Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Shedding feathers early may enhance sex appeal, new songbird study shows


Birds that migrate early in the season may have a distinct advantage when it comes to attracting the opposite sex, say researchers from Queen’s University and the Smithsonian Institution.

And it’s all about the feathers.

Researchers were surprised to discover that the timing of a male songbird’s reproduction cycle affects the colour of his feathers and may have important implications for his success in attracting mates. When migratory songbirds raise their young extremely late in the summer, many don’t have time to molt (shed their feathers and replace with new growth) before heading south, the new study shows.

"This means they must molt at stopover sites on their journey to tropical winter habitats," explains Ryan Norris, who conducted the research as part of his PhD in biology at Queen’s, supervised by Professors Laurene Ratcliffe (Queen’s Biology) and Peter Marra (Smithsonian Environmental Research Center).

"Their replacement feathers, grown en route, are less colourful than those of birds that had time to molt before migration, which may put them at a disadvantage in attracting females the following breeding season," says Dr. Norris. "Both findings – that molting in some songbirds occurs after migration has begun, and that their new feathers are duller in colour – were surprising."

The study will be published Dec. 24 in the journal Science.

Until now scientists have assumed that most species of migratory birds molt before they migrate. The team discovered that in fact some begin their migration, molt at a "stopover" site, then continue to their winter habitat. Forty per cent of the male American Redstarts in the study molted in their tail feathers at areas up to 2000 kilometers south of their breeding grounds.

By measuring stable hydrogen isotopes in the newly grown feathers when birds returned the following spring to breed at the Queen’s University Biology Station north of Kingston, the researchers were able to determine the approximate region where molting had occurred. And when the feathers were analyzed with a spectrometer measuring how much light of different wavelengths is reflected, significant differences in colour were also detected.

A key indicator of the songbirds’ health and quality is the concentration of carotenoid in the feathers, which causes orange-red light to be reflected in their feathers. Physiological stress during molting can reduce carotenoid deposits in the feathers.

"Studies of other bird species have shown that females prefer males with higher concentrations of carotenoids, and thus brighter, more intense colours," says Queen’s biologist Bob Montgomerie, who did the colour analysis of feathers for this project. "What we didn’t know until now is that birds’ colours in any given year may be affected by what happened to them in the previous breeding season.

"That’s exciting because ’cost of reproduction’ is a general, organism-wide problem of many species, not just birds."

The other member of the research team from Queen’s is geology professor Kurt Kyser, director of the university’s Facility for Isotope Research, where the stable isotope measurements were conducted.

Nancy Dorrance | EurekAlert!
Further information:

More articles from Studies and Analyses:

nachricht Rutgers-led innovation could spur faster, cheaper, nano-based manufacturing
14.02.2018 | Rutgers University

nachricht New study from the University of Halle: How climate change alters plant growth
12.01.2018 | Martin-Luther-Universität Halle-Wittenberg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>