Scientists of the Max Planck Institute for Ornithology have now shown that permanent night lighting alters the reproductive behaviour of birds. In those habitats that are affected by artificial light males started to sing earlier and females advanced the onset of breeding activities. Moreover, males occupying territories with street lights had a higher number of extra-pair mates than males living in the dark forest.
Artificial light at night has fatal consequences for many nocturnal animals. Millions of insects, for example, die each year through the attraction to street lamps. Migratory birds get distracted by artificial night light, and consequently, go astray and even crash into illuminated high-rise buildings. Although artificial light has not always such fatal impact, it nevertheless can have a substantial influence on an animal’s life. This problem was investigated by Bart Kempenaers and colleagues from the Max Planck Institute for Ornithology in Seewiesen in five species of songbirds. They studied the effect of street lighting at the outskirts of forest habitat on the song behaviour of male birds. Indeed, males from four out of five species started to sing earlier in the morning than males that lived in locations without artificial night light. This effect was most pronounced for those species known to engage in early dawn singing. For example, male robins living near street lights started singing on average 80 minutes earlier than their conspecifics sleeping in the dark.
The researchers were not only interested in the relationship between night lighting and song behaviour but also whether artificial light explicitly influenced the bird’s reproductive behaviour. Over seven consecutive years they monitored breeding activities in a population of blue tits. Those females that lived near artificial light started egg-laying on average one and a half days earlier than females in territories without street lights or in central forest territories. “Females that start to lay earlier usually produce more eggs. They are often in a better physical condition than those that start laying later in the season”, explains Bart Kempenaers, director in Seewiesen. “However, females that advance breeding due to the artificial light do not, overall, lay more eggs”. Earlier egg laying could be disadvantageous for the offspring if they hatch outside the peak of food availability.
Artificial night lighting had a strong effect on the reproductive success of male blue tits: The scientists found that males living in forest outskirts exposed to street lights were twice as successful in obtaining extra-pair mates than their neighbours in the darker areas within the forest. This effect was most pronounced in yearling males that are usually not very successful in siring extra-pair offspring. Under the influence of artificial light, those males sired almost as many extra-pair offspring as older males in dark habitats. “Most likely early dawn song represents a signal for the females to estimate male quality”, argues Bart Kempenaers. Thus, light pollution potentially leads to maladaptive mate-choice decisions in relation to the quality of extra-pair partners. However, whether the early singing, the early egg laying and the altered extra-pair mating behaviour have consequences for survival and fitness of the adults and their offspring remains to be investigated.Original work:
Current Biology, published online September 16th, 2010
Dr. Sabine Spehn | Max-Planck-Institut
Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute
Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy