Discovery
J G Keulemans' fine illustration of Corsican Nuthatch in Proceedings of the Zoological Society of London (1884) Corsican Nuthatch is such a delightful little bird, no bigger than a Blue Tit, and behaving very much like one of that family, that I decided to dig into the story of its discovery and then its tangled taxonomy. It was discovered surprisingly late by English ornithologist John Whitehead in June 1883. (Although Italian biologist Enrico Giglioli [1845-1909] claimed in 1890 that he saw one in September 1877, at Porte Alla Leccia, but did not collect it believing it; to be a European Nuthatch: a classic case of the Victorian collector's adage "What's hit's history, what's missed's mystery").
As noted, the 1880s seems very late for such a distinctive and delightful little nuthatch to have evaded detection by European scientists and collectors. It remains, I think, the last breeding European species of bird to have been described by scientists. Most of the apparently novel species that now crowd our field guides were described earlier, but raised (or in many cases returned) to full species status relatively recently. One example of this is Moltoni's Warbler, which many tend to think of a 'new' species despite it being described by Dutch ornithologist Coenraad Temminck long ago in 1820.
Things might have been different if the renown 19th century ornithologist Charles Lucien Bonaparte [1803 - 1857] had spent more time in, Corsica, the birthplace of his father and famous uncle. I wonder whether the extraordinary speed with which Richard Bowdler Sharpe [1847 – 1909]. ornithological curator at the British Museum, described the species had anything to do with the habitual rivalry between the two great colonial powers. What better way to put one over on the French than a British scientist describing a new species from their own back yard?! Bowdler Sharpe first saw Whitehead's specimen in October 1883, announced its discovery in April 1884 (see here) and formally described it in print, complete with a fine illustration by J G Keulemans, in June 1884 when he named it Sitta whiteheadi in honour of its finder (Proceedings of the Zoological Society of London June 1884 - see here)
As noted, the 1880s seems very late for such a distinctive and delightful little nuthatch to have evaded detection by European scientists and collectors. It remains, I think, the last breeding European species of bird to have been described by scientists. Most of the apparently novel species that now crowd our field guides were described earlier, but raised (or in many cases returned) to full species status relatively recently. One example of this is Moltoni's Warbler, which many tend to think of a 'new' species despite it being described by Dutch ornithologist Coenraad Temminck long ago in 1820.
Things might have been different if the renown 19th century ornithologist Charles Lucien Bonaparte [1803 - 1857] had spent more time in, Corsica, the birthplace of his father and famous uncle. I wonder whether the extraordinary speed with which Richard Bowdler Sharpe [1847 – 1909]. ornithological curator at the British Museum, described the species had anything to do with the habitual rivalry between the two great colonial powers. What better way to put one over on the French than a British scientist describing a new species from their own back yard?! Bowdler Sharpe first saw Whitehead's specimen in October 1883, announced its discovery in April 1884 (see here) and formally described it in print, complete with a fine illustration by J G Keulemans, in June 1884 when he named it Sitta whiteheadi in honour of its finder (Proceedings of the Zoological Society of London June 1884 - see here)
J G Keulemans' executed this second charming illustration of Corsican Nuthatch for Whitehead's account in Ibis in 1885 Perhaps, though, despite being the era of pen-and-ink and the penny post, they just did things quicker back then as Whitehead's description of his momentous discovery followed quickly in Ibis in 1885 (see here).
Being accustomed to good metalled roads pushing high into the mountains and an ease of access afforded by motor vehicles, it's easy to forget just how difficult it was during Victorian times (and well into the 20th century) to reach thinly populated mountainous regions, even in Europe.
Being accustomed to good metalled roads pushing high into the mountains and an ease of access afforded by motor vehicles, it's easy to forget just how difficult it was during Victorian times (and well into the 20th century) to reach thinly populated mountainous regions, even in Europe.
Although this mule track is in Spain, it reflects the sort of track then available across the Mediterranean Whitehead's Account
A taste of this difficulty can be gleaned from Whitehead's opening comments in his account: "On the l2th June 1883, I left a small village to visit the nest of an Eagle which the shepherds had told me of. Starting at 4 A. M. with a mule and guide (taking provisions for two days), it was not until 2P.M. that we reached the summit of the mountain. As it was close upon 6 o'clock before the nest had been visited, I decided to pass the night in a small stone hut .."
Whitehead's account continues to describe the moment he found the nuthatch: "The next morning, wishing to get a shot at some Alpine Swifts, which were nesting in a high crag near, I got up early, and when returning heard a curious whistle, which I thought was that of the Crested Titmouse. After I had waited a few minutes a Nuthatch crept out to the out of the end of a pine~bough ..."
