Robert H. MacArthur:
Life, Work, and Legacy
Brad Nelson
BIOL 7083
Community Ecology
Biographical Sketch
Personal Background
Robert H. MacArthur
April 2, 1930 – November 1, 1972
• Born in Toronto, Ontario
• Youngest son of John Wood
MacArthur (geneticist)
• Married Elizabeth
Whittemore (1952)
• Had four children
• Died of renal cancer at the
age of 42
Biographical Sketch
Academic Background
• Undergraduate degree
from Marlboro College, 1951
• M.S. in Mathematics
from Brown University, 1953
• Ph.D. from Yale University, 1958
(under G. Evelyn Hutchinson)
• Postdoc at Oxford University
• Professor at University of
Pennsylvania (1958-1965)
Robert H. MacArthur
April 2, 1930 – November 1, 1972 • Professor at Princeton
University (1965-1972)
MacArthur Publications
Pianka and Horn (2005)
MacArthur Publications
Pianka and Horn (2005)
MacArthur Publication Characteristics
• Hypothetico-Deductive
(H-D) method
• Most ecological studies
at the time were
descriptive
MacArthur Publication Characteristics
• Use of simple analytical
models to generate and
test hypotheses
MacArthur Publication Characteristics
• Circumvented
traditional peer review
process
• Proceedings of the
National Academy of
Science
• Princeton Monograph
Series
• Journal of Theoretical
Population Biology
MacArthur Publication Characteristics
• “Weak” tests of
hypotheses
• Observational, not
experimental
• Theory of Island
Biogeography
– Not tested
experimentally until
1969
• Warbler paper (1958)
MacArthur Publication Characteristics
• Many published
mistakes
• MacArthur and Levins’
limiting similarity paper
(1967)
• Warbler paper (1958):
MacArthur Publication Characteristics
• Limited use of citations
MacArthur and Pianka 1966
Selected Publications
The Theory of Island Biogeography
• About 4,150
citations since 2000
(Google Scholar)
On Optimal Use of a Patchy Environment
(MacArthur and Pianka 1966)
• Search time vs. pursuit time
• Considers effects of patchy environment
• Landmark paper in optimal foraging theory
and behavioral ecology
• About 110 citations since 2000 (Google
Scholar)
On Optimal Use of a Patchy Environment
(MacArthur and Pianka 1966)
• N = number of items in
diet
• TN = Time per food item
• TNS = Search time per
food item
• TNP = Pursuit time per
food item
• Food types ranked from
most efficient to least
(calories/time)
• What is the optimal
number of items to
include in the diet?
On Optimal Use of a Patchy Environment
(MacArthur and Pianka 1966)
Search vs. Pursuit
(Uniform prey item abundance)
Search vs. Pursuit
(Non-uniform prey item abundance)
On Optimal Use of a Patchy Environment
(MacArthur and Pianka 1966)
Hunting time vs. travelling time
In a patchy environment
Patches ordered by
prey density
(Number of patches utilized)
On Optimal Use of a Patchy Environment
(MacArthur and Pianka 1966)
Population Ecology of Some Warblers
of Northeastern Coniferous Forests
Population Ecology of Some Warblers
of Northeastern Coniferous Forests
• Five congeneric species of
warblers found together
without obvious interspecific
differences
• How do they coexist?
Population Ecology of Some Warblers
of Northeastern Coniferous Forests
• MacArthur notes:
“…differences … are neither
always necessary nor
always sufficient to prevent
competition and permit
coexistence”
• He then documents species
differences and concludes
that they permit coexistence
Population Ecology of Some Warblers
of Northeastern Coniferous Forests
• Data
– Local censuses
• Staggered population changes
– Museum and diet records
– Field observation
• 27 to 90 minutes of continuous
observation
– Wintering grounds
observation
Population Ecology of Some Warblers
of Northeastern Coniferous Forests
• Warbler coexistence attributed
to differences in foraging zone
(MacArthur 1958)
• If competition limits diversity
(limiting similarity), more
species should exist in more
complex habitats because more
types of foraging sites are
available, reducing competition
(MacArthur 1958, 1972)
Population Ecology of Some Warblers
of Northeastern Coniferous Forests
• Evidence of competition and
food limitation indirect or
absent
Martin 1993:
Population Ecology of Some Warblers
of Northeastern Coniferous Forests
• Alternative: “Potential-preysite hypothesis”
• Bird species nest
preferentially in different
foliage
• Predators should search
foliage where abundant
species nest
• Preferential nest predation
allows persistence of rare
species
Martin 1993
MacArthur’s Legacy
• Added open-mindedness to the list of traits
desirable in a scientist (along with empiricism
and skepticism) (Fretwell 1975)
• Popularized H-D method in ecology
– In roughly 5% of Ecology papers before MacArthur
and 50% by 1975 (Fretwell)
• Optimal foraging and island biogeography
theory continue to be fruitful avenues of
research
MacArthur’s Legacy
• Many ecologists tried to adapt the style of his
warbler paper, typically with less success
(Fretwell 1975, Kaspari 2008)
• Differences between species continued to be
used as explanation for coexistence despite
the lack of quantitative testing
MacArthur’s Legacy
• Does MacArthur’s research style have a place
in community ecology today?
• Still common in biogeography (Esselstein?),
where patterns can be observed, but
laboratory and field experiments are not often
possible
“To spread, a scientific meme should be
correct. But it has to be infectious.”
--Kaspari (2008)
References
Fretwell, S.D. The impact of Robert MacArthur on Ecology. Annu. Rev. Ecol.
Syst. 1975.6: 1-13.
Kaspari, M. 2008. Knowing your warblers: thoughts on the 50th anniversary of
MacArthur (1958). Bulletin of the Ecological Society of America.
MacArthur, R. H. 1958. Population ecology of some warblers of Northeastern
coniferous forests. Ecology 39: 599-619.
MacArthur, R.H. and E.R. Pianka. 1966. On optimal use of a patchy
environment. The American Naturalist 100(916): 603-609.
MacArthur, R.H. and E.O. Wilson. 1967. The theory of island biogeography.
Princeton University Press. 205 pp.
Martin, T.E. 1993. Nest predation and nest sites: new perspectives on old
patterns. Bioscience 43(8): 523-532.
Pianka, E. R. and H. S. Horn. 2005. Ecology's Legacy from Robert MacArthur.
Chapter 11 (pp. 213-232) in K. Cuddington and B. Biesner, eds. "Ecological
Paradigms Lost: Theory Change." Academic Press.
Wilson, E.O. and G.E. Hutchinson. 1989. Robert Helmer MacArthur.
Biographical Memoirs 58: 318-327.
Questions?