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Northwestern Salamander
The northwestern salamander (''Ambystoma gracile'') is a species of mole salamander that inhabits the northwest Pacific coast of North America. These fairly large salamanders grow to 8.7 in (220 mm) in length. It is found from southeastern Alaska on May Island, through Washington and Oregon south to the mouth of the Gualala River, Sonoma County, California. It occurs from sea level to the timberline, but not east of the Cascade Divide. Its range includes Vancouver Island in British Columbia and The San Juan Islands, Cypress, Whidbey, Bainbridge, and Vashon Islands in Washington.Snyder, R.C. 1963. Ambystoma gracile. Catalogue of American Amphibians and Reptiles: 1-2. Description The egg mass is very firm, it feels much like a brain with a jelly layer around the entire mass. The individual eggs are 2 mm diameter with the entire egg mass the size of your fist. The egg masses are laid in water about 0.5– 2 meters below the surface. The hatchlings are 1-35mm long with fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baird (taxonomy)
Spencer Fullerton Baird (; February 3, 1823 – August 19, 1887) was an American naturalist, ornithologist, ichthyologist, herpetologist, and museum curator. Baird was the first curator to be named at the Smithsonian Institution. He eventually served as assistant Secretary of the Smithsonian from 1850 to 1878, and as Secretary from 1878 until 1887. He was dedicated to expanding the natural history collections of the Smithsonian which he increased from 6,000 specimens in 1850 to over 2 million by the time of his death. He published over 1,000 works during his lifetime. Early life and education Spencer Fullerton Baird was born in Reading, Pennsylvania in 1823. His mother was a member of the prominent Philadelphia Biddle family; he was a nephew of Speaker of the Pennsylvania Senate Charles B. Penrose and a first cousin, once removed, of U.S. Senator Boies Penrose and his distinguished brothers, Richard, Spencer, and Charles. He became a self-trained naturalist as a young man, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paedomorphic
Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny is found in modern humans compared to other primates. In progenesis or paedogenesis, sexual development is accelerated. Both neoteny and progenesis result in paedomorphism (as having the form typical of children) or paedomorphosis (changing towards forms typical of children), a type of heterochrony. It is the retention in adults of traits previously seen only in the young. Such retention is important in evolutionary biology, domestication and evolutionary developmental biology. Some authors define paedomorphism as the retention of larval traits, as seen in salamanders.Schell, S. C. ''Handbook of Trematodes of North America North of Mexico'', 1985, pg. 22 History and etymology The origins of the concept of neoteny have been traced to the Bible (as argued by Ashley Monta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mole Salamanders
The mole salamanders (genus ''Ambystoma'') are a group of advanced salamanders endemic to North America. The group has become famous due to the presence of the axolotl (''A. mexicanum''), widely used in research due to its paedomorphosis, and the tiger salamander (''A. tigrinum, A. mavortium'') which is the official amphibian of many states, and often sold as a pet. General description Terrestrial mole salamanders are identified by having wide, protruding eyes, prominent costal grooves, and thick arms. Most have vivid patterning on dark backgrounds, with marks ranging from deep blue spots to large yellow bars depending on the species. Terrestrial adults spend most of their lives underground in burrows, either of their own making or abandoned by other animals. Some northern species may hibernate in these burrows throughout the winter. They live alone and feed on any available invertebrate. Adults spend little time in the water, only returning to the ponds of their birth to bree ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clear-cutting
Clearcutting, clearfelling or clearcut logging is a forestry/ logging practice in which most or all trees in an area are uniformly cut down. Along with shelterwood and seed tree harvests, it is used by foresters to create certain types of forest ecosystems and to promote select species that require an abundance of sunlight or grow in large, even-age stands. Logging companies and forest-worker unions in some countries support the practice for scientific, safety and economic reasons, while detractors consider it a form of deforestation that destroys natural habitats and contributes to climate change. Clearcutting is the most common and economically profitable method of logging. However, it also may create detrimental side effects, such as the loss of topsoil, the costs of which are intensely debated by economic, environmental and other interests. In addition to the purpose of harvesting wood, clearcutting is used to create land for farming. Ultimately, the effects of clearcutt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Old Growth Forest
An old-growth forestalso termed primary forest, virgin forest, late seral forest, primeval forest, or first-growth forestis a forest that has attained great age without significant disturbance, and thereby exhibits unique ecological features, and might be classified as a climax community. The Food and Agriculture Organization of the United Nations defines primary forests as naturally regenerated forests of native tree species where there are no clearly visible indications of human activity and the ecological processes are not significantly disturbed. More than one-third (34 percent) of the world's forests are primary forests. Old-growth features include diverse tree-related structures that provide diverse wildlife habitat that increases the biodiversity of the forested ecosystem. Virgin or first-growth forests are old-growth forests that have never been logged. The concept of diverse tree structure includes multi-layered canopies and canopy gaps, greatly varying tree height ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by total area. Its southern and western border with the United States, stretching , is the world's longest binational land border. Canada's capital is Ottawa, and its three largest metropolitan areas are Toronto, Montreal, and Vancouver. Indigenous peoples have continuously inhabited what is now Canada for thousands of years. Beginning in the 16th century, British and French expeditions explored and later settled along the Atlantic coast. As a consequence of various armed conflicts, France ceded nearly all of its colonies in North America in 1763. In 1867, with the union of three British North American colonies through Confederation, Canada was formed as a federal dominion of four provinces. This began an accretion of provinces an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breeding Season
