Grebes

(reproduced from issue 48, Summer 2000, of The Review)
Friends Member Richard Kershaw writes: Battersea’s grebes are doing well, budding Bill Oddies will be pleased to hear. Not only are some of them becoming year round residents (Great Crested Grebes usually go to the coast in deep winter, to avoid iced-over inland waters - this must be yet another sign of global warming) but they are also breeding prodigiously. Two years ago, three pairs produced no fewer than twenty-four fledged young. Last year the figure again was around twenty.This year, in March four pairs have already bred. Two of the pairs have successfully hatched five chicks between them. What is more, they are off the nest and even off their parents’ backs. Since hatching normally takes about four weeks from laying, and newborn chicks then spend a couple of weeks riding around hiding under the adults wing feathers, egg laying must have started in January. Winter really is ceasing to exist altogether.The other two pairs are happily nesting off the main island facing Prince of Wales Mansions - they seem to know that their worst enemies, young humans rowing the Battersea tin boats, are being diverted this year to the other side of the lake..

The bird books say that Greater Cresteds sometimes do have more than one brood. Ours are breaking the mould and tending to have at least three broods each every year. Among other things this must mean that there is a lot of healthy reproduction going on among the fish below the surface, because the availability of food seems to be the determining factor in multiple breeding. Grebes are excellent parents, but last year there was a tragedy for which they cannot be blamed; a number of young birds became entangled in the nets which were being used by the Park to catch and change the nature of the fish population. Nets are of course lethal to air-breathers that have to dive for their living.