The secret life of the robin - hatching plans
Ornithologist David Tideswell from Stramshall in East Staffordshire provides an insight into the 'secret life of the robin'. In this third of the series, he outlines the early life of robin chicks.
Female robins have a fairly standard time to sit on their nest (incubating the eggs) - few have longer than a fortnight to wait before the eggs hatch.
The chicks at birth are naked, blind, helpless and poorly developed except for their digestive system.
Young robins make great demands on their parents, they feed voraciously in their early days before leaving the nest.
Their early life is spent entirely in a state of anticipating or swollowing food.
When he arrives with food she takes it from him and tenderly feeds the chicks.
As they grow and get a covering of down, then feathers, the female joins in the search, and so long as the parents can maintain a sufficiently rapid rate of feeding, all the young will get a more or less equal share of food.
They grow dramatically: in just two weeks their weight will increase ten fold, from just under 2g at birth to near 20g at fledgling.
Most of the protein comes in the form of insects (moths, flies etc), especially caterpillars and other insect larvae, but they may also receive the odd ant, spider, centipede or juicy earthworm.
Nearly 2,000 will be collected over the two weeks. The time when the young are in the nest is the busiest in the life cycle of the parent birds, as there is much to do apart from feeding the young.
The nest must be kept clean to keep it free from disease and parasites. This starts with removal of the egg shells and later the chicks` droppings.
The output of the nestlings is called a faecal sac in which the unwanted matter is neatly packaged in a gelatinous casing.
These faecal sacs are carried away by the parents so that no telltale signs build up, while droppings around the nest would soon attract predators.
You get an idea of the work involved when you realise that each chick produces one sac an hour during the day.
last updated: 10/04/2008 at 07:26