Entries in environment (61)

Thursday
Nov032011

Killer whale changes its colour 

Whilst watching Frozen Planet, has it crossed your mind why the killer whales in the Antarctic are slightly off colour? This slight yellow tinge is caused by nutrient rich diatoms and algae found in these chilly waters which attach to the mammals skin. John Durban of the NOAA has offered a new proposal as to why a certain type of killer whale will migrate thousands of miles in relation to this yellow tinge. 

Since the killer whales travel at a constant speed during this migration, researchers believe that they are not traveling to find prey or to give birth. Type B killer whales (which feed mainly on seals) were tagged off the Antarctic Peninsula and it was revealed that they move towards sub – tropical waters continually. One tagged individual travelled over an incredible 5, 000 miles to Brazil, only to return just 42 days later to Antarctica! The speed and distance travelled is unprecedented in killer whales and it implies the individual departed from Brazil immediately, but why?

Killer whales return from this journey to warmer seas ‘cleaner’ than when they left. It is thought the warmer water helps killer whales to shed the algal growth and regenerate skin tissue. It is possible that the energy they would need to expend in the cold Antarctic waters can be utilised to repair any tissue damage created by diatoms or algae. Further evidence for this theory is shown by killer whales actually slowing down their speed in warmer waters. They do not travel slowly enough to indicate calving or extensive feeding, but it would give the killer whales extra time in warmer waters to shed and heal their skin. 

As more research is conducted on these beautiful mammals, the more we are finding out about how clever they are. This may provide interesting comparisons when researching into the evolution of intelligence and how similar to the intellectual capability of humans they may be.

Haley Dolton

Wednesday
Nov022011

The birds of Britain

 

Bird stories have been soaring into the nature headlines over the past week, however unfortunately the reasons behind their appearance are not so good.  Attention has been drawn to the issue that many British seabird populations are coming under increasing threat due to problems such as climate change and anthropogenic waste.  Alongside this, extreme global weather conditions are causing unusual migrations to take place, resulting in great opportunities for birdwatchers, but potentially causing issues for our native species.

Sea bird populations are struggling particularly in Scotland where decreases in already threatened populations are causing increased concerns.  One reserve on Orkney Island has recorded a 53% decline in numbers since the last full UK seabird population census in 2000.  On another Orkney reserve, populations of Guillemots have not managed to raise a single chick this year. A similar case has shown that only one pair of Kittiwakes remain in an area that was once home to 150 breeding pairs.

Reasons for these vast declines are related mainly to gale force winds that occurred in May, which particularly affected arctic turns and disrupted the nesting of many other species.  The overall situation has been described as “bleak” and the RSPB is proposing another census is carried out so that trends can be properly identified and conservation methods be put in place.

Another issue facing seabirds is the increasing build-up of plastics in oceans.  Off the welsh coast, 40,000 breeding pairs of gannets arrive on Grassholm Island to breed and nest.  However researchers from the University of Plymouth have found that an increasing amount of birds are using synthetic materials to make their nests, which they find floating off shore.  The new resources include pieces of plastic, synthetic rope, fishing line and unwanted nets.

These materials don’t biodegrade meaning that the breeding pairs that return to the same sites every year are continually accumulating the rubbish, with an estimated 18.46 tonnes of plastic now on the Island.  This leads to further problems with many birds becoming caught in the nests, resulting in an annual effort trying to release trapped birds.  Each year the majority of birds are successfully released, however around 65 birds die from their entanglement.  It is hoped that in the future, marine reserves can be extended further out to sea to ensure that the areas the birds use for feeding and nesting materials are not affected by anthropogenic disturbances and waste.

In other, more optimistic, bird related news we have seen a close to record high number of species arriving in Britain from all over the world this year. The 442 species are set to rival the 2008 total of 445 and bird watchers are optimistic that this will happen.  The influx of species is said to be because of the extreme weather conditions and hurricanes that have occurred in North America and Asia, which are being linked primarily to climate change.  The strong winds have redirected migration paths towards Britain and we are now playing host to a number of exhausted species who have travelled very long journeys to get here.  Other reasons for the high numbers are thought to be the melting of Arctic sea ice, also related to climate change, which are opening up new routes for migrating birds from the pacific to Britain.

