| ecdysis |
emergence from a cocoon or pupa. |
|
| echidna |
an egg-laying insectivorous mammal of the genus Tachyglossus or Zaglossus, native to Australia and New Guinea, with a covering of spines, a long snout, and long claws. |
|
| echinodermata |
Group of marine invertebrates that
have a five-fold body symmetry, members of which develop armour in the form of hard
shells and spines (the group name means spiny
skins); includes such familiar forms as starfish,
sea urchins, sea cucumbers and sea lilies |
|
| echinoid |
Member of the group of marine invertebrates known as the Echinodermata, which
bears an external shell and an armour of moveable spikes; includes the familiar forms known
as sea urchins, sand dollars and pansy shells |
|
| echo-location |
used by bats; the sending and receiving of ultra high frequency sound emissions to determine the exact location of an object or organism |
|
| ecological capacity |
The ability of vegetation to support animals and maintain them in a healthy and reproductive state, without the deterioration of the vegetation in the long-term |
|
| ecological index method |
a method used to determine the veld condition of an area, using the ecological status of grasses |
|
| ecological niche |
that portion of habitat that a specific species has become uniquely adapted to. |
|
| ecological status class |
classification of grasses based on their reaction to grazing pressure. |
|
| ecology |
the study of the inter-relationships between all organisms and their environment |
|
| ecosystem |
a definable ecological area in nature, consisting of all living and non-living components |
|
| ecotone |
a boundary between two plant communities of a major rank |
|
| ecotourism |
the purposeful travel to a specific location with the aim of experiencing natural phenomena and local culture |
|
| ecozone |
an area with a similar geology, rainfall, land shape and therefore its own unique combination of plants and animals |
|
| ectoparasites |
a parasite that lives on the outside of an organism |
|
| ectothermy |
a state of being dependent on the environmental temperature for body heating. These organisms exercise thermoregulation to keep their temperature at the optimum level |
|
| edaphic factors |
relating to soil |
|
| edentates |
the Order of mammals representing the sloths, armadillos and anteaters |
|
| edge species |
Species that prefer the ecotone between different habitats (e.g., impala, waterbuck, sable, roan). |
|
| ediacaran fauna |
Late Precambrian multicellular
animals constituting earliest macroscopic fauna |
|
| effluent |
a substance that flows out, e.g. pollution or waste materials into rivers or seas |
|
| egestion |
the elimination of undigested food material through the mouth |
|
| eia |
Environmental Impact Assessment See Module # 11 |
|
| eluviation |
the movement of soil material from one horizon to another |
|
| endangered |
under threat of becoming extinct |
|
| endemic |
an animal or plant particular to a given area |
|
| endoparasite |
a parasite that lives inside an organism |
|
| endoskeleton |
a skeleton situated interior to the muscles, e.g. all vertebrates |
|
| endothermy |
the regulation of internal body temperature independent of the external temperature |
|
| energy flow |
the flux of energy originating with the process of photosynthesis from sunlight through to plants, herbivores, etc |
|
| energy method |
a technique used to determine grazing capacity |
|
| entomology |
the study of insects |
|
| envenomation |
the transmission of venom into an organism, usually through the venomous animals bite or sting |
|
| environment |
the external conditions (soil, water, air, etc) and other organisms surrounding a living thing |
|
| environmental audit |
the assessment of how well an environmental body is performing at its allotted task |
|
| epicuticle |
The outermost layer of cuticle of an arthropod exoskeleton, composed mostly of wax. |
|
| epidemiology |
The study of a disease as it progresses through a population |
|
| epidermis |
the outer most layer of an organism |
|
| epiphragm |
a mucous layer secreted by the pedal glands of terrestrial Molluscs, covering its foot and shell opening, preventing desiccation |
|
| epiphyte |
plants that grow while attached to another species of plant in order to gain a more beneficial position, e.g. tree orchids |
|
| epoch |
a very long segment of time |
|
| equatorial |
Geographical region of the equator (cf tropical). |
|
| equilibrium species |
a species whose population exists in equilibrium with the resources and at a stable density |
|
| erectile |
Capable of erection, e.g. hair, which fear and anger cause to bristle, making the animal look bigger. |
|
| erosion |
an ongoing natural process caused by weathering, transporting and depositing of the earth's surface by wind, water, other natural forces or human and animal influence |
|
| escarpment |
the Eastern Transvaal escarpment is the steep break between the Highveld and the Lowveld |
|
| esophagus |
food pipe. The structure that directs food from the mouth to the stomach |
|
| estimation method |
a technique used to determine grazin capacity |
|
| estrus |
see oestrus |
|
| estuary |
the location where a river flows into the ocean and the segment of that river that is affected by the ocean, in terms of tidal and saline influence |
|
| ethology |
the study of animal behaviour |
|
| etiolated |
the loss of chlorophyll from a plant due to it being blocked from the sun for a prolonged period Grass yellowing = etiolated grass |
|
| eubacteria |
Primitive form of bacteria |
|
| eukaryote |
Eukaryotic: A single-celled or multicellular organism whose cells contain a distinct membrane-bound nucleus. A 'true' cell. Also see Prokaryotic. |
|
| eukaryote (2) |
Organisms whose cells have a complex
structure, including a nucleus and organelles |
|
| eusocial |
a social group in which members are fully integrated and cooperate in caring for young. |
|
| eutrophic |
a term applied to a body of water with a high nutrient content and high productivity |
|
| evapotranspiration |
the amount of water lost via evaporation and transpiration from an area |
|
| evergreen |
a plant that does not shed its leaves with a change of season |
|
| evolution |
a theory which maintains that organisms have their origin in previously existing forms |
|
| exfoliation |
the removal of a surface layer from an object or organism |
|
| exoskeleton |
the hard outer shell of an insect or other invertebrate |
|
| exotic |
not indigenous, introduced from abroad |
|
| extant |
not extinct, still living |
|
| extinction |
the dying out of a species |
|
|