Ecological Niches 115resource partitioning in animals is well documented and
includes studies in tropical forests of Central and South
America that demonstrate little overlap in the diets of
fruit-eating birds, primates, and bats that coexist in the
same habitat. Although fruits are the primary food for
several hundred bird, primate, and bat species, the wide
variety of fruits available has allowed fruit eaters to spe-
cialize, thereby reducing competition. Resource parti-
tioning may also include timing of feeding, location of
feeding, nest sites, and other aspects of an organism’s
ecological niche (see What a Scientist Sees).- What are three aspects of an organism’s
ecological niche? - What is resource partitioning?
WHAT A SCIENTIST SEES
Resource Partitioning
Robert MacArthur’s study of five American warbler species is a clas-
sic example of resource partitioning. Although it initially appeared
that the niches of the species were nearly identical, MacArthur
determined that individuals of each species spend most of their
feeding time in different portions of spruces and other conifer
trees. They also move in different directions through the canopy,
consume different combinations of insects, and nest at slightly dif-
ferent times. The photo shows a male Blackburnian warbler.
Interpreting Data
Which two warblers are least likely
to overlap when feeding? Why?© Johann Schumacher/AlamyAdapted from MacArthur, R. H. “Population ecology of some warblers ofnortheastern coniferous forests.”Ecology, Vol. 39 (1958).Yellow-rumped warbler Bay-breasted warbler Cape May warbler Black-throated green warbler Blackburnian warbler