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Jaydee Media

Thursday, 28 February 2019 13:36

White Shark Facts

Did you know that....

  • White Sharks are also known as Great White Sharks, Carcharodon carcharias(Latin) and White Pointer Sharks.
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  • Their bodies are counter-shaded with a charcoal to black, grey or even dark brown top (dorsal surface) and completely white underneath (ventral surface)
  • Counter-shading makes it difficult for their prey to see them
  • One of the most successful predators in the world
  • Live on a diverse diet of fish, other sharks, seals, dolphins and even scavenge on dead whales
  • They have many different ways to catch their food from chasing fish, to sneaking up on stingrays to attacking from below when trying to eat seal
  • Have taste buds inside their mouth and throat and are more fussy than other sharks like tiger sharks
  • Have a lateral line made of special hair-like cells which runs from their tail to their head and can detect small water vibrations and currents 090711DSC_0286
  • Use their electrosense to detect the electric field given off by all living animals and can even find prey hidden under the sand
  • They are sensitive to low frequency sounds as produced by struggling prey
  • They use body language and smell to communicate with one another

  • Deepest recorded dive was over 1200
  • Can breach out of the water over 2m into the air
  • One of the most widely distributed sharks found in all oceans, except the polar seas
  • Areas with the highest concentrations are Western Cape, South Africa, South Australia, West coast USA, Guadalupe Island Mexico and New Zealand
  • Found near the coast and in deep oceanic waters
  • Grow slowly only becoming mature after 10 years (males) and 15 years (females)
  • Live for more than 60 years
  • Reproduce slowly with litters of 2 - 10 baby sharks, called pups
  • Gestation is thought to be over 12 months
  • Give birth to live young (viviparous)Each pup is between 1.2 - 1.7 meters long when it is born
  • There is no parental care
  • World's largest predatory shark/fish growing up to 6.1 metres
  • Females grow bigger than male 09080224-03-09
  • They weigh over 2000 kgs
  • They have six senses: sight, smell, taste, touch, hearing and electroreception
  • They can see in the day and at night and can see colour
  • They don't have eyelids, but instead roll their eyes back to protect them
  • Sometimes they will stick their heads out of the water which is called spyhopping
  • They have the strongest smell out of all sharks and can smell one drop of blood in a million parts water
  • Man kills over 100 million sharks a year,
  • Sharks cause less than five deaths worldwide per year.
  • Chairs and toasters kill more people than sharks
  • Great White Sharks are Vulnerable to Extinction

 

The diver – Jasmine Santana of the Catalina Island Marine Institute – reportedly thought, “I have to drag this thing out of here or nobody will believe me.”

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While snorkeling off the coast of southern California Jasmine Santana made what some are now calling “the discovery of a lifetime.” It was the silvery body of a dead, serpent-like oarfish measuring 18 feet (5.4 meters) in length. Santana, who is an instructor at the Catalina Island Marine Institute, dragged the carcass as far as she could toward shore, and needed more than 15 helpers to pull the oarfish to shore. Experts say these oarfish may have been responsible for ancient legends of sea serpents. 

Thursday, 28 February 2019 13:23

10 Amazing Facts About Ocean Animals

With over 72% of the Earth’s surface covered by salt water, the Earth’s oceans are home to 230,000 known species. And that’s with only 5% of the Earth’s oceans considered explored! In celebration of the vast unknown of the ocean, we present our favorite amazing facts about ocean animals: amazing-facts-ocean-animals-blue-whales

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amazing-facts-ocean-animals-jellyfish

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 January 2014 LIMA, Peru (AP) — More than 400 dead dolphins were found last month on the Pacific Ocean beaches of northern Peru where twice that amount were encountered in 2012, officials said Monday.

