Due to the fact that the Ospreys in Manton Bay have failed to breed this year, we have all been wondering whether they will leave on their migration earlier than usual, as they do not have to wait for their chicks to be independent of them before they do. However, it has also been known for Ospreys who have not bred to stay later than usual, so we must just wait and see. In 2007 and 2008, a different pair of Ospreys occupied the Manton Bay nest. This pair unfortunately failed to breed in 2008. That year, the female migrated on 23rd August, which was six days earlier than she did the year before. The male, however, remained until 13th September, which was ten days later than the year before. This goes to show that these things cannot be predicted!
Ospreys do not migrate together. Even the chicks make their way to Africa without the company of their siblings or parents. The male and female may not see each other again until they return the next spring to breed. They are drawn back to the same nest, and bond together for one purpose – to bring more Ospreys into the world.
The female Osprey is usually the first to leave. After the chicks have fledged she spends more time fishing and feeding, getting herself in a suitable condition to travel the necessary 3,000 miles to her wintering grounds. Unlike the male Ospreys, who spend most of their time fishing during the breeding season (and are therefore lean, mean, fishing machines) females spend all of their time on the nest with the chicks. This means that her fitness level will drop throughout the season, so she needs to regain it. Once she has gained the necessary fitness to migrate, she doesn’t hang around. Up she’ll soar, circling higher and higher, gaining swiftly in altitude until suddenly she points her compass south, and off she goes.
Males, on the other hand, are usually the last to go, as they still feel the need to feed their youngsters, and the youngsters will still call for food. Thus, male Ospreys will stick around a while longer, and continue to provide fish for the juveniles. There will come a point though, when the juvenile Ospreys suddenly feel a pull, an unseen force that they do not understand but cannot ignore. This pull draws them south, away from the familiar ground where they were born, and towards an unknown place, a foreign land. They do not know that it is called Africa, but there they will go, and there they will remain until they are two years old, and another pull, more familiar this time, will draw them back to Rutland Water.