A saga of swans: an episode of cultural and natural history

Abstract

Mute Swans Cygnus olor were introduced, either deliberately or “self-introduced” to various water bodies from ca 1920 to ca 1965 in the southern parts of South Africa, and in some cases survived for more than a decade. The success of local populations, their survival and subsequent extinctions are discussed, together with possible reasons for their demise. An attempt, on a much smaller scale, to introduce Black Swans Cygnus atratus was also made at about the same time, and this was not at all successful, with no breeding attempts and almost no survivors of initial introductions. The largest number of Mute Swans in one area was at the Kromme River complex in the Eastern Cape Province, where the introduction of the original Mute Swans to the area is fraught with conjecture and speculation. The facts and the dates of the introduction cannot be verified, but the best guess on circumstantial evidence is that the swans arrived on a dam near the Kromme River via an escape from a crate on deck that was washed overboard from a ship during a storm. Subsequent introductions of Mute Swans to Groenvlei (Goukamma Nature Reserve) and the Wilderness-Sedgefield-Lakes-Complex in the Western Cape and to other localities in that province were of swans caught at the Kromme and other waters. None of the populations of swans survived beyond the early 1980s, and their demise is as mysterious as are the origins of the founder population at the Kromme River.

Keywords:

• Mute Swan Cygnus olor
• Black Swan Cygnus atratus
• Kromme River
• Goukamma Nature Reserve
• Wilderness-Sedgefield Lakes Complex
• De Hoop Nature Reserve

Acknowledgements

The authors thank Bridget Elton, Janine Dunlop, Doug Harebottle, Alan Harris, Truus Hedding, Bev Howard, Gordon Johnston, Margaret Koopman, Maggie Langlands, Bartle Logie, William Massyn, Dieter Oschaleus, Guy Palmer, Kevin Shaw, Roy Siegfried, Chris Stuart, Colin Urquart, Gideon van Zyl, Phil Whittington and Gay Youthed for notes on Mute Swans, and Sue Milton for comments on this manuscript. We are especially grateful to Tom Heinecken, whose memories and unpublished notes on the Mute Swans at the Kromme and Groenvlei added much to this report.

Notes

1 Marking of swans. From at least the thirteenth century until relatively recently, it was customary for Mute Swans in England, even those on open water, to be regarded as private property. Marks on the beak, and sometimes on the leg or less often a punch mark on the foot, signified the identity of the owner. All such marks had to be registered with the royal Swan-master (MacGregor, 1996).

2 The Dyers’ Company, together with the Vintners’ Company, has possessed a Royalty of a Game of Swans on the River Thames for many centuries … Certainly since Tudor Times the Dyers’ Company has, in conjunction with the Monarch and the Vintners Company, supervised the well-being of the swans on the Thames (Dyers Company, undated, cited by MacGregor, 1996).