Loss and deterioraton of indigenous habitat increasingly affect natural populations worldwide. As a result of these processes, new selection pressures are imposed upon organisms, increasing local extinction rates. Simultaneously, reduced movement among remnant patches lowers colonisation rates and affects demographic and genetic population parameters. Yet, organisms with comparable life histories often respond to habitat disturbance in various ways. Why so is a matter of great importance to evolutionists and conservationists alike.
To address the question what factors determine the persistence of species in fragmented habitats, an international team led by Belgian ecologist Luc Lens studied the relative impacts of forest deterioration and fragmentation on the persistence of eight forest-restricted bird species within 430 ha of rainforest remnants in south-east Kenya. Three species are endemic to the Taita Hills, which is part of the Eastern Arc biodiversity hotspot. Over the past decades, the indigenous forest has been reduced to 12 patches, of which only the three largest ones (94-179 ha) are inhabited by all study species. The nine other remnants are tiny (1-8 ha) and heavily disturbed, and host breeding populations of a subset of species only.
The researchers used data collected during six years of trapping, marking, and recapturing more than 3,000 birds to estimate species-specific ability to move among the forest remnants. To estimate stress tolerance, the team relied on earlier studies showing that when birds are under stress, bones in the hind limbs grow longer on one side than on the other. It was determined which species suffered the most stress by comparing measurements of modern birds to those of museum specimens captured when the forest was relatively undisturbed. Based on these estimates, it was shown that more mobile species occupied a higher proportion of patches than expected from their estimated stress sensitivity. Likewise, less sensitive species occupied a higher proportion of patches than predicted from their estimated level of mobility. Together, dispersal rate and change in asymmetry explained an astonishing 88% of the observed variation in patch occupancy between the eight study species.
Luc Lens | alfa
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The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.
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With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.
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For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.
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At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.
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Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.
K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...
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