ABUNDANCE: An estimate of the number of individuals in a population. Absolute abundance is expressed as number present per area (density), but this can not be reliably assessed for bats. Relative abundance is expressed as number caught or detected per unit time (frequency). Relative abundance can be compared between localities or over time, but reliable comparisons of relative abundance can not be made between different species of bat.
BAT DETECTOR: Any device used to render the ultrasonic calls of a bat audible to the unaided human ear.
BAT-PASS: A sequence of two or more echolocation calls registered as a bat flies within range of a bat detector. Used to measure relative bat activity.
BIODIVERSITY: Jargon for biological diversity: the variety of life forms, the ecological roles they perform, and the genetic diversity they contain (Wilcox 1984 cited in Murphy 1988).
DENIER: The number of grams in 9000 metres of fibre. A unit for measuring the fineness of mist nets. The lower the number, the finer the net.
DIVIDE-BY-n (COUNTDOWN) DETECTOR: A bat detector that divides the frequency of an incoming ultrasonic signal by a factor of 'n', thus bringing the signal into the human range of hearing.
ECHOLOCATION: The use of acoustic signals by animals to locate objects or prey in their environment. Often in the ultrasonic range. The most sophisticated form of echolocation is used by bats.
EPIPHYSEAL PLATES: Cartilaginous areas where growth takes place in bones. Their shape in finger joints can be used to differentiate juvenile from adult bats (see Fig. 2).
FEEDING BUZZ: The characteristic high repetition-rate of echolocation calls given by a bat as it closes in and attacks a potential prey item.
FLY-WAY: Any corridor used by bats commuting between roost and foraging areas. Fly-ways make excellent sites for capturing bats in mist-nets and harp traps. Often delimited by physical structures, such as vegetation or buildings.
FREQUENCY: A measure of the number of cycles in the propagation of a (sound) wave. Measured in hertz or kilohertz.
HARP TRAP: A specialized trap designed exclusively for capturing bats.
HIBERNACULUM: Any overwintering site used by hibernating bats. Bats in hibernacula are particularly vulnerable to human disturbance.
KILOHERTZ (kHz): A unit to measure frequency. One hertz is equal to one cycle per second.
LACTATION: The period of milk production by female mammals nursing young.
NET-NIGHT: A measure of mist-netting effort. One net-night is equivalent to setting up one 6 m length of net for one evening.
OVERWINTERING STRATEGY: The behaviour exhibited by species or individuals at times outside the breeding season. This can include either migration or hibernation.
PRESENCE/NOT DETECTED: A survey intensity that verifies that a species is present in an area, or states that it was not detected (thus not likely to be in the area, but still a possibility).
PROJECT AREA: An area, usually politically or economically determined, for which an inventory project is initiated. A project boundary may be shared by multiple types of resource and/or species inventory. Sampling generally takes place within smaller study areas within this project area.
RANDOM SAMPLE: A sample that has been selected by a random process, generally by reference to a table of random numbers.
ROOST: Any site used by bats for rest, sleep, torpor, food digestion, shelter etc. A distinction can be made between DAY and NIGHT roosts. Day roosts tend to be used on a more permanent basis, whereas night roosts are sites used temporarily at night between foraging bouts.
ROOSTING STRATEGY: The behaviour exhibited by roosting bats. Bats may either be solitary or colonial.
SONOGRAM: A visual display of the time (x-axis) and frequency (y-axis) components of a sound.
STRATIFICATION: The separation of a sample population into non-overlapping groups based on a habitat or population characteristic that can be divided into multiple levels. Groups are homogeneous within, but distinct from, other strata.
STUDY AREA: A discrete area within a project boundary in which sampling actually takes place. Study areas should be delineated to logically group samples together, generally based on habitat or population stratification and/or logistical concerns.
SURVEY: The application of one RIC method to one taxonomic group for one season.
SYSTEMATIC SAMPLE: Samples are selected at a predetermined interval or frequency (e.g., every 10 m along a transect). Contrasted with random sample (q.v.).
TORPOR: An energy saving behaviour during which a bat lowers its metabolic rate and body temperature and enters an inactive state.
TUNABLE NARROW BAND DETECTOR: A type of bat detector that uses an internally generated pure tone to render ultrasonic signals at the tuned frequency audible. Can only measure a narrow (3-5 kHz) frequency band at any one time.
ULTRASONIC: Any sound above 20 kHz, which is generally inaudible to human hearing.
VERSPERTILIONIDAE: The taxonomic family to which all bats found in Canada belong. The so-called 'mouse-eared' or 'plain-nosed' bats.
VOLANT: Possessing the ability to fly.