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Bird Photographer of the Year 2017 – in pictures
Winning and shortlisted images from this year’s competition, from awe-inspiring action shots to charming portraits, featured in a new book celebrating some of the best bird photography of the year
Continue reading...Research Filter: Whales, planets and ants
Search for victims after Mumbai building collapses amid floods – video report
Rescue workers in Mumbai are searching for people feared trapped beneath a collapsed building following two days of torrential rain in India’s commercial hub. At least 1,200 people have died across south-east Asia as a result of flooding caused by heavy monsoon rains, and millions of people are estimated to have been affected
Continue reading...Turnbull’s new energy target: Drop the “clean” and ignore climate
Consumers 'betrayed' over sustainability of world’s biggest tuna fishery
Skipjack tuna from the western Pacific is common on supermarket shelves, but a new coalition argues its certification as sustainable is illusory
Consumers of tuna from the world’s biggest fishery are are being “betrayed” over its sustainability, according to a coalition of scientists, retailers, politicians and campaigners, including Hugh Fearnley-Whittingstall.
The vast Western and Central Pacific fishery provides about half of the world’s skipjack tuna, the type most commonly found in cans on supermarket shelves. Some is certified as sustainably caught by the Marine Stewardship Council (MSC) and carries the group’s “blue tick” logo. But the same boats can also use, at other times, unsustainable methods to catch uncertified fish, a contradiction seen as unacceptable by the new On The Hook coalition.
Continue reading...How consumers got burned on electricity prices: It started with networks
Inspiring green homes open their doors on Sustainable House Day
Guam’s forests are being slowly killed off – by a snake
Can a snake bring down a forest? If we’re talking about the Pacific island of Guam, the answer may well be yes.
Our research adds to mounting evidence that the killing of many of the island’s bird species by an invasive species of snake is having severe knock-on effects for Guam’s trees, which rely on the birds to spread their seeds.
Invasive predators are known to wreak havoc on native animal populations, but our study shows how the knock-on effects can be bad news for native forests too.
Globally, invasive predators have been implicated in the extinction of 142 bird, mammal and reptile species, with a further 596 species classed as vulnerable, endangered or critically endangered. But the indirect effects of these extinctions on entire ecosystems such as forests are much harder to study.
Read more: Invasive predators are eating the world’s animals to extinction – and the worst is close to home.
The brown tree snake was accidentally introduced to Guam in the mid-1940s and rapidly spread across the island. At the same time, bird populations on Guam mysteriously began to decline. For years, no one knew why.
In 1987 the US ecologist Julie Savidge provided conclusive evidence that the two were linked: the brown tree snake was eating the island’s birds. Today, 10 of Guam’s 12 original forest bird species have been lost. The remaining two are considered functionally extinct.
The brown tree snake has caused a cascade of problems. Isaac Chellman, Author providedBut the ecological damage doesn’t stop there. The loss of native bird species has triggered some unexpected changes in Guam’s forests. Both the establishment of new trees and the diversity of those trees is falling. These changes show how an invasive predator can indirectly yet significantly alter an entire ecosystem.
Birds and treesBirds are very important to trees. In the tropics, up to 90% of tree species rely on animals, often birds, to spread their seeds. Birds eat fruit from the trees and then defecate the undigested seeds far away from the parent tree’s canopy, where there are fewer predators and pathogens that specialise on that species, where competition for light, water and nutrients is less intense, and where seeds can take advantage of promising new real estate when old trees die.
Without birds, roughly 95% of seeds of two common tree species on Guam (Psychotria mariana and Premna serratifolia) land directly beneath their parent tree. Compare that with the nearby islands of Saipan, Tinian and Rota – none of which have brown tree snakes – where less than 40% of seeds land near their parent tree. On Saipan, seeds that escape their parent tree are five times more likely to survive.
Close neighbours, but very different situations. Author providedWhat’s more, passing through the gut of an animal can actually increase the likelihood that a seed will germinate. On Guam, seeds that had been eaten by birds were two to four times more likely to germinate than those that hadn’t.
Overall, for the roughly 70% of tree species on Guam that rely on birds to spread their seeds, research suggests that the bird deaths caused by the brown tree snake have reduced the establishment of new tree seedlings by 61-92%, depending on the species.
Forests’ future threatenedThese numbers suggest that many tree species in Guam are under serious threat, which in turn threatens the species diversity of the island’s forests.
Our new research, published in Proceedings of the National Academy of Sciences, examined the number of seedling species growing in treefall gaps on Guam compared with Saipan and Rota, which still have their birds.
Treefall gaps appear when an adult tree dies, opening up the canopy and increasing the light that reaches the forest floor. Many species rely on this increased light for germination and early growth, so these gaps are hotspots for new seedlings.
Birds such as the Mariana fruit dove are a big help to the islands’ trees. Lainie Berry, Author providedWe found that Saipan and Rota had roughly double the number of species of seedlings growing in these gaps, compared with Guam. What’s more, seedling species on Guam tended to be clumped together, as you might expect if more than 90% of seeds are falling beneath their parent trees.
We also found that birds are important in moving the seeds of certain types of species to gaps. In forests, “pioneer species” are those that rapidly colonise gaps, exploiting the increased light to grow fast and reproduce young. Crucially, we found pioneer species in all gaps on islands with birds, but in very few gaps on Guam, where these species could be at risk of being lost entirely.
Read more: Pristine paradise to rubbish dump: the same Pacific island, 23 years apart.
Invasive predators are a reality for many ecosystems, particularly on islands, and the situation on Guam is particularly extreme. Perhaps nowhere else in the world has experienced such dramatic losses of native fauna as a result of invasion.
While these direct impacts of invasion are astounding, the indirect impacts cascading through the ecosystem are just starting to unfold, and may prove to be similarly catastrophic.
Haldre Rogers receives funding from the US National Science Foundation (NSF) and the Strategic Environmental Research and Development Program (SERDP). She is a faculty member at Iowa State University.
Elizabeth Wandrag does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.
Where the swallows skitter – a bypass and space travel?
Llanbedr, Gwynedd With sadness I realised a proposed road, improving access to the planned spaceport, would cut across the floodplain I had just explored
The train along the Cambrian coast route stops at Llanbedr only by request, and on this occasion I was the only passenger to alight. To the west fields of wet grassland, divided by drainage channels brimming with rushes, spread towards the sea.
Related: Snowdonia fears impact of UK spaceport decision
Continue reading...Telling the story of our National Heritage List
Great Barrier Reef: plan to improve water quality ignores scientific advice
Australian government’s draft Reef 2050 Water Quality Improvement Plan provides new water quality targets, but has very few other concrete changes
Australia’s draft plan to improve water quality on the Great Barrier Reef has ignored official government scientific advice, which was published by the Queensland and federal governments alongside the new plan this week.
The draft Reef 2050 Water Quality Improvement Plan is an update to the plan released in 2013, and provides new water quality targets for specific parts of the reef, but has very few other concrete changes overall.
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