#Gazelles: Facts & Pictures Gazelles are thin graceful antelopes that live in Africa and Asia. They resemble deer
and are in the same family as goats cattle and sheep. Gazelles can be identified by their curved ringed horns tan or reddish-brown coats and white rumps.
Often there are spots or stripes on their coats. Their light frames help make them agile and better able to escape from predators.
There are 19 species of gazelle according to the Integrated Taxonomic Information system (ITIS. Smaller species such as the Speke's gazelle and Thomson's gazelle are only 20 to 43 inches (51 to 109 centimeters) at the shoulder.
They weigh from 26 to 165 pounds (12 to 75 kilograms. The dama gazelle is the largest gazelle.
It weighs in at 88 to 165 pounds (40 to 75 kg) and is 4. 5 to 5. 5 feet tall (137 to 168 cm).
Most gazelles live in the hot dry savannas and deserts of Africa and Asia. To stay hydrated in these grueling environments gazelles shrink their heart
and liver according to a study published in the journal Physiological and Biochemical Zoology. Breathing can cause an animal to lose a lot of water.
A smaller heart and liver need less oxygen so the animal can breathe less and lose less water.
The Edmi gazelle also known as the Cuvier's gazelleis the only gazelle that lives in the mountains.
It migrates during the wintertime to warmer regions. Gazelles rely on their speed to escape from predators.
Gazelles can reach speeds up to 60 mph in short bursts and sustain speeds of 30 to 40 mph.
When running gazelles use a bounding leap called pronking or stotting which involves stiffly springing into the air with all four feet.
These animals are highly social. Some gazelle herds have as many as 700 members though some herds are segregated small
so that the newborn fawns will have plenty to drink. Gazelles carry their young for around six months before giving birth.
Baby gazelles are called fawns or calves. To keep her calves safe from predators a female gazelle will hide her babies in tall grasses.
While the young are still nursing they stay with their mother's herd. When they are ready to fend for themselves male calves are moved to the male herd.
Gazelles are herbivores. This means they only eat vegetation typically grasses leaves and shoots of plants.
The dama gazelle is not only the world's biggest gazelle it is also the rarest according to the Smithsonian National Zoological Park.
A gazelle will flick its tails or stomp its feet to warn others of a lurking predator.
The horns of the Edmi gazelle can grow to 14 inches (35.5 centimeters) long. Goitered gazelles get their name from the large bump on their throats.
and his colleagues collected data on the environmental costs per calorie of dairy poultry pork eggs and beef foods that account for 96 percent of the calories Americans get from animals.
Compared to plants nonbeef animals require an average of six times as much land half as much irrigation water two times as much greenhouse-gas emissions and three times as much fertilizer use.
and fertilizer needed to grow food for the animals. For instance the researchers based greenhouse-gas emissions on methane associated with the animals'flatulence
and manure and pollutants associated with the tractors and fertilizer production. Other studies have identified beef as a major drain on environmental resources
When the water sinks it traps heat in the ocean depths. Ocean surface temperatures drive the current:
#The Surprising Reason Hummingbirds Love Sweets Nectar-slurping hummingbirds clearly have a taste for sweets
but they shouldn't. Like all other birds they lack sweet-taste receptors on their palates
However new research reveals why hummingbirds feast freely on nectar: At some point in their evolution the birds transformed a taste receptor that's typically used to detect savory
or umami flavors into one that's used to taste sweets instead. Hummingbirds are constantly wavering between a sugar rush and starvation.
Their metabolisms are hyperactive their hearts can beat 20 times a second and they often need to eat more than their body weight in food each day to stay alive.
Beautiful Hummingbirds of the World The small birds eat the occasional insect but they largely subsist on nectar from flowers
which is not a typical source of food for most other birds. As a result hummingbirds have been able to carve out a distinct environmental niche.
The birds can now be found throughout North and South america in habitats ranging from high-altitude mountains in the Andes to tropical rainforests
and they're quite diverse. They have split into more than 300 species in the estimated 42 million years
since they parted from their closest relative the insect-eating swift. Scientists have been puzzled by the fact that hummingbirds maintain such a sugary diet without a sweet-taste receptor.
