Posted: Tuesday 6th July 2021 by Kim MWT

MWT ringing 2021MWT ringed chicks in nest 2021

We have ringed the chicks - we have a boy and a girl - introducing Dysynni and Ystwyth.


June the 24th 2021 dawned cool, grey and still on the Dyfi. Absolutely perfect conditions for ringing our osprey chicks. The whole ringing process took just 47 minutes from start to finish and was undertaken by Tony Cross who has ringed all of the Dyfi osprey chicks since 2011. 


Idris and Telyn with fish and chicks just before ringing

MWT Idris fish and chicks


Our chicks were ringed with a small metal British Trust for Ornithology (BTO) ring on their left legs and with a blue plastic darvic ring on their right legs, as is the convention for Wales (and England). In Scotland the blue darvic ring goes on the left leg. All darvic rings are read from the bottom up. This year we used ring numbers 490 and 491. 

As well as ringing the chicks we also take various measurements that help us to determin the sex of each bird. Tony carefully measures the wing length, weight and  beak length of each chick.


Ringing Data 2021
Chick Ring
Weight Sex Age Name
Chick 1 490 1600g M 35.2 days Dysynni
Chick 2 491 1690g F 31.3 days Ystwyth







Once we know if we have boys or girls then chicks are named. To keep the naming process simple all of the Dyfi osprey chicks are named after Welsh rivers or lakes. This year we have chosen the names of two local rivers. The Dysynni is to the north of the Dyfi and is home to the Broadwater where ospreys are regularly seen fishing. The Ystwyth is to the south and gives its name to the university town of Aberystwyth where our osprey's DNA has been studied. 


Here is the video of the ringing process. 




As you can see from the video both chicks were calm throughout the ringing process and Telyn was quick to return once the ringers left the nest area. In the week since their ringing we have seen an big increase in wing stretching and flapping behaviour. It won't be long now until they are helicoptering above the nest in preparations fro their first short fledging flights. 


Dysynni and Ystwyth relaxing on the nest

MWT Dysynni and Ystwyth on the nest

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