Female Eavesdropping on Male Song Contests in Songbirds

Abstract

Male song reflects the quality of the singe many animals and plays a role in female ch, of social and copulation partners. Eavesdropi on male-male vocal interactions is a means which females can compare different ma singing behavior directly and make immed comparisons between potential partners the basis of their relative vocal performa (1, 2). Using an interactive playback exp ment followed by microsatellite pater analysis, we investigated whether female black-capped chickadees (Poecile atricapilla) base their reproductive decisions on information gained through eavesdropping.Black-capped chickadees are socially monogamous songbirds that follow a mixed reproductive strategy in which one-third of broods include young that are not related to their social father (3). From 1999 to 2001, we assessed dominance ranks in a free-living population of chickadees at Queen's University Biological Station, Canada, to predict which males were likely to be sought for extrapair copulations (high-ranking males) and which males were likely to lose paternity within their nests (low-Fi ranking males) (3, 4). sl At the start of the breeding season, (t when male-male song contests are corn-s mon and females actively solicit copu-tf lations, we used interactive song play-al back to engage territorial male chicka-ti dees in countersinging interactions with rz a simulated intruder (5). We performed 6.0-min playback trials to dyads of neighboring high-ranking and lowranking males from the same winter flock control treatments, we mimicked natural ten rial encounters; we simulated an intruder sang submissively (Fig. 1A) with the high-n ing playback subject and sang aggressively ( 1B) with the low-ranking neighbor. In exl mental treatments, we attempted to alter ea dropping females' perceptions of their sc mates; we simulated an intruder that sang gressively with the high-ranking playback ject and sang submissively with the low-ranl neighbor. To test whether interactive playl altered the normal pattern of paternity in nests of subject males, we conducted pater analysis on blood samples collected from spring (6).High-ranking males that lost song cont with a simulated intruder lost paternity in their nests (Fig. 1C); high-ranking males that received playback simulating an aggressive intruder showed a significantly greater level of paternity loss than high-ranking males that received playback simulating a submissive intruder (control I; Fisher's exact test, P = 0.05) and a significantly greater level than a control group of high-ranking males that received no playback (control II; P = 0.05). As predicted (3, 4), we observed little A Submissive playback N 4.5: Y 4.0-) 302 2.5 U-*1-B Aggressive playback -1

Vocally correlated seasonal auditory variation in the house sparrow (Passer domesticus)

“…The biological significance of variation in song has not been studied in house sparrows but the acoustic structure of song may encode information important to both sexes such as individual identity, dominance status, parasite load, fighting and parenting abilities and genetic quality, as in other songbirds (Collins, 2004). Females may use this information to choose social mates or partners for extra-pair copulations, as shown in blackcapped chickadees [Poecile atricapillus (Mennill et al, 2002)]. In house sparrows, 40% of males in an Oklahoma population were found to be cuckolded, and 20% of offspring could be attributed to extrapair fertilizations (Whitekiller et al, 2000).…”

Computational mate choice: Theory and empirical evidence

“…For example, in female black-capped chickadees, Poecile atricapillus, the probability of extra-pair copulations depends on the outcome of male-male vocal contests. By experimentally manipulating the outcome of contests between the female's social partner and either an aggressive or submissive simulated opponent, Mennill et al (2002Mennill et al ( , 2003 showed that females paired with high-ranking males were more likely to accept extra-pair sires when their partner had been exposed to aggressive rather than to submissive opponents. Interestingly, Ophir and Galef (2004) showed that, in Japanese quails, the use of public information depends on females' previous sexual experience: when observing an antagonistic interaction between two males, young virgin females preferred the most aggressive male, whereas the sexual experienced females preferred the least aggressive male.…”

The social interaction role of song in song sparrows: implications for signal design

“…Furthermore, observations of singing in songbird neighborhoods reveal that the interactive communication is usually an ongoing process that lasts throughout the breeding season, and that birds may use direct interaction as well as eavesdropping on other interactions to continually adjust their assessment of the status of their neighbors. For example, recent field experiments on songbirds have shown that males make decisions concerning whom to challenge and females make decisions concerning whom to mate with based on information acquired by eavesdropping on singing interactions (Naguib & Todt, 1997;Otter et al, 1999;Mennill et al, 2002). In the species studied to date, song overlapping, song-type matching, frequency matching, and/or song leading seem to be some of the critical cues that indicate relative status between two singers (Mennill & Ratcliffe, 2004;Peake et al, 2005;Kunc et al, 2006).…”