On the basis of calculations of energy use associated with traversing sloped terrain by such large animals, the researchers found that this behavior is likely related to the fact that even minor hills represent a considerable energy barrier for elephants because of the added calorie consumption required for such movements. The findings are reported by Fritz Vollrath of the University of Oxford and elephant experts Jake Wall and Iain Douglas-Hamilton of Save the Elephants, and appear in the July 25th issue of Current Biology, published by Cell Press.
Understanding the factors that determine locations of elephant density hot-spots and use corridors is critical in helping to secure safe niches for elephants in the face of growing human encroachment on elephants' native habitat. In their study of elephant movements, the authors focused on the Samburu/Isiolo/Laikipia districts in northern Kenya, which represent an area of about 32,000 square kilometers of mostly unprotected habitat. This range is home to about 5,400 elephants.
In the course of studying the influences of a range of environmental factors on elephant movement, the authors found that elephant density dropped off significantly with increasing hill slopes. While this effect may well involve such factors as risks of injury and overheating, or lack of water, the authors' calculations of the energy required for elephants to traverse sloped terrain indicate that the energetic costs of such movement could be a main factor influencing this behavioral tendency. For example, the authors calculate that climbing 100 meters would "burn" energy that would take an extra half hour of foraging to replace--or would need to be paid for by expenditure of body reserves. In light of their calculations, the authors point out in the paper that "clearly, climbing is something that an elephant should not do lightly, but should weigh very carefully."
On the basis of their findings, the authors suggest that large animals probably take a rather different view of their surroundings than do lightweight animals, and that this is probably especially true of heavyweight animals, like elephants, that are herbivores, for whom energy replenishment can be especially time consuming.
A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
Value from wastewater
16.08.2017 | Hochschule Landshut
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
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21.08.2017 | Materials Sciences
21.08.2017 | Health and Medicine
21.08.2017 | Materials Sciences