For most mammals the sweet-taste receptor that responds to sugars in plant-based carbohydrates is made up of two proteins:
T1r2 and T1r3. The taste receptor that detects savory or umami flavors found in meat
But after the chicken genome was sequenced in 2004 researchers noticed the birds lacked the gene that encodes T1r2 a crucial component of the sweet-taste receptor.
This same pattern was seen in other bird genomes. If a species is missing one of those two parts then the species can't taste sweet at all said Maude Baldwin a doctoral student of evolutionary biology at Harvard university and one of the researchers on the study.
When scientists sequenced the genomes of cats lions tigers and cheetahs true carnivores that also don't have a taste for sweets#they found these species still have a nonfunctional pseudogene (a nonfunctional gene that's lost its protein-coding powers) for the sweet-taste receptor.
But in bird genomes scientists never even found a trace of a pseudogene for a sweet tooth Baldwin told Live Science.
To figure out what made hummingbirds like sweets despite their lack of the sweet-taste receptor Baldwin and colleagues cloned the genes for the T1r1-T1r3 taste receptors from omnivorous chickens insectivorous swifts and nectivorous hummingbirds.
The researchers then tested how the taste-receptor proteins produced by these genes reacted to different flavors in a cell culture.
For chickens and swifts the receptor had a strong reaction to the amino acids behind umami flavors.
The hummingbird receptor on the other hand was stimulated only weakly by umami flavors but it did responded strongly to the sweet flavors of carbs the researchers found.
Then to look for the molecular basis for this change in function Baldwin and colleagues made taste-receptor hybrids using different parts of the chicken and hummingbird receptors.
They found that by mutating the chicken receptor in 19 different places they could get it to respond to sweets
but the researchers suspect there are more mutations that contributed to the change in hummingbirds. Further research could eventually show where this change for hummingbirds arose in the evolutionary process
and how other nectivores like orioles and honeyeaters developed a taste for sweets. It's still not clear why birds lost their sweet receptor in the first place
but perhaps it was due to the loss of sweets in their diet. Birds are the descendants of carnivorous dinosaurs so maybe this gene was lost early on because of the diet of their ancestors Baldwin said.
That would be very cool but we're still not sure. The findings were detailed today (Aug 21) in the journal Science.
Follow Megan Gannon on Twitter and Google+.+Follow us@livescience Facebook& Google+.+Original article on Live Science o
Climate, Animals & Plants The Devonian period occurred from 416 million to 358 million years ago.
#although significant events also happened in the evolution of plants the first insects and other animals.
Reef ecosystems contained numerous brachiopods still numerous trilobites tabulate and horn corals. Placoderms (the armored fishes) underwent wide diversification
and became the dominant marine predators. Placoderms had simple jaws but not true teeth. Instead their mouths contained bony structures used to crush
or shear prey. Some Placoderms were up to 33 feet (10 meters) in length. Cartilaginous fish such as sharks and rays were common by the late Devonian.
Devonian strata also contain the first fossil ammonites. By the mid-Devonian the fossil record shows evidence that there were two new groups of fish that had true bones teeth swim bladders and gills.
The Ray-finned fish were the ancestors of most modern fish. Like modern fish their paired pelvic
and pectoral fins were supported by several long thin bones powered by muscles largely within the trunk.
The Lobe-finned fish were more common during the Devonian than the Ray fins but largely died out.
and pelvic fins articulating to the shoulder or pelvis by a single bone (humerus or femur)
which was powered by muscles within the fin itself. Some species were capable of breathing air through spiracles in the skull.
Lobe-finned fishes are accepted the ancestors of all tetrapods. Plants which had begun colonizing the land during the Silurian period continued to make evolutionary progress during the Devonian.
which was important for development of terrestrial animals. At the same time carbon dioxide (CO2) a greenhouse gas was depleted from earlier levels.
Arthropod fossils are concurrent with the earliest plant fossils of the Silurian. Millipedes centipedes and arachnids continued to diversify during the Devonian period.
The earliest known insect Rhyniella praecusor was a flightless hexapod with antennae and a segmented body.
Fossil Rhyniella are between 412 million and 391 million years old. Early tetrapods probably evolved from Lobe-finned fishes able to use their muscular fins to take advantage of the predator-free and food-rich environment of the new wetland ecosystems.
The earliest known tetrapod is Tiktaalik rosae. Dated from the mid-Devonian this fossil creature is considered to be the link between the lobe-finned fishes and early amphibians.
