PATTERN AND PROCESS IN COMPETITION
0
Birch (1953) also states that it includes no differential exploitation,
merely interference between species. I n this connection, they assert that
there is no competition unless a common resource is involved and unless
one species seeks power over this resource a t the expense of another,
and seem therefore to imply that interference is not a sufficient mechanism for this purpose. This objection seems, however, to have no real
connection with either the Lotka-Volterra model or the question of
interference or exploitation. As long as competition is defined in terms
of a limiting resource, which is clearly contained in the term for carrying
capacity ( K ) in the model, “seeking power” in its broadest sense could
be accomplished either by interference or exploitation - in fact interference would appear to be the more effective mechanism for gaining
power over a resource at the expense of another species.
Some authors have introduced special terms to distinguish between
interspecies and intraspecies interference or territoriality (cf. Frank,
1952; Simmons, 1951), but the evidence that is available supports the
view that mechanisms such as interspecific territoriality do not differ
from those involved in intraspecies relationships (Hinde, 1956) and it
is doubtful that such mechanisms will be evolved unless they have first
arisen among members of the same species. Indirect interference
through chemical repellents may constitute a class of exceptions, although this is by no means certain. Wilson and Bossert (1964) list
several examples of territory and home range marking by chemical
secretions in different taxonomic groups. They state, “There is no
reason to doubt that the essential characteristics of intraspecific communication . . . are also true of interspecific chemical communication.”
The evidence they give also suggests that most chemical repellents that
act as isolating mechanisms between closely related species may act as
interspecies interference mechanisms as well, and have their origins in
intraspecific relationships.
The spatial organization and requirements of animal populations
are usually discussed in relation to territory, but attempts to assign
common origins and functions to the territories of different species
have led to considerable disagreement and misunderstanding among
ecologists (cf. Lack, 1954; Hinde, 1956). Wynne-Edwards (1962) has
compiled an impressive number of examples that are presumed to show
that animal dispersion is mostly in relation to an optimum food supply
and that competition for territory or individual rank and dominance
is the proximate agent limiting numbers for this purpose. This is supposed to provide an effective proximate buffer to limit density near the
optimum for that species, in relation to the ultimate agent of food.
Unfortunately, Wynne-Edwards attempts to categorize all species in
the same way, limited proximately by territory and ultimately by food,
0
Birch (1953) also states that it includes no differential exploitation,
merely interference between species. I n this connection, they assert that
there is no competition unless a common resource is involved and unless
one species seeks power over this resource a t the expense of another,
and seem therefore to imply that interference is not a sufficient mechanism for this purpose. This objection seems, however, to have no real
connection with either the Lotka-Volterra model or the question of
interference or exploitation. As long as competition is defined in terms
of a limiting resource, which is clearly contained in the term for carrying
capacity ( K ) in the model, “seeking power” in its broadest sense could
be accomplished either by interference or exploitation - in fact interference would appear to be the more effective mechanism for gaining
power over a resource at the expense of another species.
Some authors have introduced special terms to distinguish between
interspecies and intraspecies interference or territoriality (cf. Frank,
1952; Simmons, 1951), but the evidence that is available supports the
view that mechanisms such as interspecific territoriality do not differ
from those involved in intraspecies relationships (Hinde, 1956) and it
is doubtful that such mechanisms will be evolved unless they have first
arisen among members of the same species. Indirect interference
through chemical repellents may constitute a class of exceptions, although this is by no means certain. Wilson and Bossert (1964) list
several examples of territory and home range marking by chemical
secretions in different taxonomic groups. They state, “There is no
reason to doubt that the essential characteristics of intraspecific communication . . . are also true of interspecific chemical communication.”
The evidence they give also suggests that most chemical repellents that
act as isolating mechanisms between closely related species may act as
interspecies interference mechanisms as well, and have their origins in
intraspecific relationships.
The spatial organization and requirements of animal populations
are usually discussed in relation to territory, but attempts to assign
common origins and functions to the territories of different species
have led to considerable disagreement and misunderstanding among
ecologists (cf. Lack, 1954; Hinde, 1956). Wynne-Edwards (1962) has
compiled an impressive number of examples that are presumed to show
that animal dispersion is mostly in relation to an optimum food supply
and that competition for territory or individual rank and dominance
is the proximate agent limiting numbers for this purpose. This is supposed to provide an effective proximate buffer to limit density near the
optimum for that species, in relation to the ultimate agent of food.
Unfortunately, Wynne-Edwards attempts to categorize all species in
the same way, limited proximately by territory and ultimately by food,