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.

Eggciting News

Regular readers will know that I like to add a little variety to the blog but never stray too far from birds. After all, birds are not just for looking at and it's doubtful that curiosity ever really killed a cat, least of all an enquiring mind, amateur or professional. 

Birds feature in many branches of science, history, art, and in recent years, studies of evolution, and the origin of birds via dinosaurs. Research in the past few decades has shown many traits once thought to define modern birds, including feathers, wishbones, brooding behaviours, avian-style lungs, and hollow skeletons evolved first in their dinosaur forebears. 

Bird eggs have been admired since ancient times for their many hues and patterns, from the turquoise-blue of the Common Starling to the blotchy browns of the Curlew. And now, a study shows the colours and markings on birds’ eggs are even older than thought. They may have graced dinosaur eggs some 150 million years ago. 

Curlew eggs 

Mini dinosaur hatching

Starling nest

Yale University. "Dinosaurs put all coloured birds' eggs in one basket, evolutionarily speaking." 

ScienceDaily. 31 October 2018. 

"According to researchers at Yale, the American Museum of Natural History, and the University of Bonn, birds inherited their egg colour from non-avian dinosaur ancestors that laid eggs in fully or partially open nests. 

Last year, molecular paleo biologist Jasmina Wiemann of Yale University published the first evidence of dinosaur egg colouration, using chemical analysis to detect two pigments—blue-green biliverdin and red-brown protoporphyrin—in the eggs of a 70-million-year-old parrot-beaked oviraptorosaur called Heyuannia from China. 

"This completely changes our understanding of how egg colours evolved," said author, Jasmina Wiemann. "For two centuries, ornithologists assumed that egg colour appeared in modern birds' eggs multiple times, independently." 

The egg colours of birds reflect characteristic preferences in nesting environments and brooding behaviours. Modern birds use only two pigments, red and blue, to create all of the various egg colours, spots, and speckles. 

Wiemann and her colleagues analysed 18 fossil dinosaur eggshell samples from around the world, using non-destructive laser micro spectroscopy to test for the presence of the two eggshell pigments. They found them in eggshells belonging to Eumaniraptoran dinosaurs, which include small, carnivorous dinosaurs such as Velociraptor. 

"We infer that egg colour co-evolved with open nesting habits in dinosaurs," Wiemann said. "Once dinosaurs started to build open nests, exposure of the eggs to visually hunting predators and even nesting parasites favoured the evolution of camouflaging egg colours, and individually recognizable patterns of spots and speckles." 

Co-author Mark Norell, the Macaulay Curator of Palaeontology at the American Museum of Natural History, noted that "Coloured eggs have been considered a unique bird characteristic for over a century. Like feathers and wishbones, we now know that egg colour evolved in their dinosaur predecessors long before birds appeared."  

Eggs of British Birds - Seebohm - 1896

Now never let it be said that Another Bird Blog doesn't offer its readers food for thought.

Back soon with more birds and things.

In the meantime, linking with Stewart's World Bird Wednesday.

Wot! No Redwings.

It’s the start of a new month at Oakenclough following 237 birds caught here in what proved to be a rather quiet October. The most ringed bird was Redwing with 84, followed by Goldfinch and Lesser Redpoll almost tying on 24 and 23 respectively. Lots of twos and threes in that total of 237 but disappointingly, only 19 Chaffinch and 10 Goldcrest in what should be a peak month of migration for both species. 

I couldn’t make it on Thursday when Andy kicked off November with a very nice 30 birds that included 4 more Redwings, a single Fieldfare, 3 Lesser Redpoll, more Goldfinches, and a “cracking” Bullfinch. 

Fast forward to Friday as Andy and I met up for another 0630 start. The morning was slow and slightly disappointing in the way of both migration and the number of birds caught. We finished early at 1100 due to the slowness of the session with just 16 birds captured: 7 Goldfinch, 3 Blue Tit, 2 Coal Tit, 1 Goldcrest , 1 Dunnock, 1 Chaffinch and 1 Lesser Redpoll. 

