Neighbour-stranger song discrimination in territorial ortolan bunting Emberiza hortulana males

2014

Ethology

Acoustic Neighbour‐Stranger (N‐S) discrimination is widespread in birds and has evolved to settle territorial disputes with low costs. N‐S discrimination was found both in song‐learning oscines and non‐song‐learning bird taxa, irrespective of the repertoire sizes they have. Therefore, it seems that more than just a single mechanism enable N‐S discrimination. Species with larger repertoires, where males have unique phrases or syllables may rely on such interindividual differences. The majority of birds have rather small repertoires, which often are shared among neighbours. In this case, males are facing the problem of individual recognition when rivals produce songs, at least superficially, identical. To better understand the acoustic basis of N‐S discrimination in species with small and shared repertoires, I studied the ortolan bunting (Emberiza hortulana). Males of this small oscine species are able to N‐S discrimination based on a single song rendition when presented in a playback experiment, regardless of song‐type diversity and song‐sharing level within a particular population. It was also found that songs of the same type sung by different males differ in the frequency of the initial song phrases and these differences persist over years. Here, I tested whether males are able to discriminate among the natural songs and the artificially modified songs of their neighbours in which the frequency was experimentally changed by relatively small value in comparison with the variation range found in this population. Subjects responded significantly more aggressively to the songs with an artificially modified frequency, suggesting that males treat such songs as having come from the repertoire of a non‐neighbour. These results confirm an earlier prediction that differences in the frequency of shared song types enable N‐S discrimination. The study presents one of the possible mechanisms enabling N‐S discrimination in songbirds with small repertoires and stress the role of within‐song‐type variation, which is still understudied song characteristic.

Section: Discussionsupporting

confidence: 59%

Section: Introductionmentioning

confidence: 95%

Differences in Frequency of Shared Song Types Enables Neighbour‐Stranger Discrimination in a Songbird Species with Small Song Repertoire

2014

Ethology

“…In all three experiments, we simulated intrusion into an owner territory with a playback of a stranger rival. These simulations reflect natural agonistic situations and evoked strong responses in the study species (e.g., Osiejuk et al., ; Skierczyński et al., ). If a soft song is a signal of aggressive intent, then we should expect—according to the context criterion—more soft songs produced in a more aggressive context (Searcy & Beecher, ).…”

Section: Discussionmentioning

confidence: 96%

“…A typical response to an intruder consists of approaching the rival, ceasing the singing and starting the calling (e.g., Osiejuk, Ratyńska, & Dale, , 2007b). Males can discriminate among rivals with different threat values, for example neighbour vs. stranger, and flexibly adjust their responses (Osiejuk, ; Skierczyński, Czarnecka, & Osiejuk, ; Skierczyński & Osiejuk, ). Low‐amplitude songs have been observed during such male–male interactions and are known to share the same structure as broadcast songs, but sometimes low‐amplitude songs can be slightly shortened (Conrads, ; Jakubowska, ).…”

Section: Introductionmentioning

confidence: 99%

Soft songs in male ortolan buntings are used in an aggressive context but are not an aggressive signal

Jakubowska

2018

Ethology

Many bird species produce low‐amplitude acoustic signals that have been poorly studied in comparison with loud, broadcast songs used for mate attraction and repelling rivals. In some birds, these soft signals were found to be emitted in an antagonistic context and were the most reliable predictor of a subsequent physical attack. The function of this signal is poorly understood, and several hypotheses have been proposed to explain the mechanisms and possible functions of such low‐amplitude signals. The subject of this study is the ortolan bunting, a small passerine species that produces soft songs during territorial defence. In this study, we aim to study whether the soft songs of the ortolan bunting are a signal of increased aggressiveness by testing if they meet the context, prediction and response criteria of aggressive signals. We simulated stranger male intrusion into a focal male territory with three different playback experiments. We found no significant differences in the male responses to the taxidermic model regardless of whether they were or were not producing soft songs in response. The males responded more strongly to loud songs than to soft songs during the simulated intrusions, and the males did not treat soft songs as a predictor of conflict escalation. Although soft songs clearly appeared during territorial encounters and were not present during spontaneous singing before the intrusions, our results did not support the hypothesis that soft songs indicate aggressive character. We suggest that soft songs in the ortolan bunting are intentionally used by birds to modify their intentions or target‐specific individuals within a close range.

“…Other experimental studies have addressed questions related to dialect function and mechanisms of dialect recognition (Pellerin 1983;Hansen 1984;Baker et al 1987;Osiejuk et al 2007a). The other aspects of song behaviour that have been investigated are territorial defence (Kreutzer & Güttinger 1991;Nemeth 1996;Osiejuk et al 2007b;Suter et al 2009, neighbour-stranger recognition (Hansen 1984Osiejuk et al 2007a, b;Skierczyński et al 2007;Skierczyński and Osiejuk 2010) and male-female communication (Nemeth 1994;Wingelmaier et al 2007). However, in these studies, ornithologists have focussed on just five common European species: Corn Buntings, E. calandra; Ortolan Buntings, E. hortulana; Yellowhammers, E. citrinella; Cirl Buntings, E. cirlus; and Reed Buntings, E. schoeniclus.…”

mentioning

confidence: 99%

The song of the Cinnamon-breasted Bunting, Emberiza tahapisi, in the Bamenda Highlands (NW Cameroon)

2011

J Ornithol

In this study, I describe the song of the Cinnamon-breasted Bunting (Emberiza tahapisi)-a common and widespread species in sub-Saharan Africa. Several aspects of song behaviour were addressed based on recordings of 58 males in the Bamenda Highlands (NW Cameroon). The song of the Cinnamon-breasted Bunting is discontinuous and consists of short (1.2 s on average), relatively broadband (range 2.5-9.2 kHz) strophes repeated at a highly variable rate (2-14 strophes per minute). Each male sang a single song type consisting of 4-9 different syllable types. Syllable types differed in acoustic structure, and I describe a total of 40 discrete types. At the song type level, only 8 different song types were found. Males from local groups tended to have slightly more similar songs than strangers separated by a distance of more than 500 m. However, males with shared song types clearly did not aggregate. All males within the studied population shared a characteristic final whistle syllable, which resemble some other buntings. The birds sang from locations elevated above the surrounding vegetation, usually from trees or rocks. I found no significant relationship between song rate, time after sunrise, time of season and song post height.