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Authorities never established the cause of the deaths in 2012. They are doing autopsies on the latest dolphins found during January in the Lambayeque region on the northern coast. Technician Jaime de la Cruz of Peru's IMARPE marine life agency said about 220 dead dolphins were found in the last week of January, the rest during the previous three weeks. De la Cruz said autopsy results are expected in two weeks. Exams will focus on lungs, kidneys and livers. Autopsies of some of the more than 870 dolphins found in 2012 were inconclusive. Speculation ranged from biotoxins in the sea to seismic testing to an unknown ailment. Yuri Hooker, director of the marine biology unit at Cayetano Heredia University, told The Associated Press that in other parts of the world dolphin deaths generally are caused by environmental contamination when the sea mammals eat fish or other smaller species filled with toxins. Hooker said others die after ingesting discarded plastic floating in the sea. The marine biologist said determining the death of dolphins is "complicated" in Peru because government laboratories have only three or four of the world's 100 or so chemical reagents that can be used for determining the animals' cause of death CNN May 23, 2012

Official: 'Natural causes' behind dolphin deaths in Peru

Lima, Peru (CNN) -- Hundreds of dolphins that washed up on Peruvian shores died of natural causes, a government official said in a radio interview Tuesday.

"One of the things that we can confirm is that ... the deaths of the dolphins were not caused by any human activity, and this is a very important subject," Peruvian Production Minister Gladys Triveno told RPP Radio.

Government investigators have also ruled out theories that bacteria or a virus could be behind the deaths, she said, adding that further details would be revealed in a report from the Sea Institute of Peru released Tuesday.

"It is natural causes. It is a natural death, and also the report explains the process of natural selection. Let's say that the species that are more prepared, the dolphins that are more prepared, are those that are going to survive," Triveno said. "And this happens periodically. This is not the first time it has happened. And it is not only happening in Peru, but also has happened in New Zealand, in Australia, in other countries where these phenomena happen."

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According to the report, authorities sent specimens to no fewer than four laboratories for a battery of tests.

The results ruled out a number of theories of the cause of death. Hunger, interaction with fishermen, pesticides, bacterial infections, viral infections and heavy metals contamination were all ruled out.

The appearance of nearly 900 dead dolphins in a 220-kilometer (137-mile) area in northern Peru so far this year, and the deaths of thousands of pelicans there and in neighboring Chile, have sparked concern among local residents and environmentalists.

At least one Peruvian environmental group has said loud sounds from nearby oil exploration could be to blame for the dolphins' deaths.

"We see that in their bodies there are air bubbles caused by heavy pressure. These animals are underwater holding their breath, facing a sudden and violent noise. These animals release nitrogen, and this forms the bubbles that end up destroying living cells," Carlos Yaipen-Llanos of the Scientific Organization for the Conservation of Aquatic Animals told CNN en Español this month.

Government officials have dismissed that assessment, arguing that it is not supported by evidence.

The report explained that the dead dolphins began washing up on the shore before the seismic activity started and that similar activity in the past has not been linked to marine deaths.

This month, Peruvian authorities said warm waters off that country's coast were to blame for the deaths of more than 5,000 marine birds.

The Peruvian Ministry of Environment said seafood is still safe to eat and encouraged everyone to continue to support local fishermen, according to the state-run Andina news agency.

The report suggested some courses of action, including the creation of a task force among multiple agencies to implement programs for caring for the marine ecosystem.

It also called for an awareness campaign about Peruvian ocean life and its conservation, aimed at the general public.

The dolphin deaths in Peru mark the third set of high-profile strandings in the past several months.

In February, 179 dolphins --108 of which were dead -- washed ashore in Cape Cod, in the eastern United States, according to the International Fund for Animal Welfare. Marine biologists are still trying to determine the cause of those deaths.

In early March, amateur video taken from a beach in Rio de Janeiro, Brazil, showed more than 30 dolphins on shore. In that instance, all the dolphins were safely returned to the sea.

STORY HIGHLIGHTS
  • NEW: Tests rule out pesticides, heavy metals, hunger, fishing, viruses, bacteria as causes
  • NEW: Report rejects theory that man-made seismic activity is to blame
  • Deaths of hundreds of dolphins "not caused by any human activity," official says
  • "This happens periodically. And it is not only happening in Peru," production minister says

Abandoned fishing nets and pots, trap, maim, and kill hundreds of marine animals daily

Unseen below the surface, fishing gear reaps the oceans bounty the world over. Viewed from below, nets appear as veil walls lightly dancing the currents with a serene and silent intent. Ever since nets began to be cast out at sea eons ago, more and more fishing gear has been entering our oceans daily. And much of this gear remains in the water — lost, torn away, or simply abandoned.

