WOW Day 4: Migration

WOW Day 4: Migration

(c) Steve Waddingham

Day 4 of World Osprey Week is all about their migration - read this blog to find out more...

Ospreys are very special birds and can only be found in the UK between the middle of March to the end of August/beginning of September. This is because they are a migratory species and spend only part of their year here in the UK. When they aren’t in the UK, they travel to countries that have a much warmer climate such as Gambia, Senegal, southern Spain and southern Portugal! This is an epic journey and can mean that our Ospreys are travelling upwards of 3000km, and bearing in mind Ospreys don’t have maps of satnavs, this is an incredible journey. And even more amazing is that unlike other migratory birds for example geese and swans, which travel as family units, young Ospreys will take on the mammoth journey all by themselves!

There is still a lot of mystery surrounding migration, like how do they know when to leave, or how do they know where to go? Well, there are thoughts that migratory animals, use changes in day length or temperature to help guide them to when they need to set off on a migration, as well as thoughts that birds like the Osprey, use the magnetic field to navigate – as in theory they are travelling either south or north.

There is an important piece of technology which helps us track the movements of our Ospreys. Over the years, a handful of Rutland Ospreys have been fitted with a satellite tracker, which allows us to learn a huge amount about where they are, how fast they travel, how high they are flying and also in what direction. From this, we have learned that Ospreys must to an extent recognise geographical features along their migratory route, as each migration looks to mirror a previous one. The satellite trackers are very lightweight, weighing only 30g and are carefully fitted to an Osprey – a bit like a rucksack.

There are many threats Ospreys face during their migration, for example there is a risk they get blown out to sea by strong winds, particularly if they cross the Bay of Biscay rather than following the coast of France south, as well as from predation. These are all natural causes, and sadly they aren’t the only risks to the Ospreys. Ospreys can get tangled up in discarded fishing nets and also collide with low powerlines, but Ospreys are still seen as a threat to fishermen in some countries and are persecuted as a result