Plastic colour rings and the incidence of leg injury in flycatchers (Muscicapidae, Monarchidae)

Abstract

Studies of birds involving colour ringing can provide much detailed information concerning bird movements and behaviour without the need for recapture. However, a fundamental premise of colour ringing, and indeed all ringing studies, is that the rings applied should neither cause harm to the birds concerned nor alter their behaviour or survival. Colour rings have been used safely for many studies on a wide range of species, and problems are rarely reported. Here, we report on problems associated with colour‐ringing several species of flycatcher, and discuss the nature and extent of the issue. Unacceptable levels of leg injury were reported when flycatchers were ringed using either celluloid or PVC colour rings, particularly when the colour ring was proximal to the foot. In the light of our evidence, we would urge those considering embarking upon colour‐ringing projects involving flycatchers to consider using anodised aluminium colour rings and to avoid the use of plastic colour rings.