Negative impact of urban noise on sexual receptivity and clutch size in female domestic canaries

Abstract

In oscines, male song stimulates female reproduction and females are known to adjust both their sexual preferences and their maternal investment according to song quality.Female domestic canaries are especially responsive to wide frequency bandwidth (4 kHz) male songs emitted with a high-repetition syllable rate and low minimal frequencies (1 kHz). We previously showed that low-frequency urban noise decreases female sexual responsiveness for these low-frequency songs (1-5 kHz) through auditory masking. Based on the differential allocation hypothesis, we predicted that urban noise exposure will equally affect female maternal investment. Using a crossover design, we broadcast low-frequency songs to females either in an overlapping noise condition or in an alternating noise condition. Females decreased both their sexual responsiveness and their clutch size in the overlapping noise treatment relative to the alternative noise treatment. No differences were found concerning egg size or egg composition (yolk and albumen mass, testosterone concentration). Due to our experimental design, we can exclude a general impact of noisy conditions and thereby provide evidence for a detrimental effect through masking on avian courtship and reproductive output. These results suggest that noisy conditions may also affect avian communication in outdoor conditions, which may partly explain field reports on noisedependent breeding success and reduced breeding densities at noisy sites. K E Y W O R D Santhropogenic noise, birdsong, clutch size, domestic canary, maternal investment

How urbanization affects sexual communication

“…Indeed, females experiencing anthropogenic noise often show weaker preferences for male traits (des Aunay et al, 2014 , 2017 ; Bent et al, 2018 ; Swaddle & Page, 2007 ). For example, the monogamous zebra finch ( Taeniopygia guttata ) showed a weaker preference for pair‐bonded males when exposed to high‐amplitude white noise, suggesting that normally monogamous songbird populations may show more extra‐pair behavior in areas with more anthropogenic noise (Swaddle & Page, 2007 ).…”

“…For example, the monogamous zebra finch ( Taeniopygia guttata ) showed a weaker preference for pair‐bonded males when exposed to high‐amplitude white noise, suggesting that normally monogamous songbird populations may show more extra‐pair behavior in areas with more anthropogenic noise (Swaddle & Page, 2007 ). In canaries ( Serinus canaria ), females do not express typical preferences for low‐frequency male songs in noisy conditions, thereby weakening sexual selection (des Aunay et al, 2014 , 2017 ). If preferred low‐frequency signals are consistently masked, it is unclear whether females will begin preferring higher frequency songs (thereby disrupting signal‐cost associations and underlying signal honesty), whether sexual selection will weaken in the population because males rarely produce preferred signals (des Aunay et al, 2014 ), or whether females will shift the relative importance of other signal modalities during mate choice (Partan, 2013 ; Rios‐Chelen et al, 2015 ).…”

Mate choice in a polluted world: consequences for individuals, populations and communities

“…When individuals reduce their investment into mate choice, maladaptive choices may follow that lower the number and quality of offspring they produce. For instance, canaries (Serinus canaria) produce smaller clutch sizes when choosing a mate in a noisy environment, probably because hampered male-female vocal communication reduces female motivation to reproduce [66]. Such reduced investment can be adaptive under natural, fluctuating conditions if conditions improve with time.…”

An experimental test of chronic traffic noise exposure on parental behaviour and reproduction in zebra finches

“…In contrast to field studies, playback experiments in the laboratory allow researchers to keep environmental factors constant which allows to separate direct versus indirect effects of noise on reproductive success. Huet des Aunay et al (2017) tested whether noise affected female investment (clutch size) in domestic canaries ( Serinus canaria ), a species where male song is sufficient to stimulate egg laying even in the absence of a male ( Kroodsma, 1976 ). Tested females were exposed to playbacks of male song and urban noise in two conditions: the noise was played in between or during songs, therefore exposing females to the same amount of overlapping (masking parts of the song spectrum) or non-overlapping noise.…”