The Sumatran rhinoceros began its decline one million years ago

There were only an estimated 200 Sumatran rhinoceroses living in the wild by 2011, making this species one of the most endangered on the planet. After sequencing the first-ever genome of a Sumatran rhinoceros, an international team of researchers has found that the threat of extinction to this species began nearly one million years ago.

The new analysis suggests that Sumatran rhinoceroses have been endangered since around the middle of the Pleistocene. The researchers explain that this insight is useful in placing the current status of the species’ population into a broader ecological and evolutionary context.

“Our genome sequence data revealed that the Pleistocene was a roller-coaster ride for Sumatran rhinoceros populations,” said study co-author Herman Mays, Jr., of Marshall University.

By the end of the Pleistocene, many large mammals had suffered from the invasion of continental mammals into Southeast Asia, and from rising sea levels that swallowed much of mainland Asia. The Sumatran rhinoceros population peaked at the onset of the mammal invasion, approximately 900,000 years back.

“Their population bottomed out and never showed signs of recovery,” said Mays.

As their habitats were fragmented from rising sea levels, the Sumatran rhinoceros populations continued to shrink. Today, habitat loss and hunting are still putting pressure on the remainder of this species.

The researchers estimate that the Sumatran rhinoceros population peaked at an estimated effective population size of around 57,800 individuals about 950,000 years ago. According to the genome analysis, the effective population size was reduced to only about 700 Sumatran rhinos by 9,000 years ago.

The findings of the study indicate a major shift in the ancient climate, which reduced the genetic diversity of Sumatran rhinos and left them more susceptible to additional strain.

“The Sumatran rhinoceros species is hanging on by a thread,” said study co-author Terri Roth. “We need to do more to save it.”

The study is published in the journal Current Biology.

By Chrissy Sexton, Earth.com Staff Writer

Image Credit: Tom Uhlman

New species of Plesiosaurs survived mass extinction event

A newly unearthed skeleton is bringing unexpected information to light about marine reptiles known as plesiosaurs. Scientists have been examining what is thought to be the oldest known plesiosaur fossil, and have determined that these ancient reptiles may have emerged 50 million years earlier than previously realized.

Experts believe that the earliest plesiosaurs had advanced limbs that took to the water like wings in the air. Over 200 million years ago, the reptiles foraged in the open seas using “underwater flight” similar to that of sea turtles.

The remains provide the very first evidence that plesiosaurs existed in the Triassic period, dating back around 201 million years. The fossil was discovered by paleontologists from the University of Bonn in a clay pit outside of Bonenburg, Germany.

Study co-author Professor Martin Sander told MailOnline, “The beds from which the skeleton came from was dated by fossil shells and by a chemical signal as latest Triassic. I could not believe that there was a plesiosaur from the Triassic, given that these animals had been studied by paleontologist for nearly 300 years, and never was there one older than Jurassic.”

The new species was named Rhaeticosaurus mertensi by the research team. Plesiosaurs had smaller bodies with four pointed flippers and tiny heads on long necks. The new specimen was 7 feet 7 inches long, and growth marks in its bones suggested it was warm-blooded and young.

Professor Sander explained to MailOnline how the unique species of plesiosaurs may have dodged extinction at the end of the Triassic period.

“Plesiosaurs evolved warm-bloodedness, enabling them to live in the open ocean, removed from the bad environmental conditions that made life difficult in shallow, coastal waters at the end of the Triassic,” he said.

The study is published in the journal Science Advances.

