The role of exaggerated male chelicerae in male–male contests in New Zealand sheet-web spiders

  title={The role of exaggerated male chelicerae in male–male contests in New Zealand sheet-web spiders},
  author={Leilani A. Walker and Gregory Ian Holwell},
  journal={Animal Behaviour},

Defining an intrasexual male weapon polymorphism in a New Zealand harvestman (Opiliones: Neopilionidae) using traditional and geometric morphometrics

Traditional linear morphometrics is used to describe a weapon trimorphism in the endemic New Zealand harvestman, Forsteropsalis pureoraTaylor, 2013 and it is shown that alpha males are different in weapon shape, whereas beta and gamma males have similarweapon shape, but vary in their body size and chelicera length.

Population differences in the strength of sexual selection match relative weapon size in the Japanese rhinoceros beetle, Trypoxylus dichotomus (Coleoptera: Scarabaeidae) †

Observations of local habitat conditions and breeding ecology point to shifts in the relative abundance of feeding territories as the most likely cause of population differences in selection on male weapon size in this species.

Sexual behavior of Metaltella iheringi (Keyserling, 1891) (Araneae: Desidae): sexual patterns, female quiescence and comparisons with other spiders

The reproductive behavior of Metaltella iheringi (Keyserling, 1891), a species that is characterized by complex genitalia in both sexes, is described for the first time and the possible implications in a pre- and post-copulatory sexual selection context are discussed.

Testing sexual size dimorphism and nocturnal surface activity in the coastal wolf spider Allocosa alticeps

The results highlight the importance of studying A. alticeps and Allocosa senex, since they could reflect the transition to reverse SSD, for understanding the evolution of sex role reversal in the subfamily Allocosinae.

Natural history and ecology of the New Zealand sheet-web spiders Cambridgea plagiata and C. foliata (Araneae: Desidae)

Key ecological differences and population dynamics in two sympatric species of sheet-web spider, Cambridgea plagiata and Cambridgea foliata, are investigated, finding significant differences in the distribution, web size and substrate, and predominant diet.

Variations in the carapace shape of whip spiders (Arachnida: Amblypygi)

This study analyzes the ontogenetic modifications in prosoma outline shape in whip spiders during growth and concludes that a one‐dimensional measure suffices for mature specimens of a single species or family, but for larger studies, or when including immature specimens, at least the prosoma area should be used as a size estimator.

Intrasexually selected weapons

  • A. Rico-GuevaraK. Hurme
  • Environmental Science, Biology
    Biological reviews of the Cambridge Philosophical Society
  • 2018
It is conceptualized that there are five ways in which a sexually dimorphic trait, apart from the primary sex traits, can be fixed: sexual selection, fecundity selection, parental role division, differential niche occupation between the sexes, and interference competition.

The hidden links between animal weapons, fighting style, and their effect on contest success: a meta‐analysis

In many species that fight over resources, individuals use specialized structures to gain a mechanical advantage over their rivals during contests (i.e. weapons). Although weapons are widespread

Contest dynamics and assessment strategies in combatant monkey beetles (Scarabaeidae: Hopliini)

This work aims to demonstrate the efforts towards in-situ applicability of EMMARM, which aims to provide real-time information about the distribution and habits of E.K. larvae found in South Africa.

All by myself? Meta‐analysis of animal contests shows stronger support for self than for mutual assessment models

The results indicate that rivals settle contests following the rules predicted by WOA and E‐WOA in most species, however, they also found inconsistencies between the behaviours exhibited during contests and the assumptions of WOA models in most Species.



Chelipeds are the real weapon: cheliped size is a more effective determinant than body size in male–male competition for mates in a hermit crab

This work investigates the function and relative efficacy of body size and major cheliped size in male–male contests for females in the hermit crab Diogenes nitidimanus and suggests that large chelipeds have evolved as a true weapon and are effective in escalated fights for resources.

Weaponry, color, and contest success in the jumping spider Lyssomanes viridis

Sexual Selection in the Water Spider: Female Choice and Male-Male Competition

It is found that females approach and choose large males as mating partners, despite the risk of male cannibalism, which seems to be important for the evolution of the peculiar sexual size dimorphism of water spiders.

Imperfect assessment and limited information preclude optimal strategies in male–male fights in the orb-weaving spider Metellina mengei

Agonistic behaviour between male orb–web spiders Metellina mengei competing for access to female webs was examined in field experiments to test the major predictions of game theory and a failure of some contestants to obtain information on resource value and relative contestant size necessary to optimize fight strategy is discussed.

Tusked Males, Male Dimorphism and Nesting Behavior in a Subsocial Afrotropical Wasp, Synagris cornuta, and Weapons and Dimorphism in the Genus (Hymenoptera: Vespidae: Eumeninae)

Abstract Synagris wasps (Hymenoptera: Vespidae: Eumeninae) include some of the most spectacular examples of exaggerated secondary sexual “weapons” known. I examined the scaling relationship between

Male-male competition and mating success in the orb-web spider,Nephila clavata, with reference to temporal factors

  • T. Miyashita
  • Biology, Environmental Science
    Ecological Research
  • 2006
Seasonal occurrence patterns of adults of both sexes, intensity of male-male interactions, and mating success in the spider,Nephila clavata, were examined in the field. Adult males began to attend

Exaggerated Trait Allometry, Compensation and Trade-Offs in the New Zealand Giraffe Weevil (Lasiorhynchus barbicornis)

The scaling relationship between rostrum and body size is characterised and it is shown that males have a steep positive allometry, but that the slope is non-linear due to a relative reduction in roStrum length for the largest males, suggesting a limitation in resource allocation or a diminishing requirement for large males to invest increasingly into larger rostra.