"When partners duet, they signal to other magpie-larks that they are working as a team to defend their territory," said Dr. Michelle Hall of the Max Planck Institute for Ornithology of the new findings. "The level of precision in their duets seems to let others know how ‘good’ they are—their ability and/or motivation to cooperate for territorial defense."
Coordinated displays are widely used among animals to defend shared resources, and may signal coalition strength so that groups can assess the relative competitive ability of rivals and avoid unnecessary fights. For example, lions roar in choruses that provide information about their group’s size to intimidate rivals, as do gibbons, chimpanzees, and wolves, Hall said.
Paired Australian magpie-larks sing notes in rapid alternation to produce duets for territorial defense. One member of the pair repeatedly makes a call that sounds like ‘peewee,’ and the other responds each time with ‘wit,’ Hall said. Experiments have shown that the birds’ duets are more threatening territorial displays than songs sung solo.
However, magpie-lark pairs vary considerably in their singing skills. Highly coordinated partners create alternating notes so closely spaced that they can sound like a single bird. In contrast, others’ relatively poorer vocals often include gaps, overlaps, or irregular tempos. Yet the influence of those timing differences on the level of threat perceived by members of the birds’ listening audiences remained uncertain.
Hall and study collaborator Robert Magrath of Australian National University, Canberra, tested the function of duet precision by broadcasting coordinated and uncoordinated songs on twelve magpie-lark territories. Male magpie-larks responded most aggressively to coordinated duets, evidence that the sound of precise pairs signaled a strong coalition more likely to fend off intruders.
Longer-term partners more often produce well-coordinated duets, they found. Thus, they said, duetting talent may signal the pairs’ ongoing motivation to act collectively—the stability of their unions. Duet precision might also indicate the ability for concerted action. For instance, duet ‘tempo’ slows when partners are farther apart.
Hall said she hopes to continue exploring the magpie-larks’ duets in different contexts, to find out "whether precision of duets signals coalition quality by revealing fighting ability, or motivation, or both."
Erin Doonan | EurekAlert!
One step closer to reality
20.04.2018 | Max-Planck-Institut für Entwicklungsbiologie
The dark side of cichlid fish: from cannibal to caregiver
20.04.2018 | Veterinärmedizinische Universität Wien
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
20.04.2018 | Physics and Astronomy
20.04.2018 | Interdisciplinary Research
20.04.2018 | Physics and Astronomy