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Science Friday: Persistence Hunting in the Kalahari Desert | Neolithic Hunting Zone in Syria | Raptor Hunted by Night


"Persistence hunting" - running down antelope

    The incomparable David Attenborough narrates this 7-minute segment from the BBC's Life of Mammals series. It documents how a man can chase a kudu for 8 hours until the animal collapses from exhaustion. A very thought-provoking and touching video.



Ancient gazelle "killing zones" documented in Syria

    It was slaughter on a huge scale. Hundreds of migrating gazelles would be funnelled into enclosures where they could be butchered en masse.

    It has long been suspected that the enigmatic stone structures that dot the Syrian landscape were involved in harvesting gazelles. Built perhaps as far back as 10,000 years ago, these structures display converging pairs of low stone walls.

    When British air force pilots first flew over them in the early 20th Century, they dubbed them "desert kites" because of their characteristic appearance from the air...

    Drs Bar-Oz, Melinda Zeder and Frank Hole describe in PNAS the discovery of a large deposit of gazelle bones at the site of Tell Kuran, near the town of Hasseke in the Khabur Basin. This killing pit is very close to a number of desert kites and contains thousands of gazelle parts. "It is manifest that these remains are from a catastrophic hunting episode - a full herd was killed," said Dr Bar-Oz...

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Velociraptor hunted by night

    As dramatic fossils go, it’s hard to beat the Mongolian fighting dinosaurs – a Velociraptor and a Protoceratops locked in mortal combat. The Protoceratops, an early horned dinosaur, has the raptor’s arm in its mouth, and the raptor appears to be kicking its prey in the neck. The two combatants were killed in this pose, around 75 million years ago. And according to a new study, they probably met and died sometime around dawn or dusk.

    Most dinosaur reconstructions portray the animals walking about in bright sunlight but of course, we know that living animals are active at all times of the day. The diurnal ones prefer the daylight hours, while nocturnal species haunt the night. Crepuscular animals favour twilight hours, while cathemeral ones are active in short bursts throughout the day.

    It’s easy enough to work out which group a living animal falls into, but the task becomes far more difficult if the animal in question is extinct. With the exception of tracks, burrows or other trace fossils, behaviour doesn’t fossilise easily. But Lars Schmitz and Ryosuke Motani have developed a clever way of working out when dinosaurs were active, using something we have in abundance – their skulls.

    The eyes of all birds and many reptiles are reinforced by a bony disc called a scleral ring (which you can clearly see in my photo of Deinonychus above). The form of these rings closely follows their function. In nocturnal animals, the ring has a wide hole to let in as much light as possible. In diurnal species, the ring is thicker and has a narrower hole. That gives them sharper vision (think about how your focus gets better when you squint) without overloading the retina. Crepuscular or cathemeral species have rings that are somewhere in between, but they also tend to have larger-than-average eyes for their body size.

    Schmitz and Motani developed a new model that takes the size of an animal’s scleral ring and eye socket, and works out when it would have been active. The model also accounts for the evolutionary relationships between different species. The duo tested it using data from 164 living animals, and found that it could accurately predict their daily habits. Next, they used it to analyse the skulls of 23 dinosaurs, as well as 10 other extinct reptiles, including eight of the flying pterosaurs.

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more at the link

http://blogs.discovermagazine.com/notrocketscience/2011/04/14/dinosaurs-around-the-clock-or-how-we-know-velociraptor-hunted-by-night/