Like so much in our globalized lives, natural history is becoming an increasingly international pastime. I have just come back from a wintery fortnight in England — my memory flooded with images of wintering thrushes (Fieldfares and Redwings), Red Kites over frosty fields and rafts of Teal and Gadwall on the local ponds — to find an email from a friend in Connecticut, US. Attached to it is a photograph of a bird he snapped in Costa Rica some years ago — could I please identify it.
As always it is a pleasure, though something of a challenge as I have never been to Costa Rica. Indeed I have never been south of southern Guatemala in the Occident. The bird I have agreed to identify is a dull passerine, the size of a large warbler or a small thrush, uniformly dull gray throughout with a darker head — not unlike a gray version of our Common Bulbul. There seems very little else to go on. But on a closer look the bill is utterly distinctive, not in size but in shape. The lower mandible is angled upwards, and the upper is longer and ends with a sharply de-curved point. I have seen it once before in a book given to me many years ago called Birds of the World by
Oliver Austin, illustrated throughout by one of my favorite wildlife artists Arthur Singer.
I have it here in Cairo, a thick tome aged not just by the 1966 publication date but by the price on the inside cover, 27 shillings and 6 pence, when the United Kingdom was still using pre-decimal pounds, shillings and pence. And on page 292, in the chapter on tanagers, a strictly New World family of birds, is the plate I am looking for. Among the dazzlingly plumaged species typical of the family — including the multi-hued Paradise Tanager, the brilliant Scarlet Tanager, the enigmatic Rose-breasted Thrush Tanager and the sublimely aquamarine Swallow Tanager — is the rather more dowdy Cinnamon-bellied Flower-piercer. The plumage does not match the species I have on my laptop, but the bill is absolutely spot on — I have a flower-piercer. A few minutes on Google Images and hitting the books and I have an ID. The mystery bird from the highlands of Costa Rica is a Slaty Flower-piercer.
So even in these times of economic hardship, bills may be welcome, the bills in question being attached to birds. And perhaps no more so than in trying to tackle the identification of the shorebirds overwintering here on Egypt’s coasts and wetlands. In winter plumage, the assemblage of different species, many rather dull and dowdy before donning their breeding finery, can be daunting. But focusing on the bill cannot only separate similar-looking species but can also shed light on a bird’s feeding habits and even a clue to an individual’s sex.
Take the Spoonbill. This large, all-white relative of the ibises is a rare breeder in the mangrove groves along the Red Sea and a more widespread winter visitor to coastal and inland wetlands, with the western end of Lake Qarun in the Fayoum normally hosting loose flocks. At any distance the Spoonbill looks much like other all-white water birds such as the Great White Egret and the Little Egret or, along the Red Sea coast the Western Reef Heron. Whereas these species have a pointed dagger-like bill, however, that of the Spoonbill is just as the name suggests: It is shaped exactly, and somewhat improbably, like a spoon. Identification sorted — no other bird on the Egyptian list shares this feature. The bill is actually used as a sieve, filtering worms and other invertebrates from the mud as it probes through the wetland shallows.
Sharing this habitat and often found alongside the Spoonbill is the Pied Avocet. This is a rather more distinctive species, resplendent in black and white, though at a distance and in deep water possible to confuse with the Common Shelduck, or, along the southern Red Sea coast the unique Crab Plover. Again, look at the bill. The Pied Avocet has a very long, very slender black bill that is strongly up-curved, more so than any other Egyptian wader. In contrast, the Crab Plover has a heavy, straight hatchet-like bill ideally adapted for cracking open its heavily armored crab prey, while the Common Shelduck has a short, bright scarlet bill with, in the drake, a strongly swollen knob.
Staying in the muddy shallows are two wader species that are superficially very similar, both with long dull-colored legs, dull grayish-brown above and pale below, barely speckled at the sides and neck. These are the Greenshank and the smaller, more elegant Marsh Sandpiper. When seen together, the former is noticeably larger and heavier than the latter but this is much harder to deduce in solitary birds. Once more, go for the bill. The Greenshank has a long, rather robust though slender bill which is slightly but distinctly upturned (but nowhere near to the degree of the Pied Avocet mentioned above). The Marsh Sandpiper has an almost impossibly slender, sharp and dead straight bill. And once more, the bills reflect their different food strategies. The Greenshank takes larger more robust mollusks and invertebrates, and the Marsh Sandpiper pokes at much smaller more delicate prey.
But where does sex come in? For, as promised, it does. Egypt’s largest wader is the Eurasian Curlew, some 55 centimeters long, streaked brown throughout and with a very long down-curved bill. It is a rather scarce winter visitor to wetlands throughout the country both coastal and inland. While there is some overlap, female Eurasian Curlews have rather longer bills than the male. This reduces competition for food as the females can probe in deeper mud than the males and thus exploit different prey resources. In a wintering flock of Eurasian Curlews, or indeed on migration in Spring and Fall, the longer billed individuals are likely to be the females.
The smaller, stockier Whimbrel has a shorter, less de-curved bill than even the male Eurasian Curlew and is further distinguished by distinct eye and crown stripes. A third species with old records from Egypt, the Slender-billed Curlew, is now considered by most authorities as extinct — not just here but globally.
Extinct too is the Huia. It was a large, superficially crow-like bird confined to New Zealand. Both sexes were glossy black with a bold white tip to the tail. As befits members of a small family known as the New Zealand wattlebirds, adults had prominent orange wattles at the base of the bill. But it is the bill itself that made the Huia so unique. While the bills of male and female Eurasian Curlews may differ subtly in length, those of the male and female Huia differed also in form and function. The male Huia had a pale, short, sharp and straight bill that was used to actively chisel away at dead wood to expose beetle grubs and the like. That of the female was much longer, thinner and strongly down-curved and was used as a probe, reaching into the wood for insect larvae hidden deep inside their burrows.
Sadly, little is known about the habits of the Huia, not least whether the sexes worked independently in searching for food or co-operatively. The last confirmed sighting was in 1907 with a well-documented record from near Wellington in 1922 and less likely sight records from the 1960s. While a few believe it may still cling on in some remote corner of New Zealand’s forests, most agree that the Huia exists now only as specimens, including individual feathers in Maori relics, in a number of museums. While habitat destruction was a major cause of its demise, so was heavy hunting for the Victorian trophy trade. Its unique bill made it a major target for collectors wanting a pair for their taxidermy collection.
So alas for the Huia, as for us in this era of austerity, bills may not be a good thing after all.
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