112
D AV I D L . G A R S H E L I S
Terminology
The word habitat has two distinct usages. The true dictionary definition is the
type of place where an animal normally lives or, more specifically, the collection of resources and conditions necessary for its occupancy. Following this
definition, habitat is organism specific (e.g., deer habitat, grouse habitat). A
second definition is a set of specific environmental features that, for terrestrial
animals, is often equated to a plant community, vegetative association, or
cover type (e.g., deer use different habitats or habitat types in summer and
winter). Nonhabitat could mean either the converse of habitat in the first sense
(a setting that an animal does not normally occupy) or the second (a specific
vegetative type that the animal views as unsuitable); here, the two meanings of
habitat converge (see also pages 392–396 in this volume).
Hall et al. (1997) argue that only the first definition of habitat is correct
and that the second represents a confusing misuse of the term. They reviewed
50 articles dealing with wildlife–habitat relationships and, based on their definition, found that 82% discussed habitat vaguely or incorrectly. I suggest that
given the prevalent use of habitat to mean habitat type, this alternative definition is legitimate and well understood in the wildlife literature. Moreover, this
common usage of the term is consistent with the normally accepted meaning
of habitat use: the extent to which different vegetative associations are used.
Hall et al. (1997:175) define habitat use as “the way an animal uses . . . a collection of physical and biological components (i.e., resources) in a habitat”
(emphasis mine), which seems difficult to measure.
Habitat selection and preference are also more easily understood in terms
of differential use of habitat types. Selection and preference are often used interchangeably in the wildlife literature; however, they have subtly different meanings. I will adopt the distinction posed by Johnson (1980), who defined selection as the process of choosing resources and preference as the likelihood of a
resource being chosen if offered on an equal basis with others. Peek (1986)
suggested that innate preferences exist even for resources not actually available.
Furthering this concept, Rosenzweig and Abramsky (1986) characterized preferred habitats as those that confer high fitness and would therefore support a
high equilibrium density (in the absence of other confounding factors, such as
competitors). Thus use results from selection, selection results from preference, and preference presumably results from resource-specific differential fitness. In controlled experiments, preferences can be assessed directly by offering equal portions of different resources and observing choices that are made
D AV I D L . G A R S H E L I S
Terminology
The word habitat has two distinct usages. The true dictionary definition is the
type of place where an animal normally lives or, more specifically, the collection of resources and conditions necessary for its occupancy. Following this
definition, habitat is organism specific (e.g., deer habitat, grouse habitat). A
second definition is a set of specific environmental features that, for terrestrial
animals, is often equated to a plant community, vegetative association, or
cover type (e.g., deer use different habitats or habitat types in summer and
winter). Nonhabitat could mean either the converse of habitat in the first sense
(a setting that an animal does not normally occupy) or the second (a specific
vegetative type that the animal views as unsuitable); here, the two meanings of
habitat converge (see also pages 392–396 in this volume).
Hall et al. (1997) argue that only the first definition of habitat is correct
and that the second represents a confusing misuse of the term. They reviewed
50 articles dealing with wildlife–habitat relationships and, based on their definition, found that 82% discussed habitat vaguely or incorrectly. I suggest that
given the prevalent use of habitat to mean habitat type, this alternative definition is legitimate and well understood in the wildlife literature. Moreover, this
common usage of the term is consistent with the normally accepted meaning
of habitat use: the extent to which different vegetative associations are used.
Hall et al. (1997:175) define habitat use as “the way an animal uses . . . a collection of physical and biological components (i.e., resources) in a habitat”
(emphasis mine), which seems difficult to measure.
Habitat selection and preference are also more easily understood in terms
of differential use of habitat types. Selection and preference are often used interchangeably in the wildlife literature; however, they have subtly different meanings. I will adopt the distinction posed by Johnson (1980), who defined selection as the process of choosing resources and preference as the likelihood of a
resource being chosen if offered on an equal basis with others. Peek (1986)
suggested that innate preferences exist even for resources not actually available.
Furthering this concept, Rosenzweig and Abramsky (1986) characterized preferred habitats as those that confer high fitness and would therefore support a
high equilibrium density (in the absence of other confounding factors, such as
competitors). Thus use results from selection, selection results from preference, and preference presumably results from resource-specific differential fitness. In controlled experiments, preferences can be assessed directly by offering equal portions of different resources and observing choices that are made