Lesser Redpoll

We tried to catch thrushes this morning but the few that were around simply did not play ball. There was an early rush of c125 Fieldfare and 40 Redwing from the west but by 0900 even that spurt died out, after which we saw none. Similarly the visible migration of finches was pretty much non-existent and limited to handfuls of Chaffinches, one definite Brambling, and the arriving Goldfinch likely to be more local birds. 

During 2018 Goldfinches proved to be the staple ringer’s diet here and elsewhere with around 300 captured by group members at various locations, including members' gardens where the Goldfinch remains omnipresent and widespread.  A quick glance at our data shows that of the 300, only 50 were full adults and the remaining 250 sub-adult or juveniles, an indication of the runaway productivity and continued success of this species.     

Goldfinch 

I called in at Gulf Lane, Cockerham where has been an unavoidable delay in our ongoing project to ring wintering Linnets. After the two winters 2016/17 and 2017/18 when we caught over 400 Linnets through the winter months, the corresponding season of 2018/19 has seen very few Linnets return to this regular site. 

The lack of Linnets here on the west coast this autumn is something of a mystery as good numbers have been reported at observation watch points on the East Coast. The graph below shows counts of migrating Linnets for the autumn period 2018 from Spurn Bird Observatory, Yorkshire. While most of these Linnets are likely to be of Scottish origin, a proportion will originate from Scandinavia, with their overall route south taking them to the south of England, France & Spain.

Linnets at Spurn 2018 -  Trektellen   

Only in the last weeks of October did I notice that the field of bird seed mix at Gulf Lane was beginning to entice a few Linnets with irregular counts of up to 35. In addition there had been a Stonechat and a handful of Tree Sparrows. 

Linnet 

We are now hopeful that numbers of Linnets here will build as the winter grows colder, wider food availability recedes and greater numbers of Linnets discover the ready-made field of finch food.

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

Picture This

The postman knocked on the door. Katrina had emailed to say there was a package on the way. I slid the precious contents from the tube. This was rather like Christmas.  But here was a job for an expert picture framer, so I made my way to Garstang Picture Gallery. But bad news, they were busy and I must wait three weeks for the framing job.

Picture This

Meanwhile here on the Lancashire coast, where many, many thousands of wild Pink-footed Geese spend the winter and where their calls and daily flights are part of everyday life, it is impossible not to become a fan of these rather special creatures. 

Into the New Year when the shooting season is over and the daily legions of wildfowlers lay down arms, our geese become comparatively less wild. They quickly learn that not every human wishes them harm and perhaps understand that us birders thrill to the sight and sound of their daily coming and going. 

With luck, and if the feeding on new grass or unharvested potatoes is especially good, the geese become tolerant of an inquisitive car with a telescope poked from a partly lowered window.  Mostly the Lancashire hordes are “pinkies”, but with the occasional bonus of a Bean Goose, White-fronted Goose or Barnacle Goose hidden in the mix. Very often, a gaggle of Greylags tag along for the daily ride. 

Pink-footed Geese 

White-fronted Goose 

Pink-footed Goose 

Bean Goose

Greylags

Barnacle Goose

To whichever species they belong, all geese share certain characteristics. Geese are highly intelligent team players - protective of their environment, inquisitive, amicable, loyal, caring, helpful, but aggressive where necessary.  Geese have eyesight more highly developed than man or dog, with hearing superior to both; hence the employment of domesticated geese as security guards in many situations, not least in the average farmyard where urban thieves, naïve in the ways of the countryside, may get a bite on the leg for their trouble. 

Yes, I'm a devotee of geese. So when I saw author and illustrator Katrina’s van Grouw’s stunning evocation of geese in her new book Unnatural Selection, I made enquiries as to how I might acquire a copy.

Unnatural Selection is the finest book I have read in many a year. Read my original review at Another Bird Blog.  

