The many faces of extinction

'Toughie', last Rabbs' Fringe-limbed treefrog

Rabbs' Fringe-limbed tree frog

This post is inspired by the incredibly sad news that the last Rabbs' Fringe-limbed tree frog (Ecnomiohyla rabborum) has died and this species has now been declared officially extinct. This species of frog was a forest canopy dweller found in Panama and was only discovered as recently as 2005 and classified as a separate species in 2008.  Sadly, around this time the chytrid fungus was noted in other frog species in the same habitat as the Rabb's Fringe-limbed tree frog which was the primary cause of the drastic decline of this species which resulted in one remaining male frog, 'Toughie', being left in captivity by 2012. This fungus has had devastating impacts on huge numbers of amphibians and scientists suggest that this is the worst disease to have ever impacted a group of vertebrates as it thought that it can infect every species of amphibian and is nearly always fatal.  Although there is a vain hope that there may still be some of this species of tree frog left in the wild, none have been reported in many years, so the strong likelihood is that this species is now gone forever.

Other types of extinction 

Scimitar-horned oryx

Not all cases of extinction are quite this straight forward.  For instance, a species may be relatively common in captivity but extinct in the wild.  An example of such a species is the Scimitar-horned oryx which was one of the most common mammals in Africa but hunted to almost extinction in the 20th century (primarily for its meat) until it was declared extinct in the wild in 1999.  A captive breeding programme is currently being set up for this species and small-scale reintroductions have begun so it is hoped that this status can be reversed.  

One of the remaining three northern white rhinos

Perhaps the most frustrating type of extinction includes species that are functionally extinct.  This describes a situation where the a species is still present but no longer viable to breed and therefore it is just a matter of time before they disappear. Arguably the most famous current example of this is the northern white rhino as this species only has three individuals remaining, one male and two females.  These rhinos are too old to naturally reproduce as these females a highly unlikely to have a successful pregnancy to produce a calf.  The situation is almost beyond hope but a handful of scientists are continuing to pursue new strategies to keep this species going.  One strategy is to remove the reaming eggs from these rhino females and fertilise them with the sperm of this male to create an embryo (IVF) that can then be carried by female southern white rhinos which are a far more numerous subspecies. This task is far from simple however as it is extremely difficult to access these female's eggs and then successfully fertilise them without risking the lives of these old rhinos.  If it is pulled off, it will be a first for rhino's and perhaps give this species, and others in a similar position, a lifeline.  It may be a big 'if' but these beautiful animals deserve all the help we can give them. 

Is extinction really forever?

There is a budding area of science that may change the stories of all these species and that is the theory of 'de-extinction'.  Our understanding and ability to work with genetic material has improved immensely in even the last decade with the possibility of bring wildlife species back from the dead perhaps not such a radical idea.  This is a very controversial concept which will always cause arguments but it will also continue to grow as, after all, the human race is in desperate need of a back up plan if we continue to decimate wildlife at the current rate.

At any rate, conservation should and will focus on trying to prevent other wildlife species becoming any type of extinct as is our duty.  We have failed the Rabbs' Fringe-limbed treefrog. I can only hope that our list of successes slowly starts to increase to make these failures more bearable.  

Sloth Backpack Project

Most people are very familiar with sloths.  The general perception of these creatures is that they are very slow moving, tree abiding animals that can be hard to spot.  This is all true but, surprisingly for such an iconic species, not much is actually known about them at a scientific and conservation level.  This is due to a lack of research focusing on this animal of which there are two types, two-toed and three-toed, with six different species: Pygmy three-toed sloth, Maned sloth, Brown-throated three-toed sloth, Lannaeus's two-toed sloth and Hoffman's two-toed sloth.  

Pygmy three-toed sloth

At present, only the Pygmy three-toed sloth is critically endangered with the Maned sloth also being declared vulnerable.  All these species rely on tropical rainforest as their habitat and they are found in Central and South America.  The Pygmy three-toed sloth is separated from the rest of the species as it is endemic to a small island off Panama (Isla Ecudo de Veraguas) where it is only found in red mangrove forest.  This habitat is being reduced through logging and degraded through increased tourism which is affecting this sloth's populations.  It has also been reported that local people and tourists hunt these animals for food and sport further reducing their numbers.  


