Jul 7

The Galápagos archipelago is known for its extraordinarily rich abundance and diversity of native plants and animals found nowhere else in the world. However invasive species present on islands are threatening the Galápagos’ rare species, pushing many to the brink of extinction. To date, seven vertebrate species have become extinct, while 40% of the still existing 96 species are endangered – with invasive species as the primary threat.

The world’s only marine lizard, the endemic Galápagos marine iguana, is extremely vulnerable to invasive species which consume the young and even occasionally adults

Island Conservation began working to protect species in the Galápagos Archipelago in 2008. In 2011,  the Galápagos National Park, supported by Island Conservation, Charles Darwin Foundation, The Raptor Center, and Bell Laboratories, removed invasive rats from the islands of Rábida, North Plaza, three Beagle islets, and three of the Bainbridge Rocks to protect 12 unique Galápagos species considered by the International Union for Conservation of Nature to be threatened with extinction.  One success story from this project was the rediscovery of a land snail species on Rábida Island, which was presumed to be extinct as no live specimens had been observed or recorded since 1905-1906.

In 2012, work began to remove invasive species from another island in the Galápagos Archipelago, Pinzón Island. Over 150 years ago, invasive black rats invaded this island and began feeding on the defenceless eggs and hatchlings of the Pinzón giant tortoise. By the turn of the 20th century the island endemic tortoise was unable to establish its next generation of tortoises, resulting in a captive rearing program being set up.

Pinzon giant tortoise 2

Adult Pinzón giant tortoise © Island Conservation

By December 2012, the project to remove the invasive rat species from this island was completed. With the removal of the last remaining invasive vertebrate species threat, tortoise hatchlings are now emerging from native tortoises on the island and the Galápagos National Park have successfully returned 118 hatchlings to their native island home.

The removal of invasive species from these islands is part of a much larger project to restore other key Galápagos Island ecosystems to protect native plants and animals. The next major endeavour is to remove multiple invasive species from Floreana Island. Feral goats have already been removed from the island, but other invasive species remain which are a threat to the island’s rich biodiversity. This rich biodiversity includes the Critically Endangered Floreana mockingbird which has disappeared from the island, mainly as a result of invasive species. Now only surviving on two small neighbouring islets, the removal of invasive rats and cats from Floreana will allow for this bird to comeback from the brink of extinction.

The Critically Endangered Floreana mockingbird

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

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.

Jun 7

Atlantic bluefin tuna (Thunnus thynnus)

Species: Atlantic bluefin tuna (Thunnus thynnus)

Status: Endangered (EN)

Interesting Fact: The Atlantic bluefin tuna can swim at speeds of up to 72 kilometres per hour when pursuing its prey.

More information: The enormous Atlantic bluefin tuna can grow to lengths of 4.6 metres and weigh up to 684 kilograms. This fish species has two types of muscle, one for continuous long-distance swimming and the other for short, fast bursts of speed. This amazing adaptation means that individuals of this species are able to swim across the Atlantic Ocean in just 60 days. Although the Atlantic bluefin tuna is generally found swimming in mixed species schools close to the surface of the water, it is capable of diving to depths of up to 1,000 metres when chasing prey. Another fascinating adaptation of the Thunnus genus is the blood exchange system known as the rete mirable which enables individuals to swim in water that is much to cold for other fish. The Atlantic bluefin tuna is a highly migratory species and has a naturally occurring magnetic mineral located in its head that helps with navigation to and from its spawning grounds.

The severe exploitation of the Atlantic bluefin tuna has led to the drastic decline of every known population, particularly in the North Atlantic Ocean. Despite quotas being in place to ensure sustainable numbers are removed from the population, the limits are frequently not respected and unless the legal levels are suitably enforced, it is predicted that some Atlantic bluefin tuna stocks will collapse. The western Atlantic stock may have already collapsed and is now in grave danger of extinction due to overfishing. In the Mediterranean, tuna ranching poses the greatest threat to this species. Individuals are captured alive and taken to a ranch where they are fattened before being sold. Since 1998, catch limits have been in place and in 2006 the International Commission for the Conservation of Atlantic Tunas (ICCAT) established a 15 year recovery plan for the Atlantic bluefin tuna. The plan includes stricter catch limits and closing certain fisheries at specific times of the year to allow the local stocks to recover.

Find out more about Atlantic tuna conservation: International Commission for the Conservation of Atlantic Tunas (ICCAT).

See images and videos of the Atlantic bluefin tuna on ARKive.

Hannah Mulvany, ARKive Content and Outreach Officer.

Jun 5

As you know, back in May we celebrated our 11th birthday, and to mark the occasion we asked our followers to vote for their favourite Arkive highlight from the past year. A huge thank you to everyone who filled out the survey, it has been fantastic to get your feedback on what we have been doing and to find out what you felt was the most important focus for Arkive.

The results are now in and we are thrilled to announce that you chose our work profiling the world’s most endangered species as your winner. This has been a key aim for Arkive since the very beginning, and today we have over 16,000 species profiles in our collection. Of course, this work wouldn’t be possible without the support of the world’s best wildlife filmmakers and photographers, conservationists and scientists, who contribute their imagery and lend their support and advice.

Why not dive in and discover something new today?

Cotton-headed tamarin

The stunning cotton-headed tamarin is one of South America’s most endangered primates

Our 11th birthday also seemed like the ideal opportunity to give the Arkive website a fresh new look and feel, making the most of our amazing imagery. Check out our beautiful new homepage today.

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

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