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Yellow-footed Gull
The yellow-footed gull (''Larus livens'') is a large gull, closely related to the western gull and thought to be a subspecies until the 1960s. It is endemic to the Gulf of California. Description Adults are similar in appearance to the western gull with a white head, dark, slate-colored back and wings, and a thick yellow bill. Its legs are yellow, though first winter birds do display pink legs like those of the western gull. It attains full plumage at three years of age. This species is tied with slaty-backed gull for the world's fourth-largest gull species and is one of the largest gulls in the world, being slightly larger than the western gull. It measures in length and spans across the wings.''Gulls: Of North America, Europe, and Asia'' by Klaus Malling Olsen & Hans Larsson. Princeton University Press (2004). . The body mass of this species can vary from .''CRC Handbook of Avian Body Masses'' by John B. Dunning Jr. (Editor). CRC Press (1992), . Among standard measurements, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jonathan Dwight
Jonathan Dwight V (1858–1929) was an American ornithologist. Life Jonathan Dwight was born December 8, 1858 in New York City. His father was civil engineer Jonathan Dwight (1831–1910), grandfather Jonathan Dwight (1799–1856), great grandfather Jonathan Dwight (1772–1840), and great-great grandfather also named Jonathan Dwight (1743–1831), all part of the large New England Dwight family. His mother was Julia Lawrence Hasbrouck. In 1861 the family moved to Madison, New Jersey. His family had a summer home in Tadoussac, Quebec, and his first paper was published in 1879 on the birds observed there. He graduated from Harvard University in 1880, and joined his father in railroad design. He enlisted in the New York National Guard in 1889. After serving in the ambulance corps, he developed an interest in medicine. In 1893 he entered the Columbia University College of Physicians and Surgeons. He worked for a while in a hospital and private practice, but over time devoted more ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scavenger
Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding behavior. Scavengers play an important role in the ecosystem by consuming dead animal and plant material. ''Decomposers'' and detritivores complete this process, by consuming the remains left by scavengers. Scavengers aid in overcoming fluctuations of food resources in the environment. The process and rate of scavenging is affected by both biotic and abiotic factors, such as carcass size, habitat, temperature, and seasons. Etymology Scavenger is an alteration of ''scavager,'' from Middle English ''skawager'' meaning "customs collector", from ''skawage'' meaning "customs", from Old North French ''escauwage'' meaning "inspection", from ''schauwer'' meaning "to inspect", of Germanic origin; akin to Old English ''scēawian'' and German ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Birds Of Western Mexico
Endemism is the state of a species being found 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 be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larus
''Larus'' is a large genus of gulls with worldwide distribution (by far the greatest species diversity is in the Northern Hemisphere). Many of its species are abundant and well-known birds in their ranges. Until about 2005–2007, most gulls were placed in this genus, but this arrangement is now known to be polyphyletic, leading to the resurrection of the genera ''Ichthyaetus'', ''Chroicocephalus'', ''Leucophaeus'', and '' Hydrocoloeus'' (this last had been recognized more often than the other genera) for several species traditionally included in ''Larus''. They are in general medium to large birds, typically grey or white, often with black markings on their heads or wings. They have stout, longish bills and webbed feet. The taxonomy of the large gulls in the herring and lesser black-backed complex is very complicated, with different authorities recognising between two and eight species. Taxonomy The genus ''Larus'' was introduced in 1758 by the Swedish naturalist Carl Linn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Least Concern
A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. They do not qualify as threatened, near threatened, or (before 2001) conservation dependent. Species cannot be assigned the "Least Concern" category unless they have had their population status evaluated. That is, adequate information is needed to make a direct, or indirect, assessment of its risk of extinction based on its distribution or population status. Evaluation Since 2001 the category has had the abbreviation "LC", following the IUCN 2001 Categories & Criteria (version 3.1). Before 2001 "least concern" was a subcategory of the "Lower Risk" category and assigned the code "LR/lc" or lc. Around 20% of least concern taxa (3261 of 15636) in the IUCN database still use the code "LR/lc", which indicates they have not been re-evaluate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. 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 partnerships. The organization is best known to the wider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fledge
Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable condition in the nest, the nestling and fledging stage can be the same. For precocial birds, those that develop and leave the nest quickly, a short nestling stage precedes a longer fledging stage. All birds are considered to have fledged when the feathers and wing muscles are sufficiently developed for flight. A young bird that has recently fledged but is still dependent upon parental care and feeding is called a fledgling. People often want to help fledglings, as they appear vulnerable, but it is best to leave them alone. The USA National Phenology Network defines the phenophase (or life cycle stage) of fledged young for birds as "One or more young are seen recently departed from the nest. This includes young incapable of sustained fli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egg Incubation
Egg incubation is the process by which an egg, of oviparous (egg-laying) animals, develops an embryo within the egg, after the egg's formation and ovipositional release. Egg incubation is done under favorable environmental conditions, possibly by brooding and hatching the egg. Multiple and various factors are vital to the incubation of various species of animal. In many species of reptile for example, no fixed temperature is necessary, but the actual temperature determines the sex ratio of the offspring. In birds in contrast, the sex of offspring is genetically determined, but in many species a constant and particular temperature is necessary for successful incubation. Especially in poultry, the act of sitting on eggs to incubate them is called brooding. The action or behavioral tendency to sit on a clutch of eggs is also called broodiness, and most egg-laying breeds of poultry have had this behavior selectively bred out of them to increase production. Avian incubation A wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Territory (animal)
In ethology, territory is the sociographical area that an animal consistently defends against conspecific competition (or, occasionally, against animals of other species) using agonistic behaviors or (less commonly) real physical aggression. Animals that actively defend territories in this way are referred to as being territorial or displaying territorialism. Territoriality is only shown by a minority of species. More commonly, an individual or a group of animals occupies an area that it habitually uses but does not necessarily defend; this is called its home range. The home ranges of different groups of animals often overlap, and in these overlap areas the groups tend to avoid each other rather than seeking to confront and expel each other. Within the home range there may be a ''core area'' that no other individual group uses, but, again, this is as a result of avoidance. Function The ultimate function of animals inhabiting and defending a territory is to increase the indi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seabird
Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations. The first seabirds evolved in the Cretaceous period, and modern seabird families emerged in the Paleogene. In general, seabirds live longer, breed later and have fewer young than other birds do, but they invest a great deal of time in their young. Most species nest in colonies, which can vary in size from a few dozen birds to millions. Many species are famous for undertaking long annual migrations, crossing the equator or circumnavigating the Earth in some cases. They feed both at the ocean's surface and below it, and even feed on each other. Seabirds can be highly pelagic, coastal, or in some cases spend a part of the year away from the sea entirely. Seabirds and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate subphylum Vertebrata. Familiar examples of invertebrates include arthropods, mollusks, annelids, echinoderms and cnidarians. The majority of animal species are invertebrates; one estimate puts the figure at 97%. Many invertebrate taxa have a greater number and variety of species than the entire subphylum of Vertebrata. Invertebrates vary widely in size, from 50 μm (0.002 in) rotifers to the 9–10 m (30–33 ft) colossal squid. Some so-called invertebrates, such as the Tunicata and Cephalochordata, are more closely related to vertebrates than to other invertebrates. This makes the invertebrates paraphyletic, so the term has little meaning in taxonomy. Etymology The word "invertebrate" comes from the Latin word ''vertebra'', whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods. Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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