Nov 28

The observance of Thanksgiving Day is primarily associated with the United States, and is a tradition which is thought to date back to colonial times following the safe arrival of the first European settlers to the untamed shores of North America. Nowadays, families and friends congregate to give thanks for what they have, so to celebrate Thanksgiving in our own wild way, we’ve gathered together a few of nature’s special inhabitants that we think owe each other thanks: symbiotic species!

 

Exclusive residence

Common clownfish image

Common clownfish are able to live among the tentacles of stinging sea anemones

Simply speaking, symbiotic species are those that interact in some way, to the benefit of one or both of the critters in question. A classic example, and one that many Disney fans will be familiar with, is the relationship that exists between clownfish and sea anemones.

Sea anemones usually sting fish that come into contact with their tentacles, but clownfish have developed a clever, yet rather gross, method of disguise. By covering its skin in mucus, the clownfish can trick the anemone into thinking it is touching itself, and so does not get stung. In return for a safe place to live and food in the form of debris and parasites found amongst the anemone’s tentacles, the clownfish is thought to scare away fish that may prey upon the anemone, and even lure fish in for its tentacled home to eat – a classic win-win situation! The clownfish is also believed to provide the anemone with good water circulation through fanning its fins as it swims around.

Did you know?

There are different kinds of symbiotic relationships. Some benefit both species involved, and are known as ‘mutualistic’ symbioses, whereas ‘parasitic’ relationships are those in which one species profits at the expense of the other. In some cases, one species benefits but the other is affected neither positively nor negatively, and these are known as ‘commensalistic’ symbioses.

 

Nutritious nectar and pollen parcels

Small garden bumblebee image

Bees, such as this small garden bumblebee, play an important role in plant pollination

Bees feed on pollen and nectar sourced from a variety of flowering plants, with honey bees using the nectar to make their sticky, sugary treat. Although flowers appear to lose out by ‘donating’ nectar, they actually benefit from these flying visits. As a bee rummages around the flower head for food, some pollen gets stuck to its hairy body and legs, and this accidental cargo is then transferred to the next flower the insect visits, pollinating it and enabling the plant to reproduce.

Did you know?

The traditional origin of the modern Thanksgiving Day is commonly thought to be the festivities that occurred at the Plymouth Plantation in Massachusetts in 1621, when the European settlers celebrated their safe voyage, peace and good harvest. However, there is some evidence to suggest that Spaniards in Florida were the first to truly celebrate Thanksgiving back in 1565.

 

Getting a little peckish…

Roan antelope image

Oxpeckers help remove parasites from large mammals such as this roan antelope

In the wilds of the African savanna, large mammals such as this roan antelope can quickly become covered in ticks and all sorts of other creepy crawlies, which doesn’t sound entirely pleasant! Luckily, help is at hand in the form of winged wonders known as oxpeckers. Oxpeckers are known to hitch a ride on the backs of a range of iconic species including hippos, buffalos, giraffe and various antelopes, gorging themselves on ticks, botfly larvae and other parasites – the mammals get cleaned, and the birds get fed, and so this has often been classified as a mutualistic relationship. However, more recent studies have shown that oxpeckers often pick at scabs and cuts to keep them open to get more food, subjecting the wounds to possible infection and potentially harming the host mammal, making this symbiotic relationship more of a parasitic one.

 

Helpful houseguests

Acropora formosa image

Reef-building corals rely on tiny blue-green algae to survive

Reef-building corals provide homes for single-celled blue-green algae known as zooxanthellae, and in return these microscopic plants provide energy-containing compounds for the coral through the process of photosynthesis. The coral uses these vital compounds to build its calcium carbonate skeleton. In a way, these tiny blue-green algae are like live-in coral chefs…and they even clean up after themselves by removing any waste products! Brilliant!

 

Nature’s six-legged gardeners

Leaf-cutter ant image

Leaf-cutter ants tend to their fungus garden by creating ‘mulch’ from leaf fragments

Leaf-cutter ants are known as nature’s gardeners, as they spend their time foraging for leaves and cutting them into suitably sized fragments before transporting them back to their huge underground nests where the leaves are used to cultivate a fungus garden. While the ant colony is entirely dependent upon this fungus supply for food and so greatly benefits from this situation, the fungus benefits by being cultivated by the ants but also loses out by being eaten, and so this relationship could be classified as a more commensalistic one.

Did you know?

Most of us think of the US in relation to Thanksgiving, but did you know that several other countries observe similar days, too? These include Canada, Puerto Rico and Liberia. Additionally, the city of Leiden in South Holland celebrates the traditional US Thanksgiving Day, making the Netherlands the only non English-speaking country to formally celebrate this particular occasion.