Deforestation is the most serious and common threat facing all species of sloth.  However, lack of behavioural and biological knowledge of these species means scientists are uncertain as to how sloths will react to this threat and how to conserve them.  An issue that has already arisen is an increase in deformed young sloths that is probably due to an increase in inbreeding that has occurred because of habitat fragmentation.

Therefore, this is a vital area of research that has begun to be explored by the 'Sloth Saunturay' in Costa Rica which is involved in the 'Sloth Backpack Project' that is spearheaded by a British zoologist Becky Cliffe. This research currently focus's on Brown-throated three-toed and Hoffman's two-toed sloths which are being fitted with 'backpacks' that combine VHF transmitters and GPS tags.  This provides information about these sloth's habitat preference, range, diet and reproduction.  This information can be used to highlight important areas for these species and therefore conservation efforts can focus on protecting these habitats. In addition, this information can also help in the captive breeding of these species as the 'Sloth Sancuray' receives many orphaned sloths that have been separated and injured by local people that persecute them.  At present there have been few successful releases of these orphans but this research can provide information about what these sloth's require to learn in order to be released into the wild.  

Orphaned sloth at the santuary

So far, 17 sloths have been fitted with these backpacks but there are plans to increase this number in order to construct a more comprehensive understanding of sloth ecology.  This is an exciting project that should inspire all conservationists to uncover similar creatures that although seem abundant and well understood
actually require our help.   I'm sure this will not be the first time we're shocked about our lack of understanding about the nature around us but I hope this will only go on to inspire more essential and fascinating research.

More information can be found about this project at Becky Cliffe's blog (http://beckycliffe.com/sloth-backpack-project/) and the 'Sloth Santuary' website (http://www.slothsanctuary.com/research/). 

Stormy times...

The UK's climate seems to have taken a dramatic turn for the worse over the past couple of months.  We have been hit by violent storms with strong winds and, more recently, flooding in southern areas.  This has already caused a huge amount of damage to human populations but wildlife has also suffered significantly.

Natural England have reported that at least 48 Sites of Special Scientific Interest (SSSIs) have been affected and 37 of these are of international importance.  Coastal areas are obviously more vulnerable and  flooding has extended over 4500 hectares of designated coastal reserves in areas including Lincolnshire, Yorkshire, Norfolk and Suffolk.  Species that have been affected by this weather include seal pups as initial reports suggest that 170 may have been swept away from colonies on the north Norfolk coast.  Otters are also vulnerable to physical damage from these storms and some many seabirds have died through pure exhaustion and inability to access food.

 These case are worrying in themselves but there is greater concern over the long-term effects of this flooding on freshwater habitats through breaching of sea walls.  This influx of salt-water will cause a dramatic decline in insect species which of course affects those animals that rely on them, such as wading birds.  Bitterns are an example of an endangered bird species (red status on the RSPB) that is particularly vulnerable to these habitat changes as they rely on freshwater reedbeds in which to breed and these have already been damaged, e.g. the Norfolk Wildlife Trust's Cley Marshes nature reserve.

Suffolk Wildlife reserve

The climate is changing so this will not be the only instance of flooding that the UK will have to face. Therefore, many organisations, such as the Wildlife Trusts, are proposing for more natural solutions to control flooding that are likely to be more sustainable.  This involves restoring habitats such as upland bogs and moors, woodlands, wetlands and species-rich grasslands, which are more effective at absorbing and holding water.  Rivers should also be reconnected to their floodplains.  There have already been examples of how effective this method is, such as in upland areas where drainage ditches have been blocked and overgrazing reduced.  This has allowed for the growth of sphagnum mosses and heather which hold water in the hills for longer and reduce peak flows downstream during high rainfall.

As is often the case, reverting back to the way nature intended is the only way we are going to survive Nature's next test.

The life of a garden bird...

Its the RSPB's Big Garden Birdwatch this weekend (25-26th of January) where everyone in Britain is encouraged to spend an hour counting the birds that are visiting their gardens or local green areas.  This can provide a large amount of information about the abundance and distribution of bird species.  This information can be used to assess current conservation efforts for species and/or highlight other species that may need help.  For example, the last birdwatch highlighted a decline in both starlings and house sparrows which promoted research into the reasons for this decline to enable conservationists to employ strategies to boost numbers.