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Photo by Tim Sheerman-Chase/Wikimedia CommonsSome abandoned nets and lines wrap themselves on reefs, shipwrecks, or rocks, ensnaring marine animals, maiming, drowning or simply starving hundreds of thousands of them. Abandoned fishing gear devours sea-life with insatiable hunger. To a number of conservationists, these derelict nets are darkly referred to as “ghost gear.” In more technical terms, it can be called Abandoned, Lost, or Discarded Fishing Gear (ALDFG). ALDFG functions in a number of ways. Floating nets wander around, collecting a plethora of organisms, and eventually sink under the weight. As this biomass breaks apart in the ocean’s benthic regions, the nets shake their load and lumber upwards again, ready to wreak more havoc. Some nets and lines wrap themselves on reefs, shipwrecks, or rocks, ensnaring marine animals, maiming, drowning or simply starving hundreds of thousands of them. Pots intended for crab, lobster, and shrimp see an eclectic range of visitors. Entire crab or lobster lineages, scavenging bottom dwellers that venture inside for a hapless predecessor’s remains, perish in these traps. Abandoned gear makes no distinctions, capturing marine mammals, fish, turtles, whales, birds, sharks, rays, and invertebrates. To combat the problem, an organization called Ghost Fishing arose from a hardy band of clean up divers in the North Sea. The group started out clearing shipwrecks near their native Netherlands. Now, it’s grown into a global network of cleanup groups.. Cas Renooij, director of Ghost Fishing, explains how the organization began. “About five years back some people in the Netherlands started to clean up nets from wrecks. It turned into an environmental attempt to not just make the wrecks more attractive, but also to prevent fish from dying in those nets. Later in the process it [saving marine life] became a number one priority.” Abandoned fishing gear has become a global problem. One report, jointly issued by the Food and Agriculture Organization and the UN Environment Program (UNEP), estimates that 640,000 tons of such abandoned nets are spread across the world’s oceans, comprising up to a staggering 10 percent of oceanic litter. In the Puget Sound alone, derelict fishing gear kills over a half million sea-creatures each year, according to a Northwest Straits Marine Conservation Initiative estimate. Fifty or sixty years ago, nets were commonly made from biodegradable hemp or cotton. With the advent of synthetic, degrade-resistant materials such as nylon, nets now can remain active in the water for hundreds of years. Some plastics can remain in the marine environment for up to 600 years. When gear does finally break apart, further damage is done when marine animals eat plastic particles and polyurethane chemicals leach into the water. After seeing the destruction wrecked by derelict gear, Ghost Fishing began reaching out for help worldwide. “We looked around to see if there were more initiatives like this in the world, and we actually found some. We also found out there was no connection between them. That’s why we came up with the Ghost Fishing network. We reach out to those groups to give them a platform to get stories told, and raise awareness for the problem. We did some research and found that it wasn’t just a local problem, but a global problem,” says Renooij. “Depending on the area where we clean fishing gear, it’s a different situation everywhere,” says Renooij. The project’s has to date removed 4,500 nets, 3,081 crab pots, and 47 shrimp pots. However, preventing gear being lost in the first place has proven far less expensive than retrieval from the depths. Washington State, for instance has to spend approximately $190 to retrieve a single crab pot.

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Photo by Courtesy of Doug Helton/NOAA A sea turtle entangled in a ghost net. Since 2010, the Olive Ridley Project freed and rehabilitated 51 endangered turtles trapped or injured in nets inthe Maldives, illustrating how such gear puts added strain on an already endangered species. Though fishermen are the source of ALDFG, they have perhaps the strongest investment in fisheries’ sustainability. Due to extremely variability in gear, regional conditions, and catch rates, and due also to insufficient data, it is exceedingly difficult to ascertain total catch killed by ghost gear. What data does exist, however, is liable to make fishermen listen. According to the California SeaDoc cleanup initiative, one abandoned net can kill $20,000 Dungeness crabs in one year. Removing the net costs $1,358. According to one study cited in a UNEP report, lost tangle nets catch around 5 percent of total commercial catch globally. Unfortunately, there is little immediate incentive to use gear that is biodegradable. Polyurethane based nets became popular in fisheries largely because they were resistant to breaking down. Implementing new technologies that would reduce ghost gear’s longevity is vital to solving the problem. The difficulty lies in convincing fishermen to take on added expenditures and trips to the net shop. “We are trying to walk to diplomatic route and convince [fishermen] to use biodegradable technologies,” Renooij says. There’s been some initial success with Dutch fishermen. “One success was switching lead weights to steel weights, it’s a definite change, not a hundred percent, but the awareness we need is starting to come up. And they are using lines that over time biodegrade, but the problem is it still takes a long time,” he says. As with so many “tragedy of the commons” scenarios, the responsibility to act lies with everyone, and the incentive with no one. The 1973 International Convention for Prevention of Pollution from Ships is a start in curtailing marine pollution, but it does not adequately address the problem of ghost fishing gear. Another area that needs attention is shoreline collection facilities. Whether due to barriers to access, unwanted costs, or downright absence of facilities, not enough used gear is making its way to shore. While it is difficult to build consensus and take action to clean international waters, fostering a sense of national stewardship could motivate people to repair coastal areas in their own countries and localities.

