In a paper published this week in the open access journal PLoS Biology, Thomas Alerstam, Mikael Rosen, and colleagues from the University of Lund in Sweden analyze the flight speeds of 138 bird species and overturn the general assumption that maximum flight speed of a species is solely determined by such rules. Flight speed doesn’t just depend on the size of the bird (mass and wing loading), but also reflects functional constraints and the evolutionary lineage of the species in question.
The authors argue that only empirical measurements of flight speeds enable you to evaluate how general such aerodynamic rules really are. They used tracking radar measurements of the cruising speeds of migrating birds (collected by themselves and others) to do the analysis and provide the comprehensive dataset with the paper (e.g. this contains the flight speed of approximately one-third of all European bird species). Their analysis reveals that the difference between the speed of small and large birds is not as great as expected; they suggest that this surprising result is likely to be the result of disadvantages associated with very slow speeds among smaller birds and with very fast speeds for larger birds. They also show that the evolutionary history of the species helps explain much of the variation in flight speed: species of the same group tend to fly at similar characteristic speeds. For example, birds of prey and herons had slow flight speeds, on average, given their mass and wing loading, whereas the average speed for songbirds and shorebirds was faster than would be predicted.
This study suggests that there are different functional adaptations affecting flight differently among different types of bird, and that there exists a diversity of cruising flight characteristics among birds that remain to be explored and understood.
Natalie Bouaravong | EurekAlert!
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22.09.2017 | Max-Planck-Institut für Biochemie
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
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Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
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For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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