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E
cologists have long sought
to understand how species
in a community interact to
exploit resources. A key concept
in the explanation of this interplay
is the idea of guilds, first developed
by American biologist and ecologist
Richard B. Root in 1967.
Root had researched the way
the Blue-gray Gnatcatcher exploits
its ecological niche for his doctoral
thesis. The concept of ecological
niches dates back to 1917, when
American biologist Joseph Grinnell
used the term to describe how
the California Thrasher fittedinto its dry, scrubby chaparral
environment. The thrasher’s
“niche” describes the aspects
of its habitat for which it is
suitably adapted.
Root observed that the Blue-
gray Gnatcatcher feeds on insects
that live on oak leaves. By
analyzing stomach contents, he
showed that several other birdsThe Blue-gray Gnatcatcher is a
member of a guild of small birds that
eat insects living on oak trees. Other
members of the guild include Hutton’s
Vireo and Oak Titmouse.IN CONTEXT
KEY FIGURE
Richard B. Root (1936–2013)BEFORE
1793 Alexander von Humboldt
uses the word “association” to
describe the mix of plant types
within a particular habitat.1917 In the US, Joseph
Grinnell coins the term “niche”
to describe how a species fits
into its environment.1935 British botanist
Arthur Tansley identifies
ecoystems—integrated biotic
communities—as fundamental
units of ecology.AFTER
1989 In the US, James
MacMahon suggests that it
does not matter how ecological
guild members use resources.2001 Argentinian ecologists
Sandra Diaz and Marcelo
Cabido propose grouping
species that have a similar
effect on their environment.A GROUP OF SPECIES
THAT EXPLOIT
THEIR ENVIRONMENT
IN A SIMILAR WAY
THE ECOLOGICAL GUILD
US_176-177_Ecological_guild.indd 176 12/11/18 6:25 PM