Why metal rings only? (2 Viewers)

[Gander]

I have terns on my local patch that obviously have metal rings. This is hugely frustrating! What is the point of using an unreadable metal ring, when you would get back so much more info if you used coloured rings/darvics?

It just seems to be lost opportunities.

 

[vergan]

I have terns on my local patch that obviously have metal rings. This is hugely frustrating! What is the point of using an unreadable metal ring, when you would get back so much more info if you used coloured rings/darvics?

It just seems to be lost opportunities.

Why is it a lost opportunity?

cheers

 

[Mike Crawley]

I don’t know the answer but logically:-
Is it because the B.T.O. started ringing studies before the advent of coloured plastic ?
Is it perhaps because the metal rings are durable and suitable for lifetime study, whereas the plastic/darvic rings lose colour/fade/become unreadable after a few seasons.
Darvic/plastic rings in a variety of colours are used for specific purposes or f studies of limited longevity.

I imagine a note to your local B.T.O. Representative will get y the exact answer.

https://www.bto.org/community/regional-network/rn-directory/fife-kinross

 

[Gander]

Why is it a lost opportunity?

cheers

The lost opportunity is to gain more information than can be gathered using only metal rings. I am involved with a couple of projects (Shag in the Firth of Forth) and GBBGs from Norway) that gather a lot of bird movement info by using darvics. I've only ever got close enough to one bird to get a clear shot of its engraved metal ring. Metal rings seem to only be of use if the bird is recaptured or found dead. Just think they are missing a trick compared to other projects.

 

[DonRA]

I heard that the metal ring data was requested by BTO should you find the bird dead. In Scotland the Loch Garten ospreys have the BTO ring on the right leg and on the left leg they have a readable blue Darvic ring - so both aspects are covered.

 

[delia todd]

I heard that the metal ring data was requested by BTO should you find the bird dead. In Scotland the Loch Garten ospreys have the BTO ring on the right leg and on the left leg they have a readable blue Darvic ring - so both aspects are covered.

Hi Don and a warm welcome to you from all the Staff and Moderators. Thanks for supplying this extra information about ringing.

I'm sure you will enjoy it here and I look forward to hearing your news.

 

[Jacana]

It also depends a bit on what data you want to get out of it. Darvics are great if you want to track individuals for dispersal purposes. But if you're more interested in survival, then a simple metal ring is all that's needed as each bird will be caught each year at the breeding colonies.

Darvics are expensive too and the code combinations are much more limited. The more letters/numbers included, the harder it is to get a readable code in the field, especially on smaller birds like terns. So it often just isn't worth it.

 

[wheatearlp]

... as each bird will be caught each year at the breeding colonies.

Will they?