Social transmission in the wild reduces predation pressure on novel prey signals

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.

Methods
This data was collected at Madingley Wood (Cambridgeshire, UK) during summer 2018. We introduced novel palatable and unpalatable foods into a wild blue tit and great tit population and recorded individuals’ food choices using RFID technology at feeding stations. We have five different datasets that include records of birds' visits to feeders with 1) plain almonds ("PooledForSocNet"), 2) palatable green and unpalatable red almonds ("GreenRedRawData2"), 3) palatable purple and unpalatable blue almonds ("PurpleBlueRawData2"), 4) palatable purple and palatable blue almonds ("PurpleBlueReversalRawData2"), and 5) palatable orange and unpalatable yellow almonds ("OrangeYellowRawData2"). In addition, we have a datasheet that includes individual attributes ("IndividualsData").