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In the Gansbaai/Kleinbaai South Africa area there has been one encouraging development — DICT Beach Cleanup program that mobilize school kids to collect beach litter. This partnership between DICT and Volkswagen prove to be successful in creating awareness of this problem recently in a unique conservation effort. They built a life size wire whale and filled it with 534kg plastic during whale week. 

Thursday, 28 February 2019 13:06

Scientists Solve Mystery of Birds' Flying V

 

Migrating birds flap in and out of rhythm depending on where they are in formation flight_formation_ group

Secret weapon of birds and underdog hockey players alike, the flying V formation is believed to be ideal for energy and aerodynamics. A study published today in Nature not only confirms this idea, but it also fills in the blanks of how and why birds use it. Most of what we know about the physics of flying comes from studying airplanes—birds push air down to stay aloft and glide through the air similarly. Wings also leave a vortex of air in their wake: air flowing off the top of the wingtips (upwash) creates lift, and air coming off the bottom (downwash) pushes down. “The simple rule is upwash is good air, and downwash is bad air,” says Steve Portugal, a comparative ecophysiologist at the Royal Veterinary College in Hatfield, UK, and a co-author of the new study.

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Whether you’re a bird or a plane, you theoretically want to ride the small upwash part of the vortex. And the flying V configuration, the authors find, helps birds to do that. Previously, scientists suspected that birds formed a V in flight because the shape allowed some of them to burn less energy. A 2001 study found that pelicans at the front of the V had faster heart rates—and probably used more energy—than those further back. But how do birds behave within that configuration? Studies of flying birds in the wild are few and far between, and theoretical models of birds in flight only get you so far. So, Portugal and his colleagues teamed up with Waldrappteam, a conservation group that is reintroducing the critically endangered northern bald ibis (Geronticus eremita) to southern Europe. If northern bald ibis hatchlings are born in captivity, they think of humans as their parents and grow to rely on humans for everything. Reintroducing them to the wild is tricky—to survive, they needed to learn their natural migration route. Waldrappteam teaches these routes. Portugal and colleagues remotely observed birds that were born in a zoo in Vienna, Austria, on one such navigation lesson. First, the scientists developed data loggers, slightly smaller and lighter than an iPod, and strapped one to each bird. Then, over several weeks, the birds followed their human “parents” in a microlight parachute aircraft to spend their winter in Italy.

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How do birds sense when to flap to the beat? Bret Tobalske, a biologist who studies the biomechanics of flight at the University of Montana Flight Laboratory in Missoula, points out that the mechanism may come down to a combination of vision, whisker-like receptors on avian wingtips called filoplumes, and reflexive reaction pathways in the brain. Scientists just don't know. The study is at the forefront of a scientific trend looking at animal movement in the natural environment. “It demonstrates a dramatic step forward in measuring the dynamics of animal locomotion in the wild,” says Tobalske. The ibis project is part of a series of animal movement studies—other projects include examining packs of wild African dogs, flocks of pigeons, and herds of sheep.   

THE HATCHFISH

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Given the extreme depths to which scientists must go to find these frightful–and tiny–fish, little is known about the hatchetfish. Making top models around the world jealous, the morose-looking creatures derive their name from how razor-thin they are. Anatomically speaking, the hatchetfish’s thorax is supposed to resemble the blade of the hatchet, and its cold, silver glint the metal. Their name is somewhat deceiving, though; measuring in at a mere one to five inches in length, the hatchetfish is hardly deadly. It’s just, well, pretty terrifying.