 

Food on the go…

Dugong image

Dugong

Loggerhead turtle image

Loggerhead turtle

 

 

 

 

 

 

 

 

Leopard shark image

Leopard shark

Giant manta ray image

Giant manta ray

 

 

 

 

 

 

 

 

Scientists are somewhat divided over whether the relationship that exists between specialised fish known as remoras and a variety of larger ocean species is a mutualistic or commensalistic one. Also known as suckerfish, remoras have a specially adapted first dorsal fin which has been modified into a sucker-like organ. Remoras use this to attach themselves to other marine animals such as sharks, rays, sea turtles and dugongs, feeding on material dropped by the host species while also getting a free ride and protection from potential predators. This seems rather one-sided, but some scientists believe that the remoras may also feed upon certain parasites on the host’s body or gills, therefore providing a great cleaning service to their marine meal providers.

If these beholden bovids, indebted invertebrates and contented chondrichthyans haven’t quenched your thirst for wild Thanksgiving-related information, why not check out last year’s blog, which features a whole host of awesome animals that the first European settlers might have seen upon arriving in North America.

Happy Thanksgiving!

 

Kathryn Pintus, ARKive Text Author

 

Aug 28

A significant improvement in the health of seagrass in a central Californian estuary is due to the return of sea otters, according to recent research.

Sea otter image

Researchers have found that the presence of sea otters may be improving the health of seagrass beds

Seagrass decline

Seagrass has been suffering drastic declines worldwide, and coastal California is no exception. Urbanisation has led to a massive increase in nutrient pollution along the state’s coast, with run-off from fields treated with nitrogen-rich fertilisers being blamed for the reduction in seagrass beds in the region. However, new research has revealed that the return of sea otter populations to the area may be enabling seagrass levels to recover.

Sea otters were hunted to near extinction in the late 19th and early 20th centuries, mainly for their dense pelt which was extremely sought-after for the fur trade. This latest research, published in the journal Proceedings of the National Academy of Sciences (PNAS), suggests that the drastic reduction in sea otter numbers may have exacerbated the decline of seagrass in the region.

Sea otters are now returning to the area, and, despite the continued pollution of the ocean, the water-dwelling plants are now doing much better. It is thought that the return of sea otters has triggered a complex ecological chain reaction which favours the survival of seagrass.

Sea otter feeding image

Sea otters feed on crabs and other shellfish

Seagrass saviour

Scientists assessed seagrass levels in part of Monterey Bay, California, over the past 50 years, mapping increases and declines. A whole host of factors which could potentially affect seagrass levels were studied, but the only one which matched the recorded changes was sea otter numbers. The health of the marine ecosystem relies upon a delicate balance of predator and prey species, and scientists have theorised that it is a readjustment in this balance that is now enabling seagrass to thrive.

Increased nutrients in the ocean due to fertiliser run-off have favoured the growth of a particular type of algae which grows on seagrass, shading the leaves and causing them to die off. Ordinarily, this algae is kept in check by small invertebrates which feed upon it, but with the reduction in sea otters came an increase in one of its main food sources – crabs. Crabs feed on marine invertebrates, so higher numbers of crabs meant fewer invertebrates to keep algae levels down, therefore contributing to the drastic reduction in seagrass.

Testing the hypothesis

To test their theory, the researchers set up experiments in similar estuaries with and without sea otters, and carried out other tests in the field as well as in the lab. One experiment involved putting cages on the seagrass, with some being accessible to sea otters and some not. The results of the tests confirmed the hypothesis.

Sea otter image

Sea otters

Fighting climate change

Brent Hughes, lead author of the study, described seagrass as being ‘the canary in the coalmine’, as it can be used to predict the levels of nutrient pollution in the water. He marvelled at the positive effect the return of the sea otters is having, saying, “This estuary is part of one of the most polluted systems in the entire world, but you can still get this healthy thriving habitat, and it’s all because of the sea otters. So it’s almost like these sea otters are fighting the effects of poor water quality.”

Seagrass plays an extremely important role in the marine ecosystem, acting as a nursery habitat for a wide variety of fish species, and taking in carbon dioxide from the water and the atmosphere, therefore potentially helping in the fight against climate change. In addition to this, seagrass contributes to the stability and protection of the shoreline.

It’s what we call a foundation species, like kelp forest, salt marsh or coral reef,” said Hughes. “The major problem from a global perspective is that seagrass is declining worldwide. And one of the major drivers of this decline has been nutrient inputs from anthropogenic sources, via agriculture or urban runoff.”

Benefits

A ban on sea otters that was in place to prevent them from impinging on fisheries in the southern California area was lifted last year, and so the findings from this latest research are particularly relevant.

