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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.
Apr 24
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Guest Blog: The marine iguanas of San Cristobal island – Amy MacLeod

Amongst the black lava rocks that line the wave-lashed edges of the Galapagos Islands, the world’s only sea-going lizard can be found.  Amblyrhynchus cristatus, the marine iguana, is a remarkable and well-known endemic reptile of the Galapagos Archipelago.  Though widespread and highly abundant on certain islands, small, declining and genetically distinct populations on other islands are causing concern for conservationists.  One population in particular, found at the very tip of the easternmost island of San Cristobal has garnered attention not only for its critically small size, but also for being highly distinctive in genetic terms.  This ‘Punta Pitt population’, named after its location, is so genetically distinct that we are investigating whether it deserves recognition as a new species or sub-species.

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A marine iguana at Isla Lobos, San Cristobal Island. Larger males, like this one, swim and dive to forage on sub-tidal algae, whereas smaller individuals graze along the intertidal zone

 Since 2012 we have travelled to San Cristobal each year to collect information and new samples that will teach us more about Punta Pitt iguanas.  Before we started, iguanas on San Cristobal were known from only two colonies which seem not to interbreed with one another.  We began in 2012 by sailing around the island and sampling iguanas wherever we encountered them.  We found and sampled many new colonies, all on the west coast.  The entire eastern side of the island, wild and wave-battered, sadly eluded us.

Processing samples in the field at La Galapaguera, where Punta Pitt type iguanas are found

Processing samples in the field at La Galapaguera, where Punta Pitt type iguanas are found

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Weighing a young iguana at Islotte Pitt

In 2013 we returned to San Cristobal, this time to take a closer look at Punta Pitt and investigate the threat posed by feral cats, known to eat marine iguana hatchlings.  We camped at a remote beach for seven weeks.  During this time we fitted four feral cats with GPS-enabled radio collars and followed their movements.  We also collected measurements, samples and photographs of marine iguanas in order to investigate both physical and genetic differences between iguanas on the island.  Though we were only three people at the camp, we were certainly not lonely; the resident mocking birds, as curious as they are comical, watched our every move.  Constant vigilance was needed to prevent the legion of local hermit crabs from stealing all manner of things, and most evenings provided a cascade of newly hatched green turtles on the dunes, making their way down to the sea.

The resident mocking bird, who assumed ownership of all our things at camp (especially any unguarded porridge)

The resident mocking bird, who assumed ownership of all our things at camp (especially any unguarded porridge)

Frigate birds oversee the dish washing at camp

Frigate birds oversee the dish washing at camp

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The finches give our packing boxes a close inspection

Galapagos_April_2013 159

Newly hatched green turtles begin their journey down the dunes to the sea at Salinas beach

We are now in the midst of the final field-season of my PhD.  This season will be shorter, and we intend to find a way to sample the East coast.  This will involve searching for safe landing sites with an experienced fisherman, and a lot of walking along lava rocks.  If we are successful, we will have surveyed and sampled almost the whole island.  Back in Germany, we are working hard to analyse the morphological and genetic data that will tell us whether or not Punta Pitt iguanas are a new species.  In any case, the information we have gathered here in San Cristobal will be a valuable contribution to assessing the conservation status of marine iguanas on this island, where their population is the smallest of any of the Galapagos Islands.

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Punta Pitt type iguanas on the headland at Playa Cafe, the white cross is a temporary mark which indicates a sampled iguana

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Amy MacLeod is in the final year of her PhD at the Technische Universität Braunschweig in Germany. You can contact her by email at ms.amymacleod@gmail.com

Apr 23
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Guest Blog: British Freshwater Fish – Jack Perks

It’s a well-known fact that Britain is a nation of animal lovers and is particularly obsessed with its wildlife. However, there is one group which often gets overlooked – our piscatorial friends the freshwater fish. Currently there are 54 species of freshwater fish swimming around the United Kingdom, including species like the mullet and flounder which, despite just visiting the estuarine parts of rivers, can be found surprisingly far up from the sea! Non-native species such as the wels catfish, which resembles a giant tadpole, and the topmouth gudgeon are also present in the UK. Despite the UK not suffering from the presence of non-native species as much as other countries such as Spain, the tiny topmouth gudgeon does still cause big problems by outcompeting native fish and spreading disease.

