echolocation The process by which an animal locates itself with respect to other animals and objects by emitting sound waves and sensing the pattern of the reflected sound waves.
ecological extinction The reduction of a species to such low abundance that, although it is still present in the community, it no longer interacts significantly with other species.
ecology The study of the interrelationships among plants, animals and other organisms and their interaction with all aspects of their natural environmental
a. "...the more fundamental conception is ... the whole system ..., including not only the organism-complex, but also the whole complex of physical factors forming what we call the environment of the biome - the habitat factors in the widest sense.
It is the systems so formed which, from the point of view of the ecologist, are the basic units of nature on the face of the earth.
These ecosystems, as we may call them, are of the most various kinds and sizes..."
(Introduction and definition of a new term, "ecosystem," by Alfred Tansley in 1935)
b. All the individuals, species and populations in a spatially defined area, the interactions among them, and those between the organisms and the abiotic environment.
ecotone A transition between two or more different habitats; e.g. between forest and grassland.
ecotype A genetically induced variety within a single species, adapted for local ecological conditions
edaphic Influenced by the soil rather than the climate.
eel long, snakelike fishes that live in major oceans, freshwater lakes, and rivers. Eels belong to about 20 different families, most of which are relatively unknown. They live in tropical seas or deep in the ocean. Freshwater eels are members of the family Anguillidae. They live in the waters of almost every continent. Commonly known saltwater species are the conger eels, members of the family Congridae, and the moray eels that belong to the family Muraenidae.
egg All animals and plants, except for the most primitive types, begin their journey toward independent life when an egg is fertilized. An egg is a single female germ cell, or reproductive cell. It eventually develops into a new organism after it has been fertilized by a male germ cell. The egg cells of plants, when fertilized, develop into seeds.
embryonic diapause At about the time a female gives birth (e.g. in most kangaroo species), she also becomes receptive and mates. Embryos produced at this mating develop only as far as a hollow ball of cells (the blastocyst) and then become quiescent, entering a state of suspended animation or "embryonic diapause." The hormonal signal (prolactin) which blocks further development of the blastocyst is produced in response to the sucking stimulus from the young in the pouch. When sucking decreases as the young begins to eat other food and to leave the pouch, or if the young is lost from the pouch, the quiescent blastocyst resumes development, the embryo is born, and the cycle begins again. (Macdonald 1984)
endangered species any plant or animal "which is in danger of extinction throughout all or a significant portion of its range."
endemic A species is "endemic" to a particular area if it occurs naturally only in that area. The term is usually applied to a species with a very limited range, or a species that only occurs in one country.
endentate A member of an order comprising living and extinct anteaters, armadillos, pangolins (sometimes under Pholidota) and sloths.
enzootic A disease that is persistently found in an animal population
epiphytic Referring to a plant that lives on the surface of another plant and obtains its moisture and nutrients from the air and rain.
epizootic A disease outbreak in an animal population that occurs at a particular time and does not persist
equids A term collectively referring to asses, horses and zebras
escarpment A long cliff separating two relatively level or gently sloping surfaces
estrus The period in the estrus cycle of a female mammal when she is usually attractive to males and receptive to mating.
estrus cycle In female mammals (other than most primates), the hormonally controlled, regularly repeated stages by which the body is prepared for reproduction
exoskeleton A hard supporting structure on the outside of the body, enclosing all living cells ("external skeleton").
exotic species Introduced, non-native species.
extinct is a plant or animal where in which living individuals of its kind no longer exists
extirpate To wipe out.
BE AWARE. BE CONCERNED. SAVE THE ANIMALS. SAVE US. SAVE THE EARTH.
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