A taste of this difficulty can be gleaned from Whitehead's opening comments in his account: "On the l2th June 1883, I left a small village to visit the nest of an Eagle which the shepherds had told me of. Starting at 4 A. M. with a mule and guide (taking provisions for two days), it was not until 2P.M. that we reached the summit of the mountain. As it was close upon 6 o'clock before the nest had been visited, I decided to pass the night in a small stone hut .."
Whitehead's account continues to describe the moment he found the nuthatch: "The next morning, wishing to get a shot at some Alpine Swifts, which were nesting in a high crag near, I got up early, and when returning heard a curious whistle, which I thought was that of the Crested Titmouse. After I had waited a few minutes a Nuthatch crept out to the out of the end of a pine~bough ..."
Modern readers may be shocked at Whitehead's reason, shooting Alpine Swifts, for going out the next morning but the final words of Whitehead's sentence above are even more chilling as he finished with the bleak words "... and was promptly shot". However, at a time when optics were primitive and portable bird guide guides non-existent, this was the standard method used by ornithologists to identify birds, particularly when exploring unfamiliar areas. Not unreasonably, as he had no texts to guide him, Whitehead did not realise the importance of his discovery at the time. He later wrote that he "... thought no more about it (i.e. the nuthatch) until the month of October, when, wishing to know if I had correctly named a few small warblers, l brought the skin of the Nuthatch to Mr. Sharpe, who assured me that he did not know the bird. At the end of the month, on the night of' my departure, lie wrote to me:-" 'There is no doubt your bird is a new species".
Corsican Nuthatch's nest from Whiteheads account Whitehead returned to Corsica in May 1884, but this time his focus was firmly on discovering more about the bird that was about to be named after him. He later wrote that on the second day of his exploration of the area he had found the nuthatch "... after wandering about until past mid-day, without seeing any thing ... I heard the same curious whistle, and looking about, soon saw and shot ... the new Nuthatch ... Knowing that the mate must he near, I remained quiet and in a few minutes it shared the same fate; ... this bird proved to be the female. A few hours later I came across a small band, three of which I shot. Such carnage seems unnecessary and inexplicable today but Whitehead wasn't finished as he had yet to find a nest. He continued his account as follows: On the 12th, provisions having fallen short, I was forced to return to my head-quarters; but on the 16th I returned to search for the nests. and was most fortunate. The same evening I ... saw the female go twice to a very small and neatly-packed hole in a very old pine-stump, some 20 feet from the ground. He found a second nest on 20th May and then a third the following day. Although modern sensibilities may find his actions hard to defend, there's no doubt that he put himself at great risk to satisfy his (scientific) curiosity, writing that the nests "... proved in nearly every case to be most difficult of access, the trees being high, very rotten, without branches, and much too big to swarm; the once mighty giants of the forest--now but whitened skeletons, being in the Iast stage of decay." Interestingly, this is a pretty accurate description of the nest sites we found on my visit to Corsica this year. Whitehead continued that the "... first nest took nearly three hours' hard work to reach ... The second nest was in a much worse position and quite 40 feet high; but by climbing up a neighbouring tree, with the aid of a rope I managed to swing to a branch, and soon cut open the nest...
During the eleven days he looked for them he found nine nests "... three of which were in holes from 70 to 100 feet from the ground, the trees in places nearly eaten through with decay; so that it would have been foolish to have attempted to reach them". For over a decade, Whitehead remained the only source of information about this enigmatic species.
Corsican Nuthatch from Henry Dresser's "A History of the Birds of Europe" Interestingly, Despite, or perhaps because of his depredations, Whitehead never revealed the exact location of his discovery because he feared "... that if he made it known where it is to be met with, it would soon be exterminated by over-zealous collectors. Hence, though other naturalists have since visited Corsica, and have used every endeavour to obtain specimens, no one has hitherto succeeded in so doing ..." (from Henry Dresser's "A History of the Birds of Europe" - Vol IX Supplement 1896 see here). Interestingly, J G Keulemans seems to have enjoyed a monopoly of illustrating Corsican Nuthatch. As Sharpe's protégé, perhaps he was the only artist with access to the specimens!
