Rigor Vitae: Life Unyielding

Monday, March 23, 2009


In 1925, three pale, unusual-looking young falcons, two males and one female, were removed by otter-hunters from an eyrie in southern Chile, near Punta Arenas. They were sold to M. Carlos Strauss, a German animal dealer living in Punta Arenas, who shipped them to the Münster Zoo. All three lived through their first moult, and their skins survive today as study specimens, two in a museum in Münster, and the remaining male in Bonn. Little is known about the lives of the Münster specimens, but the Bonn bird is known to have died at the Münster zoo in October 1932, but not before being paired with a female Austral Peregrine (Falco peregrinus cassini), who laid a clutch of eggs that he was reported to have incubated, one of the first records of attempted nesting by captive falcons. He was ultimately examined by ornithologist Otto Kleinschmidt, who at first doubted the bird's South American origin, mistaking him for a Barbary Falcon (F. pelegrinoides). In 1929, Kleinschmidt described it as a new species, F. kreyenborgi, after the falconer who had brought the bird to his attention.

It was over a decade before another one of these birds would be collected, and taxonomists argued vehemently over the status of the species. Some called it a subspecies of Peregrine (in a 1939 paper, Kleinschmidt himself referred to it as Falco peregrinus kreyenborgi) or Barbary Falcon, others thought it was allied to the Gyrfalcon-Saker-Prairie Falcon complex. Some believed the birds simply represented a single aberrant clutch. Careful measurements of the specimens revealed them to be morphologically identical to the local Patagonian Peregrines, but their plumage differed so radically that most taxonomists hesitated to lump them together.

Further data on Kleinschmidt's Falcon were slow in coming. On April 7, 1940, the eminent Swedish-Argentine ornithologist C. C. Olrog collected specimen number four, followed by a fifth, a juvenile, by Károly Kovaks in August 1961. On March 10, 1979, David Ellis and R. L. Glinski took the first known photograph of a Kleinschmidt's Falcon, and in December of the same year, my homeboy Terry Roundy took the first known movie footage. From 1979 through 1981, the field work in Santa Cruz province, Argentina, of Ellis, Glinski and Roundy, along with C. M. Anderson and Cesar Peres Garat provided a solution to the mystery. Observations of nine eyries revealed mixed pairs of typical Peregrines with Kleinschmidt's as well as normal Peregrine pairs yielding phenotypical Kleinshmidt's. F. kreyenborgi was not a valid species after all, but instead just an alternate color phase in the only known case of polymorphism in the Peregrine, and evidently a recessive trait with a high level of heterozygosity in the population.

In retrospect, it seems obvious that this should have been the case, but it was common knowledge at the time that Peregrines were a monomorphic species, and such dogma can effectively block one's vision. The names “Kleinschmidt's Falcon” and Falco kreyenborgi have been relegated to the history books; the preferred name for the color phase is “pallid falcon,” but those old monikers still serve as effective reminders to always give the obvious the consideration it deserves.
Pallid Falcon photograph taken last year in southern Argentina by Steven R. Chindgren


Blogger Camera Trap Codger said...

Just love those kind of stories. Thanks.

6:14 PM  
Anonymous Anonymous said...

Hi Carel

I have some great close up shots of captive Pallid Falcons from a bird conservation program I worked for. I can e-mail them free of charge (if credits are mentioned with the pic)


6:00 AM  
Anonymous Anonymous said...

My e-mail


6:06 AM  
Blogger Jeremy Pearse said...

Fascinating Carel, thanks for that update. Lovely photo too!

7:56 AM  
Blogger Carel Brest van Kempen said...

Chris and Jeremy: Thanks! Glad you liked the post.
Gerardo: Thanks for your offer. I don't have any "use" to put your photos to, but I'd love to see them.

7:41 AM  
Anonymous Anonymous said...

Hi Gerardo,

I would like to see those pictures of captive Pallid Falcons. I am only interested in seeing the photos from a personal interest. My email is: merlin0558@bellsouth.net

7:56 AM  
Blogger Steve Bodio said...

A friend has one or two in his breeding project in Texas. Except for color they look more "Peregrine" than Barbary, which he also has.

3:58 PM  
Anonymous Me said...

Great..!! lets join Kampus Inovasi

7:46 PM  

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