DOI: 10.5061/dryad.cvdncjt1c
title: Extra-territorial forays by great tits are associated with dawn song in unexpected ways

description: Conspicuous male signals often play an important role in both attracting
 mates and deterring rivals. In territorial species with extra-pair mating,
 female and male forays to other territories may be an important component
 underlying female choice and male mating success and might be influenced
 by male advertisement signals. Yet, whether off-territory foraying is
 associated with male signals is still not well understood. Here, we tested
 how female and male forays are associated with short-range visual and
 long-range acoustic signals (dawn song). We used an automated
 radio-tracking system to follow the movements of wild great tits (Parus
 major) to other territories in relation to male dawn song, plumage
 ornaments, and extra-pair paternity. We show that both sexes frequently
 forayed into others’ territories throughout the breeding period. Movements
 of both males and females were associated with male song, but not with
 plumage ornaments. Contrary to our expectations, females stayed away from
 territories where males sang elaborately, while males were attracted to
 those territories. Moreover, neither female nor male forays were
 associated with the occurrence of extra-pair offspring. Our results thus
 suggest that while forays into other territories are associated with male
 dawn song, females may not be attracted and males not repelled by dawn
 song. This sheds a different light on the sex-specific effects of male
 advertisement signals, expanding the view on the selection pressures
 shaping such communication systems.
description: We used the automated radio-tracking system called “Encounternet”
 (Encounternet LLC, Portland, USA) to track movements of male and female
 great tits (Parus major) during the breeding season. We placed
 Encounternet-receivers up to 5 m from nest boxes at a height of
 approximately 2 m to monitor tagged birds entering the area around a nest
 box. From the raw logs saved by each receiver, we exlcuded logs estimated
 to be further away than 15m and calculated visits using a sliding window
 approach, treating a bird as present in the area as long as its tag was
 logged by the respective receiver at least three times during any 30
 second time window (i.e. the receiver logged 50% of the signals sent out
 by the tag in 30 seconds). This way, we considered any time a bird was
 present near a nest box that was not its own breeding box as an
 extra-territorial foray/visit to that nest box area. For details on
 the tracking method and data processing see the mansucript method section
 and supplementray material. We additionally quantified male vocal (dawn
 singing) and plumage (yellowness and size of the black breast stripe)
 ornaments and determined the occurence of extra-pair offspring in broods
 (details on methods provided in manuscript). Please see the read_me txt
 file for detailed descriptions of all variables inlcuded in the provided
 data files. 
description: Please see the read_me txt file for detailed descriptions of all
 variables inlcuded in the provided data files.