Artificial eyespots on cattle reduce predation by large carnivores

Cameron Radford,Ben Maslen,Neil Jordan,Tracey Rogers,John Weldon Mcnutt

doi:10.1038/s42003-020-01156-0

Abstract

Eyespots evolved independently in many taxa as anti-predator signals. There remains debate regarding whether eyespots function as diversion targets, predator mimics, conspicuous startling signals, deceptive detection, or a combination. Although eye patterns and gaze modify human behaviour, anti-predator eyespots do not occur naturally in contemporary mammals. Here we show that eyespots painted on cattle rumps were associated with reduced attacks by ambush carnivores (lions and leopards). Cattle painted with eyespots were significantly more likely to survive than were cross-marked and unmarked cattle, despite all treatment groups being similarly exposed to predation risk. While higher survival of eyespot-painted cattle supports the detection hypothesis, increased survival of cross-marked cattle suggests an effect of novel and conspicuous marks more generally. To our knowledge, this is the first time eyespots have been shown to deter large mammalian predators. Applying artificial marks to high-value livestock may therefore represent a cost-effective tool to reduce livestock predation.

Highlights

Eyespots evolved independently in many taxa as anti-predator signals
Our results suggest that artificial eyespots were successful in deterring ambush predators from attacking cattle on which they were painted during the study period (Fig. 2)
The relative effectiveness of artificial mark types in this experiment allows us to speculate on the mechanism of their anti-predator effects, shedding new light on the evolution of antipredator signals more generally

Summary

Introduction

Eyespots evolved independently in many taxa as anti-predator signals. There remains debate regarding whether eyespots function as diversion targets, predator mimics, conspicuous startling signals, deceptive detection, or a combination. A classic example of anti-predator markings are eyespots on moth and butterfly wings[2,3,4,5], but many other animal groups including other insects, fishes, molluscs, amphibians and birds, use concentric circles to deter predators[1,2,6,7,8] While these patterns ostensibly resemble a vertebrate eye, the mechanism behind their anti-predator effects remains debated[7,8,9,10,11]. Eye images have been shown to increase human charitable donations in shopping malls[36] and to decrease bike theft[37] These studies may suggest inherent responses to such features, despite this evolutionary strategy being naturally limited to non-mammals, or responses may instead relate to speciesspecific social cues. Woodcutters and other forest users have worn ornamental human face masks on the back of their heads in the Sundarbans in eastern India and western

Methods

Results

Conclusion