The changing of bird populations and species in Britain are certainly keeping ornithologists busy and it can be hoped that conservation techniques can be developed to help stabilise our sea bird populations while being able to enjoy the exotic variety of species arriving to our shores.

By Lizy Tinsley

Monday
Oct312011

Investigation uncovers bloody reality of ivory trade

 

A new documentary to come out of Kenya highlights the impact that poaching is having on elephant populations. In 2011 so far, more than 3000 elephants are known to have been slaughtered with many more unaccounted for. The Environmental Investigation Agency (EIA) went to Kenya and witnessed the grim reality of the ivory trade.

In an undercover operation, the EIA travelled to the Samburu National Reserve to document and report on the extent of poaching in the country. According to locals, the region is a poaching hot spot with numerous elephants slaughtered every year for their tusks.

Upon arrival in the reserve, the EIA were alerted to the presence of poachers nearby and went to report on the situation. In the midst of the investigation, more than five shots were heard followed by the sound of the elephant’s tusks being hacked off with machetes. Unfortunately, the animal did not survive the hideous ordeal. The following day the team found the carcass of a matriarch with her face completely hacked off. In the swift operation, the elephant’s tusks would then have been transported to a nearby vehicle to be sent to buyers in the Far East.

Executive Director of the EIA, Mary Rice, said that despite being alerted to the presence of poachers in the reserve, there was little they could do to deter them, particularly with the knowledge that they were armed. According to reports, the Kenyan Wildlife Service (KWS) should have been at the scene yet did not show up until three hours after the call went out.

The EIA have established a database of poaching across Africa and Asia and found that in 2011 over 11,000kg of ivory have been seized meaning that over 3000 elephants have died as a result. Unfortunately, this is only an account of the ivory that is known and according to the EIA this number represents a mere 20% of undetected ivory.

Despite global anti-poaching efforts and conservation awareness, the threats to species hunted for illegal trading are clearly of increasing concern.   

The Nat Geo Wild documentary covers environmental crimes in a series called Crimes Against Nature with the investigation on elephants appropriately titled Blood Ivory.

Holly Alsop

Thursday
Oct272011

Fungus to blame for bat casualties

 

The disease known as white – nose syndrome (WNS) has been ripping through North America killing vast numbers of bats. Scientists have recently discovered it is likely to be caused by a fungus.

These findings were obtained from experiments conducted by researchers from a number of US institutions. They found that bats infected with the fungus Geomyces destructans not only developed WNS, but also had the ability to pass this disease from one bat to another through physical interactions. Thankfully, other experiments by researchers revealed that the fungus spores are unable to be spread through airborne transmission.

The behaviour of bats in the wild appears to make the transmission of the fungus highly effective. They tend to congregate in vast groups outside caves where they hibernate. Individuals in these groups will literally rub shoulders with each other, members of different species and bats from other caves. G. destructans tends to be found on the snouts of bats where it causes lesions on the skin, characteristically in a white colouration.  

Consequently, researchers suggest that WNS “has the potential to decimate North American bat populations”. First identified in 2006, WNS has been the cause of over one million bat deaths and more is expected in the future.

Unfortunately for bats there is no cure at the moment that could prevent the spread of the disease. However, there are measures that could be employed to reduce its transmission such as the closure of caves. This may help to stop humans from transporting spores to other unaffected areas but it would not stop bat populations form intermingling.

Other possible solutions would be to change the environmental conditions of bat caves, so as to slow the fungal spread but leave it habitable for bats and other wildlife. It has been shown that G. destructans favours low temperatures and particular levels of humidity. Therefore, altering those conditions may slow fungal growth.  

Fortunately some species of bat appear to be immune or resistant to G. destructans such as the North American grey bat and the Virginia big – eared bat. Scientists are aiming to conduct further studies in order to understand why these species are resistant and whether their natural immunity can be turned into a defence for vulnerable species.

