Glossary Database

Select a Letter to view the associated terms.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

 Glossary Term: 

Definition:

 Nape  1.) Dorsal portion of body from the occiput to origin of dorsal fin. 2.) The back of the neck (Morris 1992)
 nares  Nostrils.
 Naris  The openings of the nasal cavity (Morris 1992).
 Nasolabial groove  A depression or trough running from the external naris (nostril) to the edge of the upper lip in Plethodontid (lungless) salamanders (Peters 1964).
 Natal  relating to or occurring at birth (Morris 1992).
 natal river  Stream or river in which an anadromous fish was spawned.
 Natality  refers to births. Specifically, it refers to the birth rate of an animal, while mortality specifically refers to the death rate.
 Neonate  Newly hatched or born (Peters 1964).
 Neotony  Retention of larval or embryonic characteristics past the time of reproductive maturity (Pough 1996).
 Nest  A structure made by some caterpillars, typically from leaves tied together with silk. The caterpillars live and feed within the nest together.
 Nesting density  The amount of bird nesting in the area.
 Neutron  A subatomic nuclear particle that has no electrical charge but a mass almost the same as a proton. Neutrons comprise about half of the mass of an atom.
 Neve  Granular ice formed by recrystallization of snow. Synonymous with firn.
 Niche  the unique position occupied by a particular species, conceived both in terms of the actual physical area that it inhabits and the function that it performs within the community (Morris 1992).
 Nivation  1. Frost action and mass wasting beneath a snowbank. 2. The work of snow and ice beyond the limits of glacier action
 Nocturnal  Describing an animal that is active mainly or exclusively at night, rather than by day (Morris 1992).
 Nodule  A small, irregular, knobby, or rounded rock that is generally harder than the surrounding rock.
 Nomadic  A way of life in which there is no permanent residence site and the group moves from place to place according to the season, the available of food supply and other such factors; the route of travel often follows a traditional pattern (Morris 1992).
 Nonconformity  An unconformity in which stratified rocks rest on unstratified igneous or metamorphic rocks.
 Normal fault  A steeply inclined fault in which the hanging wall has moved downward in relation to the footwall.
 North pole  Point at which the northern end of the earth's axis of rotation intersects the earth's surface.
 North pole (magnetic)  One of the two ends of a magnet. The uncorrected direction indicated by the north-seeking end of the needle of a magnetic compass. True north differs from magnetic north by the amount of magnetic declination at the given point.
 Noxious  Harmful to the health (Guralnik 1970).
 Nucleus  The solid central part of an atom consisting of most of the mass (protons and neutrons) but almost none of the volume (orbiting electrons).
 NuTe ardent  A swift flowing, often red-hot cloud of gas, volcanic gas, and other pyroclastics formed by an explosive volcanic eruption. Syn. Ash flow. Deposits formed by nuTe ardentes are welded tuffs or ignimbrites.