Trees around PP
 

Does anyone know why black plastic discs are screwed down by trees around the town & along Pine walk ? My theory is aliens have landed in PP & these are meeting markers or for a special purpose, please comment !
Thanks

Ha ha...I asked the same question last year....apparently they are for monitoring the trees..this is the reply from Papillion to my question

Was wondering myself and saw a couple of young lads installing them so stopped to ask. They are micro chips that monitor the trees, the info is downloaded regularly to a central computer.
Seems they they are in Pollensa as well.

Many thanks, technology for you what ever next !!
🙄