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Amphibian Declines
Since the 1980s, decreases in amphibian populations, including population decline and localized mass extinctions, have been observed in locations all over the world. This type of biodiversity loss is known as one of the most critical threats to global biodiversity. The possible causes include habitat destruction and modification, diseases, exploitation, pollution, pesticide use, introduced species, and ultraviolet-B radiation (UV-B). However, many of the causes of amphibian declines are still poorly understood, and the topic is currently a subject of ongoing research. Modeling results found that the current extinction rate of amphibians could be 211 times greater than the background extinction rate. This estimate even goes up to 25,000–45,000 times if endangered species are also included in the computation. Scientists began observing reduced populations of several European amphibian species already in the 1950s. Nevertheless, awareness of the phenomenon as a global problem an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bufo Periglenes2
''Bufo'' is a genus of true toads in the amphibian family Bufonidae. As traditionally defined, it was a wastebasket genus containing a large number of toads from much of the world but following taxonomic reviews most of these have been moved to other genera, leaving only seventeen extant species from Europe, northern Africa and Asia in this genus, including the well-known common toad (''B. bufo''). Some of the genera that contain species formerly placed in ''Bufo'' are '' Anaxyrus'' (many North American species), '' Bufotes'' ( European green toad and relatives), '' Duttaphrynus'' (many Asian species, including the Asian common toad introduced elsewhere), '' Epidalea'' (natterjack toad) and '' Rhinella'' (many Latin American species, including the cane toad introduced elsewhere). Description True toads have in common stocky figures and short legs, which make them relatively poor jumpers. Their dry skin is thick and "warty". Behind their eyes, ''Bufo'' species have wart-lik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newts
A newt is a salamander in the subfamily Pleurodelinae. The terrestrial juvenile phase is called an eft. Unlike other members of the family Salamandridae, newts are semiaquatic, alternating between aquatic and terrestrial habitats. Not all aquatic salamanders are considered newts, however. More than 100 known species of newts are found in North America, Europe, North Africa and Asia. Newts metamorphose through three distinct developmental life stages: aquatic larva, terrestrial juvenile (eft), and adult. Adult newts have lizard-like bodies and return to the water every year to breed, otherwise living in humid, cover-rich land habitats. Newts are threatened by habitat loss, fragmentation and pollution. Several species are endangered, and at least one species, the Yunnan lake newt, has become extinct recently. Etymology The Old English name of the animal was , (of unknown origin), resulting in Middle English ; this word was transformed irregularly into , , or . The initial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat Destruction
Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease in biodiversity and species numbers. Habitat destruction is in fact the leading cause of biodiversity loss and species extinction worldwide. Humans contribute to habitat destruction through the use of natural resources, agriculture, industrial production and urbanization (urban sprawl). Other activities include mining, logging and trawling. Environmental factors can contribute to habitat destruction more indirectly. Geological processes, climate change, introduction of invasive species, ecosystem nutrient depletion, water and noise pollution are some examples. Loss of habitat can be preceded by an initial habitat fragmentation. Fragmentation and loss of habitat have become one of the most important topics of research in ecology as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Sentinel
Sentinel species are organisms, often animals, used to detect risks to humans by providing advance warning of a danger. The terms primarily apply in the context of environmental hazards rather than those from other sources. Some animals can act as sentinels because they may be more susceptible or have greater exposure to a particular hazard than humans in the same environment. People have long observed animals for signs of impending hazards or evidence of environmental threats. Plants and other living organisms have also been used for these purposes. Historical examples Many observations of animals point to toxicity in food, water or air that would or could harm humans. Canaries The classic example is the " canary in the coal mine". The idea of placing a warm-blooded animal in a mine to detect carbon monoxide was first proposed by John Scott Haldane in 1895, and canaries were used as early as 1896. Countries such as Britain, the United States, and Canada used canaries a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atelopus Varius
''Atelopus varius'', the Costa Rican variable harlequin toad or clown frog, is a small Neotropical true toad from the family Bufonidae.Crump, M.L. 1986. "Homing and site fidelity in a Neotropical frog, ''Atelopus varius'' (Bufonidae)." ''Copeia'' 1986(4): 1007–1009. Once ranging from Costa Rica to Panama, ''A. varius'' is now listed as critically endangered and has been reduced to a single remnant population near Quepos, Costa Rica (rediscovered in 2003), and has only relict populations in western Panama. Recent variation in air temperature, precipitation, stream flow patterns, and the subsequent spread of a pathogenic chytrid fungus ('' Batrachochytrium dendrobatidis'') linked to global climate change have been the leading cause of decline for ''A. varius''.Lips, K.R., Green, D.E. and Papendick, R. 2003. "Chytridiomycosis in wild frogs from southern Costa Rica." ''Journal of Herpetology'' 37(1): 215–218. Pounds, J.A., Bustamante, M.R., Coloma, L.A., Consuegra, J.A., Fogde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Costa Rica
