From ScienceDaily

The ‘early bird’ strategy has been revealed by a team studying the winter foraging behaviour of birds in Wytham Woods, Oxfordshire. The researchers fitted over 2,000 birds with tiny PIT radio tags. They then used 101 feeders which detected these tags and captured the exact time individual birds found each feeder. By moving 36 of these feeders around the forest throughout the day, and recording the results, the team showed that birds gathered information about new food sources during the morning so that they can then eat it later in the day.

The birds studied were a mixture of great tits, blue tits, marsh tits, coal tits and nuthatches. The full report, published this week, can be downloaded here

Damien Farine of Oxford University, who led the research, says that ‘birds have to store body-fat to avoid starving during the cold winter nights, but this can make them slower and less manoeuvrable so that they are more likely to be caught by predators’. ‘So there is a trade-off, where birds need to remain lean enough in order to ‘outrun’ their predators, or at least the next slowest bird, during the day but also store enough fat to survive each night.’

The team knew from previous studies at Wytham Woods that, when the predation risk appears high, birds delay putting on fat until late in the day. The researchers wanted to test the idea that, instead of simply ‘idly waiting’ until the afternoon, birds were actively seeking out new sources of food to work out where their next meal was coming from.

‘We used new tracking technologies to investigate how great tits, blue tits, and other common garden birds, balance the competing risks of predation and starvation’. ‘Our results show that these birds display very different patterns of food discovery in the morning and afternoon; very few new food sources were found during the afternoon, whereas nearly every new food source that we put out during the morning was quickly discovered. It supports the idea of an ‘early bird’ strategy of scouting for food early on so that they can return to feast a couple of hours before dusk in preparation for a long winter’s night.’

Winter is a tough time for small garden birds as not only is there less natural food available but their predators, such as the sparrowhawk, are keen to stock up their own fat reserves and so are hunting every day. The short days and long cold nights mean that small birds can lose around 10% of their body weight over a single night so that individuals failing to pile on the grams on even one day can starve and won’t be around to pass on their genes the next summer.

‘Because small birds can’t reproduce without surviving the winter they have evolved a complex set of behaviours that enables them to maximise their chance of both surviving predators and avoiding starvation,’ said Damien Farine ‘It’s a good example of how animals alter their behaviour to respond to constantly changing environmental conditions. It also shows how new technologies, like tiny PIT tags, are enabling us to explore questions about animal survival strategies at an unprecedented scale.’

From The Independent

Anglo-Scottish rivalry takes a completely new turn. In a surprising story of contrasting wildlife fortunes, southern England is rapidly losing some of its most attractive summer birds, from swallows to willow warblers, while at the same time, Scotland is gaining them.

It’s not that birds are quitting the South of Britain to go and nest in the North. Rather, the southern populations of several species of summer visitors are rapidly declining, while their northern populations are expanding substantially. The striking and so far unexplained divergence has been revealed by the magnificent new atlas of British and Irish (and Channel Islands) birds, all 700 pages of it, which has been six years in the making and is published next week. See a taster of the new atlas here

It displays a growing North-South contrast in abundance, over the past two decades, in at least eight species – swallow, house martin and sand martin, willow warbler, garden warbler and grasshopper warbler, plus tree pipit and cuckoo. (Other species are showing signs of this, but it is in these eight that the shift is clear).

Scotland, long seen in bird terms as the grandiose home of the golden eagle, is now a much better place than the Home Counties to hear two of spring’s most delicate sounds – the musical double note of the cuckoo and the silvery cascade of the willow warbler – and to witness the exhilarating springtime sight of swallow acrobatics.

The population of the willow warbler, for example, has declined by 28 per cent in England since the early 1990s but in Scotland it increased by 33 per cent over the same period. Willow warbler was lost too as a Jersey breeding species. Over the same period, the cuckoo declined in England by no less than 63 per cent and it is missing now across much of the South (it too no longer breeds in Jersey). But over Scotland as a whole, while there was a total decline of 5 per cent, in some areas such as the Highlands and Islands there was a notable growth in numbers.

Swallows too are increasingly thin on the ground in the South-East of England but increasing north of the border, and the same can be seen for house martin and sand martin.

These shifts are vividly displayed, with green for losses and red for gains, in the maps of Bird Atlas 2007-2011 (see willow warbler here) – the most complete overview of bird distribution and change in Britain, Ireland, Channel Islands and Isle of Man ever put together. Produced by the British Trust for Ornithology with BirdWatch Ireland and the Scottish Ornithologists’ Club, the atlas examines the breeding and wintering fortunes of nearly 300 species over the 2007 to 2011 period, as noted down by 40,000 volunteer observers who between them contributed 19 million records. More than 99 per cent of the land surface of the British Isles has been covered.

The resultant snapshot of the present is engrossing, but the real value is in the contrasts the atlas affords with the two previous bird atlases of the British Isles, done for the periods 1968-1972 and 1988-91. What results, says the BTO’s director, Andy Clements, is “a 40-year story of change”.

There are changes in all directions. An arresting one is the spread eastwards of a pair of species once persecuted by gamekeepers – the buzzard and the raven. Two decades ago they were largely confined to the west of a line drawn from the Pennines to Southampton; now (perhaps because persecution has ended) both birds have spread all over England. During this period the buzzard has also colonised Jersey.

There are many such: the hobby, the dashing summer falcon, is moving steadily northwards in distribution, while the nightingale is shrinking back remorselessly towards South-East England and its stronghold in Essex, Kent and Sussex. In terms of sheer increase, the prize is taken by the little egret, which at the time of the last atlas did not breed in Britain; now there are about 700 breeding pairs (with around four small colonies in Jersey). But it is the English-Scottish shift of the willow warbler et al. which is most remarkable. All eight birds concerned winter in sub-Saharan Africa, and it is very probable that this offers a clue to what is happening, although it has not been teased out yet. Climate change, affecting the hatching of their caterpillar food, may also be playing a role.

Yet whatever the cause, there it is in the maps. “We have removed observer bias and we are sure this is a real phenomenon, and a notable one,” said co-author Dr Simon Gillings. Have a look for yourself from next week. It is the most riveting bird book produced in Britain for years.

From Alderney Wildlife Trust

Following action by The Wildlife Trusts, RSPB and RSPCA the International Maritime Organisation (IMO) decided to reclassify Polyisobutelene (PIB), under the International Convention for the Prevention of Pollution from Ships (MARPOL), making it illegal to discharge any amount into the sea.

The IMO is stopping ships from discharging PIB at sea after birds covered in the sticky substance were washed up on the Channel coastline. Over 4,000 seabirds washed ashore, dead or dying between February and May, after there were two separate spills. The substance which has been likened to PVA glue in consistency, coats the birds feathers, rendering them unable to fly or maintain core body temperature.

The tragedy, the largest marine pollution incident of its kind in the region since Torrey Canyon, shocked thousands of people. At a meeting of the IMO’s working group on the Evaluation of Safety and Pollution Hazards of Chemicals (ESPH), it was decided to change the classification of high viscosity PIBs and prohibit any discharge at sea from 2014. This will also apply to new “highly-reactive” forms of PIB, which are currently being transported un-assessed.

The recommendation to do this had been made by the Maritime and Coastguard Agency (MCA) on behalf of the UK Government, following vigorous campaigning by wildlife charities and the public.

This was a decision which was expected to take years and the efforts of all those who lobbied so hard in the Channel Islands should not be forgotten.

Thanks go out to GSPCA, JSPCA, Durrell,  La Société Guernesiaise,  La Société Jersiaise and the National Trust for Jersey who joined the AWT campaign and all of their Facebook and Twitter followers! The Birds On The Edge report can be read here.

Today’s decision is a real step forward, safeguarding our seas and sealife for future generations.

From BirdLife International

It is becoming increasingly obvious that our already declining bird populations, threatened by widescale habitat and climate changes, are put under further pressure through the actions of humans. Scientists with Environment Canada have found that human-related activities destroy roughly 269 million birds and 2 million bird nests in Canada each year. Most human-related bird deaths (about 99%) are caused by impacts of feral and pet cats, and collisions with buildings, vehicles, and electricity transmission and distribution lines.

Over the last four years, 20 Canadian scientists conducted extensive analyses that enabled them to release the first-ever estimates of annual direct bird mortality from human-related sources. The results have just been published in a special issue of Avian Conservation and Ecology.

“Because birds are excellent indicators of biodiversity, the newly-released articles from Environment Canada highlight areas where broader biodiversity may be impacted”, said Dr George Finney, President of Bird Studies Canada. “These results provide a crucial first step toward understanding the relative importance of bird mortality factors, and will inform future research directions, conservation actions, and policy decisions.”

Cats appear to kill as many birds as all other sources combined. Feral and pet cats are believed to kill more than 100 million birds per year in Canada. An estimated 60% of those are killed by feral cats. Bird species that nest or feed on or near the ground are especially vulnerable to cat predation.

“We are deeply troubled by the disquieting research published today on the number of birds killed every year in Canada due to human-related activities”, said Ian Davidson, Executive Director of Nature Canada. “Fortunately, there are concrete and sensible ways that people and governments can prevent the needless death of birds, especially now during the migratory season.”

Collisions with electricity transmission and distribution lines have been identified as the second-largest human-caused source of bird mortality in Canada. Between 10-41 million birds per year are killed by collisions with transmission lines; between 160,000 and 800,000 birds are electrocuted by distribution lines; and about 400,000 nests are destroyed annually due to vegetation clearing under powerlines.

Collisions with residential and commercial buildings are the third-highest of the human-related sectors, killing an estimated 16-42 million birds each year – mostly at houses. Following bird-friendly building guidelines can help individuals and building managers reduce the risk to birds. Using commercial products, special glass, or homemade solutions to make windows more visible to birds can reduce daytime collisions. Night-time window collisions can be reduced by leaving lights off in low-rise and high-rise buildings.

An estimated 13.8 million birds are killed annually by colliding with vehicles on Canada’s primary and secondary roads.

There are about 10 billion birds in Canada. The estimated total of 269 million bird deaths per year caused by human-related factors constitutes less than 5% of the overall population. Bird deaths from other causes (such as natural predation, disease, severe weather, or habitat loss) are not reflected in the estimates.

Whilst Canada is undoubtedly a very large country we can still see that the Channel Islands will contribute annually to the global, and un-estimated, man-made, and avoidable, toll of wild birds. We are increasingly beginning to realise how important our islands are too for migratory birds just passing through. How many each year fail to reach their destination through some man-made structure in their path that they don’t see? Or from the house cats and feral cats that are found everywhere in Jersey except on our offshore reefs – and even there birds aren’t safe from man-made problems! And, when thinking of feral cats, is it any wonder why we have so few lizards in some places!

From ABC News

TV and radio towers, blamed for nearly 7 million bird deaths each year in North America are doing the most damage to species that can hardly afford the loss, according to a new study published in Biological Conservation.

In the United States and Canada, at least 97% of the birds that crash into the towers, or the guy wires that hold them up, are the tiny songbirds – mostly warblers – that are considered “birds of conservation concern”.

The latest study comes from the same researchers, members of the Los Angeles-based Urban Wildlands Group, that warned last year of the spiralling mortality of birds that are attracted to the lights, usually red, atop the towers. The lights are required by the USA’s Federal Aviation Administration (FAA) for any tower over 200 feet tall, and there are thousands in North America that are more than 10 times that height.

The deaths usually occur during the nocturnal migration of songbirds, especially when the cloud ceiling is low and there is fog or rain. The lights create an illuminated area around the tower and it is thought the birds become confused, switch off their night navigation and begin to spiral around the tower. Some run into the support cables, or into each other, and plunge to the ground.

Travis Longcore, from the University of Southern California and lead author of the current study, said his group wanted to look beyond the sheer numbers and focus on which types of birds were suffering the greatest loses, based chiefly on the number of deaths compared to the overall population estimate of each species.

“Many bird species are killed at towers disproportionate to their abundance,” the study says.

“This lets us look at this (the tower deaths) as a factor in the trajectory of the population”. The study indicates that towers are a very significant factor for a number of species, especially small songbirds, some of which are declining in numbers overall.  The researchers found that 58% of the birds killed each year are warblers, including Swainson’s warbler Limnothlypis swainsonii, which loses 8.9% of its population each year, and the black-throated blue warbler Dendroica caerulescens loses 5.6%. It’s not just songbirds though, each year yellow rail Coturnicops noveboracensis loses about 9% of its total population because of communications towers, many of which are taller than the Empire State Building.

In addition to communications towers, however, the birds have to fend off cats and other predators, and many are killed when they crash into windows, as urban dwellers know so well. So towers are only part of the problem, but this study suggests they may be more significant than had been thought, at least for certain species.

A solution?

Some recent experiments have shown that a flashing (blinking) light attracts fewer birds than a light that remains on. The FAA recently ruled that tower operators may switch to blinking lights, and some have done so. It could be too that when a steady light is replaced by a blinking light, the birds simply leave. This is not an expensive modification but the results may be immediate.

This research is, of course, based on estimates, some of which wildly disagree with estimates from other researchers, and that may be partly because the situation varies so dramatically across the country. And just simply collecting the data is difficult. Longcore pointed out that a dead bird doesn’t hang around very long.

“Scavengers and predators and decomposers are incredibly effective,” he said. In one case an owl was spotted as it zipped through the night sky and grabbed small birds before they even hit the ground.

However, sometimes it’s easier to find how many birds have died. Scientists found that an estimated 5,000 to 10,000 birds, mostly Lapland Longspurs, were killed on Jan. 22, 1998, near a 420-foot tower in western Kansas. It happened, as is often the case, during a heavy snowstorm. See bibliography of bird kills in USA here

And the number of kills from towers still lags far behind the estimated number of deaths caused by birds hitting windows. And still, the estimates vary widely. One group of researchers, for example, estimated that the number of window-kills was somewhere between 97.6 million to 976 million annually.

Longcore said he believes that if most towers are modified, just by switching to flashing lights, many more songbirds will be around to serenade us in our gardens.

The situation with tall masts in the Channel Islands is unclear. However, there are such things such as those on the north coast of Jersey and this may be an area for future research.