By Chrissy Sexton, Earth.com Staff Writer

 

Earth.com exclusive: Hummingbirds appear where you’d least expect

A skylight above where I was working with dinosaur bone casts buzzed with movement. At first I assumed that an insect had strayed inside the workshop building with the summer breeze through the open doors. Looking closer I saw bright, metallic feathers. A hummingbird was flying desperately against the square of sun and sky set in glass above me. I looked around hoping to find a way to rescue the bird, not knowing exactly how to help. The hummingbird became more exhausted then I’ve ever seen another of his kind. The bird paused, sitting on the lip below the skylight, wings drooped and then flew against the glass, only to collapse again on his perch. I walked into the other room of the workshop and found an insect net leaning against the wall, undoubtedly to remove unwanted arthropods without killing them. Carefully I climbed up a ladder and quickly scooped the tiny bird into the net. I moved as fast as possible towards the door and opened the net outside, smiling as the hummingbird zipped away past the surrounding bushes.

Hummingbirds are a common sight in Western Colorado where I once lived but are easy to miss, zipping by before many notice them. I’m sure most Colorado residents would be greatly surprised to learn that as many as 12 species have been found in there state. Hummingbirds would surprise many by where they are and aren’t. Most people think of hummingbirds as exotic tropical animals but they’ve been found in every US State –except Hawaii. Hummingbirds.net reports 4 species for Alaska and only three species in New York. The New York Times reported the paradox of finding more hummingbirds in highly populated parts of New York, where city parks and potted plants attract them than in more rural areas.

Still, the tropics are great places to encounter hummingbirds. I first saw a hummingbird nest sewn with spider silk onto the back of a leaf by a female Hermit hummingbird in the lowland rainforest of Ecuador (subfamily Phaethornithinae). In Jamaica I sat in a bird reserve holding a tiny bottle of sugar water in my hand while the delicately feathered swallow tailed hummingbird (Trochilus Polytmus) ate from it. In the Bahamas while collecting data on parrots, I occasionally saw the buzzing rush of a passing Bahama Woodstar (Calliphlox evelynae).

Later Erin, my girlfriend, and I spent three months as volunteer managers at a nature reserve in Ecuador, where part of our duties was monitoring hummingbirds. Every day we sat by hummingbird feeders and tallied up the visitors. The first few days collecting data on hummingbirds was overwhelming. For the research we had to mark the number and sex of each hummingbird visiting the feeders hung on the porch. We were baffled; Is that a male Brown Violet Ear or a Female White Necked Jacobin? Time with the birds and checking ourselves against the bird books brought more knowledge and finally some confidence. Soon we could sit eating our eggs and toast, sipping coffee and eyeing visiting hummingbirds as if they were old friends. It was in Ecuador that I learned some peculiarities about hummingbirds, not only is there an enormous diversity of hummers, there are more species in the Andes than in the Amazon rainforest. This pattern of diversity is opposite of most other organisms in South America with some exceptions, including moss, which is most diverse in higher elevation cloud forests.

A visiting European professor told us with pride of an Andean hummingbird that drops its heartbeat into a slow torpor every night to survive the horrible cold of the montane environment. Male hummingbirds compete in lekking dances to compete for females but do nothing to help in rearing the young they spawn. Female hummingbirds with babies collect more insects and less nectar to provide proper nutrition for their chicks.

I’ve watched videos of the Sword-Billed Hummingbird feeding chicks, the chicks look like carnival sword swallowers. My own videos of hummingbirds have been disappointing. Photos are small, lacking the dynamic color of moving birds, disappointing. Even seeing a Hummingbird for long unaided in the wild is a rare treat, which is why feeders are so often used. A visiting biology student from Italy told us he liked everything at the reserve except the feeders; he had a point. An old manager’s journal entry told how previous managers had left the feeders unattended for two days because of a minor emergency. Upon return, the managers found the hummingbirds lethargic, hanging around the feeders but with less speed.

In the mornings, the hummingbirds, eager to be fed would dive bomb us. Flying close with angry needle sharp beaks, they threatened, demanding sugar water. The Yellowstone Grizzly Bears come to mind. In recent history the bears fed from dumps in Yellowstone National Park. The close association between food and humans in ursine minds made the bears a dangerous nuisance. Bears were shot. Tourists were mauled. Yellowstone no longer allows bear feeding or unguarded trash. But, hummingbirds aren’t bears.

