Do Zebra Finch Parents Fail to Recognise Their Own Offspring?

Wolfgang Forstmeier,Alain Jacot,Hendrik Reers,Tapio Mappes

doi:10.1371/journal.pone.0018466

Wolfgang Forstmeier, Alain Jacot + Show 2 more

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https://doi.org/10.1371/journal.pone.0018466

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Abstract

Individual recognition systems require the sender to be individually distinctive and the receiver to be able to perceive differences between individuals and react accordingly. Many studies have demonstrated that acoustic signals of almost any species contain individualized information. However, fewer studies have tested experimentally if those signals are used for individual recognition by potential receivers. While laboratory studies using zebra finches have shown that fledglings recognize their parents by their “distance call”, mutual recognition using the same call type has not been demonstrated yet. In a laboratory study with zebra finches, we first quantified between-individual acoustic variation in distance calls of fledglings. In a second step, we tested recognition of fledgling calls by parents using playback experiments. With a discriminant function analysis, we show that individuals are highly distinctive and most measured parameters show very high potential to encode for individuality. The response pattern of zebra finch parents shows that they do react to calls of fledglings, however they do not distinguish between own and unfamiliar offspring, despite individual distinctiveness. This finding is interesting in light of the observation of a high percentage of misdirected feedings in our communal breeding aviaries. Our results demonstrate the importance of adopting a receiver's perspective and suggest that variation in fledgling contact calls might not be used in individual recognition of offspring.

Highlights

Whenever information is transferred between two individuals, this happens via a signalling system
Individual variation in fledgling distance calls The cross-validated discriminant function analysis (DFA) on 493 calls from 84 fledglings revealed that 70.6% (348 calls) of all calls were assigned to the correct individual
We demonstrate that adult zebra finches do call in response to playback of fledgling distance calls, they do not respond differently to the calls of their young compared to alien young

Summary

Introduction

Whenever information is transferred between two individuals, this happens via a signalling system. Signalling systems consist of three parts: the sender, the signal and the receiver. Is the signal used to indicate the identity of the sender to the receiver, for example a young fur seal Arctocephalus tropicalis calling for its mother in a nursing colony [1], certain signal properties are needed to ensure reliable recognition by the receiver. It is well established that between-individual variation in acoustic signals commonly occurs. An extensive body of literature has shown that virtually all acoustic signals of animals across many taxa show between-individual variation [1,4,5,6]. From a receiver’s perspective, an animal must be able to perceive these between-individual differences in order to respond [7]

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