If you like it then you'd better put a ring on it

A newly ringed hen harrier chick, Bowland 2011. Hen harriers are very site-faithful and when they reach maturity, chicks will often return to the same area where they themselves were hatched. Using BTO leg rings like this causes no harm to the birds and allows us to identify individuals, helping to track their progress and gain valuable information about things like survival rates. - photo by Jude Lane