How bird wings evolve


This October 2018 video is called LONGEST ANIMAL Migration – Arctic Tern.

From the University of Bristol in England:

Analysis of bird species reveals how wings adapted to their environment and behavior

May 18, 2020

Bird wings adapted for long-distance flight are linked to their environment and behaviour, according to new research on an extensive database of wing measurements, led by the University of Bristol.

The Arctic tern flies from the Arctic to the Antarctic and back again each year, while the Inaccessible Island rail — the world’s smallest flightless bird — never leaves its five-square-mile island.

This November 2018 video says about itself:

Inaccessible is perhaps best known for the Inaccessible rail, the world’s smallest living flightless bird.

Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species including the well-known ratites (ostrich, emu, cassowary, rhea and kiwi) and penguins.

The University of Bristol article continues:

The way different organisms vary in how much they move around is a key factor in understanding and conserving biodiversity. Yet since tracking animal movement is difficult and expensive, there are still huge gaps in knowledge about animal movements and dispersal, particularly in more remote parts of the world. The good news is that bird wings offer a clue.

Measurements of wing shape — particularly a metric called the ‘hand wing index’, which reflects the elongation of the wing — can quantify how well the wing is adapted for long-distance flight and is easily measured from museum specimens.

New research published today in Nature Communications has analysed this index for over 10,000 species of birds, providing the first comprehensive study of a dispersal-linked trait across an entire class of animals.

A global team of researchers, led by the University of Bristol and Imperial College London, measured the wings of 45,801 birds in museums and field sites around the world.

From these, the team created a map of the global variation in wing shape, showing that the best-adapted fliers were primarily found in high latitudes while birds adapted to more sedentary lifestyles were generally found in the tropics.

By analysing these values along the bird family tree, together with detailed information about each species’ environment, ecology, and behaviour, the authors found that this geographical gradient is primarily driven by three key variables: temperature variability, territory defence, and migration.

The study’s lead author, Dr Catherine Sheard from the University of Bristol’s School of Earth Sciences, said: “This geographic pattern is really striking. Given the role we know dispersal plays in evolutionary processes, from speciation to species interactions, we suspect this relationship between behaviour, the environment, and dispersal may be shaping other aspects of biodiversity.”

Examples of fundamental patterns potentially explained by variation in dispersal include the smaller geographical ranges noted in tropical species.

Dr Joseph Tobias, senior author of the study, based at Imperial College London, added: “We hope our measures of wing shape for over 10,000 bird species will have numerous practical applications, particularly in ecology and conservation biology, where so many important processes are regulated by dispersal.”

British Overseas Territories islands wildlife


This video says about itself:

Nightingale Island Oil Spill

24 March 2011

Nightingale Island, part of the remote Tristan da Cunha group in the South Atlantic, was hit on March 16th, 2011 by the MV Oliva, a freighter carrying soybeans from Brazil to Singapore. Over 800 tons of fuel oil was spilled onto the island’s shores, poisoning the local population of endangered northern rockhopper penguins. I arrived on the site on March 23, 2011. This is what I saw.

From BirdLife:

Pioneering wildlife audit reveals 1500 exclusively ‘British’ species overseas

By RSPB, Tue, 20/05/2014 – 10:45

One of the world’s smallest lizards, a ‘spiky’ yellow woodlouse, a blue iguana, a flightless moth, a seabird thought to be extinct for three centuries and a predatory shrimp confined to just two rockpools, are just some of the amazing 1547 species unique to the islands of the UK’s Overseas Territories, which extend from the sub-Antarctic to the tropics.

The amazing haul of native and unique species, which have been highlighted during an RSPB wildlife ‘stocktake’ of the UK Overseas Territories, show these Territories contain at least 1500 endemic species: those species found nowhere else on earth. Compared with the 90 endemic species in the UK, the report shows that the UK’s Overseas Territories hold more than 94% of known unique British species. Staggeringly, the scientists compiling the figures have calculated there could be another 2100 endemic species awaiting discovery by science, as there are still many gaps in the understanding of the wildlife of the Territories.

Some of the species and habitats present on the UK’s Overseas Territories are found nowhere else on earth. Information from the better-understood wildlife groups, such as birds, reveals the severe conservation pressures faced by the wildlife on these islands, including habitat destruction, climate change and attacks from non-native species. The purpose of the report by BirdLife’s UK Partner, which was funded by the UK Government’s Foreign and Commonwealth Office, was to obtain a broad overview of the wildlife known to occur on each of the island Territories, including unique, native and non-native species. A further step will now be to assess the risk of extinction for these species. …

Dr Tim Stowe is the RSPB’s International Director. Commenting on the report, he said, “Our report shows that not only are the UK’s Overseas Territories wildlife jewels, but also they hold some of most globally important UK wildlife. This report reminds us that these species are solely the UK’s responsibility, and we need to ensure that the investment in conservation in the territories rises to a level that is proportionate to their world importance.”

Worryingly, only 9% of the species known to be unique to the UK Overseas Territories have ever had their conservation status assessed. The RSPB’s Jonathan Hall said, “Because there has been no assessment of the majority of these unique British species, we have no idea how they are faring: they could be thriving, or hurtling off a cliff. We simply don’t know, but we urgently need to find out.” The RSPB is reminding Defra, which has wildlife conservation responsibility for the Territories, to establish a scientific plan to assess the status of the 91% of the Territories’ unique species whose fortunes are unknown.

