The oldest chick being 40 days old and the youngest 33 days old, meant that this was the prime window to ring the chicks before they become too feisty, and crucially able to fly!

Paul ringing the Osprey chicks – taken by volunteer Mark Wright

They were ringed (shown in age order oldest to youngest) 5R0, 5R2, 5R1 and a very special ring for the youngest, 5H6. Often you can determine the sex of Osprey chicks during the ringing process, taking multiple measurements, including weight, which can indicate whether a chick is male or female. Female Osprey, as in many raptor species, are typically larger and heavier than the males, and this size difference can usually be seen while still in the nest.

Sexing the chicks was tricky this year as all of the weights, aside from 5H6, were in the overlap zone for males and females at about 1600g. 5H6 weighed around 1400g, indicating that he is likely to be male, even taking into account his age gap. The other three chicks, however, could go either way! Considering how well-fed they have been this year, there is an outside chance that all four chicks are male, which would be excellent news, given their higher pre-disposition to returning to their natal area to breed.

We’ll keep assessing as time goes on via the webcam, as size can become more exaggerated and behaviour can also become a useful indicator of sex, but for now this is a fantastic moment for the Ospreys, with all growing really well and fitted with identifiable colour rings!

You can keep up with the action from the webcams here.

All four Osprey chicks in the nest after ringing