The University of the Unusual (2)

The Mystery of Avian Migration

    It is now known that many birds, like most Canadians, travel great distances in search of comfortable climates. One can even ‘watch’ some of them do it. For example, here is what the cuckoo (‘Victor’, by name) is up to:

“Victor on his way back to Africa - 05 Jun 2017

Locations received from Victor's tag during the late afternoon on 4 June showed that he had left the UK and was in central France. Last spring he left the UK around 25 June, stopping briefly in northeastern France before moving to Central France. He is currently in an area of forest just south of Orleans and around 100km (65 miles) north of the area close to Chateauroux where he spent 10 days last spring.”

    It was not that long ago that the most dedicated naturalist or bird enthusiast would have no idea where birds went, or if they even left. How would they know? I do not know where the birds around my feeder went last night or where they go during a short thunderstorm or a long winter. Brits thought the cuckoo was a British bird, but as you can see, he spends more time in the air and in Africa. Birds are difficult to track.

    While some aspects of bird migration are still puzzling, an unusual event in 1822 helped solve the mystery behind the annual disappearance of storks.

Arrow Storks

    

    In that year in Northern Germany a stork was shot, obviously for the second time. When retrieved, it was found impaled with a long spear or arrow, clearly of African origin. That bird which had travelled from somewhere in Africa is now the stuffed “Arrow Stork” (Pfeilstorch) exhibited in the Zoological Collection at the University of Rostock. Although it is amazing that a stork wounded in such a manner could continue on its journey, there are around two dozen similar examples that have been recorded. Bird banding would later offer additional proof that birds often travel vast distances. Now even monarch butterflies are monitored.

“European” Storks

   

 Storks are not common in North America and one only thinks about them in relation to the delivery of babies. I was surprised to find them so frequently mentioned in the books of Patrick Fermor, which have to do with his wanderings on foot through Europe in the 1930s. Nests seem to be in every village. Apart from the nests, he does offer a description of their migration and one is reminded of Audubon and passenger pigeons.

    

“Swifts were still skimming through the air and a heron flew across the river from wood to wood. A number of large and mysterious birds were floating high overhead and at first I thought they were herons too, but they carried their necks extended instead of coiled between their shoulders, and they were white. They were larger and more slender and less hurried than swans: the spread of wings scarcely moved as they revolved on the air-currents. There were about a dozen, snow-plumed except for black flight-feathers which ran along the inner edge of their wing like a senatorial swipe of mourning. They were storks!

When they circled lower, the long beaks and the legs that trailed in the slipstream showed red as ceiling wax. An old shepherd was leaning on the lamp close by and gazing up at them too. When some of the great birds drifted lower, the draught of their feathers brushed our upturned faces, and he said something in Magyar -- ‘Net, gobyuk’ and smiled. He hadn’t a tooth in his head. Two of the birds glided upstream. One dropped on a haystack and fluttered to regain its balance. The second landed underneath in the meadow -- becoming, as it folded its wings, a white bobbin with red lacquer stilts and bill -- and paced the water’s edge. The others, meanwhile, were alighting on the tiles of the two little bridgehead towns and advancing with ungainly steps along the roofs to inspect the dishevelled nests that cumbered many of the chimneys. Two of them were even attempting, in defiance of the bells which were tolling there, to land on one of the Cathedral belfries -- they remembered the harmless hazard from former incumbency. The bell-hampers were choked with tangles of last year’s twigs.

    Touching my arm, the shepherd pointed downstream at something in the dark-shadowed east high above the river and just discernible across the failing sky. Ragged and flocculent, fading to grey, scattered with flecks of pink from the declining sun, varying in width as random fragments were dropping away and re-cohering and agitated with motion as though its whole length were turning on a single thread, a thick white line of crowding storks stretched from one side of the heavens to the other. Mounting Africa along the Nile, they had followed the coasts of Palestine and Asia Minor and entered Europe over the Bosphorous. Then, persevering along the Black Sea shore to the delta of the Danube, they had steered their flight along that shining highway until they had come to the great bend a few miles downstream. Defecting from the river, their journey was now following westerly as well as a northern bias; they were bound for Poland, perhaps, and shedding contingents as they went at hundreds of remembered haunts. We gazed at them in wonder. It was a long time before the rearguard of that great sky-procession had vanished north Before nightfall the whole armada would subside in a wood or settle all over some Slovakian hamlet -- astonishing the villagers and delighting them, for storks are birds of good omen -- like a giant snow storm; taking to the air again at first light. (Six months and hundreds of miles later, I halted on the slopes of the Great Balkan Range, and watched the same migration in reverse. They were making for the Black Sea, retracing their spring journey before wintering beyond the Sahara.)
From Chapter 11: “The Marshes of Hungary”, A Time of Gifts, pp.309-10.

Sources:

To see where Victor is now go to this BTO SITE.

https://www.bto.org/science/migration/tracking-studies

See the entry for Pfeilstorch in Wikipedia and the essay in that source on “Bird Ringing” is also good.

See also: “100 Wonders: The Arrow Stork” by Dylan Thuras, Atlas Obscura, Sept. 23, 2015.

And: “Flight Paths: On Nature,” Helen Macdonald, The New York Times, May 15, 2015

P.S.