Tiktaalik was probably mostly aquatic walking#on the bottom of shallow water estuaries. It had a fishlike pelvis
but its hind limbs were larger and stronger than those in front suggesting it was able to propel itself outside of an aquatic environment.
It had a crocodile-like head a moveable neck and nostrils for breathing air. The close of the Devonian period is considered to be the second of the big five#mass extinction events of Earth s history.
Rather than a single event it is known to have had at least two prolonged episodes of species depletion and several shorter periods.
The Kellwasser Event of the late middle Devonian was largely responsible for the demise of the great coral reefs the jawless fishes and the trilobites.
The Hangeberg Event at the Devonian/Carboniferous Boundary killed the Placoderms and most of the early ammonites.
and animals were unaffected largely by these extinction events. Related v
#Belly Up to the Bamboo Buffet: Pandas vs. Horses This Behind the Scenes article was provided to Live Science in partnership with the National Science Foundation. 2014 is the year of Year of the Horse in China.
But pandas it turns out aren't celebrating. Why not? Because livestock particularly horses have been identified as a significant threat to panda survival.
The reason: Horses have been beating pandas to the bamboo buffet. Michigan State university (MSU) panda habitat experts revealed the oft-hidden yet significant conservation conflict between pandas and horses in a recent article in the Journal for Nature Conservation.
Across the world people are struggling to survive in the same areas as endangered animals
and often trouble surfaces in areas we aren't anticipating said Jianguo Jack Liu of MSU.
Creating and maintaining successful conservation policy means constantly looking for breakdowns in the system. In this case something as innocuous as a horse can be a big problem.
Pandas have specific habitat needs they live in gently sloping areas far from human populations. And they only eat bamboo.
Watch a panda bellying up to the bamboo buffet here. China invests billions to protect its panda habitat and conserve the 1600 remaining endangered supported by this habitat.
Panda in Wolong Nature Reserve eating lunch from CSIS at MSU on Vimeo. For years timber harvesting has been the panda's biggest threat.
But conservation programs limiting timber harvesting have chalked up wins in preserving panda habitat. Vanessa Hull a doctoral student at MSU's Center for Systems Integration and Sustainability (CSIS) has been living off and on for seven years in the Wolong Nature Reserve most recently tracking pandas that she has outfitted with GPS collars.
Over the years she started noticing that uninvited guests had apparently been serving themselves at the bamboo buffet
and they were eating like horses#literally. It didn't take particular panda expertise to know that something was amiss
when we'd come upon horse-affected bamboo patches. They were in the middle of nowhere and it looked like someone had been in there with a lawn mower Hull said.
Alarmed by the increasing devastation Hull learned that keeping a horses in this region serves a similar function as maintaining a bank account.
Because horses are prohibited from grazing in designated grazing areas to prevent them from competing for food with cattle some farmers have been letting horses graze unattended in forests.
When these horse-keeping farmers need cash they track down their horses in the forest and sell them.
Eventually some Wolong farmers though not traditionally horse-keepers learned from horse-keeping friends who lived outside of the reserve that they too could cash in by keeping horses
and letting them loose to graze unattended in Wolong. Where unfortunately they would compete for food with pandas.
Over time the popularity of this practice soared. In 1998 only 25 horses lived in Wolong.
By 2008 350 horses lived there in 20 to 30 herds. To understand the scope of the problem Hull
and her colleagues put the same type of GPS collars they were using to track pandas on one horse in each of four herds they studied.
Then over a year they compared the activity of the horses with that of three collared adult pandas in some of the same areas and combined resulting data with habitat data.
The researchers discovered that the galloping gourmets are indeed big on bamboo and are drawn to the same sunny gently sloped spots as pandas.
Pandas and horses eat about the same amount of bamboo but a herd of more than 20 horses created veritable feeding frenzies destroying areas that the reserve was established to protect.
The researchers presented their findings to Wolong's managers who have banned since horses from the reserve.
But Hull and Liu note that this work has shed light on how competitive livestock can be in sensitive habitat an issue that is duplicated across the globe.
Livestock affect most of the world's biodiversity hotspots Liu said. They make up 20 percent of all of the earth's land mammals
and therefore monopolize key resources needed to maintain the earth's fragile ecosystems. This research project received funding from the National Science Foundation.
