Since departing on their migration last month FR3 and FR4 have shown us that they both have very different approaches to making the journey. FR3 arrived in France on 22nd August and seems to be showing no signs of being in a hurry to reach West Africa, still sticking to the same area since arriving on 26th August. FR3 has been flying at an average speed of about 58kph, at an altitude of around 240m. Interestingly FR3 spent significantly more time flying over water than FR4, and whilst over water average flying height dropped considerably to just 80 or 90m. Total distance flown is currently 1770km.
FR4 on the other hand, has taken the seemingly most efficient route, reaching the Islamic Republic of Mauritania by 13th September. Flying almost three times the distance of its sibling in just half the time, it would appear to the untrained eye that FR4 had done this journey before! This osprey has been flying at an average speed of about 45kph, at an altitude of around 813m. Total distance flown is currently 4477km.
It is evident from just these two individuals that there is more than one way to conduct a migration, and that we cannot apply the same rule to each individual. The purpose of tagging these birds is to build up a more comprehensive picture of the routes they take on migration, where they stop off, and where they ultimately end up. If a large proportion of the birds stop off in certain areas along the way as FR3 has done, then it may highlight to us that those areas should be protected, as they are in the UK. These two juveniles have shown us with remarkable clarity that we cannot apply the same rule to every osprey, and that they are true individuals.
Visitor Centre Assistant