THE BLOBFISH

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More gelatinous than your grandma’s pudding, the blobfish’s strikingly jiggly appearance has captivated the attention of millions for the past several years. So striking is the mass with fins that just this year it was deemed the world’s ugliest animal. Life isn’t all that bad for this Oceania-dwelling creature, though. As the blobfish’s den is primarily near the bottom of the ocean, the water pressure is understandably high, causing the blobfish’s skin to have the approximate density of water. You might think that lack of muscle tissue would prove disadvantageous, but you’d be wrong. All that means is that when it comes time to eat, the blobfish simply opens its mouth while floating merrily above the ocean’s floor. Its lack of density means that it doesn’t have to expend any energy in order to eat. Lazy chefs around the world, direct your ire to the blobfish.

THE FANGTOOTH

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Consider the fangtooth fish to be the underwater equivalent of a menacing pitbull with a heart of gold. Despite their threatening appearance, the fangtooth is incredibly benign–especially as its poor eyesight means that if it wants to hunt, the fangtooth quite literally has to bump into its prey in order to find it. Its chompers certainly paint a different portrait, though: protruding from its mouth, in proportion to the fish the fangtooth has the largest teeth of any fish in the ocean. Good luck catching a glimpse of the sharp-mouthed animal: it resides as far as 16,400 feet beneath the sea.

THE SEA CUCUMBER

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These icky echinoderms certainly boggle the mind. Lacking a true brain and any semblance of sensory organs, the sea cucumber boasts about the same mental capacity as the food for which it is named. Nevertheless, the cuke serves as vital part of the oceanic ecosystem, as it recycles nutrients and breaks down detritus that comes its way. Unlike the actual cucumber, the sea cuke’s collagen levels allow it to make some pretty kooky maneuvers: if the sea cucumber needs to wedge itself into a tiny crevice, the collagen will loosen and the sea cucumber will effectively liquify itself to seep into its desired locale.

THE GOBLIN SHARK

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Deemed by some scientists as a “living fossil” and overshadowed by its flashy counterparts, the goblin shark leads a relatively mysterious existence deep below the ocean blue. The only extant survivor of a 125 million-year old family of sharks, the goblin is truly unique…and ugly. Apart from its most salient features (re: its long, flattened snout and protruding jaws), the goblin is relatively unremarkable. Given its flabbiness, most scientists speculate that the goblin shark is sluggish and relatively inactive. It’s highly unlikely you’ll ever see a goblin shark in your lifetime; when one was brought to an aquarium in Japan, it died soon after.

THE ANGLER FISH

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The angler fish is perhaps one of the most fascinating and bizarre sea creatures known to man. Not only known for their wily predation techniques (re: having a spine that grows its own fleshy mass that the angler can wiggle about so that it resembles prey, and then devouring its soon-to-be predators in one fell swoop) but also for its mating habits. When scientists first discovered the angler, they noticed that almost all of them were female…and that these specimens had what appeared to be some sort of parasitic growth attached to their lower parts. Turns out that those “parasites” were actually just greatly reduced male angler fish, whose puny size renders their sole objective in life to finding and mating with a female. Once they do find a female partner, the male anglers quickly bite into the female’s skin and thus fuses them together. From this point on, the male’s life literally depends on its female host, as they share a circulatory system. When the female is ready to mate, he pays his dues by providing her with sperm on the spot.

 

 

 

Thursday, 28 February 2019 12:47

12 Fun Facts About Sea Hawks

Number one: There's no such thing as a "seahawk" You could use the name sea hawk to refer to an osprey (pictured below auger hawk) or a skua (itself a term that covers a group of seven related species of seabirds). Both groups share a number of characteristics, including a fish based diet.

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1. Ospreys live on every continent besides Antarctica. Although they hunt over water, ospreys generally nest on land, within a few miles of either the ocean or a body of fresh water. Unlike most bird species, they are remarkably widespread, and even more surprising, nearly all these widely dispersed ospreys (with the exception of the eastern osprey, native to Australia) are part of one species. Ospreys that live at temperate latitudes migrate to the tropics for the winter, before heading back to their home area for the summer breeding season. Other ospreys live in the tropics year-round, but also return to the specific nesting grounds (the same ones where they were born) each summer for breeding.