The hope is that a successful solution to the disease can be found before the fungus spreads further and species of bat are pushed towards extinction.

By Anthony Kubale 

Tuesday
Oct252011

Javan rhino extinct in Vietnam

 

A subspecies of Javan rhino, Rhinoceros sondaicus annamiticus, has recently entered into Vietnam’s history books after the last known individual was found dead. Unfortunately, this also happened to be the last remaining species on mainland Asia.

There are two other subspecies of Javan rhino, one of which is already extinct, while the other (R. sondaicus sondaicus) is found in Java and Indonesia. Current population numbers are estimated at being no more than 50 individuals.

This news has fallen painfully on the ears of WWF’s Vietnam director Tran Thi Minh Hien who said that “despite significant investment in Vietnamese rhino conservation, efforts failed to save this unique animal”.

According to a report on the ‘Extinction of the Javan Rhino from Vietnam’, the authors found that genetic analysis of dung samples collected between 2009 – 2010 in the Cat Tien National Park showed that they all belonged to just one individual. It was shortly after these surveys were completed that conservationists discovered that the rhino had in fact been killed. The blame for this was mainly directed towards poachers since it had been shot in the leg and its horn cut off.

On a global scale there has been an increasing number of reports of rhino poaching which led to the International Union for Conservation of Nature (IUCN) publishing a report highlighting that rhino populations in Africa were facing their worst poaching crisis for decades.

A recent assessment made by Traffic, the global wildlife trade monitoring network, suggested that the illegal trade in rhino horns was being driven by the Asian medicinal markets.

Dr Bibhab Kumar Talukdar, chairman of the IUCN's Asian Rhino Specialist Group mentioned that the “key to the success of the species is appropriate habitat management, as the Javan rhinos are browsers and need secondary growing forests." However habitat within the national park is being degraded by an invasive species of palm, therefore, control of this palm is vital for the future of the Javan rhino.

The rhino protection units and national park authorities in Indonesia have been highly successful in preventing poaching over the past decade. It is important now that this protection is continued in order to safeguard the future of the Javan rhino.

By Anthony Kubale

Monday
Oct242011

Spotting a jaguar now made easier

 

Thanks to a revised photograph identification technique, developed originally for tigers, researchers from the Wildlife Conservation Society (WSC) are able to better recognise individual jaguars in Bolivia than previously possible.

Coat patterns are as unique as our fingerprints, allowing researchers to accurately log data about individuals. The technique involves creating a digital map of an individual’s coat pattern by stitching a series of photographs together which have been taken by camera traps or even tourist photographs. The use of this method has spread throughout the animal kingdom to include species such as grey seals, cheetahs, whale sharks and now, jaguars.

The technique is also proving to be useful for persecuting those involved in the illegal fur trade. Animals can now be traced back to their natural habitat through the development of ‘maps’ created by digital imaging. This drives the direction of investigative enquiries by establishing the location of the population in the wild.

WSC researchers using the photograph identification technique have been able to recognise 19 individual jaguars from a total of 975 photographs taken by only one camera. The number of photos taken during this study is at record high due to digital cameras being used rather than the normal traps that use film. The practice of using spot patterns to identify individual jaguars has been made possible due to the high resolution offered by digital cameras.

The ability to accurately identify individuals at such a high resolution will allow researchers to gain an intimate insight into the lives of these secretive animals and how best to protect them against the dangers of poaching.  

Haley Dolton

Friday
Oct212011

A unicorn whale?

 

You would probably recognise them by their distinctive appearance, but how much do you know about the toothed whale, the narwhal? It turns out researchers are also vague about the specifics of a narwhal’s life and how it may change as a result of global warming.  