Seasonal breeders are animal species that successfully mate only during certain times of the year. These times of year allow for the optimization of survival of young due to factors such as ambient temperature, food and water availability, and changes in the predation behaviors of other species. Related sexual interest and behaviors are expressed and accepted only during this period. Female seasonal breeders will have one or more estrus cycles only when she is "in season" or fertile and receptive to mating. At other times of the year, they will be anestrus, or have a dearth of their sexual cycle. Unlike reproductive cyclicity, seasonality is described in both males and females. Male seasonal breeders may exhibit changes in testosterone levels, testes weight, and fertility depending on the time of year. Seasonal breeders are distinct from opportunistic breeders, that mate whenever the conditions of their environment become favorable, and continuous breeders that mate year-round. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossorial
A fossorial () animal is one adapted to digging which lives primarily, but not solely, underground. Some examples are badgers, naked mole-rats, clams, meerkats, and mole salamanders, as well as many beetles, wasps, and bees. Prehistoric evidence The physical adaptation of fossoriality is widely accepted as being widespread among many prehistoric phyla and taxa, such as bacteria and early eukaryotes. Furthermore, fossoriality has evolved independently multiple times, even within a single family. Fossorial animals appeared simultaneously with the colonization of land by arthropods in the late Ordovician period (over 440 million years ago). Other notable early burrowers include ''Eocaecilia'' and possibly ''Dinilysia''. The oldest example of burrowing in synapsids, the lineage which includes modern mammals and their ancestors, is a cynodont, ''Thrinaxodon liorhinus'', found in the Karoo of South Africa, estimated to be 251 million years old. Evidence shows that this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesophytic
Mesophytes are terrestrial plants which are neither adapted to particularly dry nor particularly wet environments. An example of a mesophytic habitat would be a rural temperate meadow, which might contain Solidago, goldenrod, Trifolium, clover, Leucanthemum vulgare, oxeye daisy, and ''Rosa multiflora''. Mesophytes prefer soil and air of moderate humidity and avoid soil with standing water or containing a great abundance of salts. They make up the largest ecological group of terrestrial plants, and usually grow under moderate to hot and humid climatic regions. Morphological adaptations Mesophytes do not have any specific morphological adaptations. They usually have broad, flat and green leaves; an extensive fibrous root system to absorb water; and the ability to develop perennating organs such as corms, rhizomes and bulbs to store food and water for use during drought. Anatomical adaptations Mesophytes do not have any special internal structure. Epidermis is single layered usually wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesic Habitat
In ecology, a mesic habitat is a type of habitat with a moderate or well-balanced supply of moisture, e.g., a mesic forest, a temperate hardwood forest, or dry-mesic prairie. Mesic habitats transition to xeric shrublands in a non-linear fashion, which is evidence of a threshold. Mesic is one of a triad of terms used to describe the amount of water in a habitat. The others are xeric and hydric. Further examples of mesic habitats include streamsides, wet meadows, springs, seeps, irrigated fields, and high elevation habitats. These habitats effectively provide drought insurance as land at higher elevations warms due to seasonal or other change. Healthy mesic habitats act like sponges in that they store water in such a way that it can be deposited to neighboring habitats as needed. They are common in dryer regions of the western United States, and can be a good water source to neighboring desert habitats. Healthy mesic habitats also provide forb and insects for organisms belonging t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taricha Granulosa
The rough-skinned newt or roughskin newt (''Taricha granulosa'') is a North American newt known for the strong toxin exuded from its skin. Appearance A stocky newt with rounded snout, it ranges from light brown to olive or brownish-black on top, with the underside, including the head, legs, and tail, a contrasting orange to yellow. The skin is granular, but males are smooth-skinned during breeding season. They measure 6 to 9 cm in snout-to-vent length, and 11 to 18 cm overall. They are similar to the California newt (''Taricha torosa'') but differ in having smaller eyes, yellow irises, V-shaped tooth patterns, and uniformly dark eyelids. Males can be distinguished from females during breeding season by large swollen vent lobes and cornified toe pads. Distribution and subspecies Habitats of rough-skinned newts are found throughout the Pacific Northwest. Their range extends south to Santa Cruz, California, and north to Alaska. They are uncommon east of the Cascade ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syntopic
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 in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
