Saber-Toothed Cats In California Were Not Driven To Extinction By Lack Of Food

Credit: Mauricio Anton Citation: DeSantis LRG, Schubert BW, Scott JR, Ungar PS (2012) Implications of Diet for the Extinction of Saber-Toothed Cats and American Lions. PLoS ONE 7(12): e52453. doi:10.1371/journal.pone.0052453
When prey is scarce, large carnivores may gnaw prey to the bone, wearing their teeth down in the process. A new analysis of the teeth of saber-toothed cats and American lions reveals that they did not resort to this behavior just before extinction, suggesting that lack of prey was probably not the main reason these large cats became extinct. The results, published December 26 in the open access journal PLOS ONE by Larisa DeSantis of Vanderbilt University and colleagues, compares tooth wear patterns from the fossil cats that roamed California 12,000 to 30,000 years ago. Sabertoothed cats were not limited by food in California during the late Pleistocene. The saber-toothed cat and American lion were among the largest terrestrial carnivores that lived during their time, and went extinct along with other large animals approximately 12,000 years ago. Previous studies have suggested many reasons for this extinction, including a changing climate, human activity and competition from humans and other animals for food, which may have grown scarce as a result of these changes. In the current study, the authors found that saber-toothed cats likely consumed carcass bones regularly, but found no differences in bone consumption between older fossils and more recent ones. Based on this, they suggest that the cats' diet did not change significantly near the time they became extinct. In contrast, American lions did not consume much bone even near extinction, and had tooth-wear patterns similar to cheetahs, who actively avoid bone in their prey. "Tooth wear patterns suggest that these cats were not desperately consuming entire carcasses, as was expected, and instead seemed to be living the 'good life' during the late Pleistocene, at least up until the very end," says DeSantis. The study reveals previously unknown differences in the food habits of saber-toothed cats and American lions, and also suggests that though the case of their extinction is still unknown, a lack of food was probably not the main reason. Citation: DeSantis LRG, Schubert BW, Scott JR, Ungar PS (2012) Implications of Diet for the Extinction of Saber-Toothed Cats and American Lions. PLoS ONE 7(12): e52453. doi:10.1371/journal.pone.0052453, Contacts : Jyoti Madhusoodanan, Public Library of Science, Source: Nano Patents And Innovations, Source: Image
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2012 Top Ten Most View Posts On Daily Protein Science

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Black Tiger Beautiful Tailed.

Melanistic or black tigers have tawny, yellow or white stripes on a black ground color. In October 1992, the skin of a melanistic tiger was recovered from smugglers at Tis Hazari. The skin measured eight and a half feetand was displayed at the National Museum of Natural History, New Delhi in February of 1993 (Kumar, 1993). The existence of black tigers without stripes has been reported, but has never been substantiated by specimens or photographs. Eating: Over much of the tiger’s broad geographic range, wild pig, wild cattle and several species of deer are its major prey. All prey are forest or grassland ungulates that range in size from 65 to 2,000 pounds (30-900 kg). Typically, wild tigers gorge themselves on fresh kills, and can eat as much as 40 pounds (18 kg) of meat at one time. The tiger will not eat again for several days. Hunting: Black Tigers are ambush hunters, stalking their prey, approaching as closely as possible, and then charging the animal from behind. They usually bite the neck or throat of their prey. The neck-bite, which severs the spinal cord, is typically used on small or medium sized prey, while the throat bite, which causes suffocation, is used on larger animals. Following mating, the gestation period for tigers is approximately 103 days. The male tiger does not stay with the female after mating, and does
not participate in raising the cubs. The average litter size of tigers is two or three cubs (the largest is five). One usually dies at birth. Tiger cubs are born blind and weigh only about two to three pounds (1 kg), depending on  the  subspecies.  They  live on their mother’s milk for six to eight weeks before the female begin making their own kills at about 18 months of age. Young tigers leave their mother’s range at anywhere from a year and a half to three years of age, depending on whether the mother has another litter. Females tend to stay closer to the mother’s range than males. Social Behavior: Adult tigers are solitary animals that establish their territories in areas with enough prey, cover and water to support them. The difficulty of locating prey in tiger habitat makes it more efficient for tigers to hunt alone. As a result, they do not tend to form social groups like lions. The territory of a tiger usually ranges in size from about 10 to 30 square miles (26-78 sq. km), although the territory of a Siberian tiger may be as large as 120 square miles (310 sq. km). The size of a tiger’s territory depends on the amount of prey available. Tiger territories are not exclusive. Several tigers may follow the same trails at different times, and a male’s territory usually overlaps those of several females. Source: Animal Discovery
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Jaguar And Puma Kings Tiger

