@article {GeberzahnFemales,
	title = {Females alter their song when challenged in a sex-role reversed bird species},
	journal = {Behavioral Ecology and Sociobiology},
	year = {Submitted},
	abstract = {Abstract\&nbsp;\&nbsp;Birdsong serves to attract mates and to deter territorial rivals. Even though song is not restricted to males, this dual function has almost exclusively been demonstrated for male song. To test the generality of hypotheses on birdsong, we investigated female song in the sex-role reversed, classically polyandrous African black coucal (Centropus grillii) in the context of female{\textendash}female competition. We compared spontaneously vocalizing females with females vocally responding to a playback simulating a conspecific intruder. Females changed vocal parameters in response to playbacks: They lowered the pitch of their vocalizations and enhanced the duration of song elements when being challenged. Also, the composition of the vocalizations was altered. There was no significant correlation between pitch and body size parameters in spontaneous song, but there was for response songs, with larger females having a lower pitch. These changes in vocal properties suggest that the vocalizations are important for mutual assessment of competitive abilities in females. Our findings confirm the general role of intrasexual competition in vocal communication of birds.},
	keywords = {bioacoustics, birds, communication, song},
	doi = {10.1007/s00265-009-0836-0},
	url = {http://dx.doi.org/10.1007/s00265-009-0836-0},
	author = {Geberzahn, Nicole and Goymann, Wolfgang and Muck, Christina and ten Cate, Carel}
}
@article {Beckers2008Developmental,
	title = {Developmental plasticity of mating calls enables acoustic communication in diverse environments},
	journal = {Proceedings of the Royal Society B: Biological Sciences},
	volume = {275},
	number = {1640},
	year = {2008},
	month = {June},
	pages = {1243{\textendash}1248},
	abstract = {10.1098/rspb.2007.1765 Male calls of the katydid exhibit substantial developmental plasticity in two parameters: (i) calls of winter males are continuous and lack the verse structure of summer calls and (ii) at equal temperatures, summer males produce calls with a substantially higher pulse rate than winter males. We raised female under conditions that reliably induced either summer or winter phenotype and tested their preferences for the call parameters that differ between summer and winter males. Neither generation was selective for the presence of verses, but females had strong preferences for pulse rates: only a narrow range of pulse rates was attractive. The attractive ranges did not differ between summer and winter females. Both male pulse rate and female preference for pulse rate changed with ambient temperature, but female preference changed more than the male calls. As a result, the summer call was attractive only at 25{\textdegree}C, whereas the slower winter call was attractive only at 20{\textdegree}C. Thus, developmental plasticity of male calls compensates for differences in temperature dependency between calls and preferences and enables the communication system to function in heterogeneous environments. The potential role of call plasticity during the invasion of new habitats is discussed.},
	keywords = {bioacoustics, communication, na, orthoptera, plasticity, song, tettigoniidae},
	doi = {10.1098/rspb.2007.1765},
	url = {http://dx.doi.org/10.1098/rspb.2007.1765},
	author = {Beckers, Oliver M. and Schul, Johannes}
}
