Abstract: A device for equipping birds with transponders (21) is not in the form of a foot ring but a wing tag (11) ; with the particularity that one of the at least two stiff plastic limbs (12') which are connected together at respective ends by way of a bending yoke (13) is provided with a trough-shaped or pocket-shaped receiving means (22) for a tube transponder (21) . Preferably, in the case of a three-limbed construction, a cover limb (12") which is reversibly latchable to the transponder limb (12') , when the tag (11) is still open, is disposed in the longitudinal direction between the transponder limb (12') and a rearward holding limb (12) which in turn, at its free limb end (15), can be positively lockingly connected to the cover limb (12") by means of a barb-type pin (17) , opposite the latching means, with a wing bone being engaged therebetween.