Reaching the nature reserve required a hike through forest along a muddy trail that could collapse or dissolve in a heavy rain. Puddles were everywhere, logs and rocks were laid as stepping stones through standing water. Vines, fallen branches, palm fronds covered, blocked, framed the trail. On one hike we heard a buzz of sound. Next to the trail hovered a bird we knew from books but a bird that never visited the feeders. Long thin tail feathers flared out at the end. A male Booted Racquet-Tail danced in the dappled sunlight for a moment. The hummingbird zipped away and were left in the mud, smiling.

By Zach Fitzner, Earth.com Contributing Writer

New strategies for saving an endangered species

An international research group of Brazilian and American scientists has just published a unique study depicting a more focused strategy for monitoring the survival of endangered muriquis monkeys, which live in patches of forests in Brazil. Their study revolved around the “essential question” of what knowledge is needed to help preserve the muriquis. The study focused on identifying population trends and conservation priorities.

Currently, no more than 2,300 muriquis survive in the wild. The species are split into two groups, a northern and southern species. The northern species is believed to have fewer than 1,000 individuals. For the survival of the species, the researchers need an accurate picture of these two different populations. Furthermore, simply counting individuals or breeding pairs was not going to be enough to give an accurate view of the population, the researchers would need to monitor the health of the species as well.

“Population counts at particular sites and in total don’t require a big labor force,” says Karen Strier, a professor of anthropology at the University of Wisconsin – Madison and first author of the study. “But we are usually interested in other factors, such as genetic uniqueness or geographic importance: Could this site be used to make a corridor linking isolated populations to enhance genetic diversity?”

Increased monitoring should help answer more of these questions, according to the researchers. Strier also asserts that knowing the sex ratio and what proportion of females are pregnant – while more time consuming – helps them determine whether a population is growing or declining.

Strier, who has observed muriquis in Brazil for 35 years, calls them “the most amazing primates in the world. They have a very low rate of aggression, and have been called ‘hippie monkeys.’ Females are independent and promiscuous, males don’t dominate them, and there’s no real hierarchy among males or females. They spend a lot of time hugging and socializing.”

The researchers also point out that any population monitoring plans must take feasibility into account. For example, some locations may be impossible to access due to topography or ownership. Another factor important to monitoring decisions is sites that are on the fringe of a species’ habitat. Individuals that are outliers in terms of altitude or longitude may be the first to perish as climate changes. On the other hand, a relatively cool or under populated site in the present may become an important refuge as the climate warms in the future.

With both species of muriquis listed as critically endangered, interest in these primate species has been increasing. In fact, some private landowners are even establishing muriqui reserves. Muriquis are also benefiting from the recovery of landscapes that used to be farms and are now abandoned, with nature taking over again. “Seeing the resilience of nature makes me more determined than ever,” says Strier. “We can’t reverse past assaults to the planet, but we can do everything we can to stop them and give the animals and plants a chance to come back.”

These focused monitoring processes detailed in this study – published in the journal PLOS ONE – are seen by Strier as a foundation for a new generation of scientists. “If somebody wants to know how to promote muriqui preservation, this study would be a roadmap. It gives you an idea where to start, and where to focus. We hope it will also serve as a template for scientists concerned with other endangered animals.”

By Connor Ertz, Earth.com Staff Writer

Deforestation in the Amazon is lowering fish yields

When tropical forests are converted to land for agricultural use, the result is less rain, more droughts, and deteriorating freshwater ecosystems. And now, surprising new research reveals that the clearing of tropical forests can also lead to negative changes in fish production.

Study lead author Leandro Castello is an assistant professor of Fisheries at Virginia Tech‘s College of Natural Resources and Environment. The researchers set out to investigate how deforestation along the Amazon River impacts fish yields.

