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NPWRC - Biology Encyclopedia Category: Animals and Nature > Glossary of avian terms Date & country: 22/08/2008, USA Words: 235

Genome
a full set of chromosomes (Brown and Gibson 1980:563).

Genotype
the total genetic message found in a cell or an individual (Brown and Gibson 1980:563).

Geographic information system (GIS)
a set of computer hardware and software for analyzing and displaying spatially referenced features (i.e., points, lines, and polygons) with nongeographic attributes such as species and age (Johnson 1990:31).

Global change
the large-scale alterations in climate, patterns of land and water use, environmental chemistry, etc., especially alterations related to human activities (Lubchenco et al. 1991).

Guild
two or more co-occurring species' populations that exploit the same type of resources in similar ways. Competition is expected to be especially important within guilds (Wiens 1989a:156-159; Simberloff and Dayan 1990:115).

Habitat
the place where an animal or plant usually lives, often characterized by a dominant plant form or physical characteristic (Ricklefs 1970:871).

Habitat fragmentation
the alteration of a large habitat patch to create isolated or tenuously connected patches of the original habitat that are interspersed with an extensive mosaic of other habitat types (Wiens 1989b:201).

Habitat patches
areas distinguished from their surroundings by environmental discontinuities. Patches are organism-defined (i.e., the edges or discontinuities have biological significance to an organism) (adapted from Wiens 1970:83).

Habitat selection
preference for certain habitats (Ricklefs 1970:871).

Hatching success
percentage of eggs that hatch (Robinson and Rotenberry 1990:280) (syn. hatching rate [Mayfield 1970:459]).

Hatching-year (HY) bird
(1) a bird capable of sustained flight and known to have hatched during the calendar year in which it was banded (or seen) (Canadian Wildlife Service and U.S. Fish and Wildlife Service 1990:5-47); (2) a bird in first basic plumage in its first calendar year (Pyle et al. 1980:26-27).

Heterogeneity
the variety of qualities found in an environment (habitat patches) or a population (genotypic variation) (Ricklefs 1970:872).

Home range
an area, from which intruders may or may not be excluded, to which an individual restricts most of its usual activities (Ricklefs 1970:872) (cf Territory).

Index
(1) the proportional relation of counts of objects or signs associated with a given species to counts of that species on a given area; (2) counts of individuals (e.g., at a feeding station) reflecting changes in relative abundance on a specified or local area (Ralph 1980:578).

Index method
a counting method involving sampling that yields measures of relative abundance rather than density values (Ralph 1980:578).

Indirect competition
the exploitation of a resource by one individual that reduces the availability of that resource to others (Ricklefs 1970:872).

Indirect effect
(1) the impact on a species caused by affecting the species' competitors, predators, or mutualists (Dunning et al. 1990:173); (2) the impact of toxic chemicals on a species by directly affecting interactions between species. Examples are disruptions in food resources or habitat changes that affect competitive interactions, biomagnification up the food chain, and impacts on populations parasites, ...

Interference competition
competition in which one species prevents the other from having access to a limiting resource (Ehrlich and Roughgarden 1980:624) (cf Exploitation competition).

Interspecific competition
competition between individuals of different species (Ricklefs 1970:873).

Intraspecific competition
competition between individuals of the same species (Ricklefs 1970:873).

Introduced species
species present in an area due to deliberate release by humans (including reintroductions, transplants, and restocked species) or due to accidental release through escape or indirect assistance (adapted from Long 1980:7) (syn. exotic species).

Key factor analysis
a statistical treatment of population data designed to identify factors most responsible for change in population size (Ricklefs 1970:873).

Keystone species
a species whose abundance dramatically alters the structure and dynamics of ecological systems (Brown and Heske 1990:1705).

Landscape
the landforms of a region in the aggregate; the land surface and its associated habitats at scales of hectares to many square kilometers (for most vertebrates); a spatially heterogeneous area (Turner 1980:173); mosaic of habitat types occupying a spatial scale intermediate between an organism's normal home-range size and its regional distribution (Dunning et al. 1990:169).

Landscape change
alteration in the structure and function of the ecological mosaic of a landscape through time (Turner 1980:173).

Landscape complementation
changes in population caused by the relative distributions of habitat patches containing nonsubstitutable resources in a landscape. Example

Landscape composition
the relative amounts of habitat types contained within a landscape (Dunning et al. 1990:170).

Landscape ecology
field of study that considers the development and dynamics of spatial heterogeneity, interactions and exchanges across heterogeneous landscapes, the influences of spatial heterogeneity on biotic and abiotic processes, and the management of spatial heterogeneity (Turner 1980:172).

Landscape function
the interactions among the spatial elements, that is, the flow of energy, materials, and organisms among the component ecosystems (Turner 1980:173).

Landscape indexes
indexes of landscape structure (pattern), including richness, evenness, patchiness, diversity, dominance, contagion, edges, fractal dimension, nearest neighbor probability, and the size and distribution of patches (Turner 1980:177-178).

Landscape physiognomy
features associated with the physical layout of elements within a landscape (Dunning et al. 1990:170).

