Friday, 17 November 2017

Tracking collars uncover the secrets of baboons' raiding tactics

Date:  November 8, 2017
Source:  Swansea University

New research shows how canny baboons in Cape Town use a sit-and-wait tactic before raiding people's homes in search of food.

Scientists from Swansea University are part of an international team who have revealed how canny baboons in Cape Town, South Africa, use a sit-and-wait tactic before raiding people's homes in search of food.

"Raiding baboons are a real challenge in the Cape Peninsula, South Africa. The baboons enter properties to raid in gardens and bins, but also enter homes and sometimes take food directly from people," said Professor Justin O'Riain, Director of the Institute for Communities and Wildlife in Africa at the University of Cape Town, and co-author on the study published by Scientific Reports.

In a previous study, the team showed that whilst Cape Town's baboon management strategy was keeping baboons away from the urban space, some males were still finding ways in. The team therefore built bespoke baboon tracking collars allowing them track the movements and activity levels of 10 males via GPS and accelerometer sensors.

Dr Gaëlle Fehlmann, lead author of the study, said: "People assume the baboons don't have enough food in their natural habitats and therefore have no choice but to forage in town. In fact, our research shows there is plenty of food in the natural environment where there is very little risk of the baboons being disturbed by anyone. In contrast, the chances of human-baboon conflicts in urban areas are high, but so are the food rewards, which are 10 times richer in terms of calories."

The pros and cons of large ears

Date:  November 10, 2017
Source:  Lund University

Researchers have compared how much energy bats use when flying, depending on whether they have large or small ears.

Large ears increase air resistance, meaning that long-eared bats are forced to expend more energy than species with small ears. On the plus side, large ears generate more lift and provide better hearing.

Good hearing is a prerequisite for bats' ability to echolocate, i.e. sense the echo of the sound waves they emit in order to locate and home in on their prey.

The research results therefore show that large ears have both pros and cons. Christoffer Johansson Westheim, senior lecturer at Lund University, believes that evolution has made a compromise.

"The crux is being able to fly as efficiently as possible while also having optimal echolocation ability. Bats can't be the best at both these things at the same time," he says.

The research findings also support the hypothesis that birds migrate to a greater extent than bats, and over longer distances, because bats' ears create resistance that makes flying more energy-intensive.

In Your Face! Male Crabs Gloat with 'Victory Dance'

By Mindy Weisberger, Senior Writer | November 11, 2017 08:50am ET

Some male animals are known for busting a move in elaborate mating dances to woo prospective mates. But some crab males perform a special dance for the males they've just defeated in combat, to discourage them from coming back for more, according to a new study.

Scientists had previously observed that after two male crabs tussled over a female, the victor would perform a type of "dance move" directed toward the defeated male, rather than toward the female. They suspected the motion was meant intimidate the crab that had lost the fight, but they did not know for sure.

Recently, researchers put that idea to the test with observations of Perisesarma eumolpe, a colorful type of mangrove crab native to southeast Asia. They analyzed how rivals responded to dances, and noted that when a victorious crab performed a taunting strut, the loser was more likely to slink away in defeat. [Strange Love: 10 Animals with Truly Weird Courtship Rituals]

The Story Behind That Viral Photo of a Lonely Rhino

By Stephanie Pappas, Live Science Contributor | November 10, 2017 04:02pm ET

Want to know what extinction looks like? This is the last male Northern White Rhino. The Last. Nevermore

The tweet went viral on Nov. 6: a photo of a lone rhinoceros, resting with its chin on the dusty ground of a wooden enclosure. Accompanying the photo, the caption read, "Want to know what extinction looks like? This is the last male Northern White Rhino. The Last. Nevermore."

The photo struck a chord, though the rhino in it has been the last of his kind for years now. The second-to-last male northern white rhino (Ceratotherium simum cottoni), Angalifu, died at the San Diego Zoo in December 2014. That left a single male, Sudan, shown in the viral photograph, who turns 44 this year and is very unlikely to produce any more offspring.

Sudan's story may not be new, but the stark framing of the tweet by biologist and activist Daniel Schneider earned the lonely male more than 44,000 retweets and 1,700 replies. Unfortunately, it will take more than awareness to save northern white rhinos from extinction. At this point, it may take a technological miracle. [In Photos: The Last 5 Northern White Rhinos]

Watch a monkey floss its teeth with a bird feather

10 November 2017

By Richa Malhotra

Monkeys living on an island have learned to use a startling variety of tools and techniques to obtain the juicy innards of different foods – and to floss their teeth afterwards.

The Nicobar long-tailed macaque (Macaca fascicularis umbrosus) is only found on three islands in the eastern Indian Ocean. One of them is Great Nicobar Island.

To find out about the macaques’ eating habits, Honnavalli Kumara at the Sálim Ali Centre for Ornithology and Natural History in Coimbatore, India, and colleagues followed 20 around a small coastal village on the island.

Will use anything
Many of the macaques’ favoured foods are thorny, slimy, hairy or mucky. To get rid of these inedible coatings, the macaques either wash the foods in puddles or wrap them in leaves and rub them clean. They also wrap leaves around certain foods to make them easier to hold. Trash like paper, cloth or plastic is also used for wrapping and wiping foods.

The macaques eat coconuts too, plucking them from the tree by twisting them around or using their teeth to cut them off. If it is tender, the macaques de-husk the coconut using their teeth, holding it down with their feet and hands, in order to get to the water and juicy bits inside.

If the coconut is ripe, however, they also have to crack its shell. To do so, they take it to a hard surface like a rock or concrete, and pound it.

It’s not just tool use. The macaques were seen beating bushes with their hands to disturb insects hiding within, catching those that fly out or drop to the ground.

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