That’s important because there’s a lot of these kind of degraded estuaries in southern California because of all the urban runoff from places like Los Angeles and San Diego,” said Hughes. “Coastal managers will now have a better sense of what’s going to happen when sea otters move into their systems. There’s a huge potential benefit to sea otters returning to these estuaries, and into these seagrass beds that might be threatened.”

Read more on this story at BBC News – Sea otter return boosts ailing seagrass in California.

See more photos and videos of sea otters on ARKive.

Learn more about the importance of food chains and food webs in our exciting Web of Wildlife education resource.

 

Kathryn Pintus, ARKive Text Author

Aug 2

Iraq’s Council of Ministers has approved the designation of the country’s first national park, in the Mesopotamian Marshes of southern Iraq.

Photo of Basra reed warbler among reeds

The Basra reed warbler breeds in the Mesopotamian marshes of Iraq

Once the third largest wetland in the world, the Mesopotamian Marshes are widely thought to be the original ‘Garden of Eden’. However, they were nearly destroyed during the Gulf War in the 1990s, when Iraq’s president, Saddam Hussein, drained the area and reduced the marshland to less than ten percent of its original extent.

Since Saddam’s downfall in 2003, efforts have been made to re-flood and restore the marshes, with surprising success. The new designation as a national park will hopefully help to protect this vital habitat into the future.

Wildlife returns

The Mesopotamian Marshes are of great importance to Iraq’s wildlife, providing a source of fresh water and essential habitat in a region surrounded by deserts. Despite most of the marshes being destroyed, the region’s wildlife managed to survive and is now making a remarkable comeback.

Photo of marbled duck

Restoration of the marshes has allowed species such as the marbled duck to return

They had hung on in small spots. When the water spread again, so did the birds,” said Richard Porter, BirdLife International’s Middle East Advisor. “It shows how resilient nature can be, and gives hope that other lost wetlands can be restored.”

Water politics

Unfortunately, although many parts of the marshland have recovered, others have not. One of the main threats to the wetland is the region’s water politics, with countries upstream of Iraq increasingly restricting the flows of the Tigris and Euphrates Rivers.

To counter this threat, Nature Iraq, the NGO which led the campaign for the designation of the national park, has persuaded the Iraq government to build an embankment to allow water to be diverted into the marshes in spring.

Declaring a park isn’t just a bit of paper,” said Azzam Alwash, founder of Nature Iraq. “It will mean we can reserve a percentage of the water from the rivers for the marshes.”

Photo of bladetail in habitat

Restoration of Iraq’s marshes will benefit a range of different species

Long-term protection

A further threat to the marshes comes from Iraq’s increasing urbanisation and development. The building of roads, infrastructure and water systems could all threaten the country’s natural habitats if not properly regulated.

I see areas that have been the same way for thousands of years being obstructed by roads. Development is encroaching into the wildlife’s area and taking away habitats,” said Alwash, adding that, “I want progress, but I don’t want development to overtake the Iraqi tradition of living in harmony with nature.”

Long-term protection of Iraq’s marshes will depend on international agreements on water-sharing, as well as the availability of money, which could one day come from tourism.

Photo of greater flamingos in flight

Greater flamingos also occur in the marshes of Iraq

The team who worked on establishing the new national park see it as just one step towards the protection of many of Iraq’s other natural habitats. Next year, Alwash and his colleagues hope to establish four more parks across the country.

This park is not a destination,” he explained. “It’s just a piece in the roadway to protecting Iraq’s national and natural heritage.”

 

Read more on this story at:

View more photos and videos of species from Iraq on ARKive.

Liz Shaw, ARKive Text Author

Jul 27

The UK has been experiencing some uncharacteristically hot weather over the last few weeks, so what better time to get out to our beautiful coast? Take this opportunity to find out more about the fantastic diversity of species and habitats we have off our shores, and join in The Wildlife Trusts’ annual National Marine Week! This celebration of all things marine actually runs for more than two weeks, from Saturday 27 July to Sunday 11 August, to make the most of the tides.

Velvet swimming crab image

Velvet swimming crab

We are fortunate in the UK to have an awe-inspiring range of habitats and species around our coasts. From shallow seagrass meadows and kelp forests to gullies and canyons over 2,000 metres deep, these habitats provide homes and feeding grounds for countless species, including colourful sea slugs, charismatic fish such as the tompot blenny, and the bottlenose dolphin, one of 11 species of whale, dolphin and porpoise regularly seen in our waters! Our seas are also home to the second largest fish in the world, the basking shark. This gentle giant can be spotted in the summer as it comes close to the shore, filter feeding micro-organisms.

