Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Caught in the act: Bats use the sound of copulating flies as a cue for foraging

24.07.2012
Mating at night does not necessarily lead to offspring, at least in flies: males produce a buzzing sound with their wings that can be perceived by bats.

Stefan Greif from the Max Planck Institute for Ornithology, and colleagues, observed this in a long-term study on wild Natterer’s bats that eat the copulating flies in a double-sized meal. Flies that were just sitting or walking on the ceiling did not elicit a predatory response by the bats. This is the first experimental evidence how mating itself can be risky.


Natterer's bat (Myotis nattereri)
Image: Stefan Greif

Mating activities are a dangerous business because the attention to other important events in the surroundings is often reduced. Therefore the duration of copulation itself is usually very short. About 100 years ago researchers argued that copulating animals are at a higher risk of being discovered and, consequently, being eaten by a predator. Yet, surprisingly, there are only few observations that support this hypothesis. These examples comprise studies in water-living insects, such as amphipods and water striders, and also in land insects, as investigated in a recent study in Australian plague locusts that are at a higher risk of being eaten as mating pairs compared to single animals.

Apart from decreased attention, a reduced flight response as well as an enhanced conspicuousness induces a higher risk for these winged lovers to be easy prey. Stefan Greif from the Max Planck Institute for Ornithology, and colleagues, have now provided experimental proof for this phenomenon. In a community of house flies and Natterer’s bats in a cowshed near Marburg, Germany, they analysed videotapes of the movements of almost 9000 flies. The researchers found that the flies rarely fly at night and mostly sit or run on the ceiling. Finding the flies by echolocation is nearly impossible for the bats as the faint insect echo is completely masked by the strong background echo which makes them virtually “invisible”.

This scenario completely changes when the male flies find a suitable mating partner. The subsequent copulation is a noisy event because males then produce broadband buzzing sounds that can be heard by the bats. Around five per cent of the fly pairs that engage in copulation were attacked and mostly eaten by the bats (across four observation years, even 26 per cent of the observed copulating pairs were attacked).

In order to provide evidence that it is really the sound that makes the flies detectable for the bats, the researchers mounted dead, noiseless fly pairs on the shed ceiling in a position they usually take during copulation. These exhibits provide a larger reflection area for echolocation of the bats compared to a single fly. However, they were never attacked by the bats. Only when the researchers played back the copulation sounds of the flies, did the bats try to attack the loudspeakers. Accordingly Stefan Greif summarizes the results of the study in a simplistic way: “sex kills”.

Original work:
Björn M. Siemers, Eva Kriner, Ingrid Kaipf, Matthias Simon and Stefan Greif
Bats eavesdrop on the sound of copulating flies.
Current Biology, published online on June, 23, 2012.
Contact:
Stefan Greif
Max Planck Research Group “Sensory Ecology“
Max Planck Institute for Ornithology, Seewiesen
Phone: +49 8157 932 376
Email: greif@orn.mpg.de
Dr. Sabine Spehn
Public Relations
Max Planck Institute for Ornithology, Seewiesen
Phone: +49 8157 932 421
Email: pr_seewiesen@orn.mpg.de

Dr. Sabine Spehn | Max-Planck-Institut
Further information:
http://www.orn.mpg.de

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>