Threat Reduction as a Cause of Differences in Bower Architecture, Bower Decoration and Male Display in Two Closely-Related Bowerbirds Chlamydera nuchalis and C. maculata

  title={Threat Reduction as a Cause of Differences in Bower Architecture, Bower Decoration and Male Display in Two Closely-Related Bowerbirds Chlamydera nuchalis and C. maculata},
  author={Gerald Borgia},
  • G. Borgia
  • Published 1 March 1995
  • Environmental Science
  • Emu
Major structural differences in the bowers of different bowerbird species have long been recognised, but the evolutionary significance of these differences has never been determined. I compared the bowers and displays of two congeneric species, the Spotted Bowerbird Chlamydera maculata and the Great Bowerbird C. nuchalis, and used the Satin Bowerbird Ptilonorhynchus violaceus as an outgroup to define ancestral characters. Spotted Bowerbird bowers and display courts differ from the more typical… 
The Relationship between Bower Orientation, Platform Choice and Mating Success in the Great Bowerbird Chlamydera nuchalis nuchalis
Abstract Bowers are display structures built by male bowerbirds (Ptilonorhynchidae) to court females. Avenue bowers consist of two parallel walls of upright sticks. Visiting females enter the avenue
Bower location and orientation in Satin Bowerbirds: optimising the conspicuousness of male display?
Study of Satin Bowerbird bowers in the mountainous rainforest of the Atherton Tablelands, Australia, found no significant tendency for bower platforms to face north, and a significant positive association between bower orientation and the orientation of the slope of the hill on which the bower was constructed, such that bowers were oriented upslope, further enhancing frontal illumination.
Coevolution of elaborated male display traits in the spotted bowerbird: an experimental test of the threat reduction hypothesis
The results support the threat reduction hypothesis, which suggests that accessory traits evolve because they mitigate the threat associated with intense, aggressive male displays that are most effective in causing females to become sexually receptive.
Home-range sizes and bower visitation patterns of immature male Satin Bowerbirds (Ptilonorhynchus violaceus)
Data is presented on the home ranges and movement patterns of six immature males, acquired through radio-tracking at the Bunya Mountains in south-east Queensland, and how immature males acquire the ability to display and build and decorate bowers.
Bower Structure is a Good Predictor of Mating Success in the Great Bowerbird
An analysis of the generalized linear mixed model and model selection revealed that avenue length and wall thickness correspond to the size of the bower, which suggests that a larger bower provides females with better protection from a vigorous male's display.
Labile evolution of display traits in bowerbirds indicates reduced eects of phylogenetic constraint RAB K USMIERSKI ", G ERALD B ORGIA #, A LBERT U Y#
Testing Gilliard’s (1969) transferral hypothesis indicated some support for the idea that the focus of display has shifted from bird to bower in avenue-building species, but not in maypole-builders or in bowerbirds as a whole.
Why Do Bowerbirds Build Bowers
central element of his theory of sexual selection called female choice. The high? ly sculptured structure of a bower and a male's use of brightly colored decora? tions suggested to Darwin that female
Stealing rates in the Great Bowerbird (Ptilonorhynchus nuchalis): effects of the spatial arrangement of males and availability of decorations
Differences in the spatial arrangement of males, particularly bower density, may explain variation in stealing rates both within and between populations, though alternative explanations, such as differences in resource availability, are also relevant.
Male Great Bowerbirds perform courtship display using a novel structure that rivals cannot destroy
A novel solution to male interference with external display structures in Great Bowerbirds is documented, showing that some males, including young individuals, adapt to this interference by displaying around tree trunks instead of bowers.
Bower location by the Spotted Bowerbird (Chlamydera maculata)
The results suggest that bower location is primarily determined by large-scale habitat preferences, and within suitable habitat, bowers location is influenced by male—male interactions.


Bower Destruction, Decoration Stealing and Female Choice in the Spotted Bowerbird Chlamydera maculata
The low levels of stealing and destruction in Spotted Bowerbirds, coupled with the correlation of bower quality and mating success, suggest that high levels of male interaction are not a necessary prerequisite for females to use bowers as a factor influencing mate choice.
Animal art: Variation in bower decorating style among male bowerbirds Amblyornis inornatus.
  • J. Diamond
  • Art
    Proceedings of the National Academy of Sciences of the United States of America
  • 1986
Courtship bowers of the bowerbird Amblyornis inornatus, the most elaborately decorated structures erected by an animal other than humans, vary geographically and individually, and geographically varying bower styles may be a culturally transmitted trait, like human art styles.
Molecular information on bowerbird phylogeny and the evolution of exaggerated male characteristics
Mitochondrial DNA cytochrome b sequences of 849 base pairs are reported from eight species of Australian bowerbirds and are used with three from the literature to investigate bowerbird phylogeny using maximum parsimony and maximum likelihood methods.
Rediscovery of the Yellow-Fronted Gardener Bowerbird
Observations support a derivation of bower ornamentation from ritual courtship feeding and a transfer of ornamentations from the male's plumage to the bower.
Sexual selection for sensory exploitation in the frog Physalaemus pustulosus
Female basilar papilla tuning is biased toward lower-than-average frequencies in the 'chuck' portion of the male's call, explaining female preference for the lower-frequency chucks produced by larger males.
Over the last two decades a major resurgence of work on sexual selection has occurred and Evolutionists have reexamined Darwin's ideas and are now much more impressed by their cogency.
Heritable true fitness and bright birds: a role for parasites?
Combination of seven surveys of blood parasites in North American passerines reveals weak, highly significant association over species between incidence of chronic blood infections (five genera of
The Handicap Mechanism of Sexual Selection Does Not Work
The conclusion these analyses lead to is that in polygynous species in which males contribute only gametes to their mates, mating preferences may often evolve in unpredictable ways that do not enhance the average viability or adaptation of the species.