Breeding biology of the White-fronted Plover (Charadrius marginatus) in the south-western cape, South Africa

Abstract

IntroductionThe reasons for variations in the clutch size of birds are poorly understood (Ricklefs 1970) and this is more surely the case in the Charadrii where no species normally has a clutch of more than foul' (MacLean 1972). One of the trends which is often discussed is the variation with respect to latitude where, generally, tropical species have smaller clutches than temperate species (Lack 1968). Part of the problem in these comparisons is that clutch sizes are compared in isolation whereas other aspects of the biology should also be considered. For example, Graul (1974) showed that the Mountain Plover Cha'~udrius montanv~ lays two successive clutches of two eggs, one of which is incubated by the male and the other by the female. In this case clutch size is not related to egg production. However, information on the biology of tropical species is often lacking. This paper describes the breeding biology of the White-fronted Plover Charadrius marginatus, a species which breeds mainlv on coastal beaches of Africa and normally has a clutch of two (MeLaehlan and Liversidge 1970). Those aspects which may relate to clutch size, such as the mating system, length of breeding season, frequency of clutch replacement and breeding success are examined as well as other aspects of the biology. Comparisons are then made with the Ringed Plover Charadrius hiaticula, a closely related species Which breeds on beaches or stony areas in temperate and arctic regions and normally has a clutch of four. Study area and methodsThe study was carried out at Langebaan Lagoon (33°S 18°E), a large inlet of the sea on the west coast of South Africa ( fig. 1). The lagoon has extensive sand flats rich in invertebrates and is surrounded by either salt marshes or sandy beaches and low dunes. White-fronted Plovers nest on the dunes, and the study area extended along 900 m of beach and its adjacent sand flats, dunes, salt marsh, and salt pans (figs. 2 and 3 (a)). The salt marshes and salt pans were inundated only by spring tides. The Present addresses: t Culterty Field Station, Aberdeen University, Scotland. ++ t~yeeroft, Frampton Cotterell, Bristol, England.

Habituation and habitat changes can moderate the impacts of human disturbance on shorebird breeding performance

“…5) meant that estimates of white-fronted plover annual fecundity were substantially higher in the more disturbed, urbanized area (0.05-0.37 fledged female young/female) than in the protected area (0.01 fledged female young/ female). White-fronted plover annual fecundity in another low-disturbance area, the West Coast National Park, was found to be 0.04 and 0.07 fledged female young/female over 2 years (Summers & Hockey, 1980), confirming low rates of breeding success for this species in some protected habitats. Annual adult survival of white-fronted plovers is 0.90 (Summers & Hockey, 1980;Lloyd, in press).…”

“…White-fronted plover annual fecundity in another low-disturbance area, the West Coast National Park, was found to be 0.04 and 0.07 fledged female young/female over 2 years (Summers & Hockey, 1980), confirming low rates of breeding success for this species in some protected habitats. Annual adult survival of white-fronted plovers is 0.90 (Summers & Hockey, 1980;Lloyd, in press). Assuming that post-fledging juvenile survival through the first year is 63% of adult survival, as for the African black oystercatcher occupying a similar habitat (P. A. R. Hockey, pers.…”

Waders (Charadrii) and Other Shorebirds at Cape Recife, Algoa Bay, South Africa: Seasonality, Trends, Conservation, and Reliability of Surveys

“…No large flocks of non-breeding birds were observed at Cape Recife. In contrast, in the southwestern Cape, non-breeding Whitefronted Plovers frequently gather in flocks in winter (Summers & Hockey 1980;Fraser 1985).…”

“…As in the southwestern Cape, breeders appeared to be territorial throughout the year (Summers & Hockey 1980). However, elsewhere in Algoa Bay, on the beach and adjacent Alexandria dunefield between the Sundays River estuary and Woody Cape (Fig.…”

Egg-Covering Behaviour of the White-Fronted Plover Charadrius marginatus

“…The study area and the breeding biology of the White-fronted Plover have been described by Summers and Hockey (1980). Observations were made during two 15-day periods in July and September 1976.…”