Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scared of a Younger Rival? Not For Some Male Songbirds

08.02.2012
When mature male white-crowned sparrows duel to win a mate or a nesting territory, a young bird just doesn’t get much respect.

Researchers found that older male white-crowned sparrows don’t put much of a fight when they hear a young male singing in their territory – probably because the older bird doesn’t consider the young rival much of a threat.

But a male sparrow will act much more aggressively if it hears a bird of the same age singing in a territory it claims as its own.

“These male sparrows assess an opponent’s fighting ability based on age. And for a mature sparrow, a young male is just not going to scare them,” said Angelika Poesel, lead author of the study and curator of Ohio State University’s Borror Laboratory of Bioacoustics and the tetrapod division.

Poesel conducted the study with Douglas Nelson, associate professor of evolution, ecology and organismal biology at Ohio State and director of the Borror Lab. Their results appear online in the journal Biology Letters.

This study is one of the first to suggest that some birds use each other’s songs – and not just plumage – to help determine a potential rival’s age and thus threat level.

The researchers did the study in a migratory population of white-crowned sparrows that nested in a state park in Bandon, Oregon from 2008 to 2011. The researchers have been studying this population since 2005.

A male white-crowned sparrow, like many bird species, uses its songs to claim a nesting territory, win an appropriate mate, and sometimes to find additional females to mate with. Males will often attack and attempt to chase away other birds of the same species that sing in their territories.

In some species of birds, second-year males differ in their plumage and/or their songs from older, more mature birds. In white-crowned sparrows, second-year males have some plumage differences from older males. But this study focused on another difference: second-year males will often sing two or more versions of their species’ song before they settle on the one that they will use the rest of their lives.

That means older white-crowned sparrows can tell a youngster by the fact that it will sing more than one version of the species song.

In this study, the researchers mapped out territories of 16 male white-crowned sparrows – eight of which had held territories at the park in previous years (identified by bands placed on their legs in previous years) and eight second-year males that had never held a territory there before.

The researchers placed a loudspeaker within the birds’ territories and played recordings that suggested either a second-year bird or an older, mature bird had invaded their territory.

Several measures determined how threatened the birds were by what they perceived as an incursion into their territories.

If the male perceives the bird they hear as a greater threat, it will approach the loudspeaker more closely (to confront the rival), take more flights toward the speaker, and sing more songs.

Results showed that older birds didn’t react as strongly when they heard a recording of a second-year bird than they did to one of an older male. In other words, when they heard the second-year male, they didn’t approach the loudspeaker as closely, they didn’t fly to the speaker as many times, and they didn’t sing as often in response.

“Other research suggests that younger male birds are less successful at attracting females than older males. That means older males see these young birds as little threat to them and not worth a lot of attention,” Poesel said.

But the study did show that second-year males that had established a territory did respond aggressively when they heard the recordings of other second-year males within their area.

“Another young male that is likely in search of a territory is seen as a strong threat and an equal competitor,” she said. “They will elicit a strong, aggressive response from another young bird.”

These findings suggest that some male songbirds use each other’s song as a way to conduct a “mutual assessment” of each other as a potential rival.

“There’s more likely to be a conflict when both of the birds see themselves as equal competitors,” Poesel said.

“White-crowned sparrows aren’t interested in picking a fight with another bird that is much stronger or weaker than themselves.”

The research was supported by a grant from the National Science Foundation.

Contact: Angelika Poesel, (614) 292-2176; Poesel.1@osu.edu
Written by Jeff Grabmeier, (614) 292-8457; Grabmeier.1@osu.edu

Jeff Grabmeier | Newswise Science News
Further information:
http://www.osu.edu

More articles from Life Sciences:

nachricht Unique genome architectures after fertilisation in single-cell embryos
30.03.2017 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

NASA laser communications to provide Orion faster connections

30.03.2017 | Physics and Astronomy

Reusable carbon nanotubes could be the water filter of the future, says RIT study

30.03.2017 | Studies and Analyses

Unique genome architectures after fertilisation in single-cell embryos

30.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>