Editor's Note: The researchers depicted in Behind the Scenes articles have been supported by the National Science Foundation the federal agency charged with funding basic research and education across all fields of science and engineering.
Any opinions findings and conclusions or recommendations expressed in this material are those of the author
and do not necessarily reflect the views of the National Science Foundation. See the Behind the Scenes Archive h
#The Poop on Pooping: 5 Misconceptions Explained Everyone does it. And many have developed a set of rituals and beliefs some false about the act of clearing one's bowels.
You might think that you know your stuff about poop but misconceptions are common. Here is the truth behind five common misconceptions about defecating.
Giardiasis an infection of Giardia parasites is one well-known cause of horrible-smelling poop. If you experience bad odor over a prolonged period
#Transparent Snails &'Fairy'Wasps: Top 10 New Species Revealed A fuzzy-faced tree-living carnivore a transparent snail
and ice-clinging anemones are among the top new species discovered in the last year.
The top 10 is designed to bring attention to the unsung heroes who are addressing the biodiversity crisis by working to complete an inventory of Earth's plants animals
and microbes Quentin Wheeler the president of the college said in a statement. Each year a small dedicated community of taxonomists and curators substantively improves our understanding of the diversity of life and the wondrous ways in
See Photos of the Top 10 New Species Beautiful beasties The species honored with a place on the top 10 list range from plant to animal to fungus.
Perhaps the cuddliest is the olinguito (Bassaricyon neblina) a mini-carnivore that lives in the trees of Andean cloud forests.
The animal had been known for decades and even shown in zoos but it wasn't until researchers did a thorough examination of the skulls of this creature
and its relatives that the scientists noticed they had a new species on their hands.
A closer look revealed sea anemones their bodies burrowed into the ice and tentacles extended to filter-feed from the water below.
The shrimp have translucent bodies and creep like inchworms along rocks in shallow tidal zones. Another top species the domed land snail looks like a slow-moving ghost:
Dragons fairies and giants oh my The list of top new species also includes some that seem to come out of a fairy tale.
The mother of dragons tree (actually known as Keweesak's Dragon tree) is a gorgeous 40-foot-tall (12 m) monster found in Thailand.
The tree has elongated leaves and creamy white flowers with orange filaments reminiscent of dragon fire. A world away but seemingly from the same tale is Tinkerbella nana an unbelievably small parasitoid wasp with feathery delicate wings.
The wasp measures only 0. 00984 inches (250 micrometers) long and is part of a family called fairyflies.
Tinkerbella nana comes from Costa rica. 5 Alien Parasites and Their Real-world Counterparts Rounding out the fairy tale triumvirate is a true giant at least for a single-celled creature.
Spiculosiphon oceana an amoeboid protist is between 1. 5 and 2 inches (4 to 5 cm) tall
and builds a shell out of them then extends armlike appendages out to feed on tiny invertebrates. S. oceana like any respectable giant lives in a cave.
Finally Australia provides a home for the last new creature on the list the leaf-tailed gecko (Saltuarius eximius.
along with a new golden skink and a frog that live in boulder fields during a National geographic-sponsored expedition.
The nocturnal gecko has large eyes and slender limbs and lurks on rocks and trees during its nighttime hunts.
The low-pressure system that looks to be aiming for the region this week is really a different animal#Mcmanus said
#Plan to Build'CSI Elephant'Uses DNA Forensics to Track Poachers (Op-Ed) This article was published originally at The Conversation.
The shocking news that Satao the much-loved African elephant who lvied in Kenya s Tsavo East National park has been killed
and butchered for his tusks highlights once again the terrible and unsustainable toll of poaching elephants for their ivory.
and trace the origins of seized ivory providing the means to tackle enforcement problems in the country where the animal was killed rather than just the point where the attempt was made to smuggle it out of the continent.
Satao s death is just one among the many thousands of elephants killed each year. The Monitoring the Illegal Killing of Elephants programme part of the Convention on the International Trade in Endangered Species of Flora
and Fauna (CITES) set up as part of the worldwide ban in 1989 reported that 22000 African elephants were killed illegally by poachers in 2012 based on data from 27 countries across Africa.
The figures for 2013 reported this month show a toll of over 20000 African elephants the vast majority of seizures by customs
or border officials being made in Tanzania Kenya and Uganda. The CITES report reveals that while the numbers of elephants poached appears to have stabilised among large seizures of more than 500kg the number of tusks found in each seizure is rising.