Goose Ancestry 

To cut this long story short, there’s now a new picture hanging in the hallway, a signed copy of the above in pride of place, visible from my workspace. I can't thank Katrina enough for the time and trouble she took to send me this wonderful picture. 

Goose Ancestry by Katrina van Grouw 

As you will see, Katrina is a brilliant artist. She also has a way with words that makes her prose equal to her artistry. Here she is on domestic geese, taken from “Unnatural Selection”, a passage that effectively explains the origins of the multitude of farmyard geese that cause all sorts of trouble to new (and sometimes not so new) birders. 

“By defining a species as something that can only interbreed (and produce fertile offspring) with others of the same species, you’re effectively denying any possibility that species can interbreed — otherwise, they wouldn't be species. But animal species do hybridize, and they do produce fertile offspring. And for evidence, you only need to look, once again, to domesticated animals. 

Take geese, for example. Geese are among the few domesticated animals that have not just one but two wild ancestors. I don’t just mean subtle genomic differences that suggest a hybridization event early on in their domestication history. No, pure-bred geese that derived from two totally separate species — the Swan goose, Anser cygnoides, from Central Asia and the Greylag goose, Anser anser, from Central Europe — hybridise readily and regularly. 

Out of any mixed farmyard flock, it’s normal to find a substantial number of hybrids between the two. Even several recognised breeds, like the Steinbacher from Germany, are hybrids between the two parent species. The domesticated forms of the Swan goose are the sublimely elegant Chinese goose and the more heavyweight African goose. 

Although Swan geese have a slender head and bill like a swan, with only a subtly raised “knob” at the base of the bill, both of the domesticated varieties have a deeper skull, and the bill knob is positively enormous. Both, however, share the Swan goose’s unusually smooth silky neck feathering and (unless they’re leucistic) the deep chocolate brown stripe running from the crown to the base of the neck. Greylag geese have a much deeper, more powerful bill than Swan geese and have the deeply furrowed feathering down the neck so typical of the majority of goose species." 

Unnatural Selection  

To read more about Katrina van Grouw visit  her web page.

Unnatural Selection is available from Princeton Press at £35 or Amazon at about £22.

I am not a fan of huge global companies dominating world trade to the detriment of small players whereby I deleted my Amazon account years ago. But I understand that in this case at least, the author receives the same payment as someone buying from the publisher. So there is a monetary saving to be made for those who have no issues with using Amazon.

This book would make a great Christmas or birthday gift to any aspiring author or artist.  A student of biology, science, history, or evolution would find this book indispensable. I am none of those things but I was enthralled by this most remarkable of books and I wholeheartedly recommend it to readers of Another Bird Blog. 

Linking today to Stewart's World Bird Wednesday.

Iceland Jobs

We were pretty keen to get out ringing this week but a steady wind of 15-20 mph made it impossible for days on end.  The usual check on late Wednesday afternoon suggested those pesky isobars might just pull apart for Thursday morning, so I arranged to meet Andy up at Okenclough for a ringing session. 

"Maybe" weather

Back home there was a hint of (unforecasted) drizzle at the off. As I drove up to Oakenclough, 600ft above sea level, the drizzle intensified with a wind from the North West at about 8-10mph. At first “light” there was 100% low cloud with light but spasmodic drizzle. 

But we stuck to the task in hand, the drizzle eased as the light improved slowly and we packed in about 11 am. During the whole time there was very little visible migration but in the circumstances we managed a reasonable catch, mainly Redwings. 

The birds caught tell the story of the morning: 17 Redwing, 4 Coal Tit, 2 Goldfinch, 2 Goldcrest, 2 Blue Tit, 1 Great Tit. 

In the heavy cloud conditions with very low visibility the visible migration of thrushes was virtually zero. We had maximum counts of 180 Redwing and 40 Fieldfare, mostly arriving from unseen directions as they dropped through the cloud cover.  Otherwise, the count of small birds was negligible. 