Rarest

Most of the rarest known British species occur in the UK Overseas Territories, including: Wilkin’s Bunting Neospiza wilkinsi, the rarest bird, with around 80 pairs, on Tristan da Cunha (S Atlantic); the Arlihau, the rarest known plant, of which only six individuals are known on Pitcairn Island (Pacific); the Ascension Island (mid Atlantic) predatory shrimp, the rarest marine invertebrate, confined to two rock pools; and the spiky yellow woodlouse, the rarest land-loving invertebrate, with only around 90 individuals on St Helena (mid Atlantic).

The report, the UK’s wildlife overseas, looked at the 11 UK territories that are oceanic islands or island groups.

See also here.

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Wildlife endangered in British colonies


This video is called Wildlife Falkland Islands.

While the British government spends lots of money on war-mongering sabre-rattling in the remnants of its empire, it lets its overseas historical monuments like Captain Scott’s hut rot, and presides over ecological disasters.

From BirdLife:

Seabird species face extinction in remote UK islands

Fri, Mar 30, 2012

They are more exotic than the gulls, gannets and terns of Britain’s home coastlines, but many of the fascinating and charismatic species of birds on the remote shores of UK overseas territories are now close to extinction. In a report to the government, the RSPB (BirdLife in the UK) warns 33 species of birds, including penguins, parrots and albatrosses, are now critically endangered across the remnants of the empire. And that means we have a duty to fulfil.

“Our overseas territories hold more threatened bird species than the entire European continent,” said RSPB official Graham Madge. “Yet only £1.4m a year is spent by the government protecting habitats that provide homes for these endangered creatures. We need to spend 10 times that amount to save them.”

The society’s report is part of a series of submissions to the Foreign Office, which is preparing a white paper on Britain’s strategy regarding its 14 overseas territories, including Montserrat, Bermuda, the Falklands, Tristan da Cunha and the atolls of the British Indian Ocean Territories as well [as] Gibraltar and a chunk of the Antarctic. The white paper will propose economic and political changes in policies for running these areas and will outline ways to use them more actively to bolster Britain’s defences.

The key concern for environment groups such as the RSPB is the need to improve care of the alarming number of threatened and endangered animals now found in these territories. “The overseas territories hold 85% of the threatened biodiversity for which the UK is responsible,” said Jonathan Glenn-Hall of the RSPB. A typical example is the Tristan albatross, which breeds almost exclusively on Gough Island, part of the Tristan da Cunha archipelago.

The albatross’s numbers have been destroyed by invasive species that have been brought to the island, in particular, rats, cats and pigs which eat albatross chicks. These invaders were eradicated several years ago in a campaign that only triggered a new threat to the Tristan albatross: mice. Without predators, mice on Gough Island have thrived and now grow to three times their normal mainland size. They burrow into the flesh of nesting chicks so that the birds bleed to death. Then the mice eat them. About 1,000 Tristan albatross chicks are thought to be killed each year this way. One recent survey has shown that, in 2008 numbers of Tristan albatross chicks that have managed to fledge is five times lower than normal.

“Invasive species – pests like rats and cats – are a major problem for the overseas territories,” added Madge. “The remnants of our empire consist mainly of the odd remote island on which a small number of species have settled and evolved into forms unique to that place. They have evolved in a little bubble and that makes them very vulnerable to threats introduced by humans and gives us a special responsibility for looking after them.” In the case of Gough Island, it is estimated that at least £5m will be needed to eradicate its giant mice and save the Tristan albatross from extinction. “We estimate that in total, Britain needs to spend £16m a year for the next five years to halt the worst threats to the habitats of its overseas territories,” added Glenn-Hall.

Birds are not the only concern, the RSPB admits. For example, on St Helena introduced plants such as bilberry and furze have pushed many native plants to the edge of extinction with the St Helena olive tree being declared extinct in 2004. “It is unthinkable that this would have been allowed to drop off into extinction if the last species had been found in Britain, but all too often the overseas territories are out of sight and out of mind,” added Glenn-Hall.

Other threatened species include the blue iguana on the Cayman Islands and turtles in the Caribbean which will lose many nesting sites as global warming melts ice caps and causes sea levels to rise. However, it is the importance of the bird populations of the overseas territories that is stressed by Madge, and in particular seabirds. When it comes to these, Britain is in second place among countries with the most threatened populations, he says. Only New Zealand has more endangered seabirds. “Thanks to our overseas territories, we outrank the US, Mexico, South Africa and other large nations when it comes to being responsible for saving endangered birds.”

Apart from feral invaders, ecologists have highlighted three other main dangers facing birds in overseas territories: climate change, poor planning controls and weak management of local fisheries. A typical victim of climate change is the Northern Rockhopper penguin, also found on Gough Island and suffering, not from mice, but from disruptions to its food chain brought about by global warming. Populations have declined by more than 90% in the last 50 years.

By contrast, the white-chinned petrel – which breeds on several South Atlantic islands including South Georgia and the Falklands – is suffering major population reductions because birds are getting caught in longlines towed by fishing vessels and being dragged underwater.

And in the Cayman Islands, uncontrolled development is destroying the habitats in which the Grand Cayman parrot and the Cayman Brac parrot breed, again with disastrous consequences for populations. “Many of these places rely on money brought by tourists who visit to see the exotic wildlife,” added Madge. “We have a responsibility to make sure that wildlife survives.”

Scientists have released footage of a newly discovered seamount in the Chagos Archipelago, which was established two years ago as the world’s largest no-take marine protected area: here.

UK’s most exotic natural treasures under threat from ‘legal neglect’: here.