Jaguar, Alert The jaguar and the puma are sympatric throughout the jaguar’s distribution in the Neotropics. Several studies have been conducted on these two species, but few have examined the ecological interactions between them. Trophic separation has frequently been studied, but only two studies have considered variables other than diet.The goal of this study was to identify the ecological and behavioural factors that mediate the coexistence of jaguar and puma in a mosaic landscape in the Venezuelan llanos. An understanding of these mechanisms is critical to the development of conservation and management plans for these two predators in an areawhere both are threatened by loss of preferred prey and by persecution for depredation on livestock. This study was carried out in the llanos of west-central Venezuela from January 1997 to November 1998. It was a continuation of a study initiated in 1996 by Farrell (Farrell,1999) and for that reason part of her data are included. Hato Pi˜nero, the study site, is located in the southeastern corner of the state of Cojedes (8◦40–9◦00N,68◦00–68◦18W). Pi˜nero’s 80 000 ha support both aworking ranch of 10 000 cattle, and a thriving ecotourism business. Average annual precipitation between 1961 and 1965 was 1469 mm, with 86% of the rain falling between May and October. During the rainy season up to 80% of the ranch is flooded, with water depths ranging from a few cm to 1.5m, and the workable study area is reduced to about 30 000 ha. During the wet season, the average low temperature is 19.8 ◦C, and the average high temperature is 31.8 ◦C. In the dry season, the average low temperature is 17.9 ◦C, and the average high temperature is 34.6 ◦C. The topography on the ranch includes permanentrivers, temporary creeks (semi-permanent, seasonally drying water bodies), grassland or open pasture, savanna woodland, non-flooded evergreen forest and dry forested uplands. The ratio of open to forested areas is roughly 50 : 50. While many of Pi˜nero’s streams are bordered by forests, relatively large areas of semi deciduous forest are not adjacent to streams. In general, the landscape can be characterized as a complexmosaic of interdigitated  forests and open areas with vegetation types based on interactions of elevation, substrate and hydrology. Prey diversity and abundance vary greatly across the landscape. Overall, prey diversity declined as elevation increased and was lower in savannas than forests. During the wet season, prey species seemed to become more dispersed within large annual use areas, making use of more dispersed resources, less surfacewater constraints and the phenology of favoured plant foods. Dietary habits of puma and jaguar were determined from scats and kills. Scatswere collected opportunistically from trails and roads and the identity of the predator was assigned by the presence of tracks. Scats were air dried and stored until analysed. Prey contents of the collected scats were visually identified to the lowest taxa possible by examination of teeth and/or hair scale pattern by comparing them to a reference collection. Carcasses of prey animals were located by tracking the radio-tagged cats and from the presence of scavengers and predator sign. If the predatorwas unknown, ancillary evidence such as tracks, scats, teeth marks, type of killing injury, feeding method and caching behaviour was examined to identify the predator involved. Where the identity of the predator that left the scat or made the kill was unknown, these data were excluded from the analysis. In addition to the species of prey killed, records were made of age-class, based on the descriptions given by Ojasti for capybara, and by Dimmick & Pelton for peccary and white-tailed deer.a Source: Animaldiscovery-chanel, Image: flickr.com
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Now, 'Cheetah' robot that runs faster than Usain Bolt


A Pentagon-funded robot 'Cheetah' has clocked 45.5 kilometres per hour to beat the record of the fastest sprinter, Usain Bolt. Jamaican runner Bolt's current record of 44.7 kilometres per hour is the fastest a man has ever run, 'the Telegraph' reported. The Cheetah, a quadrupedal machine built by Boston Dynamics and backed by Darpa, the US Defence Department's research division, not only topped the Olympic 100m and 200m champion's record-setting time, it also beat its previous top speed of 29 kilometres per hour, set just six months ago. However, the robot's developers qualified the achievement. "To be fair, keep in mind that the Cheetah robot runs on a treadmill without wind drag and has an off-board power supply that it does not carry. So Bolt is still the superior athlete," Boston Dynamics said. "Our real goal is to create a robot that moves freely outdoors while it runs fast. "We are building an outdoor version that we call Wildcat, that should be ready for testing early next year," Dr Alfred Rizzi, the head of Cheetah programme, said in a statement. Cheetah, according to the US Defence Department, is being developed for use on terrain where conventional wheels and tracks would struggle and will "contribute to emergency response, humanitarian assistance and other defence missions.Image Link Photobucket, "Source: Indian Express
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