Basking shark image

Basking shark

All around our coasts, Wildlife Trusts staff and volunteers will be sharing their knowledge, so whether you want to find out more about minke whales or molluscs, velvet swimming crabs or strawberry anemones, breadcrumb sponges or butterfish, and seals or seabirds, there will be events where people can enjoy the sights, sounds and smells of the sea and learn more about its riches.

The Wildlife Trusts hold these events to showcase some of the UK’s marine wildlife, and to educate and enthuse people about this fantastic resource on our doorstep. As well as being a source of wonder, our seas are also a playground, a food supply, a conduit for our imports and exports, and a climate regulator that absorbs vast quantities of greenhouse gases while releasing the oxygen we breathe. We are an island nation, and the sea is a vital part of our national identity.

Jewel anemone image

Jewel anemones

However, the seas are not as productive as they once were. For years, we have taken too much with too little care. Our seas’ resources are not inexhaustible, and their ability to cope with the pressures we put on them – damage from fishing, industrial pollution and the impacts of a changing climate – is limited. Much of our marine wildlife is in decline. Two species of whale and dolphin have become extinct in UK waters in the last 400 years, and basking shark numbers have declined by 95%. Commercial species are also under pressure, and in 2009 the EU Commission declared that 88% of marine fish stocks were overexploited.

Grey seal image

Grey seal

In order to provide better protection for our marine environment, here at The Wildlife Trusts we are campaigning for an ecologically coherent network of Marine Protected Areas – areas that offer protection not just to our most rare and vulnerable species, but to the full range of species and habitats found in the seas.

These areas will protect marine life within their boundaries, and with careful management they can also have an influence beyond these boundaries, as burgeoning populations spill out into the surrounding sea. A well-designed and effectively managed network will help boost the health of the marine environment as a whole, helping it to recover from past impacts and sustain current pressures. Although we have made a start on our network, we still have a long way to go, and at the moment progress towards achieving the network is slow.

The Wildlife Trusts’ National Marine Week and our events provide us with a crucial opportunity to highlight the need to continue to put pressure on UK Governments to ensure that this vital ambition is achieved. It offers countless opportunities for people to savour the seaside and find out so much more about what our coasts have to offer. Why not head over to The Wildlife Trusts’ marine wildlife weeks page to find an event near you!

Ali Plummer, Living Seas Officer for The Wildlife Trusts

Jul 24

A rising global demand for cashmere is putting the snow leopard and other native wildlife in Central Asia under threat, according to a new study.

Photo of wild snow leopard in stalking pose

The snow leopard is classified as Endangered on the IUCN Red List

Domestic cashmere goats are raised in many parts of Central Asia for their luxurious fur coats. Although cashmere production is not new, the global demand for this product has increased dramatically, and goat numbers have almost tripled in some areas in the last 20 years.

The new study, published in the journal Conservation Biology, reports that the increasing goat population is encroaching on the habitat of the snow leopard and its prey. Nearly all the forage across the Tibetan plateau, Mongolia and northern India is now being consumed by goats, sheep and other livestock, leaving only tiny amounts for native herbivores such as the Tibetan antelope, saiga, wild yak and Przewalski’s horse.

Photo of Przewalski's horses in habitat

Goats are also competing with native herbivores such as Przewalski’s horse

A decline in these native prey species can lead snow leopards to hunt goats, so leading to increased conflict with humans as people seek to protect their herds. Other threats to native species include disease transfer from livestock and the killing of wild animals by herders’ dogs.

Green labelling

Cashmere production is an important source of income for many local communities in Central Asia.

According to Dr Charudutt Mishra of the Snow Leopard Trust, “Cashmere production is a complicated human issue. Understandably, indigenous herders are trying to improve their livelihoods, but the short-term economic gain is harming the local ecosystem.”

Photo of snow leopard female and juvenile

Snow leopards prey mainly on wild sheep and goats, but will take livestock if wild prey has been depleted

Dr Mishra suggests that ‘green labelling’ of cashmere clothes could help increase awareness of the issue among consumers. “One of the intentions is to bring together some of the local communities who produce cashmere and the buyers from the international market. We want to address everyone’s concerns and develop a programme where we can make grazing more sustainable, and that allows for wild and domestic animals to co-exist,” he said.

According to Dr Mishra and the other authors of the study, the iconic species of the region’s mountains and steppes will become victims of fashion unless action is taken on both a global and a local scale.

 

Read more on this story at BBC News – Cashmere trade threat to snow leopards and The Guardian – Snow leopards and wild yaks becoming ‘fashion victims’.

View more images and videos of the snow leopard on ARKive.

Liz Shaw, ARKive Text Author

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