For another case where a great deal was learned from an impalement, read about Phineas Gage in a Wiki entry which is longer than a novella. Or: “Phineas Gage: Neuroscience’s Most Famous Patient,” Steve Twomey, Smithsonian Magazine, Jan. 2010

Vanishing Vultures

Buzzards

    To the growing list of things to be worried about, I will add another subject which is too interesting to avoid. I first became aware of the vulture problem over a decade ago, but was reminded of it today as I read this powerful description:

“At magic hour, when the sun is gone but the light has not, armies of flying foxes unhinge themselves from the Banyan trees in the old graveyard and drift across the city like smoke. When the bats leave, the crows come home. Not all the din of their homecoming fills the silence left by the sparrows that have gone missing, and the old white-backed vultures, custodians of the dead for more than a hundred million years, that have been wiped out. The vultures died of diclofenac poisoning. Diclofenac, cow aspirin, given to cattle as a muscle relaxant, to ease pain and increase the production of milk, works—worked—like nerve gas on white-backed vultures. Each chemically relaxed milk-producing cow or buffalo that died became poisoned vulture bait. As cattle turned into better dairy machines, as the city ate more ice cream, butterscotch-crunch, nutty-buddy and chocolate-chip, as it drank more mango milkshake, vultures’ necks began to droop as though they were tired and simply couldn’t stay awake. Silver beards of saliva dripped from their beaks, and one by one they tumbled off their branches, dead.”

   The above appears at the beginning of Arundhati Roy’s The Ministry of Utmost Happiness and is found in a review of that book by Joan Acocella in the June 5 & 12, 2017 issue of The New Yorker.

While the new novel is a work of fiction the dramatic decline in vultures in South Asia is a fact and, in fact, diclofenac is the cause.

Sky Burials

    Perhaps you were more upset to learn  from that passage that sparrows have gone missing, but the loss of ugly buzzards should be lamented as well. In very warm countries with lots of people and animals, having carrion cleaned away quickly is a good thing. For the Parsis the loss is even more problematic since the vulture plays the role of undertaker. Bodies are left on “Towers of Silence”, exposed to the elements and to the vultures, and it is best if they are quickly removed.

 Pharmaceutical Pollution

    The disappearance of these large birds became apparent back in the 1990s as increasing numbers of vultures crossed over into the carrion category. Gradually it was determined that diclofenac was the culprit. It was widely used by veterinarians to treat cows and there are many of them in India. The drug is now banned for veterinary use in India and attempts are being made to restrict multi-dose vials for humans so as to discourage illegal use of the drugs for animals. (Some sources are provided below.)

Turkey Buzzards in Ontario

     I am pleased to report that the vulture population seems to be fine here. Apparently years ago, buzzards were fairly rare in this area. Now one sees them even in the colder months and there seems to be evidence that their range is extending north. Canadian articles relating to diclofenac are generally focussed on human consumption and I did not find any discussing veterinary use and the vulture problem.

Buzzard Day in Hinckley, Ohio

    You may not have celebrated that day or traveled to Hinckley, but you are likely aware that the buzzard has a day just like the groundhog. This year marks the 60th anniversary of “Buzzard Day” in Hinckley.  It was in 1957 that a reporter noted that someone there had kept a log which observed, over a number of years, that the buzzards always returned on March 15. Several thousand people showed up to see if it was true and a tradition was born.

Sources:

This is one of the first about the discovery of diclofenac as the cause of vulture deaths:

“A Mystery Solved, the Killer Found”, Sunny Sebastian, The Hindu, June 1,  2003 The Hindu.

“Professor Lindsay Oaks of Washington State University, working in Pakistan with the support of Peregrine Fund, has come out with the finding that Diclofenac, a widely used painkiller and anti-inflammatory drug, is behind the large-scale morbidity and mortality of the vulture species.”

A story from The New York Times:

“A Drug Used for Cattle Is Said to Be Killing Vultures,” By James Gorman, Jan. 29, 2004.

“A mysterious and precipitous plunge in the number of vultures in South Asia, which has pushed three species to the brink of extinction, is probably a result of inadvertent poisoning by a drug used widely in livestock to relieve fever and lameness, scientists reported yesterday.”

“Studies in Pakistan showed that the drug, diclofenac, an anti-inflammatory commonly prescribed for arthritis and pain in people, caused acute kidney failure in vultures when they ate the carcasses of animals that had recently been treated with it. The findings, which followed a two-year investigation by an international team of 13 scientists, were published online by the journal Nature.

Dr. J. Lindsay Oaks, an assistant professor of veterinary medicine at Washington State University who was the primary author of the report, said the devastation of vulture populations was the first clear case of major ecological damage caused by a pharmaceutical product.”

Here is the Nature citation:

“Diclofenac Residues as the Cause of Vulture Population Decline in Pakistan,”

J. Lindsay Oaks, Martin Gilbert, Munir Z. Virani, Richard T. Watson, Carol U. Meteyer and Bruce A. Rideout, Nature. 427.6975 (Feb. 12, 2004): p.630.

For Ontario buzzards see:  http://www.discover-southern-ontario.com/turkey-vulture.html

For their movement north: https://www.allaboutbirds.org/vultures-riding-north/