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2. Ospreys have reversible toes. Most other hawks and falcons have their talons arranged in a static pattern: three in the front, and one angled towards the back, as shown in the illustration on the left. But ospreys, like owls, have a unique configuration that lets them slide their toes back and forth, so they can create a two-and-two configuration (shown as #2). This helps them more firmly grip tubular-shaped fish as they fly through the air. They also frequently turn the fish to a position parallel to their flying direction, for aerodynamic purposes. 3. Ospreys have closable nostrils. The predatory birds typically fly between 50 and 100 feet above the water before spotting a shallow-swimming fish (such as pike, carp or trout) and diving in for the kill. To avoid getting water up their noses, they have long-slitted nostrils that they can close voluntarily—one of the adaptations that allows them to consume a diet made up of 99 percent fish. 4. Ospreys usually mate for life. After a male osprey reaches the age of three, upon returning to his natal nesting area for the summer breeding season in May, he stakes claim to a spot and begins performing an elaborate flight ritual overhead—often flying in a wave pattern while clutching a fish or nesting material in his talons—to attract a mate. A female responds to his flight by landing at the nesting spot and eating the fish he supplies to her. Afterward, they begin building a nest together out of sticks, twigs, seaweed and other materials. Once bonded, the pair reunites every mating season for the rest of their lives (on average, they live about 30 years), only searching out other mates if one of the birds dies. 5. The osprey species is at least 11 million years old. Fossils found in southern California show that ospreys were around in the Mid-Miocene, which occurred 15 to 11 million years ago. Although the particular species found have since gone extinct, they were recognizably osprey-like and assigned to their genus. 6. In the Middle Ages, people believed ospreys had magical powers. It was widely thought that if a fish looked up at an osprey, it would be somehow mesmerized by the sight of it. This would cause the fish to give itself up to the predator—a belief referenced in Act IV of Shakespeare's Coriolanus: "I think he'll be to Rome/As is the osprey to the fish, who takes it/By sovereignty of nature."

Pomarine Skua

A pomarine skua, frequently called a sea hawk. (Photo by Patrick Coin) 7. Skuas steal much of their food. Unlike ospreys, skuas (the other birds often called "sea hawks") obtain much of their fish diet through a less noble strategy: kleptoparasitism. This means that a skua will wait until a gull, tern or other bird catches a fish, then chase after it and attack it, forcing it to eventually drop its catch so the skua can steal it. They're rather brazen in their extortion attempts—in some cases, they'll successfully steal from a bird three times their weight. During the winter, as much as 95 percent of a skua's diet can be obtained through theft. 8. Some skuas kill other birds, including penguins. Although fish makes up the majority of their diet, some skuas use their aggressiveness to not only steal the catch away from other birds, but occasionally to kill them. South Polar skuas, in particular, are notorious for attacking penguin nesting sites, snapping up penguin chicks and eating them whole:   [youtube]http://www.youtube.com/watch?v=6Xl5GSvyVfU[/youtube] 9. Skuas will attack anything that comes near their nests, including humans.​ The birds are extremely aggressive in defending their young (perhaps from seeing firsthand what happens to less protective parents, like penguins) and will dive at the head of any animal that approaches their nest. This even applies to humans, with skuas occasionally injuring people in the act of defending their chicks. 10. Sometimes, skuas will fake injuries to distract predators. In especially desperate situations, the birds will sometimes resort to a remarkably ingenious tactic: a distraction display, which involves an adult bird luring a predator away from a nest full of vulnerable skua chicks, generally by faking an injury. The predator (often a larger gull, hawk or eagle) follows the seemingly-debilitated skua away from the nest, intent on obtaining a larger meal, and then the skua miraculously flies away at full strength, having saved its offspring along with itself. 11. Skuas are attentive parents. All this aggressiveness has a reasonable justification. Skuas (which mate for life, like ospreys) are attentive parents, guarding their chicks through a 57-day fledging process each year. Fathers, in particular, take on most of the responsibility, obtaining food for the chicks daily (whether by theft or honest hunting) during the entire period. 12. Some skuas migrate from the poles to the equator each year. Among the most remarkable of all skua behaviors is the fact that pomarine skuas, which spend the summer nesting on Arctic tundra North of Russia and Canada, fly all the way down to the tropical waters off Africa and Central America each winter, a journey of several thousand miles. Next time you're judging the birds for their piratical ways, remember that they're fueling up for one of the longest journeys in the animal kingdom. Hermanus Online Website 

More than 70 definitions exist for what makes a species New species of insects, worms and other creepy-crawlers are announced on a monthly basis. Similarly, just last week, two new humpback dolphin species splashed into the headlines. And in October, news broke that early humans may have included fewer species than previously thought. This forces the question: what does it take to be a distinct species?