House sparrow

'Garden birds' are not always appreciated as the most interesting of species so this birdwatch may not be an appealing activity to some people.  However, from personal experience I have noticed that these birds form a community and have their own hierarchy when it comes to access to bird feeders that is fascinating to watch.  Further research into this has indicated that much of this hierarchy is decided by size as you would expect.  For instance, the little coal tit is often surpassed by blue and great tits which themselves are out competed by nuthatches and greenfinches.  All of these birds give way to woodpeckers and if a pigeon shows up it is almost guaranteed to have the feeder all to themselves.

Starling

In addition, there is also competition within species as not all birds are of an equal status.  One of the ways that birds often judge the status of another is through visual displays as birds have four types of colour receptors which means they can see outside our visual range, e.g. UV light.  For instance, dominance in males is often indicated by the brightness of their plumage, such as the yellow on great tits chest or the orange of a blackbird's beak.  In summary, the bigger and brighter you are in this bird world, the more likely you are to get fed.  However, this may not always be the case and this can only be found out my watching these birds so I hope this is extra incentive for everyone to get involved in this birdwatch!

See this heirarchy in action in this video clip:
http://www.bbc.co.uk/learningzone/clips/feeding-relationships-and-movement-of-garden-birds/13971.html

Raptor's Story

Being an animal lover and a vegetarian I am obviously opposed to any kind of hunting.  In particular I see no appeal in hunting for 'sport' although of course this is a widespread activity.  Certain kind of hunting are clearly wrong, for example trophy hunting for wild African animals (e.g. rhinos, elephants, big cats) is widely viewed as unacceptable, particularly as many of these animals are endangered.

Looking a bit closer to home, the opinions towards hunting of game birds are less firm.  After all, the species shot are common (e.g. grouse, pheasant) and often bred for this exact purpose.  This sport can be an important input into the economy, for instance on some estates people pay £175 for every 2 birds they shoot, as well as being ingrained into some societies.

Hen Harrier

However, a dangerous indirect threat arising from this sport in the persecution of raptors that occasionally prey on game birds.  Despite the majority of these raptors being legally protected from persecution, many a still poisoned and shot and this is a serious problem for species that are already suffering low population numbers.  Hen harriers are an example of one of these species as only 1% of their naturally occurring numbers are successfully breeding in grouse moors.  This species is one of the most threatened raptors in the UK with only 570 breeding pairs left.  Another critically endangered species suffering is the Golden eagle as only this month (19th December) another satellite-tagged bird was found poisoned on a moor that is intensively managed for grouse shooting.

Golden Eagle

Buzzards are a conservation success story in the UK as despite historical declines, they are now this country's most common raptor, with a population of 31,000 to 44, 000 breeding pairs.  They are still a protected species under the Wildlife and Countryside Act 2001 in order to maintain and perhaps even improve these numbers.  However, a shocking development occurred in May when Natural England issued its first license to destroy buzzard nests and move adults after requests from a pheasant shooting estate.  To make matters worse, research has indicated that buzzards play a minor role in pheasant losses as they only occasionally take young pheasants from breeding pens.  There are also alternative measures available to protect pheasant numbers such as providing more cover for young pheasants in release pens, visual deterrents to discourage buzzards and providing alternative food sources

I believe that this persecution of raptors is equally as unacceptable as ivory poaching of elephants and it needs the same level of attention to prevent further losses to our native birds.  All animals populations on this earth are precariously balanced due to their daily battles with human actions.  We cannot afford to abandon any of them, even if they are seemingly recovering as in the case of the buzzards, if we want to keep them in our world.

Buzzard

The vulture's story

As a conservationist I am often faced with shocking stories of species that are literally on the brink of extinction and I wanted to share one such story as I believe it needs all the recognition it can get.  This involves three species of Asian Vultures: oriental white- backed, slender billed and long billed vultures. All 3 are now critically endangered as their numbers have declined 97%, or 99.9% in the case of the oriental white-backed vulture in the last 10 years.  This is due to an unexpected culprit in the form of the drug diclofenac.  This is an anti-inflammatory drug used by farmers to treat their livestock and is unintentionally ingested by these vultures when they feed on the livestock carcasses.