Vizzavona station Rediscovery of the nesting sites
However, even as Dresser wrote those words, German ornithologist Dr Alexander Koenig, founder of the still extant Koenig Museum in Bonn, visited Corsica where "with considerable difficulty" obtained five specimens. Another population was found in 1900, and birds collected, but no eggs or nests were taken. However the birds seem to have been largely left in peace between these visits. No nests or eggs were taken between 1884 until 1908 when an intrepid British ornithologist made his way to the island to look for them. By this time access to the birds' habitat was greatly enhanced by the opening of a railway line into the interior which reached Corte in 1888 and was finally completed in 1894. This railway must have been a great help to the famous (or infamous?) British ornithologist and egg-collector Rev. F. C. R. Jourdain, (1865 - 1940) who it was that visited the area in 1908 and again in 1909. By then there was a station at Vizzavona in the heart of a huge pine woodland which must have cut out many hours in the saddle or on foot. Writing in the journal Ibis in 1911 (see here) he reported being "fortunate" to find "... several pairs obviously breeding in pine-forest at over 3000 ft" returning to take "... three nests with eggs" in 1908 and in 1909 taking "... two more nests with eggs ..." Like Whitehead before him, Jourdain commented that the nests were "... as a rule, only obtainable .with difficulty and considerable amount of danger" as nesting trees were in "... an advanced in decay". The drawings that accompanied his account (below) in Ibis show how perilous it was to raid a nuthatch's nest high in a rotting tree stumps. Some trunks, he recorded, had to be braced by logs to stabilise them before an assault could be mounted.
However, even as Dresser wrote those words, German ornithologist Dr Alexander Koenig, founder of the still extant Koenig Museum in Bonn, visited Corsica where "with considerable difficulty" obtained five specimens. Another population was found in 1900, and birds collected, but no eggs or nests were taken. However the birds seem to have been largely left in peace between these visits. No nests or eggs were taken between 1884 until 1908 when an intrepid British ornithologist made his way to the island to look for them. By this time access to the birds' habitat was greatly enhanced by the opening of a railway line into the interior which reached Corte in 1888 and was finally completed in 1894. This railway must have been a great help to the famous (or infamous?) British ornithologist and egg-collector Rev. F. C. R. Jourdain, (1865 - 1940) who it was that visited the area in 1908 and again in 1909. By then there was a station at Vizzavona in the heart of a huge pine woodland which must have cut out many hours in the saddle or on foot. Writing in the journal Ibis in 1911 (see here) he reported being "fortunate" to find "... several pairs obviously breeding in pine-forest at over 3000 ft" returning to take "... three nests with eggs" in 1908 and in 1909 taking "... two more nests with eggs ..." Like Whitehead before him, Jourdain commented that the nests were "... as a rule, only obtainable .with difficulty and considerable amount of danger" as nesting trees were in "... an advanced in decay". The drawings that accompanied his account (below) in Ibis show how perilous it was to raid a nuthatch's nest high in a rotting tree stumps. Some trunks, he recorded, had to be braced by logs to stabilise them before an assault could be mounted.
Illustrations (drawn from photographs) from Jourdain's account. Note the figure in the lefthand drawing.
Siberian Surprise
Small pine-loving nuthatches clearly like surprising ornithologists and may yet have another card to play. In 2006 an entomological expedition to the Siberian Russia found a nuthatch resembling Chinese Nuthatch (but with paler underparts) breeding in larches in the Altai mountains. It may be an undescribed race of Chinese Nuthatch, but given it's c1,500 km from the nearest known population, it's just as possible that it's a new species, However, without a specimen or even photos the identity of the birds remains unclear. Perhaps there was something in Whitehead's approach after all!
Small pine-loving nuthatches clearly like surprising ornithologists and may yet have another card to play. In 2006 an entomological expedition to the Siberian Russia found a nuthatch resembling Chinese Nuthatch (but with paler underparts) breeding in larches in the Altai mountains. It may be an undescribed race of Chinese Nuthatch, but given it's c1,500 km from the nearest known population, it's just as possible that it's a new species, However, without a specimen or even photos the identity of the birds remains unclear. Perhaps there was something in Whitehead's approach after all!
The range of the various "Black-capped Nuthatches"
Taxing Taxonomy
Surprisingly, by the time Jourdain visited Corsica, the species' scientific name was no longer Sitta whiteheadi, but instead Sitta canadensis whiteheadi, that is a race of the Red-breasted Nuthatch. Today, lumping two species differing in plumage and so geographically isolated from one another may seem odd, but that's what the distinguished taxonomist Ernst Hartert [1859-1933], working with the information available at the time, decided in 1905. in his monumental work on Palearctic birds
Perhaps surprisingly, this treatment persisted for over 50 years. It remained "canadensis" in the first edition (1954) of Peterson's field guide (although referred to in the text as Corsican Nuthatch). This was followed a few years later in The Atlas of European Bird (1960) by Karel Voous who also called it Corsican Nuthatch but added the alternative name Black-capped Nuthatch (to embrace Red-breasted, Kruper's, Yunnan and Chinese Nuthatches). However, in 1961, the Journal of Ornithology published a paper confirming, based on vocalisations and different breeding biology, that Corsican Nuthatch was a distinct species, something which the study of DNA has since confirmed.. This was followed by Peterson's second edition (1966), later by Voous and all works since.
