and fossil tadpoles have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foraging
Foraging is searching for wild food resources. It affects an animal's Fitness (biology), fitness because it plays an important role in an animal's ability to survive and reproduce. Optimal foraging theory, 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 fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympatry
In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sharing a common range exemplifies sympatric speciation. Such speciation may be a product of reproductive isolation – which prevents hybrid offspring from being viable or able to reproduce, thereby reducing gene flow – that results in genetic divergence. Sympatric speciation may, but need not, arise through secondary contact, which refers to speciation or divergence in allopatry followed by range expansions leading to an area of sympatry. Sympatric species or taxa in secondary contact may or may not interbreed. Types of populations Four main types of population pairs exist in nature. Sympatric populations (or species) contrast with parapatric populations, which contact one another in adjacent but not shared ranges and do not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
