'Gigantism' in birds - two chapters by different authors in the strange story of the St Kilda Wren

                                                           

The St Kilda Wren was on the front cover of W.H. Hudson's pamphlet which was published by the Society for the Protection of Birds - forerunner of the RSPB 

IN a pamphlet published in 1894, W.H. Hudson asserted that the St Kilda Wren - a sub-species of the bird  familiar on the  mainland  - had been extirpated by unscrupulous collectors.

Happily, he was wrong. The bird was not extinct - and it is the subject of a study on 'island gigantism' published in the most recent edition of  the  Evolutionary Journal of the Linnaean Society.

It seems odd to apply the term 'gigantism' to such a diminutive species - but apparently it  can occur, as discovered by Charles Darwin,  on islands when species evolve in a different way from their mainland counterparts.

At between 13 and 16 grammes, the St Kilda Wren can be twice the size of a mainland Wren which typically weighs in at 7-10g.

The authors of the new study on gigantism note that the former typically lives  in very open and often sheer cliff face habitats which tend to be predator-free.

They also have longer bills and  there may also be differences in song.

Unfortunately, the Evolutionary Journal is a bit of a soup, full of unfamiliar academic jargon which makes it difficult to follow.

By contrast, though written more than 130 years ago and flawed in its conclusions, the commentary of Hudson is much more accessible to the contemporary birder.

He writes of the St Kilda Wren: "This small feathered creature is a dweller among the rocks near the sea, and it frequently nests in crevices and holes just above highwater mark on the shores of places which the Great Auk once haunted.

"It will be remembered that, about nine or ten years ago,  Charles Dixon found this wren quite common at S. Kilda, where it was the only small bird resident all the year. 

"It differed from the Common Wren in its habits and more powerful song, its paler ground colour and its more distinct markings and stouter legs and feet. 

"On account of these distinguishing characters, it was described as a new species - Troglodytes hirtensis. 

"It is now believed by ornithologists that the St Kilda Wren is not specifically distinct from the Wren of the mainland but that it is a variety, or race, which has diverged from the parent form during the long centuries of its isolated life on that wintry island where not a tree or shrub exists. 

"Species, sub-species or variety, it matters little, what concerns us just now is the following fact. 

"No sooner had the news gone abroad that "lone St Kilda’s isle" possessed one little songbird of her own - a Wren that differed somewhat from the familiar Wren - than it was invaded by the army of collectors who did not mind its distance from the mainland so long as they secured something for their cabinets.

"And the result of their invasion is that the St. Kilda Wren no longer exists."

                                             

Cliff faces on St Kilda provide an all-year habitat for the island's 'giant' Wrens  (photo: Stephen Hodges via Wikimedia Commons)

'We have no desire to profit from breach of trust.' Birdfeeder company returns funds to SNP

                                                  

The feeders were bought from a company based in Canterbury, pictured (photo: Christine Matthews via Wikimedia Commons)

A COMPANY that designs and assembles birdfeeders has returned £155 to the Scottish National Party after learning  that three of its products had been purchased with misappropriated SNP money by its former chief executive, Peter Murrell.

The magnanimous gesture was today revealed by Graham Evans who is senior partner with Jacobi Jayne & Co which supplies feeders to customers all over the UK and beyond from its base in Canterbury, Kent.

In a letter published in today’s edition of The Daily Telegraph, Mr Evans writes: "While we are in the business of supporting garden wildlife, we have no desire to profit from a breach of trust.

"We are therefore donating  the full £155 received for these items back to the SNP."

He continues: "We are an entirely apolitical organisation, but we believe that stolen money has no place in our accounts.

Mr Evans concludes with a challenge to other firms that also received unauthorised payment through the actions of the former SNP chief.

"It is our hope that other suppliers named in the investigation will follow suit to ensure that such funds are returned to their rightful owners," he urges.

At a total cost of £155, the three feeders sold to Mr Murrell are likely to have been top-of-the-range products which are resistant to all but the most cunning of squirrels.

It is not known if Mr Murrell bought the feeders for others members of his family or for him and Nicola Sturgeon, now his estranged wife, to watch the finches, tits and other birds that visited their garden.

Nor is it known if the feeders will be returned to Jacobi Jayne & Co following its refund of the £155.

Population explosion? More than 4,000 pairs of Dartford Warblers counted in Britain in 2025

                                       

On the up - the Dartford Warbler feeds on small spiders and caterpillars

ALTHOUGH it is still far from being a common bird, the UK population of the Dartford Warbler is coming on by leaps and bounds.