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Name me! Australian humpback dolphins eagerly await their very own scientific name. Photo by Mendez More than 70 official species definitions exist, of which 48 are widely accepted and used by scientists. And there’s no hard rule that scientists must stick to just one definition; some apply a handful of species definitions when approaching the topic. “I personally go to my lab every day and use five species definitions to conduct research,” says Sergios-Orestis Kolokotronis, a molecular ecologist at Fordham University, and co-author of the new dolphin study, published in Molecular Ecology. “And I sleep just fine amidst this uncertainty.” Species definitions oftentimes do not translate from one organism to another. Dolphins may become isolated by distance and behavior that prevents them from reproducing, but in other cases–such as bacteria, which reproduce asexually–these distinguishing markers do not apply. Thus, the definition of what constitutes a species varies depending on whether scientists are studying dolphins, monkeys, insects, jellyfish, plants, fungi, bacteria, viruses or other organisms, Kolokotronis explains. And likewise, methods for investigating those species also vary. In the case of the four dolphin species, each occupy different sections of ocean around the world, including in the Atlantic off West Africa (Sousa teuszii), in the central to western Indo-Pacific (Sousa plumbea), in the eastern Indian and western Pacific (Sousa chinensis) and in northern Australia (researchers are in the process of working on a name for that one–Sousa bazinga, anyone?).

dolphin species 1

Two members of the newly identified Australian dolphin species. Photo by Mendez et. al., Molecular Ecology While the humpback dolphins look quite similar, their genetics tells a different story. Researchers collected 235 tissue samples and 180 skulls throughout the animals’ distribution, representing the biggest dataset assembled to date for the animals. The team analyzed mitochondrial and nuclear DNA from the tissue, which revealed significant variations between those four populations. They also compared the skulls for morphological differences. Although the line between species, sub-species and populations is a blurry one, in this case, the researchers are confident that the four dolphins are divergent enough to warrant the “species” title. The mitochondrial DNA turned up genetic signatures distinct enough to signal a separate species, and likewise, differences in the dolphins skulls supported this divergence. Although the nuclear DNA provided a slightly more confounding picture, it still clearly showed differences between the four species. “We can confidently say that such strong divergence means these populations are demographically and evolutionarily isolated,” says Martin Mendez, a molecular ecologist at the American Museum of Natural History and lead author of the dolphin paper. “The key is that all the evidence–mitochondrial DNA, nuclear DNA and morphology–exhibited concordant patterns of distinct units,” he continues, which are “usually a must for species proposals.” The genetic data the team collected does not have enough resolution to reveal how long ago the humpback dolphins diverged, and the team has yet to examine the drivers that fueled those speciation events. But Mendez and his colleagues have found that, in some dolphin populations, environmental factors such as currents and temperature play a role in separating populations and encouraging speciation. Different behaviors can help reinforce that separation, too. Most likely, however, geographic isolation plays a significant role in this case. “For populations living a couple hundred kilometers from one another, it’s perfectly possible for them to meet,” Mendez says. “But the distance from Africa to Australia is so great, it’s difficult to imagine those populations would ever be linked.” Dolphins, Mendez and his colleagues are finding, evolve relatively quickly once isolated from parent populations. New cryptic–or hidden–species have similarly turned up in waters near South America. There may very well be other species of dolphins–or any type of animal, in fact–lurking undetected within an already-discovered species. ”This really applies to most taxa,” Mendez says. Across the board, “we’re adding many more species by looking at genetic data.” Nonetheless, pondering the speciation of humans in dolphins in light of these two findings raises lots of questions: Are we fractally subdividing genetic information and brain cavity size to group and regroup organisms, or is there vast genetic diversity in even familiar species that we’ve yet to uncover? What does it mean for a species to gain or lose members of its family tree? The world and its organisms await more research. Hermanus Online Website 

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