Is the predation risk of mate-searching different between the sexes?

Torsekar, Viraj R and Isvaran, Kavita and Balakrishnan, Rohini (2019) Is the predation risk of mate-searching different between the sexes? In: EVOLUTIONARY ECOLOGY, 33 (3). pp. 329-343.

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Abstract

In animals that communicate for pair formation, generally one sex invests more effort in mate searching. Differential predation risk of mate searching between the sexes is hypothesised to determine which sex invests more effort in mate searching. Although searching by males is prevalent in most animals, in orthopteran insects and some other taxa females physically move to localise signalling males who are predominantly sedentary. Although the two sexes thus share mate searching effort in orthopterans, their behavioural strategies are different and sexual selection theory predicts that signalling males may be following the riskier strategy and incurring higher costs. However, relative levels of risk posed by the two mate searching strategies remain largely unexplored. Hence, we estimated the relative predation risk experienced in natural populations by signalling males and responding females. We did this by quantifying predation risk as a probability of mortality in the context of acoustic communication in a tree cricket, Oecanthus henryi from its ecologically relevant predator, a lynx spider, Peucetia viridans. Spiders may perceive calling in males and movement in females by their ability to detect both airborne acoustic cues and substrate-borne vibratory cues. Probability of mortality was quantified by partitioning it into three spatial components at which crickets and spiders interact, using a combination of extensive field observations and manipulative experiments in a semi-natural setup. We found no differences in predation risk faced by calling males and responding females, supporting the prediction that similar sex-specific costs can explain shared mate searching responsibilities. Our findings therefore suggest that direct benefits offered by males to females upon pair formation may better explain shared mate searching effort between the sexes in orthopterans.

Item Type:	Journal Article
Publication:	EVOLUTIONARY ECOLOGY
Publisher:	SPRINGER
Additional Information:	The copyright for this article belongs to SPRINGER
Keywords:	Communication; Sex-specific costs; Sex roles; Predation risk; Mate searching; Crickets
Department/Centre:	Division of Biological Sciences > Centre for Ecological Sciences
Date Deposited:	04 Jul 2019 06:54
Last Modified:	04 Jul 2019 06:54
URI:	http://eprints.iisc.ac.in/id/eprint/62768

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