@article {53156,
	title = {The unique sound production of the Death{\textquoteright}s-head hawkmoth (Acherontia atropos (Linnaeus, 1758)) revisited},
	journal = {The Science of Nature},
	volume = {102},
	year = {2015},
	month = {Jan-08-2015},
	abstract = {<p>When disturbed, adults of the Death\&rsquo;s-head hawkmoth (Lepidoptera, Sphingidae: Acherontia atropos) produce short squeaks by drawing in and deflating air into and out of the pharynx as a defence mechanism. We took a new look at Prell\&rsquo;s hypothesis of a two-phase mechanism by providing new insights into the functional morphology behind the pharyngeal sound production of this species. First, we compared the head anatomy of A. atropos with another sphingid species, Manduca sexta, by using micro-computed tomography (CT) and 3D reconstruction methods. Despite differences in feeding behaviour and capability of sound production in the two species, the musculature in the head is surprisingly similar. However, A. atropos has a much shorter proboscis and a modified epipharynx with a distinct sclerotised lobe projecting into the opening of the pharynx. Second, we observed the sound production in vivo with X-ray videography, mammography CT and high-speed videography. Third, we analysed acoustic pressure over time and spectral frequency composition of six A. atropos specimens, both intact and with a removed proboscis. Single squeaks of A. atropos last for ca. 200 ms and consist of an inflation phase, a short pause and a deflation phase. The inflation phase is characterised by a burst of ca. 50 pulses with decreasing pulse frequency and a major frequency peak at ca. 8 kHz, followed by harmonics ranging up to more than 60 kHz. The deflation phase is characterised by a less clear acoustic pattern, a lower amplitude and more pronounced peaks in the same frequency range. The removal of the proboscis resulted in a significantly shortened squeak, a lower acoustic pressure level and a slightly more limited frequency spectrum. We hypothesise that the uptake of viscous honey facilitated the evolution of an efficient valve at the opening of the pharynx (i.e. a modified epipharynx), and that sound production could relatively easily have evolved based on this morphological pre-adaptation.</p>
},
	keywords = {Insect acoustics, Insect anatomy, Insect head, Manduca sexta, Proboscis, Videography, X-ray imaging},
	issn = {0028-1042},
	doi = {10.1007/s00114-015-1292-5},
	url = {http://link.springer.com/10.1007/s00114-015-1292-5},
	author = {Brehm, Gunnar and Fischer, Martin and Gorb, Stanislav and Kleinteich, Thomas and K{\"u}hn, Bernhard and Neubert, David and Pohl, Hans and Wipfler, Benjamin and Wurdinger, Susanne}
}
@article {17270,
	title = {Remarkable vocal identity in wild-living mother and neonate saiga antelopes: a specialization for breeding in huge aggregations?},
	journal = {The Science of Nature},
	volume = {104},
	year = {2017},
	month = {Jan-04-2017},
	abstract = {<p>Saiga antelopes Saiga tatarica tatarica give birth in large aggregations, and offspring follow the herd soon after birth. Herding is advantageous as anti-predator strategy; however, communication between mothers and neonates is strongly complicated in large aggregations. Individual series of nasal and oral contact calls of mother and neonate saiga antelopes were selected from recordings made with automated recording systems placed near the hiding neonates on the saiga breeding grounds in Northern Kazakhstan during synchronized parturitions of 30,000 calving females. We used for comparison of the acoustic structure of nasal and oral contact calls 168 nasal calls of 18 mothers, 192 oral calls of 21 mothers, 78 nasal calls of 16 neonates, and 197 oral calls of 22 neonates. In the oral calls of either mothers or neonates, formant frequencies were higher and the duration was longer than in the nasal calls, whereas fundamental frequencies did not differ between oral and nasal calls. Discriminant function analysis (DFA) based on six acoustic variables, accurately classified individual identity for 99.4\% of oral calls of 18 mothers, for 89.3\% of nasal calls of 18 mothers, and for 94.4\% of oral calls of 18 neonates. The average value of correct classification to individual was higher in mother oral than in mother nasal calls and in mother oral calls than in neonate oral calls; no significant difference was observed between mother nasal and neonate oral calls. Variables mainly responsible for vocal identity were the fundamental frequency and the second and third formants in either mothers or neonates, and in either nasal or oral calls. The high vocal identity of mothers and neonates suggests a powerful potential for the mutual mother-offspring recognition in dense aggregations of saiga antelopes as an important component of their survival strategy.</p>
},
	keywords = {maternal care in herds, mother-offspring communication, offspring survival, vocal identity},
	issn = {0028-1042},
	doi = {10.1007/s00114-017-1433-0},
	url = {http://link.springer.com/10.1007/s00114-017-1433-0},
	author = {Sibiryakova, Olga V. and Volodin, Ilya A. and Frey, Roland and Zuther, Steffen and Kisebaev, Talgat B. and Salemgareev, Albert R. and Volodina, Elena V.}
}
