16
RICHARD S. MILLER
Elton proposed the term “niche” to describe this status of an animal
in its community and spoke of the niche in the sense of an animal’s
“profession” rather than its “address”. A reconnaissance of woodland
bird communities in England and Wales (Elton, 1935) showed, for
example, that “woodland birds in Britain form a clear-cut and ancient
community that is much the same in different woodland types. . . It
forms part of a life-zone widely spread over Europe.” Also, in a table
of comparisons between comparable plant communities in California,
Finland and Britain, Elton (1935) observed that “there is a high degree
of resemblance in the structure of such bird communities right around
the world.” Elton’s use of the niche concept was therefore primarily
one of function, emphasizing that the same niches exist in each community, regardless of what species fill these roles.
Udvardy (1859) attempts to establish that Elton and Grinnell used
the term “niche” in the same way and that their concepts are therefore
compatible, but it is obvious that Grinnell’s emphasis was on the
“address” of a species, rather than its functional role. Grinnell (1917a)
listed three facts of distribution: (1) that each animal has a habitat or
range which is distinctive enough to be included among the characters
used to describe a species, ( 2 ) that some species range widely and others
are restricted, and (3) that groups of species nearly or entirely coincide
in range so that realms, zones, faunas, and other units can be easily
recognized. These and similar observations laid the basis for his later
development of the niche as “the ultimate distributional unit” (Grinnell, 1924, 1928). He also stated that it is axiomatic that no two species
in a single fauna can occupy precisely the same niche (Grinnell, 1917b,
1924).
Dice (1952) follows Grinnell’s usage to define the niche as all of the
features of the ecosystem that a species utilizes and states that “The
term does not include, except indirectly, any consideration of the
functions that a species serves in the community.” He also emphasizes
the distinctness of the niche of each species. It is in this and Gause’s
sense that Hutchinson (1944) described the ecological niche as “the
sum of all the environmental factors acting on an organism; the niche
thus defined is a region of n-dimensional hyper-space, comparable to
the phase-space of statistical mechanics.”
A difficulty with the Grinnellian concept is that it cannot be used to
define the conditions of competition without considerable modification.
The broader concept, in which the niche is the functional status of an
animal in the trophic system, clearly implies that this function may be
filled by any of several species and that competition is not only possible
within this context, but is also highly probable. This concept also provides for the possibility of “vacant niches”, in that a functional role
RICHARD S. MILLER
Elton proposed the term “niche” to describe this status of an animal
in its community and spoke of the niche in the sense of an animal’s
“profession” rather than its “address”. A reconnaissance of woodland
bird communities in England and Wales (Elton, 1935) showed, for
example, that “woodland birds in Britain form a clear-cut and ancient
community that is much the same in different woodland types. . . It
forms part of a life-zone widely spread over Europe.” Also, in a table
of comparisons between comparable plant communities in California,
Finland and Britain, Elton (1935) observed that “there is a high degree
of resemblance in the structure of such bird communities right around
the world.” Elton’s use of the niche concept was therefore primarily
one of function, emphasizing that the same niches exist in each community, regardless of what species fill these roles.
Udvardy (1859) attempts to establish that Elton and Grinnell used
the term “niche” in the same way and that their concepts are therefore
compatible, but it is obvious that Grinnell’s emphasis was on the
“address” of a species, rather than its functional role. Grinnell (1917a)
listed three facts of distribution: (1) that each animal has a habitat or
range which is distinctive enough to be included among the characters
used to describe a species, ( 2 ) that some species range widely and others
are restricted, and (3) that groups of species nearly or entirely coincide
in range so that realms, zones, faunas, and other units can be easily
recognized. These and similar observations laid the basis for his later
development of the niche as “the ultimate distributional unit” (Grinnell, 1924, 1928). He also stated that it is axiomatic that no two species
in a single fauna can occupy precisely the same niche (Grinnell, 1917b,
1924).
Dice (1952) follows Grinnell’s usage to define the niche as all of the
features of the ecosystem that a species utilizes and states that “The
term does not include, except indirectly, any consideration of the
functions that a species serves in the community.” He also emphasizes
the distinctness of the niche of each species. It is in this and Gause’s
sense that Hutchinson (1944) described the ecological niche as “the
sum of all the environmental factors acting on an organism; the niche
thus defined is a region of n-dimensional hyper-space, comparable to
the phase-space of statistical mechanics.”
A difficulty with the Grinnellian concept is that it cannot be used to
define the conditions of competition without considerable modification.
The broader concept, in which the niche is the functional status of an
animal in the trophic system, clearly implies that this function may be
filled by any of several species and that competition is not only possible
within this context, but is also highly probable. This concept also provides for the possibility of “vacant niches”, in that a functional role