According to a press release issued this week by the RSPB, there are now reckoned to be about 4,100 pairs nationwide compared with 3,200 during the last national survey in 2006.

Of these, 264 pairs were last year counted on 14 of its own reserves - notably the ones at RSPB Arne in Dorset, with 97 pair, and Minsmere in Suffolk, with 41 pairs.

The bird is a heathland specialist, and the society has been developing this habitat wherever possible to safeguard its future.  

* Photographs: RSPB

RSPB Arne - heathland hotspot for Dartford Warblers 

Lessons from Willow Ptarmigan windfarm study came too late to save White-throated Needletail from tragic demise

The Smøla windfarm. Some of the towers have been painted, thereby seeking to reduce bird collision risk. (photo: Brukar:bsigmundg via Wikimedia Commons)

MIGHT the accident that  killed a White-throated Needletail on Harris in the Outer Hebrides in summer 2013 have been avoided?

On June 26 that year, birders looked on in horror as the mega-rare bird flew into the tower of a wind turbine, dying instantly.

In his book, Twitching by Numbers, Gary Bagnell describes watching the bird "whooshing over his head" as "the defining moment" of his twitching career .

He writes: "If Britain ever gets another twitchable one, make sure you see it as it really is the ultimate twitch".

But might the collision have been avoided if the tower had been painted black, thus making it more conspicuous?

Bird collisions with turbine rotor blades are a well-known negative consequence of windfarms, but there has been far less attention to the risk of birds colliding with the turbine towers and how to mitigate this risk.

However, data from  the 68-turbine Smøla windfarm in Norway indicates that painting part of a tower a black or a dark colour creates a visual contrast which reduces the number of collisions.

Researchers found there was a 48 per cent reduction in the number of recorded  carcasses of Willow Ptarmigan at the base of painted towers compared with unpainted ones.

Their report  states: The family of Grouse and  Ptarmigan species  are known to have poorly developed vision and flight manoeuvrability.

" In addition, many such species are often active during dusk and dawn when visibility is poor. 

"These characteristics all make grouse especially prone to collide with man-made objects.

Historically,  carcasses of collision-victim Willow Ptarmigan (Lagopus lagopus) at the Smøla wind-power plant were often found only a few metres from the tower base

"They showed signs of direct impact with a  'wall' rather than cuts and fractures which is  usual for hits by turbine blades. 

"In one case, fresh blood smear and feathers was also observed on the tower base where a fresh Ptarmigan carcass had  found.

"Species in the Galliforme family typically fly relatively low above ground."

Some 97 per cent (138 of 142 flights recorded) of the Willow Ptarmigan that were flushed on Smøla showed a flight-height lower than 15 metres.

Data from both autopsy and flight height indicate that grouse are more prone to collide with the turbine tower bases than the rotor blades. 

Elsewhere, several black grouse (Tetrao tetrix) that were found immediately under turbines in an area in Styria, Austria, are thought to have died because of collision with tower bases and not the rotor blades, even though the cause of death was never observed directly.

Corpses were analysed by veterinarians who concluded that injuries were consistent with the birds flying into a hard surface. 

Furthermore, collision between a Willow Ptarmigan and the tower base has been confirmed by an actual observation in Sweden where one individual, part of a group of 10 birds, crashed directly into the tower base at 2.7 m height above ground.

This was at 7.05am on September 25, 2011.

The report's authors conclude: "Our study shows that painting of the wind turbine tower base reduces bird collisions. 

"This relatively simple and cost-effective mitigation measure should be considered in the planning of new windfarms, especially in areas where there are species in the Galliforme family and other birds with relatively poor vision and manoeuvrability and which generally perform low altitude flights."

The report was compiled by Norwegian researchers Bård G Stokke, Torgeir Nygård, Ulla Falkdalen, Hans C. Pedersen and Roel May. Their investigations were funded by the Research Council of Norway.

* Since then, the operators of  the Smøla windfarm, Statkraft, have also applied black paint to a single blade on some of its turbines, resulting in fewer fatal collisions for raptors such as White-tailed Eagles. 

Bygone birding: a case of second time lucky for British birder on Lake Geneva jaunt in search of Wallcreeper

                               

The Wallcreeper - a species every birder wants to see 

R.S.R. Fitter was a frontline ornithologist of the 1950s and 1960s.  Below is what he wrote  in his column, In The Country, which appeared the December 4, 1964 edition of the Birmingham Daily Post.

