The study, published in the April issue of the American Naturalist, was conducted between June 2003 and June 2005 on the isle of Oléron, off the west coast of France, where Christian Bavoux and Guy Burneleau have been studying the local scops owl population since 1981.
The authors have analyzed several hundreds of hoots recorded from 17 territorial males and demonstrated that the pitch of the vocalization reflects the body weight of the male: the heavier the male, the lower the pitch of his hoots. In order to see whether this information is actually used by male owls during territorial interactions, the authors conducted a series of playback experiments (commonly used in studies of animal communication in order to assess the function of vocal signals), monitoring the reaction of subjects to the broadcast of vocalizations. To do this they modified the pitch of several hoots, creating stimuli that mimicked the hoots given by males from a range of body weights. They then played back these recordings to males with established territories, and observed and quantified their response (a combination of approaches and vocal responses). The results show that male owls respond more strongly to the high-pitched calls that simulate lighter individuals, confirming that territorial males attend to pitch information advertising body weight in the calls of their competitors. The authors also found that the territory owners give slightly lower pitched hoots in response to calls mimicking heavier males, probably indicating that they attempted to sound heavier when challenged by more threatening individuals.
"The fact that owls are essentially active during the night puts a strong emphasis on acoustic communication as a means of assessment, both during male competition and during mate choice," says Loïc Hardouin who recently completed a PhD on acoustic communication and territoriality in owls. "The next step is to see whether females use these quality cues when they choose their mating partner." "The vocal communication of owls has interesting similarities to that of terrestrial mammals where the information is typically encoded in acoustic components of the calls rather than in the diversity of the vocal repertoire as it is in songbirds," says Reby, who is an expert in the study of mammal vocal communication.
Patricia Morse | EurekAlert!
Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute
Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy