Corvids - particularly crows, ravens, and magpies - are notoriously difficult for researchers to track. The birds exhibit something called 'rescue behaviour', in which they see tracking devices as a threat and help each other remove them. Eurasian magpies are the worst, as they not only remove the devices but destroy them, usually by dropping them in bodies of water.
Boru
Boru
‘I can’t be having with this.’ - Esmeralda Weatherwax