So by the 1960's the consensus clear, the Corsican Nuthatch was an endemic to the Western Palearctic and all the other species were distinct from their American cousin. . This was just as well as, mirroring Whitehead's celebrated discovery, Jean-Paul Ledant found a new species of nuthatch in the fragments of a once extensive pine forest in North Africa, the Algerian Nuthatch. This caused as much of a sensation in 1975 as Whitehead's had done almost a century before. Although it most closely resembled Corsican Nuthatch - Corsica is only 650 km away from where it was found - its DNA showed that its closest relative was Kruper's Nuthatch of Asia Minor, the nearest population of which is over twice as distant! So where did that leave Corsican Nuthatch? Astonishingly, its closest relative proved to be Chinese Nuthatch which lives over over 7,000 km to the east!
Looking at the map, it's plain that Red-breasted Nuthatch has the widest distribution of any species in this group and probably the largest population too. This is somewhat ironic as it's thought that the ancient common ancestor of these birds once had a wide distribution across the Palearctic and spread from Siberia into Nearctic (i.e. North America). When much of the northern hemisphere was covered in ice, the pine forests (and the birds with them) retreated south to surviving 'pockets' of suitable conditions (refugia). When the situation reversed and the forests spread north for some reason the nuthatches in the Palearctic remained stuck and isolated in their refugia where they evolved into new forms. However, perhaps because mountain ranges tend to run more north-south in America, the Red-breasted Nuthatch managed to follow the pines north and spread across the continent. Interestingly, the Red-breasted Nuthatch is the only one in the group that isn't entirely resident but is often found in winter well south of its breeding range. This species' tendency to wander was well attested by the remarkable discovery of a bird in Norfolk in October 1989. Fortunately, it was still there into 1990 when I managed to catch up with it.
Surprisingly, by the time Jourdain visited Corsica, the species' scientific name was no longer Sitta whiteheadi, but instead Sitta canadensis whiteheadi, that is a race of the Red-breasted Nuthatch. Today, lumping two species differing in plumage and so geographically isolated from one another may seem odd, but that's what the distinguished taxonomist Ernst Hartert [1859-1933], working with the information available at the time, decided in 1905. in his monumental work on Palearctic birds
Perhaps surprisingly, this treatment persisted for over 50 years. It remained "canadensis" in the first edition (1954) of Peterson's field guide (although referred to in the text as Corsican Nuthatch). This was followed a few years later in The Atlas of European Bird (1960) by Karel Voous who also called it Corsican Nuthatch but added the alternative name Black-capped Nuthatch (to embrace Red-breasted, Kruper's, Yunnan and Chinese Nuthatches). However, in 1961, the Journal of Ornithology published a paper confirming, based on vocalisations and different breeding biology, that Corsican Nuthatch was a distinct species, something which the study of DNA has since confirmed.. This was followed by Peterson's second edition (1966), later by Voous and all works since.
So by the 1960's the consensus clear, the Corsican Nuthatch was an endemic to the Western Palearctic and all the other species were distinct from their American cousin. . This was just as well as, mirroring Whitehead's celebrated discovery, Jean-Paul Ledant found a new species of nuthatch in the fragments of a once extensive pine forest in North Africa, the Algerian Nuthatch. This caused as much of a sensation in 1975 as Whitehead's had done almost a century before. Although it most closely resembled Corsican Nuthatch - Corsica is only 650 km away from where it was found - its DNA showed that its closest relative was Kruper's Nuthatch of Asia Minor, the nearest population of which is over twice as distant! So where did that leave Corsican Nuthatch? Astonishingly, its closest relative proved to be Chinese Nuthatch which lives over over 7,000 km to the east!
Looking at the map, it's plain that Red-breasted Nuthatch has the widest distribution of any species in this group and probably the largest population too. This is somewhat ironic as it's thought that the ancient common ancestor of these birds once had a wide distribution across the Palearctic and spread from Siberia into Nearctic (i.e. North America). When much of the northern hemisphere was covered in ice, the pine forests (and the birds with them) retreated south to surviving 'pockets' of suitable conditions (refugia). When the situation reversed and the forests spread north for some reason the nuthatches in the Palearctic remained stuck and isolated in their refugia where they evolved into new forms. However, perhaps because mountain ranges tend to run more north-south in America, the Red-breasted Nuthatch managed to follow the pines north and spread across the continent. Interestingly, the Red-breasted Nuthatch is the only one in the group that isn't entirely resident but is often found in winter well south of its breeding range. This species' tendency to wander was well attested by the remarkable discovery of a bird in Norfolk in October 1989. Fortunately, it was still there into 1990 when I managed to catch up with it.
