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Here at Arkive, we provide the ultimate multimedia guide to endangered species, and through our blog we’ll keep you up to date with news from the world of wildlife videos, photography and conservation, alongside the latest on our quest to locate imagery of the planet’s most wanted plants and animals.
May 29

In a letter to Nature magazine, researchers have expressed their concern over the appearance of a non-native toad species, the Asian common toad, in Madagascar.

The Asian common toad (Duttaphrynus melanostictusi) is a close relative of the cane toad (Rhinella marina), an invasive toad species that rapidly spread across Australia after its introduction in the 1930s, and has devastated many native fauna and flora populations. First seen on Madagascar in March, the Asian common toad has been sighted several times in areas close to Toasmasina, the main port of the island nation. Worryingly, there have also been sightings of the amphibian just 25 kilometres from the Betampona Nature Reserve and short distances from other biodiversity hotspots. The dispersal of this species is not just limited to Madagascar and it is thought that populations may have also become established in other areas. One of the authors of the letter, Jonathan Kolby, of James Cook University in Queensland, Australia, said, ”There is now a high dispersal risk of these toads spreading from Madagascar to other Indian Ocean islands such as the Mascarene Islands, Comoros, and Seychelles.”

It is thought that populations may have also become established on other Indian Ocean islands, such as the Mascarene Islands

It is thought that the Asian common toad could have various negative impacts on the fauna of Madagascar, including spreading diseases such as ranavirus and chytridiomycosis to native amphibians and competing with them for food and breeding areas. This toad species is poisonous and is known to be toxic to animals that ingest it. Snakes are thought to be one of the animal groups most at risk from the invasion and there are over 50 endemic snake species on Madagascar, including the Madagascar ground boa. Other endemic species including fossas, lemurs, and birds will also be put at risk should the population of this harmful amphibian become established. Kolby also said, “It’s worrying because Madagascar has amazing endemic biodiversity – plants, animals, and amphibians that are found nowhere else. And this one species has the propensity to damage that.”

95 percent of the reptiles on Madagascar are endemic to the island, including the Madagascan ground boa

As well as being a threat to the animals of Madagascar, the Asian common toad is also a threat to the human population as it is known to contaminate drinking water and transmit parasites. After the devastation the cane toad has caused in Australia, it is thought that immediate action is required on Madagascar to prevent history from repeating itself. Kolby said, “The question is, can we still eradicate them? Have we caught it soon enough that eradication could be a feasible option? Obviously we all hope the answer is yes.” Suggested methods of eradication include removing adult toads, draining breeding ponds, and installing fences to prevent the toads from reaching water where they would be able to breed. Highlighting the urgency of the situation, Kolby said, ”Time is short, so we are issuing an urgent call to the conservation community and governments to prevent an ecological disaster.”

In Australia, the introduced cane toad is responsible for the declines of many native species, including the Near Threatened brush-tailed phascogale

Read more on this story at Nature – Toxic toads threaten ‘ecological disaster’ for Madagascar.

View images and videos of Madagascan species on ARKive.

Hannah Mulvany, ARKive Content and Outreach Officer

May 27

Everyone remembers their first encounter with a whale shark, just as we all remember that first kiss, but experience has taught me that each encounter is in some manner just as unique as the first time.

When I first began diving the northern islands of Wolf and Darwin in the late 1980´s, we really had no idea of the species that we were going to find. Already Darwin´s Arch had begun to get the reputation as being the best dive site in Galapagos. Within days of my arrival to these distant shores I heard rumours of schooling hammerheads, Galapagos sharks and the strangely named ¨Pez Gato¨ or ¨catfish¨ as the fishermen referred to whale sharks. I later learned that the white spots on a whale shark where likened to those of the jaguar. Perhaps some of the fishermen had spent some of their formative years in the Ecuadorian Amazon jungle!

1 Whale Shark with Creole fish - Jonathan Green

Whale shark with creole fish © Jonathan Green

As time progressed we became aware that the whale sharks were aggregating on a seasonal basis, much more frequent during the cold garua season between June and November. The larger animals were thought to be males, although as with many shark species the female whale sharks are larger on average than males. It was only when we began actively checking for male claspers that it became apparent that most of the sightings were actually of females.

By the beginning of the new millennia I was already convinced that most of those whale sharks that passed by Darwin were not only adult females, but that they were also pregnant! Their distended abdomens appear to confirm this, but how could we get solid scientific evidence? It’s not so easy when they average over 10 m in length and weigh upwards of 20 tons. Researchers working with other large pelagic sharks such as tigers and great whites are able to capture the animal and carry out certain medical procedures in a controlled environment, much as we do with humans. The shark is winched onto the deck and immobilised and although there are strict time limitations, blood samples may be taken and an ultrasound test carried out.

