@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 {SalewskiSpring,
	title = {Spring passerine migrants stopping over in the Sahara are not fall-outs},
	journal = {Journal of Ornithology},
	year = {Submitted},
	abstract = {Abstract\&nbsp;\&nbsp;The strategy of migrants crossing the Sahara desert has been the subject of debate, but recent evidence from radar studies has confirmed that most passerines use an intermittent migration strategy. The latter has also been suggested from previous studies in oases during autumn migration. It was found that migrants with relatively high fuel loads rest in the desert during daytime and continue migration during the following night, whereas lean migrants stopover in oases for several days to refuel. However, data from the Sahara are scarce for spring migration. We captured passerine migrants near B{\^\i}r Amr{\^a}ne (22{\textdegree}47'N, 8{\textdegree}43'W) in the plain desert of Mauritania for 3\&nbsp;weeks during spring migration in 2004. We estimated flight ranges of 85 passerines stopping over in the desert to test whether they carried sufficient fuel loads to accomplish migration across the Sahara successfully. High fat loads of the majority of birds indicated that they were neither {\textquotedblright} fall-outs{\textquotedblright} nor too weak to accomplish migration successfully. The flight range estimates, based on mean flight speeds derived from radar measurements (59\&nbsp;km/h), revealed that 85\% of all birds were able to reach the northern fringe of the desert with an intermittent migration strategy. Furthermore, birds stopping over in an oasis (Ouad{\^a}ne, 370\&nbsp;km to the southwest of B{\^\i}r Amr{\^a}ne) did not carry consistently lower fuel loads compared to the migrants captured in the desert.},
	keywords = {autumn\_migration, birds, fuel\_loads, mauritania, migrants, migration, migration\_strategy, oases, passerines, radar\_measurements, sahara\_desert, southwest, trans-saharan},
	doi = {10.1007/s10336-009-0464-5},
	url = {http://dx.doi.org/10.1007/s10336-009-0464-5},
	author = {Salewski, Volker and Schmaljohann, Heiko and Liechti, Felix}
}
@article {WilzeckLearning,
	title = {Learning of magnetic compass directions in pigeons},
	journal = {Animal Cognition},
	year = {Submitted},
	abstract = {Abstract\&nbsp;\&nbsp;A proof of magnetic compass learning by pigeons under laboratory conditions has been attempted for decades, but all experiments have failed so far. The aim of the present study was to test whether pigeons can learn magnetic compass directions in an operant chamber if magnetic cues are presented as true spatial cues. Experimental sessions were carried out in the local geomagnetic field and in magnetic fields with matched total intensity and inclination, but different directions generated with Helmholtz-coils. Birds demonstrated successful learning with a performance level comparable to that in learning studies with magnetic anomalies. In addition, we compared the data from magnetic learning in the laboratory with performance from homing experiments in the field. The birds that were more successful in the learning experiment had vanishing bearings farther away from the home direction than the group mean at unfamiliar, but not at familiar sites. This might suggest that better learners explore unknown locations in a different way. Our findings represent the first evidence for operant magnetic compass learning in pigeons and also provide a link between behavioural data from the field and the laboratory.},
	keywords = {birds, migration, navigation, orientation, pigeons},
	doi = {10.1007/s10071-009-0294-0},
	url = {http://dx.doi.org/10.1007/s10071-009-0294-0},
	author = {Wilzeck, Christiane and Wiltschko, Wolfgang and G{\"u}nt{\"u}rk{\"u}n, Onur and Buschmann, Jens-Uwe and Wiltschko, Roswitha and Prior, Helmut}
}