The topmouth gudgeon has been described as Europe’s most invasive fish species

In recent years, the number of native European eels has declined by around 95%. However, 2013 was recorded as one of the best elver runs in recent years, with millions making their way up the Severn. Whilst many may think that floods are not good for fish, flooding helps the European eels get into ponds and lakes where they can grow before returning to the Sargasso Sea with the next floods.

European eel image

The European eel is very long-lived, potentially reaching an impressive 85 years old

There are many other native freshwater fish species which are less well known to the general public and even wildlife enthusiasts (I bet most birders in the UK have never heard of a spined loach or allis shad, for example). One such species is the Arctic charr, a cousin of the trout, which lives in deep glacial lakes mostly in the Lake District and Scottish Lochs. The Arctic charr can also be found in Iceland where it reaches much larger sizes of up to 20lb and, unlike the British populations, goes out to sea like a salmon.

Male and female Arctic charr

So next time you’re walking by your local canal or river, take a look and see what you can spot -  you’ll be surprised by the wealth of fish life beneath the waterline in British waterways.

Video showing 28 species filmed by me: http://www.youtube.com/watch?v=mjAIUKfYtHA

Jack Perks Photography – Underwater & Wildlife Photographer

Website – http://www.jackperksphotography.com and http://www.btwlfishproject.com/
Twitter – @JackPerksPhoto

Apr 20
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ARKive’s Top Ten Eggs

With Easter just a hop, skip and a jump away, we thought we’d crack into the ARKive coll-egg-tion and have a scramble around to eggs-tract some egg-citing eggs to eggs-hibit in our blog. Along the way, we’ve also learned about the eggs-istence of some rather eggs-centric egg-laying and guarding habits, and we hope you’re as eggs-tatic about our finds as we are!

Gooseberry fool?

Peacock butterfly egg image

Peacock butterfly eggs look a lot like gooseberries!

While you might be forgiven for being fooled into thinking that these green globules are plump and juicy gooseberries, they are, in fact, peacock butterfly eggs. The eggs of this species are laid in groups under nettles, usually in May, and hatch two weeks later.

Sunny-side up? Over-easy? Well-done?

Emu egg image

Emu eggs come in various shades of greenish-black

However you like your eggs, there’s no denying that these ones look as though they’ve been char-grilled in their shells! But fear not, these emu eggs are supposed to look like this; they come in various shades of greenish-black and are the size of a small grapefruit. The male emu is an eggs-traordinary guardian, taking sole responsibility for incubating the eggs over the course of two months while the female wanders off to potentially find another mate, and protecting the chicks against predators for several months once they’ve hatched.

100 kids and counting…

Green turtle egg image

Green turtles can lay an impressive number of eggs per nesting season

In the UK, having more than about four siblings would constitute being part of a pretty large and impressive family, but in the world of marine turtles, this is a mere drop in the ocean. Female green turtles produce between 100 and 150 ping-pong-ball-like eggs per clutch, and can lay up to nine separate clutches per breeding season. While this may seem rather a lot, marine turtles don’t guard their nests or look after their young, and with the threat of land- and ocean-dwelling predators, the survival rate of hatchlings is very low.

High-flying hunger games…

Bald eagle egg image

Bald eagle nests are some of the largest of any bird species

Bald eagle nests, made with sticks and lined with moss, grass, seaweed and other vegetation, are some of the largest of any bird species, sometimes reaching several metres in width. These enormous nests presumably provide a comfy and snug environment for the eggs during the 35-day incubation period, yet things can soon turn ugly. By being bigger and louder, the first-born chick is often afforded more parental attention and food, and will even occasionally kill its younger siblings.

