• Publications
  • Influence
The role of neighbours in territorial systems: when are they 'dear enemies'?
Abstract Abstract. Many territorial animals respond less aggressively to neighbours than to strangers (the dear enemy phenomenon). The dear enemy phenomenon generally has been assumed to representExpand
  • 516
  • 55
The evolution of sexual dimorphism in animals: Hypotheses and tests.
Three major hypotheses, based upon mechanisms of sexual selection, intersexual food competition and reproductive role division, have been advanced to explain the evolution of sexual dimorphism inExpand
  • 450
  • 14
Evidence for ecological causation of sexual dimorphism in a hummingbird.
Unambiguous examples of ecological causes of animal sexual dimorphism are rare. Here we present evidence for ecological causation of sexual dimorphism in the bill morphology of a hummingbird, theExpand
  • 177
  • 12
Interference asymmetries among age-sex classes of rufous hummingbirds during migratory stopovers
SummaryThree age-sex classes of rufous hummingbirds (Selasphorus rufus) overlap temporally and defend feeding territories during migratory stopovers in the Sierra Nevada of California. We demonstrateExpand
  • 66
  • 6
The Role of Flower Width in Hummingbird Bill Length‐Flower Length Relationships1
Observations of hummingbirds feeding at flowers longer or shorter than their bills seem to contradict the view that bill lengths of hummingbirds evolved in concert with the lengths of their flowers.Expand
  • 56
  • 5
Adaptation in a Plant-Hummingbird Association
Sexual dimorphism in bill morphology and body size of the Caribbean purple-throated carib hummingbird is associated with a reversal in floral dimorphism of its Heliconia food plants. This hummingbirdExpand
  • 149
  • 4
Effect of flower shape and size on foraging performance and trade-offs in a tropical hummingbird.
Matches between the bills of hummingbirds and the flowers they visit have been interpreted as examples of coadaptation and feeding specialization. Observations of birds feeding at flowers longer orExpand
  • 62
  • 4
FORAGING AND TERRITORY ECONOMICS OF SEXUALLY DIMORPHIC PURPLE-THROATED CARIBS (EULAMPIS JUGULARIS) ON THREE HELICONIA MORPHS
Abstract We observed territorial Purple-throated Caribs (Eulampis jugularis) on three Heliconia morphs (H. caribaea and the red-green and green morphs of H. bihai) on the island of St. Lucia, WestExpand
  • 47
  • 4
Exploitative compensation by subordinate age-sex classes of migrant rufous hummingbirds
SummaryThe three age-sex classes of rufous hummingbirds (Selasphorus rufus) that directly interact on southward migratory stopovers in our California study system differ in territorial ability andExpand
  • 44
  • 4
Evolution of sexual dimorphism in bill size and shape of hermit hummingbirds (Phaethornithinae): a role for ecological causation
Unambiguous examples of ecological causation of sexual dimorphism are rare, and the best evidence involves sexual differences in trophic morphology. We show that moderate female-biased sexualExpand
  • 58
  • 3