Costa Rica, officially the Republic of Costa Rica, is a country in Central America. It borders Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, and the Pacific Ocean to the southwest, as well as Maritime boundary, maritime border with Ecuador to the south of Cocos Island. It has a population of around five million in a land area of nearly . An estimated people live in the capital and largest city, San José, Costa Rica, San José, with around two million people in the surrounding metropolitan area. The sovereign state is a Presidential system, presidential republic. It has a long-standing and stable Constitution of Costa Rica, constitutional democracy and a highly educated workforce. The country spends roughly 6.9% of its budget (2016) on education, compared to a global average of 4.4%. Its economy, once heavily dependent on agriculture, has diversified to include sectors such as finance, corporate services for foreign companies, pharmaceut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monteverde
Monteverde is the twelfth Cantons of Costa Rica, canton of the Puntarenas Province, Puntarenas Provinces of Costa Rica, province of Costa Rica, located in the Cordillera de Tilarán (Tilarán range). Roughly a four-hour drive from the Costa Rican Central Valley, Central Valley, Monteverde is one of the country's major ecotourism destinations, with the Monteverde Cloud Forest Reserve, Reserva Biológica Bosque Nuboso Monteverde (Monteverde Cloud Forest Reserve) being the largest, in addition to several other natural attractions which draw considerable numbers of tourists and naturalists, both from Costa Rica and abroad. National Geographic Society, ''National Geographic'' has called the Monteverde Cloud Forest "the jewel in the crown of cloud forest reserves". ''Newsweek'' ranked Monteverde the world's No. 14 "place to remember before it disappears"; by popular vote in Costa Rica, Monteverde was deemed one of the seven natural wonders of the nation, along with Isla del Coco, Vol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can also be referred to as an ''endemism'' or, in scientific literature, as an ''endemite''. Similarly, many species found in the Western ghats of India are examples of endemism. Endemism is an important concept in conservation biology for measuring biodiversity in a particular place and evaluating the risk of extinction for species. Endemism is also of interest in evolutionary biology, because it provides clues about how changes in the environment cause species to undergo range shifts (potentially expanding their range into a larger area or b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golden Toad
The golden toad (''Incilius periglenes'') is an extinct species of true toad that was once abundant in a small, high-altitude region of about in an area north of the city of Monteverde, Costa Rica. It was endemic to elfin cloud forest. Also called the Monte Verde toad, Alajuela toad and orange toad, it is commonly considered the " poster child" for the amphibian decline crisis. This toad was first described in 1966 by herpetologist Jay Savage. The last sighting of a single male golden toad was on 15 May 1989, and it has since been classified as extinct by the International Union for Conservation of Nature (IUCN). The golden toad was declared extinct by the IUCN Red List in 2005. Description The golden toad was one of about 500 species in the family Bufonidae—the "true toads". Males were orange and sometimes slightly mottled on the belly, while females showed a greater variety of colors, including black, yellow, red, green, and white; both sexes had smooth skin. While mal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herpetology
Herpetology (from Ancient Greek ἑρπετόν ''herpetón'', meaning "reptile" or "creeping animal") is a branch of zoology concerned with the study of amphibians (including frogs, salamanders, and caecilians (Gymnophiona)) and reptiles (including snakes, lizards, turtles, crocodilians, and tuataras). Birds, which are cladistically included within Reptilia, are traditionally excluded here; the separate scientific study of birds is the subject of ornithology. The precise definition of herpetology is the study of ectothermic (cold-blooded) tetrapods. This definition of "herps" (otherwise called "herptiles" or "herpetofauna") excludes fish; however, it is not uncommon for herpetological and ichthyological scientific societies to collaborate. For instance, groups such as the American Society of Ichthyologists and Herpetologists have co-published journals and hosted conferences to foster the exchange of ideas between the fields. Herpetological societies are formed to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Union For Conservation Of Nature
The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status of the natural world and the measures needed to safeguard it. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partners ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinct
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and recover. As a species' potential Range (biology), range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxon, Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the Fossil, fossil record) after a period of apparent absence. Over five billion species are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryotes globally, possibly many times more if microorganisms are included. Notable extinct animal species include Dinosaur, non-avian dinosaurs, Machairodontinae, saber-toothed cats, and mammoths. Through evolution, species arise through the process of specia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