This suggests two things: that there are fewer elephants to poach and that the trade is organised well and not the work of individual poachers or small groups.
This level of slaughter far exceeds the reproductive potential of the remaining elephants and will by any account lead to the extinction of the African elephant in many parts of the continent.
The international community is only now responding to this crisis for the African elephant with action.
Knowing which populations the poachers are targeting can play an important part. Work pioneered by Professor Sam Wasser at the University of Washington uses DNA profiling from seized ivory to trace it back to the geographical location within Africa from which the ivory was taken once roamed.
There are two species of elephant in Africa the savanna elephant (Loxodonta africana) and the forest elephant (Loxodonta cyclotis.
Within these two species are many subpopulations such as extended family groups where there is a greater sharing of DNA types due to inheritance from common ancestors.
Under CITES there is a total ban on the trade in elephant ivory although not from all other species that have ivory nor from tusks removed from mammoths being extinct they cannot be provided any legal protection.
The cost of mammoth ivory is approximately US$350 per kilogramme significantly cheaper than elephant ivory but often looks very similar.
Again DNA typing can distinguish between African and Asian elephants and mammoths. This aspect of wildlife forensic science is supported by the United nations Office for Drugs
and Crime and has already proved highly successful in tracking seizures and locating their source.
For example when a 6. 5 tonne shipment was seized in Singapore DNA testing revealed it had come from elephant populations in Zambia.
If nations wish to save the African elephant then action to provide and fund the tools necessary is required.
And as ivory becomes rare due to the alarming decrease in elephant numbers the concurrent increase in value will put ever more pressure on the dwindling elephant populations.
so they too are able to endure disturbances like fire insects disease and climate change.
#Lemur Lady Campaigns for Endangered Lemurs This Sciencelives article was provided to Live Science in partnership with the National Science Foundation.
A serendipitous encounter between Patricia Wright then a social worker and an owl monkey in a New york city pet store in 1968 ultimately inspired Wright to reinvent herself eventually becoming an award-winning Ph d. scientist
and conservationist devoted to saving lemurs. Lemurs are a primate found naturally only in Madagascar the world s fourth largest island located about 250 miles off the coast of southern Africa.
One of the World s Most Endangered Primates In 2012 the International Union for the Conservation of Nature described 91 percent of the 103 known species and subspecies of lemurs as threatened with extinction;
this is one of the highest levels of threat ever recorded for a group of mammals.
Because of Madagascar s island isolation most of its plant and animal species are found nowhere else in the world.
Multifaceted Approaches A professor at Stony Brook University Wright approaches to saving Madagascar s lemurs and their forest habitat involves combining science and conservation.
and 12 lemur species. In addition Wright is the founder of the Centre Valbio Research Station located on the edge of the Park.
Owl Monkeys Are Caring Fathers Too Wright partners with Malagasy villagers to develop conservation strategies that are scientifically sound
Three days later Wright#ccompanied by several lemurs#ang the New york stock exchange s Closing Bell. Along with gaggles of jumping and leaping lemurs#right is featured in the new IMAX film Island of Lemurs:
Madagascar which is currently playing throughout the U s. Also Wright recently described her early research on owl monkeys
and adventures in South american rain forests in High Moon Over the Amazon: My Quest to Understand the Monkeys of the Night (Lantern Books:
2013). ) Name: Patricia Wrightinstitution: Stony Brook Universityfield of Study: Anthropology primatology conservation Editor's Note:
<a href=http://www. livescience. com/44171-society-civilization-collapse-study. html target=blank>Society Is doomed Scientists Claim</a p><p>Like camels of the sea a species
of sea snake goes without a drink for months on end gradually dehydrating before refueling with freshwater
</p><p>Perhaps six or seven months of the year these snakes are living thirsty said Coleman Sheehy III an evolutionary biologist at the University of Florida
<a href=http://www. livescience. com/44190-sea-snakes-dehydrate. html target=blank>Camels of the Ocean:
Sea snake Dehydrates for Months</a p><p>A 3000-year-old skeleton from a conquered territory of ancient Egypt is now the earliest known complete example of a person with malignant cancer spreading from an organ findings
</p><p>When scientists account for the world's carbon dioxide their totals suggest some of the greenhouse gas disappears into land-based carbon traps.
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