The Redhead - Part-time Parasite ofthe Potholes

Abstract

While my fellow bird staff were enthusiastically commenting on the listing of their charges, I scanned this delightful collection of information - when I stopped short - at the date '' 23/ 12/64", the day of arrival of one of the zoo's nine Redheads (Aythya americana). The bird was estimated to have hatched in 1961.

I believe the oldest documented member of the Duck, Goose, and Swan family Anatidae, was a Cape Shelduck (Tadorna cana), that died at Leersum, Holland, at the collection of P. Duijzend, in June, 1975, having been imported from Pretoria in 1928 (Harvey, 1975). Jean Delacour's famous Nene (Branta sanduicensis), hatched at the Dutch collection of F.E. Blaauw, in 1898, ''vanished" in 1940, presumably eaten by the Nazis who occupied Delacour's estate at Cleres (Delacour, 1954).

Our Redhead, 27 years at Fort Worth, thus has a way to go before exceeding the family record. For waterfowl in general, though, its age is astounding. Terres (1980) gives 12 years, determined from bands, as the maximum known age of a wild Redhead. Of our hundreds of specimens, there are three birds that are certainly older. Our female Harpy Eagle, longer at Fort Worth Zoo than any other animal, arrived here as an adult October 1, 1955. One of our 14 Carribbean Flamingos was purchased in August of 1963 and was presumed to be two years old. A Chilean Flamingo sold by the New York Zoological Park in 1986 was presumed to be 24 years old at that time. Another in the same group was estimated, in 1986, to be 22. Our old Redhead (our next oldest hatched in 1985), is a male, and can be told from the five other males here only by his bands, not otherwise giving any evidence of his age at present.

Monica's inventory indicated a certain "]. Schedel" as the source of this bird. From her computerized ISIS/ ARKS data system, she confirmed that this was indeed Dr. Joseph J. Schedel, who, at his Portage Farms, near Elmore, Ohio, maintained, from the '50s into the '70s, a major collection of waterfowl, under the supervision of Melvin Block, who was also Curator of Birds at Toledo Zoo. Dr. Schedel was the first person in the U.S. to breed Cosocoroba Swans outside of a public zoo (Griswold, 1973). He donated two pairs of Redheads to the Fort Worth Zoo, December 23, 1964.

The first captive breeding of Aythya americana appears to have been by 1899, by Wilton Lockwood, of South Orleans, Massachussetts (Greenwall & Sturgeon, 1988), followed by Frederic Gallatin, of Noroton, Connecticut, sometime before 1909 (Beebe & Crandall, 1909).

Jean Delacour (1959) suggests that the '' superficial similarity" of the Redhead to the European Pochard (Athya ferina), was the reason for its late introduction to European or British aviculturc. Though some were acquired by the London Zoo in 1902, the first Redheads bred outside of their native North America hatched at the collection of Hugh Wormald, in England, the parent birds having been hand-reared, and sent from the U.S. in 1922 (Delacour, 1959). Mr. Wormald appears to be the first absolutely documented propagator of the Common Teal (Anas c. crecca), in 1913, and the first person to breed the Green-winged Teal (Anas crecca carolinensis) outside of North America, likewise, in 1924 (Delacour, 1956).

There are 12 members of the genus Aythya, the White-eyes, Pochards, and Scaup, distributed world-wide (with the exception of Mainland Tropical Africa, where several species only winter, but none breed, and South America). The genus Netta contains the three other Pochards; the Red-crested Pochard of Eurasia, the Southern Pochard of Africa and South America, and the South American Rosey-billed Pochard. Concerning the Redhead, Jean Delacour (1959) wrote, "This species is most satisfactory in confinement; in fact it is the easiest of all Pochards to manage. Several pairs, or even a number of females and fewer males will live and breed perfectly well in quite a small pen with a tiny pool." On breeder's price lists in the U.S., Redheads are very modestly priced, costing little more than Wood Ducks and American Black Ducks, usually the least expensive waterfowl, and about the same as Mandarins, Redcrested and Rosey-billed Pochards, and Northern Pintails. This translates to a pair generally costing less than a retail Gouldian Finch.

The Redhead was present in 51 U.S. public institutions on June 30, 1991, thus one of the more broadly represented American Zoo waterfowl (International Species Information System, 1991). Of the 155 male, 146 female, and seven unsexed birds collectively held by these establishments, 85 percent were certainly captive-bred and two percent were known to be wildcaught. Of these collections, the following held more than five specimens; Fort Worth and Salisbury, Maryland, both with six; St. Louis, the Arizon-Sonora Desert Museum near Tucson, and the National...