The field sheet shows how at least three of this morning’s Redwings were of the Icelandic sub-species, Turdus iliacus coburni, rather than the nominate European race Turdus iliacus. 

Spot the Iceland Jobs 

Birds of the Icelandic subspecies are marginally larger and darker than nominate birds from Europe but only around 10-15% of Icelandic birds have longer wing lengths, so relatively few are separable on size. 

But this morning it was noticeable how at least 50% of Redwing wing lengths were in the 120’s rather than the mid to late teens of recent ringing sessions. The three biggest came in at wing lengths of 129 mm, 127 mm and 124 mm with corresponding respective weights of 76.5 gms, 68.5 gms and 68.9 gms. Compare these three monsters with three of the smallest – 113 mm with 56.7 gms, 117 mm with 58.9 gms, and 117 mm with 61 gms. 

Icelandic Redwing 

European Redwing 

We’ll be trying again soon so let’s hope for a few windless days and more light for more photos.

Linking today to Eileen's Blogspot and Anni's Birding.

Extinct? Who Cares?

“The sixth mass extinction is under way, this time caused by humans. A team of researchers have calculated that species are dying out so quickly that nature's built-in defence mechanism, evolution, cannot keep up. If current conservation efforts are not improved, so many mammal species will become extinct during the next five decades that nature will need 3-5 million years to recover to current biodiversity levels. And that's a best-case scenario.” 

Date: October 15, 2018 

Source: Aarhus University 

"There have been five upheavals over the past 450 million years when the environment on our planet has changed so dramatically that the majority of Earth's plant and animal species became extinct. After each mass extinction, evolution has slowly filled in the gaps with new species. 

The sixth mass extinction is happening now, but this time the extinctions are not being caused by natural disasters; they are the work of humans.  A team of researchers from Aarhus University and the University of Gothenburg has calculated that the extinctions are moving too rapidly for evolution to keep up. 

If mammals diversify at their normal rates, it will still take them 5-7 million years to restore biodiversity to its level before modern humans evolved, and 3-5 million years just to reach current biodiversity levels, according to the analysis, which was published recently in the scientific journal, PNAS." 

Some species are more distinct than others 

"The researchers used their extensive database of mammals, which includes not only species that still exist, but also the hundreds of species that lived in the recent past and became extinct as Homo sapiens spread across the globe. This meant that the researchers could study the full impact of our species on other mammals. 

However, not all species have the same significance. Some extinct animals, such as the Australian leopard-like marsupial lion Thylacoleo, or the strange South American Macrauchenia (imagine a lama with an elephant trunk) were evolutionary distinct lineages and had only few close relatives. When these animals became extinct, they took whole branches of the evolutionary tree of life with them. We not only lost these species, we also lost the unique ecological functions and the millions of years of evolutionary history they represented. 

"Large mammals, or megafauna, such as giant sloths and sabre-toothed tigers, which became extinct about 10,000 years ago, were highly evolutionarily distinct. Since they had few close relatives, their extinctions meant that entire branches of Earth's evolutionary tree were chopped off" says palaeontologist Matt Davis from Aarhus University, who led the study. 

And he adds: "There are hundreds of species of shrew, so they can weather a few extinctions. There were only four species of sabre-toothed tiger; they all went extinct." 

Long waits for replacement rhinos 

"Regenerating 2.5 billion years of evolutionary history is hard enough, but today's mammals are also facing increasing rates of extinction. Critically endangered species such as the black rhino are at high risk of becoming extinct within the next 50 years. Asian elephants, one of only two surviving species of a once mighty mammalian order that included mammoths and mastodons, have less than a 33 percent chance of surviving past this century. 

The researchers incorporated these expected extinctions in their calculations of lost evolutionary history and asked themselves: Can existing mammals naturally regenerate this lost biodiversity? 

Using powerful computers, advanced evolutionary simulations and comprehensive data about evolutionary relationships and body sizes of existing and extinct mammals, the researchers were able to quantify how much evolutionary time would be lost from past and potential future extinctions as well as how long recovery would take. 