1 Whale Shark - Jonahtan Green

Whale shark © Jonathan Green

This is simply not possible given the size and nature of the whale shark, so how do we propose to do this? Certainly a challenge as this has never been tried before. Blood samples have been taken from captive whale sharks, but never ¨on the fly¨. Picture a diver with no means of propulsion but his fins and leg muscles, chasing down an animal the size of a single decker bus with a 4 knot current in a thousand feet of water! Sound exciting?

Next season we hope to have members from the Georgia Aquarium join us in the field to attempt taking a blood sample from a whale shark in the wild, for the very first time. They already have extensive data of the blood chemistry of captive juvenile female whale sharks that are not pregnant. By comparing the blood chemistry of a female in the wild that we are 90% certain is pregnant, we may be able to determine how close to birthing she is. We also hope to try the worlds first underwater ultrasound using a waterproof prototype unit that is self contained and can record video and still images. Perhaps this will give us an indication of the stage of development of the embryos, as well as numbers of pups. Each encounter with a whale shark provides us with more information.

Alan Purton

Whale shark © Alan Purton

Developing new techniques in order to answer some of the many questions that still remain about their natural history has always held great appeal, for it is that voyage of discovery and the resulting data that may help protect whale sharks in the future, wherever in the world they roam.

If you would like to learn more about the project in Galapagos and how you can get involved, visit whalesharkappeal.co.uk.

May 24

Russian sturgeon (Acipenser gueldenstaedtii)

Species: Russian sturgeon (Acipenser gueldenstaedtii)

Status: Critically Endangered (CR)

Interesting Fact: The Russian sturgeon can reach lengths of nearly two and a half metres.

More information: The Russian sturgeon belongs to an ancient and unique group of fish, relics from the time of the dinosaurs. This prehistoric giant was formerly found in the Black, Azov, and Caspian Seas in Eastern Europe and the Middle East, as well as the deep sections of fast-flowing rivers, such as the Volga, Danube, and Ural Rivers. Populations of this species are now mostly found in the lower reaches of these river systems and along coastlines.

The male Russian sturgeon does not reproduce until it is between 8 and 13 years old and only do so every 2 or 3 years, while the female does not reach sexual maturity until it is 10 to 16 years old and then only reproduces every 4 to 6 years. There are two distinct forms of this fish species, the anadromous type which migrates up rivers from the sea to spawn and the freshwater form which remains in its freshwater habitat to spawn, although this form is now thought to be extinct. For the anadromous type, there are two separate migrations, one in spring when spawning occurs in the lower levels of the river and one in autumn when individuals migrate into freshwater where they spend the winter before spawning upstream the following spring.

Vast areas of the Russian sturgeon’s spawning grounds have been lost due to damming and exploitation. Dam construction is highly detrimental to this and other migratory fish species, as the usual migration routes to its spawning grounds are blocked, meaning that individuals either do not reproduce, or spawn in unsafe areas. Pollution in the Caspian and Black Sea basins is causing hormonal imbalances in this species and subsequently a greater number of hermaphroditic, infertile individuals are found in these areas.

The Russian sturgeon was once very important commercially, and its caviar was one of the most sought after of any species. Illegal fishing still continues, despite legal catch quotas being in place, with the illegal catch thought to far surpass the legally set limits. The Russian sturgeon is unprotected in many areas throughout its range and the absence of a strict monitoring system makes the control of fishing very difficult. Despite restocking efforts, the creation of artificial spawning grounds, and the introduction of fish lifts to help individuals to get around dams, the population is still in decline and over the last 15 years, global catches have dropped by 98 percent. As a slowly maturing species, it does not have the ability to recover from overexploitation, especially without complete cessation of fishing.

Celebrate World Fish Migration Day and find out more about why we need to protect these species and their habitats.

Find out more about sturgeon conservation.

See images of the Russian sturgeon on ARKive.

Hannah Mulvany, ARKive Content and Outreach Officer

May 23

The 23rd of May is World Turtle Day – a whole 24 hours dedicated to highlighting the plight of turtle species around the world. Here at ARKive we thought we would celebrate by sharing our top turtle facts.

Did you know…

  • Turtles are found on every continent, except for Antarctica
  • The age of most juvenile turtles can be determined by the upper shell, which grows each year from a central point
  • Turtles are thought to have lived on earth for over 200 million years
  • The sex of most turtle hatchlings is dependent on the temperature which they are incubated at, with males hatching at low temperatures and females hatching when the temperature is higher

Lovely Loggerheads

  • The loggerhead turtle has powerful jaws that can make easy work of its hard-shelled prey.
  • It is highly migratory and is known to cross oceans.

Not a jack in a box

  • Box turtles gain their common name from their hinged shell which enables them to completely close their shell to protect themselves.
  • The male ornate box turtle has enlarged claws on its hindfeet to grip onto the female while mating.