“The conflict between raising cattle and managing fisheries is a concern that is shared with floodplain residents, but there had been no rigorous studies of how loss of forest affects the productivity of floodplain fisheries,” explained study co-author David McGrath.

Approximately one-third of the world’s wild-caught fish yield comes from tropical regions, and fisheries are critical to this production. The conditions of the area of land adjacent to a river, known as a floodplain, have a major impact on the success of fisheries.

“Floodplain forests can provide structures that protect fish and their offspring, and provide habitat for insects that many fish rely on for food,” said Castello. “Those forests also produce plant material on which fish may also feed.”

Using a study area of 1,000 square kilometers, the researchers collected data on fisheries yields over a 12-year time period. The team also created a map of the region’s 1,500 lakes and interviewed local fishermen about fish caught in different areas. By combining this data, the experts determined which areas yielded the most fish.

“We collected roughly 36,000 separate data points that were plotted in order to make a map of where the fish were coming from,” said Castello.

Satellite images from NASA allowed the researchers to collect a second data set on habitat features in the study region to examine whether the presence of floodplain forests impacted fish yields.

“Essentially, we wanted to know if fish yields in areas with forested floodplains are greater, the same, or less than areas where forests have been cut down,” explained Castello.

“Our results indicated that lakes with floodplain forests provided fishers with greater fish yields,” he said. “This allows us to infer that if you cut down the forests, fish yields in those lakes would decrease. Tropical deforestation is not only a terrestrial issue – it can also decrease the number of fish available to some of the world’s poorest populations.”

The researchers will continue to investigate what other factors affect fisheries yields, but the indications of this particular study are clear.

“You have to protect these habitats if you want to maintain the food production and the income that rivers provide,” said Castello. “If we don’t protect these areas, we lose the rivers and we lose the fish.”

The study is published online in the journal Fish and Fisheries.

By Chrissy Sexton, Earth.com Staff Writer

Dogs understand humans better than we understand them

Pet owners often feel that their furry companions are like their children. According to a recent report, one of the number one motivations for millennials looking to buy a house is so they will have space for their dog.

Dogs are particularly sensitive to humans and with a loyal nature and seemingly perpetually wagging tail, it can be hard not to infantilize or anthropomorphize canine pets.

Now, new research has found that even though we love our pets like a member of the family, treating them like children can often lead to a misunderstanding of the dog’s natural behaviors and actions.

It turns out that dogs are much more tuned in to our emotions and moods, but as owners, humans are not nearly as proficient at reciprocating and understanding our dogs.

The research will be presented at the Royal Institution Christmas Lectures by Sophie Scott, a professor of cognitive neuroscience at University College London.

Scott’s findings show that dogs have much more emotional intelligence than we think, and our tendency to treat animals like children is detrimental to the animal’s sensibilities.

According to Scott, we do not view dogs the same way they view us. Research has found that to them, humans have a similar role as an alpha animal would in a hypothetical pack in the wild.

In an interview with the Times, Scott explained this divide in human-pet relations further by using recent studies where it was proven that dogs do not like to be hugged.

One such study was conducted by Stanley Coren, a psychology professor and canine expert from the University of British Columbia.

According to an article in the Telegraph, Coren analyzed images found on the internet of dogs being hugged looking for signs of distress such as avoiding eye contact, folding its ears away, or keeping its eyes closed.

Coren found a large majority of the photographs showed that dogs were under stress while being cuddled or hugged.

“The dogs really like being with their owners, they want to be with their owners, but they don’t want to be held. It provokes anxiety in them: as an animal, they want to be able to move freely,” Scott told the Times. “Dogs are great at reading us but we are pretty shocking at reading them.”

By Kay Vandette, Earth.com Staff Writer

Bringing Tasmanian tigers back from extinction

Scientists are one step closer to bringing back a long-extinct species known as the Tasmanian tiger, or thylacine.