Landscape structure
spatial relationships between distinctive ecosystems, that is, the distribution of energy, materials, and species in relation to the sizes, shapes, numbers, kinds, and configurations of components (Turner 1980:173); composition and extent of different habitat types (landscape composition) and their spatial arrangement (landscape physiognomy) in a landscape (Dunning et al. 1990:170).

Landscape supplementation
changes in populations caused by the distribution of habitat patches containing substitutable resources in a landscape. Example increased population in a small patch found in a portion of the landscape where residents can easily forage in other nearby similar patches (Dunning et al. 1990:171-172) (see Landscape complementation).

Life form
characteristic structure of a plant or animal (Ricklefs 1970:873).

Life history
a system of interrelated adaptive traits forming a set of reproductive tactics (Stearns 1970:19).

Life table
a summary by age of the survivorship and fecundity in a population, usually of females (Ricklefs 1970:873).

Life zone
a more or less distinct belt of vegetation occurring within, and characteristic of, a particular range of latitude or elevation (Ricklefs 1970:873).

Limiting resource
a resource that is in short supply compared with the demand for it (Ehrlich and Roughgarden 1980:625).

Line transect
a sampling route, through a surveyed area, that is followed by an observer counting contacts over a measured distance (Ralph 1980:578).

Local extinction
disappearance of a population from a habitat patch or local area. Local extinctions can accumulate into regional extinctions and finally global extinction (adapted from Merriam and Wegner 1992).

Logistic equation
mathematical expression for a particular sigmoid growth curve in which the percent rate of increase decreases in linear fashion as population size increases (Ricklefs 1970:874).

Mapping method
see Spot-mapping method.

MAPS
Monitoring Avian Productivity and Survivorship program, which utilizes constant-effort mist netting and banding and intensive point counts during the breeding season at a continent-wide network of stations. MAPS is coordinated by The Institute for Bird Populations (DeSante 1992).

Mayfield method
a method used to calculate the rate of nesting success based on the number of days that a nest was under observation (i.e., nest days of 'exposure'); developed by Mayfield (1975).

Measurement bias
a systematic under- or overestimation of the true values due to a difference between the actual measurement and what one intends to measure (adapted from Gilbert 1980:11) (cf Statistical bias).

Measurement endpoint
see Endpoint.

Mesic
moderately moist (Krebs 1980:724).

Metapopulation
a collection or set of local populations living where discrete patches of the area are habitable and the intervening regions are not (Gilpin 1980:127); basic demographic unit composed of a set of populations in different habitat patches linked by movement of individuals (Merriam and Wegner 1990:151).

Microhabitat
the particular parts of a habitat that an individual encounters in the course of its activities (Ricklefs 1970:874).

Migration
regular, extensive, seasonal movements of birds between their breeding regions and their 'wintering' regions (Welty 1970:463).

Minimum viable population
a threshold number of individuals that will ensure (with some probability level) that a population will persist in a viable state for a given interval of time (adapted from Gilpin and Soul 1980:19).

Monitoring
measuring population trends using any of various counting methods (Ralph et al. in press).

Morph
a specific form, shape, or structure (Ricklefs 1970:874).

Mortality
ratio of the number of deaths of individuals to the population, often described as a function of age; death rate (Ricklefs 1970:874).

Multi-brooded
producing more than one clutch or brood per season (Ricklefs 1970:401), usually in reference to a life history trait of a species. Natal dispersal

Neotropical migrant
a migratory bird in the Neotropical faunal region. The Neotropical Migratory Bird Conservation Program focuses primarily on species that nest in the Nearctic faunal region and winter in the Neotropical region (Stangel 1992).

Nest parasitism
(1) expression used by some authors (e.g., Thomson 1960:594, Monroe 1990:225) for brood parasitism; (2) taking over nests of other species (Lanyon 1990:78).

Nest success
survival of eggs or nestlings (usually excluding those of brood parasites) (Mayfield 1970:459) (see Hatching success).

Net reproductive rate
the number of offspring that females are expected to bear on average during their lifetimes (Ricklefs 1970:875).

Niche
multidimensional utilization distribution, giving a population's use of resources ordered along resource axes (Schoener 1980:79).

Numerical response
change in the population size of a predatory species as a result of a change in the density of its prey (Ricklefs 1970:876) (cf Functional response).

Parameter
(1) A statistical parameter is a numerical characteristic about the population of interest (Freedman et al. 1970:301); (2) A model parameter is a numerical quantity that mediates the relationships between variables in a model (Starfield and Bleloch 1980:4).

Partners in Flight
a Western Hemisphere program designed to conserve neotropical migratory birds and officially endorsed by numerous federal and state agencies and nongovernment organizations (National Fish and Wildlife Foundation 1990:1). Also known as Neotropical Migratory Bird Conservation Program.

Patch dynamics
the change in the distribution of habitat patches in a landscape generated by patterns of disturbance and subsequent patterns of vegetative succession (Pickett and Thompson 1970:29).

Pattern
a statement about relationships among several observations of nature. It connotes a particular configuration of properties of the system under investigation (Wiens 1989a:18).