There are certain colourful and attractive birds that every birdwatcher hopes to see before he dies. 

High on the list are the Golden Oriole, the Hoopoe, the Bee-eater and the Wallcreeper. 

The first three are not too hard to see - the Oriole and the Hoopoe almost anywhere on the Continent, the Bee-eater if you go to the right parts of Spain or Southern France. 

But the Wallcreeper had always eluded me. 

Last January, while on a short business trip to Morges, at the west end of the Lake of Geneva, I travelled the whole length of the lake, to Villeneuve at the east end - and a very pleasant rail trip it was along the lake shore - to try to see a Wallcreeper that was reputed to frequent the old town hall there during winter. 

The town hall was easy enough to find -it is right by the station - but the only bird on it was a Treecreeper, more likely the Continental Short-toed Treecreeper. 

So I was delighted to learn, on a return visit to Morges, at the end of last month, that Wallcreepers had been seen only a few days previously on a range of Jura cliffs at Vallorbe, not far away. 

This time I was more fortunate.

Although the bird was too high up the cliff to see the red patches on its wings, I had a clear view of the unmistakable round-winged outline of a Wallcreeper fluttering about among the numerous crannies of a tall limestone crag only a few hundred yards from Vallorbe Station. 

* Photo by Imran Shah from Islamabad via Wikimedia Commons

Green or Great Spotted? Controversy over identification of bronze study of woodpecker ahead of Salisbury sale

The contentious woodpecker

THERE has been short shrift for a birder who had the temerity to suggest that the species depicted above was less likely to be a Great Spotted  Woodpecker - as identified in an auction catalogue - than a Green Woodpecker.

It is a most attractive creation in bronze which is due to go under the hammer (Lot 332) at an auction to be conducted by auction house Woolley and Wallis at their saleroom in Salisbury, Wiltshire, on June 2.

When the birder contacted Woolleys to suggest that the bird depicted is probably a Green Woodpecker, the auction house immediately contacted the artist, Geoffrey Dashwood, for clarification. 

He responded that his bird is emphatically a Great Spotted Woodpecker. And he should know - he created it!

The piece  measures 19.2cm x 11.2cm x 6.2cm. 

Whatever its species, the pre-sale estimate is that the hammer will fall at somewhere between £2,000 and £3,000. 

The Golden Oriole: 'a shy and retiring bird that appears like a golden gleam as it darts through dark-green foliage'

                                                 

Orioles nesting in maple tree as depicted in Gould's fine  book

Though scarce, the Golden Oriole is a regular summer visitor to Britain, with four  reported from one county - Lincolnshire - just since the start of this week. Among its Victorian admirers was artist-commentator John Gould who describes the species thus in The Birds of Great Britain (1873).

 

It is possible that some of my readers who are not very intimately acquainted with our native birds may think that I am introducing to their notice a species which does not fairly belong to our avifauna.

But this I can assure them is not the case, for this lovely bird has doubtless regularly visited our islands in summer from before the landing of Julius Caesar.

To enumerate all the specimens which have been shot would fill several pages. 

In Mr. Stevenson’s  Birds of Norfolk, no fewer than 20 are recorded as having been captured or seen in that county alone.

The works of Yarrell and Thompson contain many similar notices of its occurrence in other counties, both of England and Ireland.

Mr. Rodd, in his recently published  List of the Birds of Cornwall, mentions several instances of its appearance in that part of England, and the Hon. Evelyn Boscawen saw a fine male, a year or two ago, on the terrace-wall at Tregothnan.

An adult male, in full plumage, which had been shot on  April 26,1858, was placed in my hands the next day, by Mr. Leadbeater; and, were it desirable or necessary, many instances might be cited of its having been seen in our southern and western counties. 

But, although the bird is so frequently found in Britain, it can only be regarded as an occasional visitant since our islands do not lie in the direct line of its migrations. 

That those individuals which cross the straits and resort to our shores have occasionally bred here, and, if unmolested, would still

do so, cannot he doubted. 

Should any of my readers wish to see it in a state of nature, they have only to make a journey to the quiet town of Leyden, and there, on any fine spring morning, they will hear the flute-like note of the male and perchance find one of its nests among the trees growing in the very streets of that celebrated seat of learning.

During the summer, it may also be seen in every suitable locality of

the Continent, from the shores of the Mediterranean to Finland.

Being strictly a migrant, it leaves its African winter quarters in April, and, after having  spent the summer in the more northern countries of Europe, returns again in September to its winter home among the Atlas range or even further south. 