Thylacines were officially pronounced extinct in 1986, although the last known thylacine died in 1936. Thylacines were a wholly unique species with distinct striped markings and a jaw that could open up to 120 degrees.

Tasmanian tigers went extinct for several reasons. Widespread hunting and even government compensation for every thylacine that was killed had the biggest hand in the animal’s downfall.

But now, a new study has found that the tasmanian tiger’s lack of genetic diversity would have been detrimental long before humans caused the animals went extinct.

The research was led by Andrew Pask, an associate professor at the University of Melbourne, and published in the journal Nature.

Pask’s team recently tested the DNA of an infant Tasmanian tiger that had been preserved in a jar and locked away in a museum. Genetic sequencing revealed that the species was already at odds with diversity and may have been doomed even before human interference.

“Even if we hadn’t hunted it to extinction, our analysis showed that the thylacine was in very poor [genetic] health,” Pask told NPR. “The population today would be very susceptible to diseases, and would not be very healthy.”

Interestingly enough, the Tasmanian government did finally step in and attempted to protect the species, but this was days before the last known Tasmanian tiger died from exposure at Hobart Zoo in 1936.

The discovery, while shedding light on the genetic makeup of a long-extinct species, could be the key to bringing back the Tasmanian tiger shortly via cloning.

“As this genome is one of the most complete for an extinct species, it is technically the first step in bringing the thylacine back,” Pask told The Daily Telegraph.

By Kay Vandette, Earth.com Staff Writer

LA construction workers find fossils of 10,000 year old creature

As workers dig an extension for the Los Angeles Metro subway, they are uncovering the fossilized remains of ancient animals. Some of these fossils, including a mammoth skull weighing hundreds of pounds, date back to the last Ice Age, which ended 10,000 years ago.

Dave Sotero is a spokesman for the Los Angeles County Metropolitan Transportation Authority (MTA). He explained that paleontologists have been present alongside construction workers for all of the subway digs in Los Angeles, starting back in the 1990s with the development of the city’s inaugural line.

“Our crews try to be as mindful as possible to help them do their jobs. We get out of their way,” said Sotero.

Construction on the Wilshire section of the subway, known as the Purple Line, began in 2014, and the first fossils were found two years later. Now, the fossils are appearing frequently, with discoveries including a mastodon tooth, camel foreleg, bison vertebrae, and a tooth and ankle bone from a horse.

The most exciting find, however, is the intact skull of a young Columbian mammoth. Paleontologist Ashley Leger is the field director for Cogstone Resource Management, the company hired to carry out the fossil excavations.

“They’re making sure that they’re recovering every single fossil that could possibly show up,” Leger said of her monitoring team. “They call me anytime things are large and we need to lead an excavation.”

About a year ago, Leger received a phone call that led to the best discovery of her career. Leger’s team member said to her, “It looks big.”

The fossil was first thought to be a partial elephant skull. But, after 15 hours of excavation, the team realized they had actually uncovered the enormous skull of a young mammoth.

“It’s an absolute dream come true for me,” said Leger. “It’s the one fossil you always want to find in your career.”

The skull, which weighs a few hundred pounds, is exceptionally rare because both of the tusks are still attached. The young Columbian mammoth was named Hayden, after Hollywood actress Hayden Panettiere.

Leger said that there is a lot to learn from the skull. Investigation of how this animal lived and died can give scientists insight into ancient environmental conditions and also into what the Earth’s climate will look like in the future.

“Every fossil fills a gap,” said Leger. “It tells a story of what came before us, and maybe what’s to come.”

Photo Credit: Associated Press

By Chrissy Sexton, Earth.com Staff Writer

Image Credit: Associated Press

Earth.com exclusive: The Canyon Tree Frogs of Bear’s Ears

When I was in high school, my environmental science class took a small voluntary field trip after dark. At night we hiked up rough sand stone canyons dotted with scattered pools of water. We jumped over trickles and scrambled around boulders. Flashlights cut through the darkness everywhere. We made an enormous ruckus. The canyon tree frogs were singing back at us that night too. Unsurprisingly we heard but didn’t see a frog. Canyon Tree Frogs became something mysterious to me after that night; something wild and hidden.

