White Fronted Sandplover
The white-fronted sandplover Charadrius marginatus is a common bird along the beaches of Bonza Bay. This sandplover is resident but at times the numbers of residents are supplemented by visiting birds. The latter can readily distinguished from the resident as they are more warmly coloured buff or camel on their back and chest (pix below).
At Bonza Bay there are at least 25 pairs of sandplovers in 5 km of beach between Nahoon river and German Bay. In the last 30 years there numbers have remained stable unlike the water dikkop Burhinus vermiculatus which has decreased and the oystercatcher Haematopus moquini which has increased in number of breeding pairs.
The sandplovers mainly forage on the dry sand above the high-water mark where they are the only small wader there, except when groups of migratory waders roost in the dune slacks. The sandplover does feed in the inter-tidal zone where it is in pairs or solitary, and so can be distinguished from the migrant waders which collect in groups and tend to be larger and more colourful. The sanderling Calidris alba is the wader most likely to be confused with the sandplover but its feeding habit of scuttling up the beach being chased by the tide and then running bach down as the tide receeds is quite characteristic.
The sandplover nests in the dunes and nests may be found mainly spring and summer months between September and January but never in the winter between March and August incubating birds. The peak months are October and December (101 of 183 breeding records). There is a variation each year in the onset of breeding which may be related to rainfall for in drought years
the birds tend to breed latter than the years of good rains.
The sandplovers scrape a hollow in the sand to serve as a nest and in the female lays a clutch of two eggs, and sometimes three and rarely four eggs. The eggs are large relative to the size of the bird. The eggs take about 28 days to hatch but birds have sat on infertile eggs for 72 days When disturbed by an intruder, the incubating bird shuffles over the nest kicking sand over the eggs, and then runs away. This makes the nest hard to spot, and it is easiest to find by back-tracking the birds foot prints.
When the chicks hatch, the adult's behaviour towards intruders changes. Instead of just running away, the bird goes off with its wings outstretched, low to the ground and flutters them. It looks as though it is injured. This distraction display is effective as it draws the intruders attention away from the brood. The chicks in turn are hard to spot as their speckled buff down blends with the sand, more especially if the chicks are hiding under a plant or some debris.
As the chicks can run from birth, surprisingly fast for such small, when an intruder appears they may go off a few metres before crouching. This makes them even more difficult to spot. When still like that a chick can be picked up and examined but will not move. The chicks obey the commands of their parents by crouching still until they are told that they can move. Those chicks that are disobedient and run after they have been told to sit, are vulnerable to predators. A moving chick is red-rag to any dog on the beach and I've seen a Jack Russell take a chick befor it ran five metres.
In contrast, many a time, people and dogs have been observed totally unaware that they are passing less than a metre of a nest or chick.