White-backed vulture

Now, I understand that vultures do not inspire the most pleasant thoughts with many people as they are generally not the most aesthetically pleasing and their almost a symbol of death which is not exactly uplifting.  However, I personally disagree with this opinion as I believe it displays the dangerous concept of speciesism as seemingly more popular species are favoured even when their are others more desperately in need of our help.  Also, vultures contribute a very significant benefit to human societies and their decline is already beginning to have a negative impact.  For example, vultures are the natural caretakers of the environment and this prevents the spread of many diseases that would be a real threat to the poorer people in Asia.  One unprecedented example is there has now been a huge increase in the incidence of rabies, particularly in India.  This is because vultures compete with feral dogs for carcasses so without this source of competition populations of dogs have risen dramatically, along with the incidence of dog bites.

The economy is already taking a hit due to this decline in vultures, with the tanning and fertiliser industries being prime examples.  In a nutshell, more livestock carcasses have to be buried or incinerated as the vultures are not there to dispose of them naturally.  Therefore, less skins and bones are available for these industries.  A last note is that vultures draw tourists so the industry of ecotourism (sustainable tourism) will begin to suffer.

Thankfully, the campaign SAVE (Saving Asia's Vultures from Extinction) is combing of the efforts of many organisations to help these vultures.  These efforts have led the governments of India, Nepal and Pakistan all banning the use of diclofenac and a safe drug meloxicam has been produced as a replacement.  

Long-billed vulture

In addition, captive breeding centres have been set up and resulted in 30 chicks fledging to date. However, these chicks cannot be released into the wild as diclofenac is still very present despite all this work.  The main issues this campaign faces is that people in Asia are either unaware of the effects diclofenac can have or they decided not to care.  Therefore, even though as always money is an important factor in recovery of species (such as in supporting captive breeding programmes), this case has highlighted the need for education.  This education needs to encompass a wide range of people in Asia including farmers, children, conservation students etc so that so that the importance of these vultures is understood and these species can begin to recover. Beyond this, these vulture's story should become a worldwide message of equality and the fact that every species deserves to be saved.

Happy Ending

I was warned at the beginning of this placement that I would be dreaming of yellow flowers by the end of it, and now I can understand why as ragwort pulling has definitely been a significant feature of this week!  Luckily I didn’t have to undergo whole days of this task as they wouldn’t be that cruel (incidentally the team here are lovely) so it was broken up with different tasks.  There were many standard volunteer tasks amongst these, such as clearing out an old building, collecting debris from fields, cutting back brambles etc.  However, there were also some seemingly unusual tasks such as getting dropped off in a field to count sheep.  The reason for this task was to check that the graziers that rent the land off the RSPB were abiding to the agreed numbers of livestock grazing.  The proposed number of livestock on these fields has been calculated to ensure that these fields are not overgrazed or, conversely, under grazed as if there are not enough livestock then they will concentrate on small areas where there is the most palatable vegetation.  This will result in other areas becoming overgrown which will have a negative impact on certain species, such as lapwings that require short grass in which to breed.

Another unusual task took place at Loch Insh which is partly owned by the RSPB but the rest is owned by a water sports centre.  There is an obvious conflict here between water sports and wildlife so the RSPB have tried to minimise this by asking staff at the centre to instruct customers to refrain from disturbance.  One of the most vulnerable species to disturbance is a pair of ospreys that nest on an island in the middle of the loch.  This island is off limits to the general public during the bird’s breeding season, and it is particularly important not to disturb them when they are incubating eggs or trying to feed young chicks as the negative impacts of the public scaring the adults away will be more severe at these critical stages.  Therefore, our task involved monitoring the activity of the loch such as what activities were going on, where, for how long and did anyone approach the island (which thankfully nobody did whilst we were there).  Not exactly a strenuous afternoon although it did feel slightly odd to be using my binoculars to follow people in boats! 

Loch Insh

As this week draws to a close, so does my summer of volunteering, a total of 8 weeks altogether.  I feel a great sense of achievement to have accomplished this as it has definitely been hard work at times.  Saying that, more than anything it has been a joy learning how this world of conservation works alongside some wonderful people who I’ve met along the way.  Most importantly, I have reconfirmed that I have made the right choice pursuing a career in conservation and I look forward to many an exciting adventure in the future.  I will of course keep this blog updated with future stories I will no doubt encounter along the way.