Years later, again on the Colorado National Monument, I was hiking through desert canyon country. I was half catching insects for a college entomology class, half hiking for pleasure. Stopping near an ephemeral desert pool, I watched carefully for water insects. There were darting water beetles beneath the surface, water striders dancing on the top. In the bottom of the pool was also a cluster of small, gooey eggs: frog eggs. In my mind the eggs became Canyon Tree Frog Eggs. I briefly contemplated taking the eggs home and raising them in an aquarium to satisfy my curiosity. I changed my mind though, it would be illegal to take the eggs and I doubted my ability to raise them. The eggs remained a mystery.

This fall my girlfriend Erin and I drove out to Bear’s Ears National Monument. Bear’s Ears is a beautiful piece of desert. Burnt red stone out of a thousand westerns lines the horizon, yellowish stone canyons yawn at your feet. The place feels remote, alien, yet familiar; a dream landscape. We drove for an hour on dirt roads, rutted and punctuated with rock. We parked next to two other vehicles. In one vehicle, a family was getting ready to depart. The man told of finding pottery sherds that he left in the canyon and wondered if we knew of petroglyphs. We didn’t. The man and his wife sipped beer, their young daughter enthused on their trip. The family left; they were the last people we saw for three days.

The hike we chose in Bear’s Ears was Dark Canyon. Remote, wild, rugged, the canyon was both the good and the painful part of freedom. Scrambling down a steep canyon wall covered in scree, we walked broken fragments of crumbling trail. We lost the trail, only to find a small cairn leading us on, into the canyon. Cactus were everywhere, the few junipers were blessings of shade.

The bottom of the canyon was a maze of boulders and shrubs in a dry streambed. We were happy to have descended to the bottom. I still have two bruised toe nails from scrambling down the canyon. We were tired of the madness of carrying our Shih Tzu down class 3 terrain and let her down to sniff around boulders and walk. The trail from the bottom to our campsite wasn’t long.

We slept on the sand beneath a cottonwood tree. We could hear the constant mutterings of a stream by our heads. I thought sometimes I heard snippets of conversation but it was always the stream. Hiking just a little uphill from the stream we became enveloped in eerie silence. The canyon forked, calling us in too many directions for one trip. We pondered the idea of a month spent in this lonely spot.

The first morning, I stumbled towards the stream, empty coffee pot in hand, ready for the morning ritual. By the stream rested a small, greyish amphibian. Before I could stop, the frog leapt and neatly splashed into the stream. The frog swam to the bottom of the clear water and stopped; hiding. I watched for a few minutes and the frog didn’t move. Frogs are adapted to spend long periods of time underwater. Amphibians can even absorb small amounts of oxygen from water through porous skin. I filled my coffee pot and went back to camp.

I wandered down a canyon, quiet, bright, beautiful, a land of shade and sun, sand and rock. I found the tiny fossils of Crinoids or Sea Lilies embedded in stone. Sea Lilies still live in oceans today. I marveled at the beautiful opalescent quality of the fossils and the age and power of the earth. Parts of Utah were once ocean; they may again be ocean one day.

Back at camp there were more frogs near the stream, I got a better look at them. The frogs had long delicate toes ending in rounded cups. Their eyes were bright; a greyish color matching the skin. The frog’s skin was dotted with red specks. I had a growing realization, I looked in our field guide to confirm; these were Canyon Tree Frogs. The frogs swam in the stream, or sat on the banks. We only saw them in the late afternoon or early morning. Canyon Tree Frogs are nocturnal.

