Details

Autor(en) / Beteiligte

• Uetz, George W.
• Gilbert, Rachel
• Wilson, Rebecca
• Mann, Jacqueline
• Macedonia, Joseph
• Clark, David L.

Titel

Background contrast affects detection and recognition of courting wolf spiders by intended and unintended receivers

Ist Teil von

• Behavioral ecology and sociobiology, 2024-03, Vol.78 (3), p.43

Ort / Verlag

Berlin/Heidelberg: Springer Berlin Heidelberg

Erscheinungsjahr

2024

Link zum Volltext

Quelle

SpringerLink

Beschreibungen/Notizen

• We used video playback of courting male Schizocosa ocreata wolf spiders to examine responses of intended receivers (conspecific females) and eavesdroppers (competitor males, predatory spiders, toads) to manipulations of spider color (natural color, monochromatic gray, monochromatic RBG average) displayed against complex leaf litter backgrounds (color, grayscale). Models of chromatic and achromatic contrast between spider stimuli and backgrounds were used to predict receiver responses. The results support the hypothesis that interactions between spider and background coloration affect detection and recognition, although responses varied with receiver type. Detection responses of intended receivers (female S. ocreata ) did not fit predictions of the chromatic contrast model in some cases, but showed a fair fit to the achromatic model. Detection responses of social eavesdroppers (male S. ocreata ) fit the chromatic and achromatic contrast models slightly better than did female responses (poor fit and very good fit, respectively). Eavesdropping wolf spider predators ( Rabidosa ) exhibited detection responses that significantly matched predictions of the chromatic (very good fit) and achromatic (excellent fit) models. Whereas jumping spiders ( Phidippus ) showed a good fit to the chromatic and achromatic contrast models, toad predators had a good fit only to the chromatic model. Recognition responses revealed a different pattern of fit to the chromatic and achromatic models across receiver types, although Rabidosa again indicated a significant fit to both models. Taken together, the results of this study identify both chromatic and achromatic features of spider appearance as likely explanations for differences in behavioral responses of intended and unintended receivers. This outcome suggests the possibility that both sexual and natural selection likely target different features of male appearance during courtship. Significance statement Some of the most striking examples of animal displays involve conspicuous male courtship signals, although such signals often can be exploited by eavesdropping competitors and predators. In this study we manipulated the coloration of courting male Schizocosa ocreata wolf spiders and their leaf-litter backgrounds from pre-existing video footage. We then played back the altered video clips to female conspecifics and eavesdroppers (competing conspecific males and potential predators: non-conspecific wolf spiders, jumping spiders, and toads) and recorded their responses. From these responses we scored both stimulus detection (latency to orient) and recognition (receptivity movements in conspecific females, tapping bouts in conspecific males, and attack in other viewers). Color differences in the courting male stimuli and leaf-litter backgrounds proved to be important for detection and recognition, even for wolf spiders with limited dichromatic vision. Moreover, for jumping spiders and predatory toads with tetrachromatic and trichromatic vision respectively, color of the prey spider stimulus was particularly salient. Overall, our experimental results support the hypothesis that receivers with different visual capacities should vary in their responses to color and contrast of courting male spiders against complex backgrounds.