Vast vertebrate

  • The leatherback turtle is the world’s largest turtle, with the average carapace (the shell covering the back) reaching around 160 centimetres and the largest recorded individual weighing up to 916 kilograms.
  • Uniquely, the leatherback turtle is able to maintain an elevated body temperature, giving it the ability to dive to depths of up to 1,000 metres in pursuit of prey.

Snappy by name, snappy by nature

  • The alligator snapping turtle is nicknamed the ‘dinosaur of the turtle world’ due to its prehistoric, alligator-like appearance, from which it gains its common name.
  • The tongue of the alligator snapping turtle has a small, worm-like projection, which is wiggled to attract prey.

What is being done to help?

Thankfully, various conservation organisations and individuals are working tirelessly to help save turtles and tortoises from the brink of extinction. Here are some actions being taken to ensure the future survival of these fascinating creatures:

  • Shrimp fisheries are now using Turtle Excluder Devices, which only allow shrimp-sized objects to enter the nets, preventing turtles from being caught as bycatch
  • Many species are now listed on the Convention on International Trade in Endangered Species (CITES), which means that international trade is strictly monitored and controlled – this should hopefully prevent some collection of wild turtles for the international pet trade
  • Some nesting sites are protected during the nesting season to ensure that eggs cannot be collected and subsequently sold
  • Captive breeding programmes and the protection of areas which are known to support turtle populations could ensure the long-term survival of these magnificent reptiles

Are you turtley in awe of sea turtles? Want to learn more about them? Then why not check out our eggshellent ARKive Education resource – Turtle Life Cycle – and play the turtle-tastic board game!

Find out more about turtles, tortoises and their conservation:

View photos and videos of turtle and tortoise species on ARKive

May 22

Today is the United Nation’s International Day of Biological Diversity, which this year has been dedicated to island biodiversity.

Islands are home to an estimated 20% of all bird, reptile and plant species despite making up less than 5% of Earth’s land area. Islands also contain 40 percent of all critically endangered species, and the extinction rates on islands are disproportionately high despite a global extinction rate that may be 1000 times the historical background rate.

Islands contain 40 percent of all critically endangered species

“Biodiversity is crucial to meet human needs. Our economies, livelihoods, health, and cultures depend on the proper management of this natural capital.  This is even more important on islands where natural ecosystems are fragile and easily disturbed.” said Olivier Langrand, Island Conservation’s Director of Global Affairs, member of the Steering Committee of Global Island Partnership (GLISPA) and co-chair of the GLISPA Working Group on Invasive Alien Species.

The necessity of urgent action in aid of island conservation, to halt and reverse the loss in biodiversity is highlighted in the new publication , “Island Bright Spots in Conservation & Sustainability” by the Global Island Partnership (GLISPA). This report showcases inspired island conservation solutions in action, “bright spots”. These “bright spots” will also be showcased during the 2014 International Year of Small Island Developing States (SIDS) to encourage investment in scaling and replicating initiatives that work. In this publication Island Conservation’s Allen Cay and Small Islands, Big Difference (SIBD) projects are highlighted as successful examples that could serve as innovative models for island restoration around the globe.

Island Conservation’s Allen Cay

Allen Cay, The Bahamas is a small island habitat but is home to important populations of Audubon’s shearwater and provides critical habitat for the endemic, endangered Allen Cay rock iguana. However, invasive house mice were indirectly threatening the native species by providing an abundant food source for barn owls, increasing the owl populations, which predate heavily on Audubon’s shearwater and juvenile Allen Cay rock iguanas. In 2012, Island conservation collaborated with the Bahamas National Trust, Government, NGO and private partners to remove invasive house mice from Allen Cay. This successful partnership protected nationally and globally significant biodiversity, and laid foundations for future restoration and conservation projects in the Bahamas.

Allen’s Cay rock iguana on beach

Island Conservation’s Small Islands, Big Difference Project

Island Conservation’s Small Islands, Big Difference (SIBD) campaign was launched in Montreal, Canada in 2012. The goal of this campaign is to financially support hundreds of partners and island nations in protecting thousands of species through the removal of invasive species from 500 islands.

Island Conservation and local partners helped protect critical habitat for the waved albatross by removing invasive goats and feral cats from Isla de la Plata

The“Island Bright Spots in Conservation & Sustainability” publication also highlights emerging initiatives such as the recent launch of the Mālama Honua Worldwide Voyage by the Polynesian Voyaging Society, a three year open-ocean journey around the world undertaken in two Hawaiian voyaging canoes. The aim of this project is to catalyse awareness and action on how to care for Earth, the Oceans and our natural heritage. The crew aim to bring stories of our islands and oceans to inspire communities and leaders to take action to protect these critical resources.

Read more about the importance of Islands habitats

Read more about Island Conservation.

Find out how the Mālama Honua Worldwide Voyage is progressing.

Ben Hogan, Wildscreen ARKive PIPS Intern

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