My notebook drawings of Norfolk's famous Red-breasted Nuthatch
Conservation
As noted above, Whitehead, believing the species to be restricted to a single limited area, never divulged where he saw the birds fearing they could easily be driven into extinction by collectors. Although his view may have been tainted by self-interest, Jourdain was right to suggest the species wasn't as rare or vulnerable as Whitehead thought commenting that the bird "... is in no danger of extermination ... On the contrary, I have the best of reasons for believing that it is widely but somewhat locally distributed in the pine- forests of Corsica, and am aware of at least three localities, all at considerable distances apart, in which the bird is tolerably common" and cited the great difficulty in reaching their nests as a reason why oologists and collectors were not a threat.
As noted above, Whitehead, believing the species to be restricted to a single limited area, never divulged where he saw the birds fearing they could easily be driven into extinction by collectors. Although his view may have been tainted by self-interest, Jourdain was right to suggest the species wasn't as rare or vulnerable as Whitehead thought commenting that the bird "... is in no danger of extermination ... On the contrary, I have the best of reasons for believing that it is widely but somewhat locally distributed in the pine- forests of Corsica, and am aware of at least three localities, all at considerable distances apart, in which the bird is tolerably common" and cited the great difficulty in reaching their nests as a reason why oologists and collectors were not a threat.
Corsican Nuthatch distribution based on maps by the IUCN (left) and the Helm Guide (right) The species' preference for nesting in ancient rotting trees, which Jourdain believed to protect it from extinction by collectors, ironically turns out to be a long term threat to its existence. Such trees are only found in forests over 100, perhaps 150, years old so if destroyed by fire or irresponsible logging the available habitat is reduced and fragmented for a century or more. Fragmentation of habitat is a serious problem and one which published maps tend to obscure (see above). With a warming climate, fire must be a growing concern and the harder one to tackle as legislation can (in theory) moderate damage by commercial forestry. I wonder if providing artificial nest sites (using suitable nest boxes or other means) in younger forests may help to sustain the population.
Understandably maps in field guides are at such a large scale that the whole island seems awash with the nuthatch but even the map available online produced by the IUCN (International Union for Conservation) is too optimistic. The map from the Helm Guide to the group (Tits, Nuthatches & Treecreepers - 1996) better shows the fragmentation of its range (although it misses out a population in the NE of the island) Both the destruction and fragmentation of ancient forests remain a serious threat and explains why it is classed as "Vulnerable" (= at high risk of extinction in the wild) by the IUCN. It is thought that the species is slowly declining and now numbers as few as 2,000 birds although some estimates are as high as 3,000. (The Algerian Nuthatch faces similar problems but its population is much lower, perhaps half that of Corsican Nuthatch).
It's difficult to know how cherished and loved this gorgeous little bird is by the Corsicans, but I was surprised to find no information boards about the bird and the importance of ancient woodlands in its prime locations. I was disappointed too that many websites, videos and books aimed at visitors to the island fail to mention it (and even some that do use photos of European Nuthatch). Unlike in Whitehead's day, raising awareness of this unique bird can only help to protect it.
Understandably maps in field guides are at such a large scale that the whole island seems awash with the nuthatch but even the map available online produced by the IUCN (International Union for Conservation) is too optimistic. The map from the Helm Guide to the group (Tits, Nuthatches & Treecreepers - 1996) better shows the fragmentation of its range (although it misses out a population in the NE of the island) Both the destruction and fragmentation of ancient forests remain a serious threat and explains why it is classed as "Vulnerable" (= at high risk of extinction in the wild) by the IUCN. It is thought that the species is slowly declining and now numbers as few as 2,000 birds although some estimates are as high as 3,000. (The Algerian Nuthatch faces similar problems but its population is much lower, perhaps half that of Corsican Nuthatch).
It's difficult to know how cherished and loved this gorgeous little bird is by the Corsicans, but I was surprised to find no information boards about the bird and the importance of ancient woodlands in its prime locations. I was disappointed too that many websites, videos and books aimed at visitors to the island fail to mention it (and even some that do use photos of European Nuthatch). Unlike in Whitehead's day, raising awareness of this unique bird can only help to protect it.
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