Social transmission in the wild can reduce predation pressure on novel prey signals

Anthony J. Fulford,Liisa Hämäläinen,William Hoppitt,Hannah M. Rowland,Rose Thorogood,Johanna Mappes,Sebastian Sosa

doi:10.1038/s41467-021-24154-0

Abstract

Social transmission of information is taxonomically widespread and could have profound effects on the ecological and evolutionary dynamics of animal communities. Demonstrating this in the wild, however, has been challenging. Here we show by field experiment that social transmission among predators can shape how selection acts on prey defences. Using artificial prey and a novel approach in statistical analyses of social networks, we find that blue tit (Cyanistes caeruleus) and great tit (Parus major) predators learn about prey defences by watching others. This shifts population preferences rapidly to match changes in prey profitability, and reduces predation pressure from naïve predators. Our results may help resolve how costly prey defences are maintained despite influxes of naïve juvenile predators, and suggest that accounting for social transmission is essential if we are to understand coevolutionary processes.

Highlights

Social transmission of information is taxonomically widespread and could have profound effects on the ecological and evolutionary dynamics of animal communities
How social information about food unprofitability spreads among naïve predators, remains untested in field conditions where individuals have opportunities to observe both conspecifics and heterospecifics[20,25] and learn from both positive and negative feeding events of others
The coefficients for the expected number of observations of adults were larger than for the observations of juveniles in the red/green experiment (Table 2), but this difference was not statistically significant, and we, cannot make strong conclusions about the relative age effects in the red/ green experiment. These results suggest that social information from adults facilitates rapid avoidance learning among juveniles, which could reduce the predation cost that aposematic prey faces when naïve predators are abundant[12]

Summary

Introduction

Social transmission of information is taxonomically widespread and could have profound effects on the ecological and evolutionary dynamics of animal communities. 18), and a number of studies with avian predators have demonstrated that individuals learn to avoid unprofitable food by observing the foraging events of others[19,20,21,22,23,24,25] This social transmission has the potential to alter selection for prey defenses: social information about prey unprofitability might reduce predation on novel aposematic prey and facilitate the evolution of aposematism[22,23,24,25], whereas social information about palatable mimics might increase predators’ likelihood to sample both mimics and their defended models[24,26]. How social information about food unprofitability spreads among naïve predators, remains untested in field conditions where individuals have opportunities to observe both conspecifics and heterospecifics[20,25] and learn from both positive and negative feeding events of others (feeding on profitable/ unprofitable prey, respectively)

Objectives

Methods

Results