In speaking of the birds of Malta and Gozo, Mr. Wright says: "This strikingly beautiful bird is a regular visitor in the spring, where it arrives in small flocks and would probably breed were it not disturbed. 

"It is very common sometimes in San Antonio Gardens, and is very destructive to the fruit of the Japan medlars of which it appears to be exceedingly fond. 

"Occasionally females, probably old birds, are found in the brilliant plumage of the males.

"A few also repass in September."

Meanwhile,  Lieut. R. M. Sperling says: "This beautiful and essentially Mediterranean bird meets the eye round the whole of the northern coast. 

"Migrating from Africa about the middle of April, it spreads through the deep olive-woods of Corfu, the dark caroh-trees of Malta, and the thick bay and myrtle covers of Albania and Greece. 

"It is a shy and retiring bird, and generally appears like a golden gleam as it darts through  dark-green foliage; but, by sitting perfectly still, I have been enabled to watch its graceful motions for half-an- hour within five or ten yards of me."

Mr. H. E. Dresser, who has favoured me with a short note respecting the bird as observed by him in Finland, says: "In the southern and eastern parts it is very generally distributed, but I do not think it is

found higher than Abo. 

"At the country-seat of my friend Mr. Hackman (Hertnala, near Wiborg), where I spent the summer of 1856, at least four pairs must have had nests, but I could not succeed in finding them.

"The Finns call this bird 'Kuhankeittaja' from its peculiar whistle."

The species nests in high trees; and, during the first fortnight in May, the two sexes work together and firmly attach it to a bifurcation of the branches, often where they are so flexible that it is shaken by every wind that blows.

They employ pieces of straw and hemp, with spiders’ webs and similar filaments to secure them to the branches and to unite the whole together. 

One of these threads passes straight from one branch to the other, and forms the border of the nest in front; another, rolled underneath, penetrates the material of the nest, and is wound round the opposite branch to give the work stability. 

The interior of the nest is composed of wool, spiders’ webs, caterpillars’ silk, the down of flowers, horsehair and very fine

blades of grass. 

As soon as the work is finished, the female deposits four or five eggs, which are mostly oblong in form, but some are attenuated and terminate in a point.

They are of a beautiful rosy white, spotted with black or brownish black, particularly at the larger end. 

The female sits so closely that I have twice seen her taken from the nest with the hands. 

The male feeds her while thus occupied, and takes her place for the few moments she occasionally leaves the nest. 

The young are hatched about the seventeenth or eighteenth day, and the parents feed them with caterpillars, small worms and sweet and

tender fruits. 

If the young be taken, the parents continue lamenting for several days and seem to claim their progeny by mewing on the very tree on which they were produced. 

If, during their desolation, they happen to discover where the captives are, they continue calling to them all day from the summit of the nearest tree.

And the captors, recognising the cry, place the cage with the young on a tree near to their house.

The parents will then give them food through the bars for a time, but cease to do so as soon as they judge them capable of feeding themselves.

This cessation often takes place without being noticed, and the young

are left to die in their prison.

When this occurs, the ignorant country-people imagine that the parents have poisoned them in despair of ever seeing them again at liberty.

The young are reared with much difficulty, from a supply of their usual food not being easily procurable.

They may, however, be fed successfully with breadcrumbs, hemp-seed and kernels pounded together, bits of raw fresh meat, worms, the larvae of silkworms, and dried fruits which latter must be softened before being given to them. 

They soon become familiar and even attached to the person who takes care of them, and will eat out of his or her hand.

All the members of the genus Oriolus are inhabitants of the Old World, none being found in America.

Two or three are natives of Africa, and as many more of India and China; but by far the finest of the whole are found in the Philippines and the other islands lying southward, as far as Australia. 

Orioles also occur in  Java and Sumatra. 

Wherever they are, their habits and economy are very similar. 

When hanging in search of food from the outermost branches of the green-foliaged trees, which they all do more or less, they exhibit many graceful actions. 

As might be inferred from the lengthened and pointed form of their

wings, they have a quicker and more Swallow-like flight than the true Thrushes.

That the young may be brought up in cages is certain for I saw four which had been thus reared in the Zoological Gardens at Amsterdam.

These nestling birds, which had been taken about July 18,

differed from the adult in the more sombre hue of their plumage, in having the bill of a purplish flesh- colour, the irides dark brown, and their thick and swollen tarsi of a pale blue.