The WWF are trying to establish how Arctic melting is affecting ice – associated species such as the narwhal. Dr. Peter Ewins of WWF-Canada and his team tagged nine individuals in August of this year to try and establish how the elusive narwhal would cope with shrinking sea ice. Dr. Ewins is waiting on the results of their movement patterns to compare with anecdotal evidence of local Inuit’s to try and initiate a successful conservation plan. This is because narwhals are classed as near threatened by the IUCN, with their population at only approximately 50,000 - 80,000 individuals due to hunting practices for their meat and tusk.

Their long, helical tusk was thought to have initiated the fairytales of unicorns and who could blame anyone for being inspired by this mysterious species! The tusks originate from their left canine tooth and males can have tusks that reach up to 3m in length and in 1 out of 500 males, two are produced! Females also possess a tusk, but it is shorter and is not helical in shape. It is thought the tusk has evolved via sexual selection in a similar process to that of the peacock and its feathers. In addition to this, you may have thought the tusk could be used to break through ice patches enabling the narwhal to migrate with ease. However, it is thought the tusk is only used as a visual display to others as they are very rarely observed using their tusk in aggressive behavior.

They are the preyed upon by polar bears, orca and of course, humans, which further depletes their population. In addition to this, narwhals have a highly specialized diet (and therefore restricted) possibly hampering the recovery of their population in the future. When the results from this study are published it will provide greater knowledge to the scientific community when the time comes for a conservation plan for this unique species.

Haley Dolton  

Thursday
Oct202011

Shark massacre in Colombia

 

Authorities in Colombia have reported a mass shark killing in the UNESCO World Heritage Listed site, the Malpelo Wildlife Sanctuary. Over the past few days reports have emerged that almost 2000 sharks have been killed for their fins, including hammerhead, Galapagos and silky sharks.

Discovery of the slaughtered sharks was made by a team of divers who were investigating the animals in Colombia’s Pacific waters. The team reported seeing a number of finless sharks on the ocean floor, none of which were alive.  On the surface, fishing boats and trawlers were gathered approximately 500 kilometres from the mainland, all of which had illegally entered the sanctuary.

The Colombian president’s top advisor on environmental issues, Sandra Bessudo, has spent much of her career campaigning to preserve the unique marine environment in Malpelo and is shocked by the massacre, “I received a report, which is really unbelievable, from one of the divers who came from Russia to observe the large concentration of sharks in Malpelo. They saw a large number of fishing trawlers entering the zone illegally,” she said.

The Malpelo Wildlife Sanctuary is a protected marine environment that aims to provide a safe-haven for threatened species such as the targeted sharks. Covering over 8570 square kilometres, the sanctuary is home to a vast number of hammerhead sharks, silky sharks and the short-nosed ragged-toothed shark, known locally as the ‘Malpelo Monster’.

Colombia’s navy maintains a patrol in the sanctuary however there were no patrol boats present at the reported time of shark finnings in the area. After news spread of the massacre, the navy dispatched a number of boats which resulted in the seizure of an Ecuadorian fishing boat that allegedly had up to 300 kilograms of illegal catch, including sharks, on board.

Neighbouring countries have voiced outrage over the massacre and governments have vowed to co-operate to catch the criminals involved. The Costa Rican foreign ministry has also condemned the killings and said they would prosecute any vessels that were identified flying the Costa Rican flag.

Holly Alsop

Wednesday
Oct192011

Help for the world's unluckiest bird

 

In a competition for the world’s unluckiest bird, the spoon–billed sandpiper would undoubtedly be a leading contender for 1st prize. However, a last ditch breeding programme might be just enough to bring this species back from the edge of extinction.

From a distance the brown and white markings of the spoon–billed sandpiper make it seem like any of the other 200 or so species of wading bird found worldwide. Yet, closer inspection reveals that in fact, this is no ordinary wading bird. This is primarily due to its unique spatula shaped bill.

The breeding ground of the sandpiper is along the coast of Chukotka province in eastern Russia where predators, flooding and snow may prevent successful reproduction occurring in the short window of time available.

