Jun 12

“When I first landed on what was Rat Island in 2007, it was an eerily silent place. A typical Aleutian island is teeming with wildlife, swirling with noisy, pungent birds. Not this place. It was crisscrossed with rat trails, littered with rat scat, scavenged bird bones, it even smelled…wrong,” reports Stacey Buckelew, an Island Conservation biologist. Buckelew first visited the island to help document centuries of damage to native birds and plant species from introduced invasive Norway rats.

Hawadax Island (formerly Rat Island), located in the Aleutian Islands off the coast of Alaska, is a 6,861 acre island uninhabited by humans. This treeless island has steep costal cliffs, a small central mountain range and broad rolling plateaus of maritime tundra. In the early 1780’s a shipwreck left the island with invasive Norway rats. Since their arrival the rats had decimated the islands native bird species by eating eggs, chicks, adult birds and plants.

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Hawadax Island (formerly Rat Island), Alaska © Island Conservation

In September 2008, Island Conservation, The US Fish and Wildlife Service and The Nature Conservancy successfully removed invasive rats from Hawadax Island. Following the removal of the rats all direct impacts, such as predation and competition for resources, immediately ceased.

Today the island is thriving. Since the removal of the rats, breeding tufted puffins (Fratercula cirrhata) have been documented on the island for the first time and species thought to have been extirpated due to the rats, such as Leach’s storm-petrels (Oceanodroma leucorhoa) and fork-tailed storm-petrels (Oceanodroma furcate), have been recorded.

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Tufted Puffins in waters around Hawadax Island, Alaska © Rory Stansbury / Island Conservation

Ground-nesting and shorebird numbers are increasing as well. A 2008 survey documented nine glaucous-winged gull nests whereas an identical survey carried out in the summer of 2013 discovered twenty eight nests, a three-fold increase. Black oystercatchers (Haematopus bachmani) and rock sandpiper (Calidris ptilocnemis) nests have also increased significantly. Song sparrows (Melospiza melodia), thought to be nearly extirpated by rats, and snow buntings, also decimated by rats, are rebounding as well.

Snow bunting in autumn

In 2012, Rat Island formally had its original Aleut name, Hawadax, restored in acknowledgement of the absence of rats.

To find out more about the great work that Island Conservation carry out, visit their website or facebook page.

Find out about more North Pacific Islands on Arkive.

Jemma Pealing, Arkive Content and Outreach Officer

Jun 10

Located 14 miles off the coast of California, Anacapa Island is the easternmost island in the Channel Islands Archipelago. Comprised of three islands strung closely together (East, Middle and West Anacapa), Anacapa Island is part of the Channel Islands National Park. Native species to the island include the Vulnerable Xantus’s murrelet (now renamed Scripps’s Murrelet), the endemic Anacapa deer mouse and the largest breeding colony of brown pelicans in California.

West and Middle Anacapa Islands, Channel Islands National Park, California, USA

Once an island with no natural predators for nesting birds, invasive non-native black rats were inadvertently introduced to the island from ships visiting the islands in the 1940’s. The invasive rats decimated native seabird populations by eating eggs and chicks. In 2001 and 2002, Island Conservation, the Channel Islands National Park, California Department of Fish and Game, the U.S. Fish and Wildlife and the National Oceanic and Atmospheric Administration removed the invasive rats from Anacapa Island. In the absence of these invasive predators Xantus’s murrelets (now renamed Scripps Murrelet) rebounded almost immediately with nesting success increasing by 91% the year after the rats were removed. The nesting success has remained at around 90%, compared to just 20% when rats were still there.

Xantus’s murrelet on water

This was not the only success story. Since the removal of the rats, ashy storm-petrels have been recorded nesting on the island for the first time ever and the Cassin’s auklet, a small seabird which had been unable to nest on Anacapa Island due to the risk of rat predation, has returned. Populations of the island’s only endemic mammal, the Anacapa deer mouse, are also thriving after the removal of the rats which used to compete with the mice as well as predating on them.

Ancapa deer mouse

Anacapa deer mouse © Jacob Sheppard/ Island Conservation

To find out more about the great work that Island Conservation carry out, visit their website or facebook page.

Find out about more North Pacific Islands on Arkive.

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 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 Island habitats on Arkive.

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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