Recently Donald Trump ordered Bear’s Ears National Monument reduced in size by 85%. The move could open up thousands of acres to mining, to oil and gas, to ranching. The move is a blow to Native American groups, to environmentalists and everyone who loves the outdoors. The Canyon Tree Frog is not endangered. I won’t tell you that Canyon Tree Frogs may hold the cure for cancer or how many mosquitoes they eat. Canyon Tree Frogs are rather ordinary, easily missed, a small, rather cute frog. Canyon Tree Frogs are precious. Other people will tell you of Native American ruins, and fossils, or rare plants and animals. All of these things are important, they all deserve a fight.   Why should you care about one frog? Isn’t the beauty of one frog worth a fight? What we stand to lose is mundane as well as magnificent. We may lose some artifacts. We may lose fossils or an endangered bird. We’ll also lose a lot of mundane things. We’ll lose the quiet sound of a stream alone in the desert. We may lose the desert smell of one juniper or the sticky taste of a piñon nut. We can lose a hundred small, insignificant individual animals. We may lose the croaking, splashing, swimming of half a dozen frogs in a remote desert canyon.

If we give Trump even the life of one frog or a hundred, we’ve given too much. We stand to lose so much more. Others will remember Bears Ears in their own way and fight for it. I will remember the Canyon Tree Frogs. I will take my own stand.

By Zach Fitzner, Earth.com Contributing Writer

Water removal from Colorado River putting fish species at risk

The Colorado River Delta used to be a historically low-salinity river system that consisted of the huge Colorado River, which flowed into the Northern Gulf of California. Due to the unique freshwater conditions, ecological species evolved and adapted to the low-salinity environment, and are distinct from closely related species in the saltier estuaries in other regions of the Gulf.

However, due to invasive agriculture and domestic activities consuming much of the Colorado River water, the river is now more similar in salinity to the other estuary systems in the Gulf of California. The nature and severity of the impact of this fresh-water loss on the ecosystem and fisheries of the Colorado Delta and Gulf of California is controversial.

A new study in the journal PeerJ finds that there are risks to the unique local biodiversity of the tidal portion of the Delta that were previously unknown. Researchers from the University of California, Los Angeles (UCLA) analyzed species of silverside fish in a genus that is only found in the Gulf of California.

One species, Colpichthys hubbsi, only lives in the Delta and is on the endangered species list due to its restricted range. Through genetic and morphologic analyses, the researchers revealed that this species hybridizes along the western edge of the Delta with Colpichthys regis, a relative of C. hubbsi that is widespread throughout the estuaries in the Gulf. In earlier museum collections, no evidence of hybridization between these species was found.

While the genes from C. regis – the widespread species – were found to be common in the range of the C. hubbsi – the Delta specific species. However, there were no genes from the C. hubbsi found anywhere else in the Gulf. This shows clear evidence of gene movement in one direction between the two species, which may put the Delta species at risk of extinction as its genome is replaced by genes of C. regis.

But it isn’t just one species that is affected by this change in salinity. Other groups of fishes – as well as crabs – appear to have evolved as ecological species unable to leave the Colorado Delta’s ecosystem. These species may also be at risk.

As water extraction continues to accelerate in large river systems around the world, it is likely that the loss of ecological species in deltas and estuaries around the world is also accelerating. Although more work needs to be done to determine the exact causes of species separation, it’s clear that efforts need to be made to slow down the destruction being done to these ecosystems.

By Connor Ertz, Earth.com Staff Writer

Hundreds of turtles killed by entanglement in ocean trash

Hundreds of marine turtles are killed each year from becoming entangled in waste found in oceans and on beaches, including plastic six pack rings that are commonly used for packaging beer and soda cans.

The rise in plastic marine litter is harming turtles of all species, and a recent worldwide survey reports that 91 percent of turtles found entangled in garbage are dead. The research by the University of Exeter also finds that there is a substantially larger impact on hatchlings and young turtles.