The researchers came up with a best-case scenario of the future, where humans have stopped destroying habitats and eradicating species, reducing extinction rates to the low background levels seen in fossils. However, even with this overly optimistic scenario, it will take mammals 3-5 million years just to diversify enough to regenerate the branches of the evolutionary tree that they are expected to lose over the next 50 years. It will take more than 5 million years to regenerate what was lost from giant Ice Age species." 

Prioritizing conservation work 

"Although we once lived in a world of giants: giant beavers, giant armadillos, giant deer, etc., we now live in a world that is becoming increasingly impoverished of large wild mammalian species. The few remaining giants, such as rhinos and elephants, are in danger of being wiped out very rapidly," says Professor Jens-Christian Svenning from Aarhus University, who heads a large research program on megafauna, which includes the study. 

The research team doesn't have only bad news, however. Their data and methods could be used to quickly identify endangered, evolutionarily distinct species, so that we can prioritise conservation efforts, and focus on avoiding the most serious extinctions.

As Matt Davis says: "It is much easier to save biodiversity now than to re-evolve it later." 

Expect The Unexpected

Five-fifteen. The alarm buzzed. “What would the day bring?” With luck the forecasts had been right, so through the "office" window I checked the darkened trees for signs of sway. They looked still, while above the street light there were breaks in the ghostly cloud. I heaved a sigh of relief, prepared for the off and for the 35 minute drive up to Oakenclough. For a ringer, the anticipation, the excitement of expecting the unexpected never quite goes away. 

At Okenclough it was still dark at 0630 as outer branches stirred ominously. It was more like 10-12 mph than the 6mph decreed by the experts. That 4+ mph can make a difference when birds with powerful eyesight can spot movement in the fine mesh of a mist net. 

Soon after dawn Redwings arrived. We caught a few in the dark as they continued to arrive in dozens and low hundreds, mostly from the north-west. Fieldfares began to arrive a little later but not in the same numbers as Redwings and certainly not in the numbers we witnessed on Thursday. By 10 am we had caught 14 Redwings and zero Fieldfares, despite counting 900 and 300 respectively. 

About 1030 it was as if someone dropped a curtain to stem the hitherto very visible migration. Birds passing through or overhead dwindled to near enough zero and it was time to pack up from what had been a disappointing catch of 14 Redwing, 2 Goldcrest, 1 Chiffchaff, 1 Treecreeper, 1 Goldfinch, 1 Blue Tit, 1 Long-tailed Tit. 

Chiffchaff 

Treecreeper 

Redwing 

As the figures above suggest, birds other than Redwings and Fieldfares were hard to come by. It was as if all were in a hurry to reach their unknown destination with very few stopping off in our ringing site. As earlier in the week, we noted a strong movement of Woodpigeons heading south-west – circa 550 in 3+hours. 

In addition to thrushes we recorded approximately 60 Chaffinch, 20 Goldfinch, 6 “Alba” Wagtail, 4 Lesser Redpoll, 3 Siskin, 1 Bullfinch, 1 Reed Bunting, 1 Kestrel, 2 Sparrowhawk. 

Overall we enjoyed an exhilarating week of ringing with 157 birds caught, 99% of which were involved in active migration. Every one of those birds now carries a unique ring, the data associated with each capture is held on the National database, and every one of those birds could well provide more information in the coming days, weeks and years. One already has. 

A Lesser Redpoll Andy caught on Wednesday 17 October 2018, ring number ADA0166, had been ringed 364 days earlier on 18 October 2017 at Middleton, Morecambe Bay, Lancashire. 

On the way home but by barely stopping I clocked up 4 Kestrels, 2 Buzzard and 1 Sparrowhawk. Also, 125 Whooper Swans on Pilling Moss – our winter swans are back with my best count so far. 

Whooper Swans

There's more soon from Another Bird Blog.  Expect the unexpected and you won't be disappointed.

Linking this post to Anni's Birding Blog.