DOI: 10.5061/dryad.r4xgxd2mv
title: Recurrence, fidelity, and proximity to previously visited sites throughout the annual cycle in a trans-Saharan migrant, the Common Cuckoo

description: Most migratory birds return every year to the same breeding sites and some
 species show a similarly high fidelity to wintering grounds as well.
 Fidelity to stopover sites during migration has been much less studied and
 is usually found to be lower. Here, we investigate site fidelity and
 distance to previously visited sites throughout the annual cycle in the
 common cuckoo, a nocturnal trans-Saharan migrant, based on
 satellite-tracking data from repeated annual migrations of thirteen adult
 males. All birds (100%) returned to the same breeding grounds, with a
 median shortest distance of only 1 km from the locations in previous year.
 This was in strong contrast to a much lower and much less precise site
 fidelity at non-breeding sites during the annual cycle: In only 18% of the
 possible cases in all non-breeding regions combined, did the cuckoos
 return to within 50 km of a previously visited non-breeding site, with no
 significant differences among the main staging regions (Europe in autumn,
 Sahel in autumn, wintering in Central Africa, West Africa in spring,
 Europe in spring). The shortest distance to a previously visited
 non-breeding site differed among the staging regions with median shortest
 distances for the longest stopovers of 131 km [2;1223] (median [min;max])
 in Europe, 207 km [1;2222] in Sahel in autumn and 110 km [0;628] in
 Central Africa. The distance to a previously visited staging site
 decreased with the time spent at the stopover in a previous year.
 Understanding the drivers of recurrence and site selection in migratory
 birds are important for guiding conservation efforts in this group but
 further studies are needed to establish whether the patterns observed in
 cuckoos are general among terrestrial migrants with continuous
 distribution of habitat.
description: # Recurrence, fidelity, and proximity to previously visited sites
 throughout the annual cycle in a trans-Saharan migrant, the Common Cuckoo
 [https://doi.org/10.5061/dryad.r4xgxd2mv](https://doi.org/10.5061/dryad.r4xgxd2mv) ## Description of the data and file structure The file contains satellite-tracking data of the best daily position from 13 adult Common Cuckoos that were tracked during two, three, or four successive years, from June 2010 to February 2015 as described in Willemoes et al. 2014 and Hewson et al. 2016. Data fields are individual ID (ID), date and time (timestamp), geographical location (location-long, location-lat), geographical identification of stopover (Stopover), stopover region (Major_Stop), duration of stopover (DaysStop), year tracked (Migration_cycle) and Argos location quality (argos:lc). If no stopover region (Major_Stop) could be assigned to a location, the cell was left empty. Hewson, C. M., Thorup, K., Pearce-Higgins, J. W. and Atkinson, P. W. 2016. *Population decline is linked to migration route in the Common Cuckoo*. – Nature Communications 7: 12296. Willemoes, M., Strandberg, R., Klaassen, R. H. G., Tøttrup, A. P., Vardanis, Y., Howey, P. W., Thorup, K., Wikelski, M. and Alerstam, T. 2014. *Narrow-front loop migration in a population of the common cuckoo (Cuculus canorus*) as revealed by satellite telemetry. – Plos One 9: e83515.