Perinatal Acoustic Communication in Birds: Why Do Birds Vocalize in the Egg?

Abstract

Abstract:In this review the development of acoustic communication between embryos or between embryos and chicks as well as between embryos/chicks and the breeding parents will be addressed. Special emphasis is given to the impact of embryonic acoustic signals for hatching synchronization.In the Muscovy duck (Cairina moschata L. f. domestica) clicking sound communication is absolutely essential for a synchronized hatching. The mechanism underlying this special case of communication is a synchronization of clicking rates. In a clutch, embryos adapt their clicking rates to each other. Clicking rates of less developed embryos rose faster (acceleration) than clicking rates of more developed embryos (retardation). No evidence was found that vocalization of embryos, chicks and parents improve hatching synchronization.Although, many authors assume that prenatal acoustic interaction by vocalization (an exchange of acoustic signals) exists, in the Muscovy duck it was shown that an acoustic interaction started when the first embryo had hatched. Specific call types serve as communication-releasing signals. Acoustic mother-duckling interaction developed later and gradually during the process of nest-leaving also based on specific call types.Measurements on sound transmission indicate that all embryos within a clutch are in mutual acoustic contact.

Effect of species-specific sound stimulation on the development and hatching of broiler chicks

“…In addition to maternal vocalisation, embryo vocalisation plays a role in the synchronisation of hatching (Veterany et al, 1999;Vergne and Mathevon, 2008). Avian embryos produce the first sounds at IP and this true vocalisation via the syrinx gradually develops into a species specific sound (Rumpf and Tzschentke, 2010). In addition, embryos begin to regularly produce clicking sounds at external pipping (EP) due to the egg tooth tapping against the eggshell.…”

Blue petrels recognize the odor of their egg

“…By contrast, blue petrels lay monomorphic white eggs in dark burrows. A possible impact of acoustic cues on egg recognition also seems unlikely in our experiments carried out during the first half of incubation when embryos do not appear to vocalize (Gottlieb and Vandenbergh, 1968;Rumpf and Tzschentke, 2010). We therefore believe that our experiment tested primarily olfactory recognition rather than visual or acoustic recognition.…”

Perception of environment in farm animals – A review

“…It is now accepted that hearing begins in the chicken embryo on about day 12 of incubation (Rubel and Fritzsch, 2002). In the final stages of embryo development, chicks use acoustic communication to synchronize hatching (Rumpf and Tzschentke, 2010).…”