The sex in short supply varies over small spatial scales in a katydid (Kawanaphila nartee. Orthoptera : Tettigoniidae)

D.T. Gwynne, Win Bailey, A. Annells

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)

Abstract

In katydids such as Kawanaphila nartee, a female bias in the operational sex ratio (OSR) results in female competition for mates and male choice of mates. Previous work showed that the excess of sexually active females occurs when food availability is low, in part because less food increases the propensity of females to mate as they forage for the large edible spermatophores produced by males. In this study with K. nartee, a pollen-feeding species, we estimate natural variation in numbers of sexually active males and females by assessing male calling activity and the propensity of females to respond to experimental calling males. We found an excess of sexually active males at a site with many flowers and an excess of sexually active females at a site with few flowers about 900 m away. Between-site differences in gut masses of calling males were consistent with the hypothesis that pollen availability controls OSR. Finally, at a third site where flowers were at first scarce, we found that the initial excess in sexually active females changed to an excess of sexually active males after a clump of grass-trees flowered. The mean gut mass of all sampled males from this site increased after flowering. The large variation in OSR that we document for K. nartee highlights the importance of identifying the appropriate spatial and temporal scales over which OSRs are measured in studies of factors controlling sexual selection.
Original languageEnglish
Pages (from-to)157-162
JournalBehavioral Ecology and Sociobiology
Volume42
DOIs
Publication statusPublished - 1998

Fingerprint

Dive into the research topics of 'The sex in short supply varies over small spatial scales in a katydid (Kawanaphila nartee. Orthoptera : Tettigoniidae)'. Together they form a unique fingerprint.

Cite this