Silk wrapping of nuptial gifts aids cheating behaviour in male spiders

TY - JOUR

T1 - Silk wrapping of nuptial gifts aids cheating behaviour in male spiders

AU - Ghislandi, Paolo Giovanni

AU - Beyer, Michelle

AU - Velado, Patricia

AU - Tuni, Cristina

PY - 2017

Y1 - 2017

N2 - Sexual traits, such as nuptial gifts, are costly and often condition-dependent. Males should be under selection to reduce these costs without impairing their reproductive success. Spider gifts consist of silk-wrapped food, but may also consist of worthless (non-nutritive) donations that successfully lead to mating, despite yielding shorter copulations. Worthless gifts may either represent a cheaper cheating strategy or the inability to produce genuine gifts due to resource limitations (i.e. poor body condition). Unless energetic constraints limit expenditure in silk, males should apply more silk to worthless gifts to compensate for their lower reproductive value. We ask whether in Pisaura mirabilis 1) worthless gifts are condition-dependent and 2) males strategically use silk based on gift type (genuine vs worthless). We tested whether male body condition explains the gift-giving strategy and compared silk amounts covering each gift type, in gifts collected from the field and produced in the laboratory by males given different feeding regimes. Our findings show that worthless gifts are not promoted by poor body condition or limited resources. They rather result from a cheating strategy evolved to opportunistically reduce the costs of genuine gifts while ensuring nutritional advantages, with cheaters gaining body mass. Males applied more silk to worthless gifts regardless of their body condition or feeding state, suggesting they can strategically adjust silk expenditure despite its costs. By masking gift contents and prolonging female feeding, silk is crucial for the maintenance of cheating, likely resulting from an evolutionary arms race between male deception and female assessment.

AB - Sexual traits, such as nuptial gifts, are costly and often condition-dependent. Males should be under selection to reduce these costs without impairing their reproductive success. Spider gifts consist of silk-wrapped food, but may also consist of worthless (non-nutritive) donations that successfully lead to mating, despite yielding shorter copulations. Worthless gifts may either represent a cheaper cheating strategy or the inability to produce genuine gifts due to resource limitations (i.e. poor body condition). Unless energetic constraints limit expenditure in silk, males should apply more silk to worthless gifts to compensate for their lower reproductive value. We ask whether in Pisaura mirabilis 1) worthless gifts are condition-dependent and 2) males strategically use silk based on gift type (genuine vs worthless). We tested whether male body condition explains the gift-giving strategy and compared silk amounts covering each gift type, in gifts collected from the field and produced in the laboratory by males given different feeding regimes. Our findings show that worthless gifts are not promoted by poor body condition or limited resources. They rather result from a cheating strategy evolved to opportunistically reduce the costs of genuine gifts while ensuring nutritional advantages, with cheaters gaining body mass. Males applied more silk to worthless gifts regardless of their body condition or feeding state, suggesting they can strategically adjust silk expenditure despite its costs. By masking gift contents and prolonging female feeding, silk is crucial for the maintenance of cheating, likely resulting from an evolutionary arms race between male deception and female assessment.

KW - CONDITION DEPENDENCE

KW - FEEDING SPIDER

KW - GIVING SPIDER

KW - INSECTS

KW - MATE CHOICE

KW - PISAURA-MIRABILIS

KW - SENSORY EXPLOITATION

KW - SEXUAL SELECTION

KW - SPERM COMPETITION

KW - WORTHLESS DONATIONS

KW - deception

KW - mating strategies

KW - nuptial gifts

KW - sperm competition

UR - http://www.scopus.com/inward/record.url?scp=85019936785&partnerID=8YFLogxK

U2 - 10.1093/beheco/arx028

DO - 10.1093/beheco/arx028

M3 - Journal article

SN - 1045-2249

VL - 28

SP - 744

EP - 749

JO - Behavioral Ecology

JF - Behavioral Ecology

IS - 3

ER -