Song Trait Similarity in Great Tits Varies with Social Structure

Abstract

For many animals, long-range signalling is essential to maintain contact with conspecifics. In territorial species, individuals often have to balance signalling towards unfamiliar potential competitors (to solely broadcast territory ownership) with signalling towards familiar immediate neighbours (to also maintain so-called “dear enemy” relations). Hence, to understand how signals evolve due to these multilevel relationships, it is important to understand how general signal traits vary in relation to the overall social environment. For many territorial songbirds dawn is a key signalling period, with several neighbouring individuals singing simultaneously without immediate conflict. In this study we tested whether sharing a territory boundary, rather than spatial proximity, is related to similarity in dawn song traits between territorial great tits (Parus major) in a wild personality-typed population. We collected a large dataset of automatized dawn song recordings from 72 unique male great tits, during the fertile period of their mate, and compared specific song traits between neighbours and non-neighbours. We show here that both song rate and start time of dawn song were repeatable song traits. Moreover, neighbours were significantly more dissimilar in song rate compared to non-neighbours, while there was no effect of proximity on song rate similarity. Additionally, similarity in start time of dawn song was unrelated to sharing a territory boundary, but birds were significantly more similar in start time of dawn song when they were breeding in close proximity of each other. We suggest that the dissimilarity in dawn song rate between neighbours is either the result of neighbouring great tits actively avoiding similar song rates to possibly prevent interference, or a passive consequence of territory settlement preferences relative to the types of neighbours. Neighbourhood structuring is therefore likely to be a relevant selection pressure shaping variation in territorial birdsong.

Social carry‐over effects underpin trans‐seasonally linked structure in a wild bird population

“…; Snijders et al . ), potentially due to attempting to reduce competitive interference. Similarly, great tits may experience increased reproductive success under conditions of reduced competition with familiar neighbours (Grabowska‐Zhang et al .…”

“…Positioning oneself close to social associates may also reduce energy expenditure on competitive interactions, if individuals display less aggressive behaviours towards familiar neighbours (Temeles 1994). Breeding male birds, for example, appear to have more dissimilar song rates to surrounding individuals who they are more associated with (Foote et al 2008;Snijders et al 2015), potentially due to attempting to reduce competitive interference. Similarly, great tits may experience increased reproductive success under conditions of reduced competition with familiar neighbours (Grabowska-Zhang et al 2012b).…”

Exponential random graph models for networks with community structure

“…Monte Carlo simulation [25,26] is a numerical method which is ideally suited to exponential random graphs. In what follows we briefly describe the method and apply it to the classical blockmodel and its degree-corrected counterpart.…”

Sex‐specific responses to territorial intrusions in a communication network: Evidence from radio‐tagged great tits

“…Advertisement signaling is usually linked to intersexual selection and intrasexual competition and thus is a key component of a species’ ecology (Berglund, Bisazza, & Pilastro, ; Girard, Elias, & Kasumovic, ; Goodwin & Podos, ; Snijders, van der Eijk, et al., ; Waser & Wiley, ). Individuals frequently use long‐range signals, signals that propagate beyond territory boundaries and can reach multiple receivers (McGregor & Dabelsteen, ), facilitating (Maynard, Ward, Doucet, & Mennill, ), maintaining (Garland et al., ), or discouraging (Whitney & Krebs, ) social associations.…”