Nightingales in space: song and extra-territorial forays of radio tagged song birds

Abstract

Summary Most temperate zone passerines defend territories during the breeding season. Commonly the size of these territories is estimated by plotting the singing locations of the males. However, an individual’s activities need not be restricted to the area used for singing. So far, only little quantitative information has been available to determine how the singing territory relates to the activity range of male songbirds. Here, we present a study in which we used radio‐tracking techniques to collect quantitative data on the spatial behaviour of 11 male territorial Nightingales (Luscinia megarhynchos). The results show that the singing territories made up only about 50 % of the activity ranges. Nevertheless, males spent over 90 % of the time within the singing territory. Singing territories almost never overlapped but activity ranges overlapped in all cases with the activity range of at least one neighbour. Males intruded into neighbouring territories throughout the season but the longest excursions were made before and during the female fertile period. The time spent for forays correlated significantly with song rate and territories of males with higher song rates in turn were less frequently the object of forays by other males. Song rate can be indicative of male quality, so that our findings strongly suggest that foray behaviour is related to male quality in nightingales.

Nocturnal songs in a diurnal passerine: attracting mates or repelling intruders?

“…nightingales: Amrhein et al, 2002;Naguib et al, 2001;Roth et al, 2009). This is also supported by the fact that, despite singing responses and/or countersinging using complex songs being commonly used with intruders during the daytime (Nelson & Croner, 1991), countersinging was rarely observed in our large nocturnal data set.…”

“…Studies of birds' nocturnal behaviour have shown that female nocturnal movements often coincide with night-time singing by males (e.g. Naguib, Altenkamp, & Griebmann, 2001), suggesting that nocturnal songs of territorial males may be used to attract extrapair females actively foraying and seeking extrapair copulations (intersexual function). Nocturnal singing may function to attract an extrapair female while the cover of darkness allows the female to leave her social mate's territory undetected, especially as females that are detected leaving a social mate's territory are often retaliated against (e.g.…”

Social networking in territorial great tits: slow explorers have the least central social network positions

“…We used up to 93 receivers, which were placed in strategic locations throughout the study site. With this novel tracking system the locations of birds are mapped simultaneously and automatically, thus expanding data collection considerably beyond traditional radiotracking in which single individuals are followed manually (Naguib, Altenkamp & Griessmann, 2001). Tags transmitted a digital ID code every 5 s which was logged by receivers within signal range, along with a time stamp and a received signal strength indicator (RSSI).…”

Off-territory movement of male American Redstarts (Setophaga ruticilla) in a fragmented agricultural landscape is related to song rate, mating status and access to females

“…Most off-territory movement, however, is probably to pursue extra-pair copulations (Hanski 1992;Stutchbury 1998;Woolfenden et al 2005) or polyterritorial polygyny (Secunda and Sherry 1991). Therefore, the costs and benefits of movement should depend on attributes of individuals (Stutchbury 1998;Naguib et al 2001), the seasonal timing of movement, and the availability of and access to potential extra-pair mates (Perreault et al 1997;Norris and Stutchbury 2001;Fraser and Stutchbury 2004;Woolfenden et al 2005). Therefore, the costs and benefits of movement should depend on attributes of individuals (Stutchbury 1998;Naguib et al 2001), the seasonal timing of movement, and the availability of and access to potential extra-pair mates (Perreault et al 1997;Norris and Stutchbury 2001;Fraser and Stutchbury 2004;Woolfenden et al 2005).…”

“…Increased off-territory movement and intrusions onto other territories have been documented for old males (Kleven et al 2005) and males with high song rates (Naguib et al 2001); song being an honest signal of good past or current condition (Gottlander 1987;Nowicki et al 2000;Foerster et al 2002). Similarly, within-pair and extra-pair fertilizations are most often achieved by old males (Kempenaers et al 1992;Perreault et al 1997) in good body condition (Dyrcz et al 2005).…”