Any chicks that survive this ordeal then travel 8,000km (5,000 miles) to their wintering grounds in Myanmar and Bangladesh on a journey that is possibly the most perilous of any migratory bird. During this journey they pass through the world’s largest industrial powers – Japan, China and South Korea where coastal development (particularly in wetland areas) is proceeding at an exponential rate. To top it all off, if the sandpipers do reach their wintering grounds, they then become targets for poor local communities intent on trapping them for food.  

The population size of sandpipers has never been large. In the late 1970s they were estimated at 2,400 breeding pairs but by 2000 numbers had declined to 1,000 pairs. Currently scientists estimate that only 100 breeding pairs are left in the wild suggesting a 90% drop in the last decade. Unless a radical solution is found, the extinction of this species in the wild is inevitable within the next 10 years.   

Thankfully, the Wildfowl & Wetlands Trust (WWT) along with conservation partners including the RSPB and BirdLife International Russia, have made the controversial decision to take spoon billed sandpiper chicks from the wild and raise them in captivity. However, although captive breeding works in long lived species, it is much more challenging in small migratory waders such as the sandpiper. Many also argue that the limited financial resources available would be better spent on preserving wetland habitats for species that are more likely to survive in the long term.

The view of WWT, RSPB and BirdLife International however, is that these extraordinary birds should be given a chance to succeed before they join others such as the dodo in the history books.

By Anthony Kubale

Tuesday
Oct182011

Time to chill out with Sir Attenborough 

Photo courtesy of Ashley Coates

That’s right, David is back on our screens on the 26th of this month to bring us another stunning wildlife series; Frozen Planet. Little snippets of this series have been released to the media and general public over the past few days and it looks to be just as cool as the locations it's set in! A few species have already made an appearance in wildlife news recently such as crafty killer whales and thieving penguins. To get us all in the mood for the new series, here is a mini food chain detailing why some species make good predators and why some make tasty prey!

Polar bears are one of the apex predators within this food chain. Males are very large and can reach up to 350 – 680 kg and 7.9 – 9.8 ft. in length, with females measuring half that length. Because of their large size, it makes it possible for them to smash into ice dens of seals and tear into prey easily. This is assisted by shorter claws on their feet and their extremely large paws, which can measure approximately 30cm across! Their keen sense of smell also helps them when hunting prey. Polar bears are able detect unburied seals from nearly 1 mile away and buried seals under 3 ft. of snow!

Killer whales are another apex predator that drift in and out of the icy waters surrounding Antarctica and the Artic. They have a varied diet depending on which subspecies they are and their geographical location. Killer whales make excellent predators due to their high intelligence and ability to work as a team. Just recently, new images of killer whales working together to knock a seal off of an ice float have been released. A team of killer whales will rush towards an ice float causing a wave to appear that is powerful enough to knock an unsuspecting seal into the mouth of another member of their pod. They work together like this in many clever hunting situations displaying team work that some think is reinforced by their own ‘culture.’

Weddell seals are the preferred prey of apex predators as they are not as aggressive as crabeater and leopard seals, so the chance of injury by them is not as likely. Weddell seals measure between 8.2 - 11.5 ft. long and can weigh between 400 – 600kg. They are insulated with a thick layer of blubber which not only keeps them warm, but also attracts predators.  Their energy rich blubber is vital for them to stay alive because food is so hard to come by. The weddell seal does have a few tricks for avoiding gaping jaws, which are also used when hunting for their own prey. They can dive to depths of approximately 2,300 ft. and can hold their breath for around 80 minutes! That’s a very long time to play hider or seeker!  

The Frozen Planet team filmed the Adélie penguin stealing stones from neighbour’s nests to put in their own. Unfortunately for them, penguins make a tasty snack for seals and killer whales (but without the wrapper and bad joke – if you exclude that one!) Penguins may make up the bulk of a predators diet perhaps due to their sheer numbers, making them easier to locate. In the Ross Sea region of Antarctica, there are currently around 5 million Adélie penguins! This may make them an attractive option for many in such a harsh environment.

With these species featured (and I’m sure a lot more) together with the great camerawork from the BBC, I know what I will be doing on Wednesday nights!  

By Haley Dolton

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