The experts detailed serious wounds from entanglement, ranging from choking to maiming. Some of the surviving turtles were forced to drag debris along with them.

Besides plastic six pack rings, turtles are getting caught up in fishing nets, nylon fishing line, plastic packaging, wooden crates, and many other types of waste. The research is part of a growing collection that is exposing the extent of the threat of plastic pollution to marine animals.

Lead author Professor Brendan Godley says that, as plastic pollution increases, more and more turtles are likely to become entangled.

Death from entanglement has already increased substantially with both marine mammals and birds as well.

Of the 106 experts surveyed on the Atlantic, Pacific Caribbean, Mediterranean and Indian ocean coast, 84 percent said that they had found turtles tangled in waste, including plastic debris and discarded fishing gear.

Overall, the investigation showed that more than 1,000 turtles are likely to die annually due to entanglement. The researchers acknowledge, however, that this figure is likely to be a “gross underestimation” of the actual threat to turtles. Not all dead turtles get stranded on beaches and those that are stranded are not always found. For example, some turtles are taken by local people to eat.

“Plastic rubbish in the oceans, including lost or discarded fishing gear which is not biodegradable, is a major threat to marine turtles,” said Professor Godley. “We found, based on beach strandings, that more than 1,000 turtles are dying a year after becoming tangled up, but this is almost certainly a gross underestimate. Young turtles and hatchings are particularly vulnerable to entanglement.”

“Experts we surveyed found that entanglement in plastic and other pollution could pose a long term impact on the survival of some turtle populations and is a greater threat to them than oil spills. We need to cut the level of plastic waste and purse biodegradable alternatives if we are to tackle this grave threat to turtles’ welfare.”

The study is published in the journal Endangered Species Research.

By Chrissy Sexton, Earth.com Staff Writer

Image Credit: Kate Charles, Ocean Spirits

Bees improve their flower routes with experience

New research from the Queen Mary University of London reveals that bees have a strategy to find the best routes between flowers. They are constantly improving the flight paths they take and the order in which they visit flowers, according to the study.

Just like birds, humans, and other animals, bees face the challenge of finding the shortest work route that allows for all the necessary stops.

Previous studies, which examined the order that animals arrived at each destination, have demonstrated that animals often identify the most optimal course. Prior to the current study, however, it had not yet been explained how these routes are determined.

“Animals cannot simply inspect a map to find out where the best food sources are or plan how to get between them,” said lead author Dr. Joseph Woodgate.

As bumblebees set out to forage, they know nothing about the terrain and must explore the landscape. They discover the locations of food sources one at a time and then must somehow merge these memories into an organized route.

“Only by monitoring every move they make as they explore and try to generate a better route, can we understand how they tackle this challenge,” explained Dr. Woodgate.

Using harmonic radar technology, the research team tracked bumblebees as they developed routes to visit a collection of artificial flowers. The bees gradually figured out which flight paths to take to visit all of the flowers.

The experiment produced one of the largest datasets of bee flight ever recorded, along with the first-ever comprehensive look at route development. The researchers found that the movements of bees in between feeding stations are critical in understanding how animals tackle the challenge of finding optimal routes.

The study showed that the bees began flying straighter and exploring less as they gained experience. As a result, their flight path distances and the time it took for the bees to complete their routes were greatly reduced.

However, the bees never became completely dedicated to the exact same routes. The researchers uncovered evidence that suggests that they use random processes to introduce some variation into their paths, which may help them change up the order of feeding stops to test for route improvements.

“Understanding how small-brained animals like bees find efficient rules-of-thumb to accomplish complex and flexible behaviours has great potential to inform the development of artificial intelligence and advanced robots,” said study co-author James Makinson.

“It’s also important to understand how bees and other pollinating insects search for food and use the landscape is crucial to managing the risks to pollinator services posed by habitat loss and agricultural intensification.”

The study is published in Scientific Reports.

By Chrissy Sexton, Earth.com Staff Writer