AVIS-IBIS

Birds of Indian Subcontinent

Timing of attachment to wintering site as revealed by experimental displacements of Dunlins ( Calidris alpina )

Publication Type:Journal Article
Year of Publication:1999
Authors:Baccetti, N, Serra, L, Cherubini, G, Magnani, A
Journal:Journal of Ornithology
Volume:140
Issue:3
Date Published:1999
ISBN Number:2193-7192
Keywords:Calidris, Calidris alpina, Ereunetes alpina, Erolia alpina, Scolopacidae
Abstract:Summary Two groups of adult and two groups of juvenile colour-marked Dunlins ( Calidris alpina ) were moved from their wintering site in four successive years, in order to assess the existence of time- and age-dependent differences in homing behaviour and, in particular, to determine when attachment to wintering grounds is achieved by juveniles. Each group was released on different dates at the beginning of the wintering season 133 km to the south of the capture site. We expected that the behaviour of adults would not vary according to date, whereas that of juveniles would. In all four experiments the majority of birds left the release site. Juveniles displaced early in the season (5 Nov.) remained at the release site in higher numbers (34% vs 0–14%) and homed to a lesser extent (20% vs 57–62%) than juveniles displaced late in the season (13 Dec.) and both adult groups. The final return rates of adults displaced early and late in the season (8 and 24 Nov.) were similar. Most birds that left the release site departed within 20 days of displacement, whereas observations of colour-marked Dunlins at the capture site indicated a more gradual pattern of return. The first homed birds were observed three days after release, but new birds continued arriving back at the release site for at least 40 days longer. Most juvenile Dunlins seem to become attached to a wintering site during November. Recovery rates of displaced and non-displaced birds retrapped in following winters suggested that year-to-year site fidelity is developed after a longer period.
URL:http://dx.doi.org/10.1007/BF01651027
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith