What A Week

Another week goes by. There was more rain and wind with no chance of another ringing session and little in the way of productive birding. 

But Sunday dawned much better and a promise of sunshine so I set off birding over Stalmine and Rawcliffe Moss in the general direction of Cockerham. 

It wasn’t long before I met up with not one but two Barn Owls in the half-light of dawn. The owls hunted almost in tandem with at times both in the binoculars as they traversed the same stretches of grassland and hedgerows, probably an area of past success. I parked the car, wound the window down and hoped the owls might show better in the improving light, but after just a few short minutes of circling the area they flew into the farm buildings and out of sight. 

Barn Owl 

Something of a raptor hour ensued with 2 Sparrowhawks, 2 Buzzards and 2 Kestrels seen before any small birds of note. 

I stopped at Gulf Lane where 160+ Linnets was a welcome sight but I scattered a whole bucket of seed into our catching area on the basis that the heavy rain this week has either washed seed away or made it unpalatable to the finches. With luck we’ll fit a ringing session into the week ahead. 

Although Conder Green didn’t have a great variety of birds a count of 210 Teal was mighty impressive. There was a party of 60 Wigeon feeding on the far bank, with 6 Little Grebe, 2 Goosander and 2 Little Egret on the water. 

Little Egret 

Waders were less numerous, just 30 Curlew, 22 Redshank and 2 Oystercatcher; the reason I found later, many, many thousands are now feeding on fields saturated and softened by two weeks or more of often heavy and persistent rain 

At Glasson Dock the numbers of both Tufted Duck and Goldeneye proved quite high, probably because of the rising tide i.e. 70 Tufted Duck and 29 Goldeneye with a single Goosander. 

Tufted Duck 

 Goldeneye

Up on the hill above the village is a flock of at least 200 Linnets and down on the marsh at the incoming tide, 7-8,000 Lapwings. No wonder then that I saw a large female Sparrowhawk try its luck and then a Peregrine do the same. 

Linnets 

On the drive towards Cockersands I encountered another Sparrowhawk, a Buzzard, 3/400 Starlings and also 90 or so Fieldfares. Fieldfares are now feeding alongside Starlings in wet fields as there are very few berries to be had. 

Fieldfare 

I also met up with two species of swans that winter in the UK, Whooper Swan and Bewick’s Swan that are superficially alike and hence sometimes misidentified. From Moss Lane and Jeremy Lane and up to Cockersands were more than 450 Whooper Swan, while at the junction of Moss Lane and Slack Lane were 6 Bewick's Swan. While both species are winter visitors to this area, the Whooper is much more numerous than the Bewick’s with this ratio of c100/1 typical of their occurrence. 

Bewick’s Swans breed at high latitudes in Arctic Russia from the Fenno-Russian border east to the Lena Delta. They spend the winter mainly in Britain, the Netherlands and Germany, with smaller numbers in Denmark, Sweden, Belgium and France. 

Whooper Swans breed exclusively in Iceland and winter primarily in Britain and Ireland, with smaller numbers remaining in Iceland while low numbers winter on the near Continent. Whooper Swans undertake what is probably the longest sea crossing of any swan species, migrating 800-1,400 km between Britain/Ireland and Iceland. 

Whooper Swan 

 Bewick's Swan

Of the two, the Bewick’s has a more goose-like appearance but like the bigger Whooper Swan, an adult Bewick’s is snow white all over. Bewick’s has a shorter neck and proportionately bigger head than Whooper, as well as a smaller body and bill. However, this can be difficult to appreciate on lone birds or in single-species flocks and it is the bill pattern which can clinch a firm identification. 

A basal yellow beak patch is common to both species, but Bewick’s has the colour extending to less than half the length of the black bill and it generally has a squared-off appearance, always finishing behind the nostril. The beak itself is subtly more slender with a very slightly upturned shape at the tip. 

Whooper Swan’s beak is more of a Roman nose, with the yellow extending in a pointed wedge shape to the very front of the nostril. The beak shape itself is longer and more triangular than Bewick’s. 

Whooper is a larger species with a very long neck, often held erect, and a bulkier body and longer legs, making it stand out straight and tall when the two species are together. 

On the way back home and at well flooded Braides Farm I noted several thousand each of Lapwing and Golden Plover with hundreds of both Redshank and Curlew. But time was short. I’d had a good morning and a hot coffee beckoned.

Linking today to Stewart's World Bird Wednesday.

A Frosty Gulf

Last week was one to forget, seven days of wind and rain with no birding. But now on Tuesday morning it was time to make amends with a much needed visit to Gulf Lane for Project Linnet. 

A quick check on Monday evening with on-line DemOn revealed a catch total of 470 Linnets in the three winters to date. The early winter is disappointing so far with a lack of Linnets on site, the reasons as mentioned in a previous post of 22 November- “an abundance of natural food that Linnets and other species have exploited, hence their lateness at arriving at Gulf Lane to a field of bird seed mix, one that could never match their natural diet.” 

It was a cold, frosty start this morning, 0730 and setting nets in the darkness to await the Linnets that roost fairly close by and soon after dawn arrive in groups for a morning feed. Our best count of the mobile Linnets this morning was 160+, a fair number, but as yet a good deal below recent winter counts of 400+. 

Andy in the dark 

Frosty Start 

Despite the lack of numbers we are still keen to catch more and explore the theory that many of our locally wintering Linnets are of Scottish origin and from the slightly larger and darker sub-species Linaria cannabina autochthona. We were given a boost for this idea on this morning by a first winter male with a wing length of 87mm, and two more with wing length of 84mm. The 87mm is at the top end of the range of published Linnet wing lengths, a data entry that provokes a query/potential error from the set parameters of DemOn, the online BTO database. 

Birds of Western Palearctic: Linnet Wing Length

Nominate race Linaria cannabina cannabina - Average ♂ = 80.8.  Range 78- 85 

Linaria cannabina autochtona (Scotland) Average ♂ = 80 - 82.  No range given 

Linnet - First Winter Male 

Such first winter birds carry their retained primary wing feathers, the ones they were was born with in the summer of 2018. The replacement feathers grown during the latter half of 2019 will increase the wing length by one or two millimetres. It would be good to recapture this or similarly sized Linnets in consecutive seasons but this is highly unlikely with minimal recapture rates for small passerines like the Linnet. 

We caught just 11 Linnets this morning, a slightly disappointing number given the 160 we saw, and while our project is not simply about numbers, the more we catch the better the information. 

Linnet

Birds have thousands of feathers and each one is subject to wear and tear that leads to moulting. Birders who understand the moult process can recognize how birds change their appearances and why those changes are a necessary and vital part of bird biology. Understanding the process can lead to easier identification no matter what stage a bird's plumage may be in. 

Moulting is the process of a bird shedding old, worn feathers to replace them with fresh plumage. A moult may be partial and replace just some of a bird's feathers or complete when all the feathers are replaced at once. The time it takes to complete a moult varies for different species, but may last as little as two weeks or much longer for larger birds. 

I found a video on the Internet that shows the typical sequence of moult in the wing of a passerine. It is quite instructive for anyone unsure or unaware of how and when birds replace their feathers.A passerine is a bird of the order Passeriformes, small songbirds which perch - more than half of all bird species. 

Another Bird Blog is back soon with more news, views and photos.

Linking this post to Anni's Blog,  Eileen's Saturday Blog and Stewart's World Bird Wednesday.

Trends

The weather’s becoming unfit for man or beast. Storm Diana is hurtling up the Irish Sea and it looks like there will be zero birding or ringing for a few days or more. 

So for this post I'm turning to the British Trust for Ornithology (BTO) and recent information on indicators of bird population trends for UK and England, first published on 8 November 2018. 

These indicators are part of the Government’s suite of biodiversity indicators that show the fortunes of birds of farmland, woodland, waterways & and wetlands, and marine & coastal between 1970 and 2017. 

Regular readers may recognise a number of bird names here as they occur here on the blog with alarming regularity, usually for the reasons highlighted again by this latest information, the relentless downward trend of their populations. The graphs below may suggest some recent levelling off which may not be a cause for celebration when so many species are at levels which could hardy drop much more. There are still too many downward trends on the diagrams and hardly any showing upward movements. The bold highlights are my own, those that equate to the situation here in Lancashire. 

The indicators are calculated annually by the BTO, RSPB and Department for Farming and Rural Affairs (Defra) and are based almost entirely on data collected by volunteers contributing to national bird monitoring schemes such as the BTO/JNCC/RSPB Breeding Bird Survey and the BTO/RSPB/JNCC Wetland Bird Survey. 

Population trends of common birds that are native to, and breed in, the UK are assessed using two assessment periods: long-term (for most species between 1970 and 2017), and short-term (2011-2016). The wintering bird indicator shows how the internationally-important numbers of wintering waders, wildfowl and other water-birds using coasts and wetlands have changed since c1975. 

Changes in the abundance of breeding birds of woodland, farmland, water and wetlands and all-species in the UK. 

The breeding farmland bird index continued to fall and has declined by more than half between 1970 and 2017 in the UK. Whilst most of these declines occurred in the late 1970s and early 1980s, there was a short-term decline of 7% since 2011. Farmland specialists showed the most prominent declines; for example, Corn Bunting, Grey Partridge, Turtle Dove and Tree Sparrow all declined by at least 90% since 1970. Grey Partridge and Turtle Dove also declined strongly in the short-term, but there was no change for Corn Bunting or Tree Sparrow during this time. Conversely, some farmland specialists (e.g. Stock Dove and Goldfinch) have more than doubled in the long-term. This illustrates that responses to pressures are likely to vary between species. 

Changes in the abundance of  farmland birds 1970 to 2017 in the UK.

Grey Partridge

The breeding woodland bird index for the UK has declined by 25% between 1970 and 2017, and 5% over the recent short-term period. These declines are greater than documented previously, driven by the declining numbers of woodland specialists; down 46% since 1970. Generalist woodland species, typically those that also breed in gardens or wooded areas of farmland, have increased overall, by 14%. Woodland species such as Lesser-spotted Woodpecker, Spotted Flycatcher and Willow Tit have shown the most serious declines (more than 80%) since 1970, whilst numbers of Long-tailed Tit, Blackcap and Nuthatch have almost doubled, and the Great-spotted Woodpecker is three times as abundant as it was several decades ago. 

Changes in the abundance of woodland birds between 1970 and 2017 in the UK. 

The breeding water and wetland bird index for the UK fell by 6% between 1975 and 2017, but over the short-term increased slightly by 3%. Over the long-term, species associated with slow-flowing and standing water, and with reed beds, fared better than those associated with fast-flowing water or with wet grasslands. Lapwing, Redshank, Snipe and Common Sandpiper showed the strongest declines over the long-term, athough Snipe has shown a recovery of 27% in the recent short-term period. 

The abundance of breeding water and wetland birds between 1975 and 2017 in the UK. 

Snipe

Ringed Plover

The breeding seabird index was not updated this year due to a shift of effort by the JNCC Seabird Monitoring team towards the ongoing Seabird Census. In the UK, the seabird index declined by 22% between 1986 and 2015. Declines began in the mid-2000s; and more recently, between 2009 and 2014 there was a 14% decline in the indicator, driven largely by large declines for Arctic Skua and Black-legged Kittiwake. The wintering waterbird index was 106% higher than in 1975/1976 in the UK. The index peaked in the late 1990s, and has declined since; by 4% between 2010/2011 and 2015/2016. Some wintering waterbirds have increased markedly over the long-term, including Gadwall, Whooper Swan, Avocet and Black-tailed Godwit. Conversely, White-fronted Goose, Eider, Ringed Plover and Dunlin all declined.  

The abundance of wintering waterbirds between 1975 /76 and 2016/17 in the UK.   

Source -  BTO Science Monitoring Bird Populations.

Linking today with  Anni's Birding and Eileen's Saturday Blogspot.

Linnet Time

Regular readers will remember that the Linnets haven’t played ball this year with their appearances at Gulf Lane limited to small flocks of 10-40 individuals performing short and swift flyovers. There’s been little sign of the much bigger flocks of 300/400 birds of the past two winters. We have attributed this to plentiful food sources in the wider area as we have seen Linnets in decent numbers, for example, c150 half a mile away at Braides Farm two weeks ago. 

The week’s niggling easterly wind vetoed any hopes of making it to Cockerham for a crack at the Linnets where less than 10 mph is vital. Until today, when a forecast of 8 mph, freezing temperatures but with that still easterly chill dictated five layers of top clothes and a woolly hat. At 0700 I met Andy, shivering when after a week in the heat of the Egyptian desert, he was plunged into a frosty Lancashire morning. 

Minus One

A very slow start with just one bird by 8 am picked up slightly until by 1115 we had amassed a total of 17 birds - 16 Linnets and 1 Tree Sparrow. 

The Linnets comprised 7 first winter males, 6 first winter females, 3 adult males and zero adult females. We were more than pleased with this total considering the lack of birds in recent weeks, especially since this visit coincided with our best count of the season at 125+ Linnets. We are hoping that numbers build up from now. 

Linnet 

Linnet 

Tree Sparrow 

A local farmer/shooter who passes here at Gulf Lane every day stopped to ask how we were doing. Interestingly he confirmed our own recent low counts of Linnets with his own maximum counts of 30/40 Linnets. He also shared the view that this year has seen an abundance of natural food that Linnets and other species have exploited, hence their lateness at arriving at Gulf Lane to a field of bird seed mix, one that could never match their natural diet. 

The photo below is taken from Birds of The Western Palearctic. It lists the very catholic diet of the Linnet, literally dozens and dozens of species of seeds and plant matter, but also a number of insects which Linnets eat during the summer months. The insects are especially important in the spring and summer when they feature in the diet of nestlings. 

Agricultural changes over UK farmland in the last 40/50 years have depleted stocks of many of the seeds and plants listed and also decimated populations of many insects. It's little wonder and no coincidence that the Linnet and many other farmland species have suffered catastrophic declines.      

Linnet Diet 

With more breezy days to come soon, we may have another Linnet day soon. Stay tuned to see how we do.

Linking today to World Bird Wednesday, Anni's Birding and Eileen's Saturday Blog. 

Birders Cock-Up?

Never let it be said that Another Bird Blog doesn’t offer a variety of stories. We continue the rule of thumb today with a story about Modern Art in the Serbian town of Kikinda,  a samll town that is home to the planet's largest roosting population of Long-eared Owls. Between early November and mid-March, hundreds roost each day in the town square. 

Long-eared Owl - LEOs of Poland.

Reuters - November 2018 - “Phallic owl statue in Serbian town of Kikinda sparks complaints.” 

“A statue designed to brand Kikinda in Serbia as the city of owls is attracting attention for a different reason: its "phallic" shape. Critics of the recently erected 2.4 metre statue have called for its removal, claiming it is obscene. 

"This doesn't look like an owl. God save me, whoever approved this has no eyes," one person wrote on a Facebook post announcing the terra-cotta statue's unveiling. 

"Freud could say something about this statue, it looks so much like a phallus," another said. 

"Now everyone will ridicule Kikinda," another Facebook post read. 

"This statue represents something very masculine, but not an owl," said a post on Twitter. 

The statue did please some, however. "Come on people, I love art and I think the statue is really nice," one Facebook user said. 

Local sculptor Jovan Blat, who made the statue told Serbian newspaper Vecernje Novosti that he had intended to create a "stylized sculpture" with an "elongated, tubular body. It is clear that everyone does not understand contemporary art." 

Given the reaction to the statue, however, Blat said he would be prepared to make a replacement statue. 

However, Zeljiko Bodrozic, editor-in-chief of a local newspaper, said the existing owl statue should stay. "With all the hype swirling around it... in a way it also becomes a symbol of our city."  Local authorities declined to comment. 

Dragan Simic, a keen bird watcher, also has no issue with the statue. "Kikinda is now famous for its owls... across Europe, even around the world... the bird watchers are very active, numerous and loyal tourists." 

Kikinda - Serbia

Me? I couldn't possibly comment. But Dear Reader, feel free to add your point of view below.

Linking this post to Stewart's World Bird Wednesday.

Who Wants To Be A Millionaire?

Oh dear, the blog stats don’t look too good today after a week without a post. But Blogger tells me that “Page View All Time History” passed the one million mark at 1,008,401 from 1428 posts since August 2009, so all is not lost. Someone deserves a medal, probably faithful readers, a number of whom have followed the blog from day one. 

Migration time is pretty much finished here in Lancashire so unless something extraordinary takes place, for the next month or two it’s winter birds until the days lengthen in February and March. Birders forever wish their lives away to hurry along the next season and all that it brings, but somehow, winter seems to be the least favourite month for many birders. Or maybe even summer for those who take little interest in the breeding season? 

Saturday morning, and although there was a biting wind from the east a spot of welcome sunshine held out possibilities for a picture or two. I hit the lanes of Moss and Jeremy early, hoping for a few pictures of thrushes while the hawthorn berries are almost into their last days. Our winter thrushes consume the haw berry in huge quantities and if the weather turns very cold the hedgerows will very soon be stripped entirely of their already low yield of our dry summer. 

I found about 40 Fieldfares along the exact same stretch of road as a week ago, a handful of Redwings and the same of Blackbirds. Suddenly this week there are more Blackbirds around, even in our modest garden, as Blackbirds from Europe and Scandinavia move into the relative warmth of the UK. 

Fieldfare 

Fieldfare 

Fieldfare 

Blackbird 

It was watch and wait as passing cars sent the shy thrushes back and forth to escape the danger they sensed. While our garden Blackbirds can become used to humans, even in many cases, persuaded to trust us, the Blackbirds that live out in the sticks are as retiring as the very wary Redwing or reclusive Song Thrush.  If anything the larger Fieldfare is bolder than any and does occasionally let someone take a photograph. 

Redwing 

Redwing 

Blackbird 

The two Buzzards of a week ago were in the exact same spot, using a vantage tree to good effect in locating food in the adjacent field. 

I looked at Conder Green where following recent excavations and management, birds are beginning to return. Although returnees seemed to be mainly gulls I was in time to see a Great White Egret fly across towards the canal and to then count a raft of about 65 Wigeon against the far bank. Just recently a Great White has been seen at both nearby Aldcliffe and Cockersands, so possibly the same bird. 

Great Egret

Also here at the pool and in the creeks - a single Kestrel, 140 Teal, 22 Redshank, 8 Oystercatcher, 6 Curlew, 3 Little Grebe, 2 Little Egret and 1 Snipe. 

Redshank 

Redshank 

Oystercatcher

Excuse me now, I have to go to the shops and buy the Saturday night Lottery ticket. You just never know.

Linking this post to Anni's Birding Blog.

Daylight Robbery

I've been robbed of a number of days birding lately by our November weather, the month that invariably brings gloomy, wet and windy days across the Atlantic from the direction of North America.  I blame Donald Trump. There’s no other feasible explanation. 

It wasn't much different on Saturday morning after a bright start that quickly went downhill, until by 11 am there was rain and I was back home. After soup and a sandwich I sat at the keyboard only to see the sky lighten once more. Too late. 

Our Pink-footed Geese aren't playing ball with birders yet. They are shot at every day and prove hard to find, even harder to watch. At Lane Ends, Pilling was a flock of several hundred, maybe a thousand and seemingly entirely “pinkies” - unsurprising when the odds of finding the oddity goose is several thousand to one.  A large tractor drove slowly past, followed by a brightly clad jogger as the geese peeled off from their brief feed and gradually flew inland in tens, twenties and thirties in search of peace and quiet. 

Pink-footed Goose 

Out on the marsh were about 800/1000 Starlings in a tight flock, a Buzzard, a Grey Heron, plus a good number of Skylarks - perhaps 40/50 but most of them distant. 

I stopped at Gulf Lane hoping to see a good number of Linnets but best estimate was 40+ birds and none especially interested in the bird seed crop. About half a mile down the road at Braides Farm I noted that a flock of 150 or so Linnets fed along the weedy track and in the extensive fields there. It seems that the lack of Linnets at our own project site, probably as result of the good summer, mild autumn and warm-wet, early winter, has produced an abundance of food. The Linnets can pick and choose where they eat most times, more so this year. 

Linnet 

Braides Farm produced some exceptional counts of waders. The aircraft from the nearby parachute centre was around and about, often overhead at very low altitude upon which the massed waders would all take off into panic flight mode. Mostly they settled down again and I was able to achieve good but approximate counts of 2800 Lapwing, 2000 Golden Plover, 200 Redshank and 120 Curlew. Throughout all of this a Kestrel sat unperturbed along the fence line, waiting I guess for an opportune meal. 

Lapwing 

Of late there has been much disturbance at Conder Green with both habitat improvement on the pool and major construction around the old road bridge and the A588 road to and from Lancaster. That explains the relatively poor counts here of 130 Teal, 22 Black-tailed Godwit, 12 Redshank, 5 Little Grebe and just one Little Egret. 

I was about to spend an hour at Glasson, viewing the dock waters from the car, waiting for the wildfowl to come sailing by as they mostly do on quiet mornings. But then I saw that, where parking on this huge expanse of land has been free for as long as anyone can remember, folk are now expected to cough up via shiny new "Pay Here" machines.  In the village 50 yards away the little shops that sell bacon butties and ice cream to summer tourists are unhappy at the greedy tactics on display.   

Daylight Robbery 

Worse still the Canal and River Trust have sub-contracted the job to a company based in the south coast town of Brighton! Trendy Brighton, where (I'm told) bars like WTF and Naked Day fleece the sheeple punters, shops have names like ‘Vegetarian Shoes’ and ‘Choccywoccydoodah’, and kids have laughable names such as Lettuce, Rainbow and Daisy Boo. 

No, I can’t see birders paying for fancy parking here in Lancashire where folk are careful with their brass and where in the not too distant past in-your-face constructions demanding cash have been chopped at the knees during the darkest of winter nights. 

So instead I took a freebie ride in the direction of Moss Lane and Jeremy Lane and spent time watching a pair of Buzzards, about 150 Fieldfares and a dozen or more Redwings. 

Both Buzzards used a hawthorn hedgerow as a vantage point from which to watch the adjacent field. The Buzzards totally ignored the many Fieldfares that flew back and forth along the line of hedge as they scattered for no reason and then returned in unison. The Buzzards showed no interest at all in three Pheasants that walked along the hedgerow below them. No, the Buzzards were after small prey in the alongside field as one after the other they flew to ground where if necessary they ran to pounce upon the morsel they had spotted from their vantage point. 

Buzzard and Pheasants 

Buzzard 

Buzzard 

Noted many times on this blog. Buzzards principally eat small rodents, but also take birds, reptiles, amphibians, larger insects and earthworms. Buzzards do sometimes take game birds but such items make up only a tiny proportion of the diet. Buzzards are more likely to feed on carrion. 

Buzzards use three main hunting techniques. They locate prey from a perch and then fly directly to it. They may also soar over open terrain, occasionally hanging in the wind before dropping on to the prey and following up the attack on the ground. Alternatively they may be seen walking or standing on the ground looking for invertebrates. The photos are as close as we can get to Buzzards in this part of the world where the species is persecuted for any excuse and little reason. 

It was interesting that as I watched the Buzzards, the many dozens of Fieldfares using the same stretch of hedgerow displayed no fear of the Buzzards and at no time flew off because of the Buzzards’ feeding activity. 

Fieldfare 

Another thing. The fine, dry summer of 2018 produced little in the way of hawthorn berries and even now in early November, there are few berries left for wintering thrushes. Anyone who has yet to connect with a Fieldfare will find that they become scarce very soon if there is no food. 

Linking today to Eileen's Saturday and Stewart's World Bird Wednesday. 

Indoor Post

Looks like I won’t get out birding or ringing for a few more days. To put it mildly, the weather is crap by way of the usual wet and wind. 

But hopefully 2018/19 may turn out to be a “Brambling Winter”, an irruption year for this close relative of the much more common Chaffinch. Migration watch points and Bird Observatories are reporting abnormally large numbers of Bramblings when in more typical years the numbers of Bramblings seen is low in comparison to other autumn migrants and to species that overwinter. 

Trektellen shows a clear spike in UK numbers in late October early November 2018 with three or more days of 2000+ Bramblings at Hunstanton Cliffs, Norfolk and at Spurn Bird Observatory. There are also several days of counts in the high hundreds. 

Brambling 2018 - https://www.trektellen.nl

Brambling 

Brambling 

However, sightings here on the west coast are not nearly as high which is not unusual given that the range of the Brambling is biased towards the east by stretching from Scandinavia and then east through an enormous swath of taiga forest across to Sakhalin and Kamchatka. This area is at the most extreme eastern edge of the Russian Federation at the Pacific Ocean and very close to the northern tip of Japan. 

In "Brambling winters" it is often into the extremes of January and February and icy temperatures before Bramblings find their way to the warmer west coast of England. Such irruptions in a number of birds of Northern Europe most often involve species like Hawfinch, Brambling, Chaffinch, Waxwing, Bullfinch, Siskin, Coal Tit and Crossbill. The common factor is each species’ reliance upon the various seeds of trees found in northern taiga, also known as boreal forest. 

Crossbill 

Waxwing 

These irregular migrations are difficult to study because it is hard to predict when they will happen or where the birds will go each year. In each case, however, irruptions follow some type of boom-and-bust cycle of food sources. It is important to note that many winter birds will gather in flocks for the season, but that does not mean they are irrupting. An irruption is characterized by a distinct shift in the birds' typical winter range, with many birds appearing well outside the normal boundaries of their winter homes. 

Waxwing

The most common cause of this phenomenon is called “masting,” which occurs when a single tree species produces a large number of seeds across thousands of miles of forest in the same year. When the conifers in the boreal forests of Northern Europe experience a masting year, the abundance of seeds gives some species of bird a boost. The birds begin breeding earlier than usual and produce more offspring, resulting in a population boom. When autumn arrives, the bird population has doubled or even tripled, but the available habitat hasn't. Many birds move south, and young birds in particular may be pushed further and farther south and west in search of both food and somewhere to spend the winter. 

Other causes for bird irruptions include unduly harsh cold or severe weather that may force birds to find more temperate wintering grounds, or over-breeding that may deplete even plentiful food supplies. No matter what the cause of the irruption, however, it is difficult to predict where or when irrupting species may appear.

It is known that the Brambling’s strategy during winter, to roost in large dense flocks, is superior to those of other passerines. Also during summer Brambling densities can be very high even at breeding sites when food is abundant. Thus the Bramblings seem to prefer wintering in flocks as large as the available food supply allows permits. 

This may explain why flocks estimated at between 2 million and 5 million Bramblings are sometimes recorded in Scandinavia, Central Europe and Japan. Such flocks can even occur in good years for beech mast, a favoured food of the Brambling. 

Take a look at the video below. At first glance it appears to be a video of a murmuration of Starlings, but in fact all of the birds are Bramblings. The video was shot in Japan, sometime during the winter of 2015/16.  

Back soon with an outdoor post. Until them linking this post to Anni's Blog and Eileen's Saturday.