Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

You snooze, you lose

10.08.2012
Less sleep leads to more offspring in male pectoral sandpipers

During the breeding season, polygynous male pectoral sandpipers that sleep the least sire the most young. A team of researchers headed by Bart Kempenaers from the Max Planck Institute for Ornithology in Seewiesen has now discovered this extraordinary relationship.


An attentive male sandpiper on the lookout for potential competitors.

© Wolfgang Forstmeier


Courtship flight: This male is trying to impress any watching female sandpipers with its feats of flight and inflated chest.

© Wolfgang Forstmeier

During three weeks of intense competition under the constant daylight of the Arctic summer, males actively court females and compete with other males. Using an innovative combination of tags that monitored movement, male-female interactions, and brain activity in conjunction with DNA paternity testing, the authors discovered that the most sleepless males were the most successful in producing young. As the first evidence for adaptive sleep loss, these results challenge the commonly held view that reduced performance is an evolutionarily inescapable outcome of sleep loss.

Sometimes it would be nice to have 24 hours available to finish the workload of the day. However, the drive for sleep inevitably compromises our performance or even causes us to fall asleep under dangerous situations, such as driving a car. Daily sleep is therefore thought to be essential for regenerating the brain and maintaining performance. This holds true both for humans and other animals. Researchers led by Bart Kempenaers from the Max Planck Institute for Ornithology in Seewiesen have now found that during the three-week mating period male pectoral sandpipers (Calidris melanotos) are active for up to 95% of the time. This is even more remarkable considering the fact that the birds have just arrived in their breeding area in Alaska, after migrating from their overwintering grounds in the southern hemisphere.

Pectoral sandpipers have a polygynous mating system where one male mates with several females. Because males do not engage in parental care, a male's reproductive success is determined exclusively by his access to fertile females. However, gaining this access is not that easy for pectoral sandpipers: “Males have to constantly repel their rivals through male-male competition and simultaneously convince females with intensive courtship display”, says director Bart Kempenaers. Given that the sun never sets during the Arctic summer, males that can engage in this extreme competition 24/7 should be at an advantage.

Indeed, the researchers found that the most active males interacted most with females and sired the most offspring. Paternity was determined by collecting DNA from all males, all females, and all offspring in the study area. To measure activity patterns, the researchers attached transmitters to the feathers of all males and most of the females. These radiotelemetry based senders allowed the team to monitor whether the animal was moving or resting. Finally, recordings of brain and muscle activity confirmed that active birds were awake and that inactive birds were in fact sleeping.
The brain activity recordings also reveal variation in sleep intensity: “Males that slept the least had the deepest sleep”, says co-author Niels Rattenborg who conducts sleep research at Seewiesen. Although this suggests that the birds might compensate for sleep loss by sleeping deeper, the researchers found that even when this was taken into consideration, the birds were still experiencing a deficit in sleep.

Based on the team’s data on birds that returned to the study area across breeding seasons, this reproductive sleep loss apparently has no long-term adverse impact on survival. On the contrary, successful males returned to the breeding area more often when compared to males siring less offspring and were more likely to sire offspring in their second year. Does the study question the dominant view that the function of sleep is to regenerate the brain? The researchers do not wish to go that far, although the findings clearly show that under certain circumstances animals may be able to evolve the ability to forgo, or postpone, large amounts of sleep while maintaining high neurobehavioral performance. Importantly, the finding that not every male does this, even when there are fertile females around, suggests that “Long sleeping males may lack genetic traits that enable short sleeping individuals to maintain high performance despite a lack of sleep”, argues Bart Kempenaers. The researchers believe that determining why only some males engage in this adaptive sleeplessness may provide insight into the evolution of this extreme behaviour, as well as the ongoing debate over the functions of sleep and its relationship to health and longevity in humans.

Contact
Prof. Dr. Bart Kempenaers
Max Planck Institute for Ornithology
Phone: +49 8157 932-334
Fax: +49 8157 932-400
Email: b.kempenaers@­orn.mpg.de
Dr. Niels Rattenborg
Max Planck Institute for Ornithology
Phone: +49 8157 932-279
Email: rattenborg@­orn.mpg.de

Original publication
John A. Lesku, Niels C Rattenborg, Mihai Valcu, Alexei L. Vyssotski, Sylvia Kuhn, Franz Kuemmeth, Wolfgang Heidrich, Bart Kempenaers
Adaptive Sleep Loss in Polygynous Pectoral Sandpipers
Science, advance online publication August 9, 2012

Prof. Dr. Bart Kempenaers | Max-Planck-Institute
Further information:
http://www.mpg.de/5976385/sleeplessness_sandpipers

More articles from Life Sciences:

nachricht Newly designed molecule binds nitrogen
23.02.2018 | Julius-Maximilians-Universität Würzburg

nachricht Atomic Design by Water
23.02.2018 | Max-Planck-Institut für Eisenforschung GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>