Treasures of the deep

California horn shark egg image

Shark eggs, such as this California horn shark egg, are often referred to as ‘mermaid’s purses’

A mermaid’s purse might well sound like something a sea-dwelling siren would keep her money and credit cards in, but a pilfering pickpocket could get a nasty surprise if they were to try to purloin this particular purse as it is actually a shark egg-case! Mermaid’s purses vary greatly in shape, size and colour, depending on the shark species in question.

Eggs-panding eggs

 

Common frog egg image

Common frog eggs are coated in a jelly-like substance

Frog egg masses, often referred to as frogspawn, tend to look rather like a gruesome collection of eyeballs. The female common frog releases between 1,000 and 2,000 eggs at a time, which are covered in a jelly-like coating. This coating expands when it comes into contact with water, providing protection for the tadpoles growing within.

Egg pasta

 

Sea lemon egg image

Pasta del mar – sea lemons produce somewhat pasta-like egg masses

What may look like a delectable strand of abandoned tagliatelle cast into the depths of the ocean is, in actual fact, a mass of sea lemon eggs. A common sea slug around Britain’s shores, the sea lemon produces thousands of eggs at a time which form a long, coiled, ribbon-like mass. These egg masses are produced in the spring and are attached to rocks, so if you take an Easter weekend dip in the sea and find such a structure, we would advise leaving it well alone and not adding it to your carbonara!

Ha-bee Easter!

 

Honey bee egg image

Honey bee egg

A supplier of sugary goodness and a harbinger of spring to many, the honey bee lays its eggs from March to October. Honey bee colonies have a complex structure, formed of the queen, workers and drones, all of which serve different functions. Worker bees have a variety of roles within the colony, with some being tasked with feeding the developing larvae which emerge from the eggs around three days after they are laid.

Eggshellent parenting

 

King penguin egg image

King penguins incubate their egg on their feet

King penguins appear to take parenting very seriously, with each pair keeping a close eye on their precious egg. Incubation is shared by the male and female and is split into two- or three-week cycles, and parental duties remain shared once the chick has hatched. It’s a good job that king penguins don’t let their eggs out of their sight, otherwise they may not believe the chick belonged to them…the chick looks so different to the adult that they were first described as two completely different species!

Eggs-treme monotreme

Short-beaked echidna egg

A short-beaked echidna egg

While the majority of mammals give birth to live young, there are some eggs-treme mammalian species that lay eggs! These eggs-tra special critters are known as monotremes, and the short-beaked echidna is one of them. The echidna’s leathery egg is laid into a pouch on the female’s abdomen, where it is incubated for about ten days before it hatches. The young echidna, or ‘puggle’, remains there until it is 45 to 55 days old.

We hope you’ve enjoyed these eggs-amples of awesome eggs, and that you all have a wonderful Easter weekend!

Kathryn Pintus, ARKive Text Author

Apr 19
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Endangered Species of the Week: Vancouver Island marmot

Vancouver Island marmot (Marmota vancouverensis)

Species: Vancouver Island marmot (Marmota vancouverensis)

Status: Critically Endangered (CR)

Interesting Fact: The Vancouver Island marmot is thought to be one of the rarest mammals in North America, with a wild population of fewer than 100 individuals.

More information: The endemic Vancouver Island marmot is a stocky rodent that has a chestnut-brown pelage with a cream-coloured area around its nose and mouth. As with all marmots, the Vancouver Island marmot lives in family groups that usually contain one male, two females and the juveniles and young produced that year. The families occupy complex underground burrow systems in which they hibernate between the end of September and early May, surviving by using up the fat reserves that are built up throughout the summer.

Logging activities and weather fluctuations within the habitat of the Vancouver Island marmot are thought to have caused population declines. Additionally, the local deer population has recently increased and their presence is known to increase the amount of predators in an area which may also take Vancouver Island marmots.