Perennial
referring to an organism that lives for more than one year (Ricklefs 1970:876).

Phenotype
the way in which the genetic message of an individual is expressed in its morphology, physiology, and behavior (Brown and Gibson 1980:567).

Phylogenetic species concept
the idea that a species is the smallest diagnosable cluster of individual organisms within which there is a parental pattern of ancestry and descent (McKitrick and Zink 1980:2) (cf Biological species concept).

Physiognomy
the topography and other physical characteristics of a landform and its vegetation (Brown and Gibson 1980:568).

Point count method
count of contacts recorded by an observer from a fixed observation point and over a specified time interval: fixed distance (radius) point count is limited to individuals within a single fixed distance; variable distance (radius) point count is limited to individuals within distances varying according to species-characteristic detection distances (syn. variable circular plot); and unlimited distan...

Point transect
a transect along which the point count method is used. No recordings are made between stations (as opposed to strip transects with continuous recordings) (Ralph 1980:578).

Polymorphism
occurrence of more than one distinct form of individuals in a population (Ricklefs 1970:877).

Population
a group of coexisting (conspecific) individuals that interbreed if they are sexually reproductive (Sinclair 1989).

Population viability analysis (PVA)
analysis that estimates minimum viable populations (Gilpin and Soul‚ 1980:19) (syn. population vulnerability analysis).

Postfledging mortality
the death rate of young after fledging, calculated from the following: the fates of young birds after fledging (or hatching in the case of precocial young), when these fates can be observed directly; changes in the ratio between juvenile and adult birds in populations; and the number of surviving young needed to replace adult losses, when adult mortality rates and the production of fledglings are ...

Precision
a quality, associated with a class of measurements, that refers to the way in which repeated observations conform to themselves (Marriott 1990:159).

Primary succession
the sequence of communities developing in a newly exposed site devoid of life (Ricklefs 1970:877).

Process
the operation of some factor or factors that produce a particular relationship among observations (Wiens 1989a:19).

Productivity
the number of young produced per pair of birds, or the reproductive performance of the population, estimated as the proportion of young in the total population just after the breeding season (Ricklefs 1970:417).

Proximate factors
aspects of the environment that organisms use as cues for behavior; for example, daylength (Ricklefs 1970:877) (cf Ultimate factors).

Quadrat
a small sample plot, usually square or rectangular (Ralph 1980:578).

Recovery plan
a plan that details actions or conditions necessary to promote species recovery, that is, improvement in the status of species listed under the Endangered Species Act to the point at which listing is no longer appropriate. Plans are required for virtually all listed species (adapted from Rohlf 1980:87-89).

Recovery team
a group, established by the U.S. Fish and Wildlife Service (USFWS) or National Marine Fisheries Service (NMFS) (the agencies that share authority for listing species as endangered or threatened under the Endangered Species Act), that prepares a recovery plan for a species listed under the Endangered Species Act. The team usually consists of representatives from agencies that are charged with imple...

Recruitment
the addition of new individuals to a population by reproduction (Ricklefs 1970:878), commonly measured as the proportion of young in the population just before the breeding season (Ricklefs 1970:418).

Refugium
an area that remains unchanged while areas surrounding it change markedly; hence the area serves as a refuge for species requiring specific habitats (Brown and Gibson 1980:569).

Relative abundance
a percent measure or index of abundances of individuals of all species in a community (Ralph 1980:578) (syn. dominance [in Europe]; cf Index, Frequency, Density).

Relative frequency
see Frequency.

Remote sensing
the imaging of earth features from suborbital and orbital altitudes, using various wavelengths of the visible and invisible spectrum (Richason 1970:xi).

Resident
inhabiting a given locality throughout the year; sedentary (Welty 1970:463).

Resource
a substance or object required by an organism for normal maintenance, growth, and reproduction (Ricklefs 1970:878).

Restoration ecology
the re-creation of a natural or self-sustaining community or ecosystem (Jordan, Gilpin, and Aber 1980:331).

Riparian
along the bank of a river or lake (Ricklefs 1970:878).

Second-year bird
a bird in its second calendar year of life (Pyle et al. 1980:27; Canadian Wildlife Service and U.S. Fish and Wildlife Service 1990:5-47).

Secondary succession
progression of communities in habitats where the climax community has been disturbed or removed entirely (Ricklefs 1970:878).

Sedentary
not migratory; see also resident (Welty 1970:46).

Sere
a series of stages of community change in a particular area leading toward a stable state (Ricklefs 1970:879).

Short-distance migration
a pattern of latitudinal migration used by species that move within, rather than between, temperate or tropical zones (Welty 1970:465).

Sink habitat
a habitat in which reproduction is insufficient to balance local mortality. The population can persist in the habitat only by being a net importer of individuals (adapted from Pulliam 1980:653-654).

Sink population
a population that occupies habitat types in which reproductive output is inadequate to maintain local population levels. The population may be replenished by emigrants from source populations (Wiens and Rotenberry 1980:531).

Source habitat
a habitat that is a net exporter of individuals (Pulliam 1980:654).