The Vancouver Island marmot is legally protected through its listing on the British Columbia Wildlife Act. A recovery plan was established in 1988 in an attempt to save this species from the brink of extinction, and a captive breeding programme is now in place, with reintroductions of captive-bred individuals planned for the future.

See images of the Vancouver Island marmot on ARKive

Find out more about Vancouver Island and other islands of the North Pacific

Find out more about other marmot species

Hannah Mulvany, ARKive Content and Outreach Officer

Apr 18
Share 'The most important eggs this Easter: Saving the Rarest Bird in Galapagos' on Delicious Share 'The most important eggs this Easter: Saving the Rarest Bird in Galapagos' on Digg Share 'The most important eggs this Easter: Saving the Rarest Bird in Galapagos' on Facebook Share 'The most important eggs this Easter: Saving the Rarest Bird in Galapagos' on reddit Share 'The most important eggs this Easter: Saving the Rarest Bird in Galapagos' on StumbleUpon Share 'The most important eggs this Easter: Saving the Rarest Bird in Galapagos' on Email Share 'The most important eggs this Easter: Saving the Rarest Bird in Galapagos' on Print Friendly

The most important eggs this Easter: Saving the Rarest Bird in Galapagos

Earlier in 2014, sixteen tiny eggs were collected from two small pockets of mangrove forest on the western side of Isabela in the Galapagos Archipelago. These eggs, each the size of the nail on your little finger, belong to one of the rarest and most range restricted birds in the world: the mangrove finch (Camarhynchus heliobates). This small, brown, unassuming bird is one of the famous Darwin’s finches and is today the rarest endemic bird in Galapagos. There are less than 100 mangrove finches alive today and last year there were only 14 breeding pairs. But why are they so critically endangered?

Mangrove Finch © Michael Dvorak

Mangrove Finch © Michael Dvorak

Until recently, one of the main threats to mangrove finches was introduced rats. As generalist carnivores, rats would seek out and feed on the eggs and chicks of finches during the breeding season. Fortunately, rats are now being controlled at the breeding sites but now a much smaller invasive species poses an even larger threat.

Philornis downsi is a species of fly native to Trinidad and Brazil. It was introduced to Galapagos in the 1960s and has now spread to 14 islands within the Archipelago. The adults of this fly are harmless, feeding almost exclusively on nectar, but in their larval stage they are blood-sucking parasites. Female flies lay their eggs in the nests of small breeding land birds. Blind, naked and weak, the mangrove finch hatchlings are an easy target for the fly larvae which feed on their blood, very often resulting in the death of the chick. In 2013, 37% of chicks were killed this way – a massive hit to such a tiny population.

Philornis downsi larvae © A. Muth

Philornis downsi larvae © A. Muth

So why are the scientists removing eggs? In an effort to ensure that the mangrove finch does not become the first bird to go extinct in Galapagos since before Darwin’s time, scientists from the Charles Darwin Foundation and San Diego Zoo are, with support from the Galapagos National Park, taking action. During the mangrove finch breeding season, females lay up to five clutches of eggs but the first few rarely survive. By taking this first clutch, hatching and raising the chicks in captivity, then releasing them back into the wild when they are old enough, the project should result in more individuals being added to the population each year.

Chick being hand fed © Juan Carlos Avila

Chick being hand fed © Juan Carlos Avila

By raising the chicks in captivity, they will have avoided the nest-bound parasites and will have been given a ‘head-start’ in life. 2014 was the first time ‘head-starting’ has been trialled on mangrove finches and it is proving a great success. The sixteen eggs have hatched and the mangrove finch chicks are being released back into the mangroves right now. The future of the mangrove finch is starting to look a little brighter.

2. Remaining mangrove finch habitat 2 - (c)Francesca Cunninghame

Remaining mangrove finch habitat © Francesca Cunninghame

For more information on the project and to keep up to date with progress, please visit www.mangrovefinchappeal.org

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