DOI: 10.5061/dryad.8sf7m0d2p
title: Data from: Long-distance dispersal is asymmetrical with respect to age, sex and breeding latitude in a long-lived monogamous bird

description: Although relatively rare, long-distance dispersal significantly impacts
 population persistence by facilitating range expansion, range shifts, and
 genetic exchange. For individuals dispersing northwards, it may be a
 suitable adaptation strategy to escape negative effects of climate change
 on their original breeding sites. In this study, we constructed a joint
 live encounter – dead recovery model under a Bayesian multistate framework
 to quantify long-distance dispersal between the Barents Sea, Baltic Sea,
 and North Sea subpopulations of the Russia/Germany & Netherlands
 flyway population of barnacle goose (Branta leucopsis), using long-term
 mark-recapture data of 22,413 individuals ringed between 1995 – 2023.
 Long-distance dispersal was strongly biased by age-, sex- and direction.
 Natal dispersal predominantly occurred in northward direction with 23.9%
 of juvenile males and 8.6% of juvenile females estimated to transition
 annually from the North Sea to the Barents Sea subpopulation. In contrast,
 breeding dispersal in the same direction in adults was minimal, estimated
 at only 0.49% and 0.21% for males and females respectively, and was not
 always distinguishable from temporary (moult-) migrations. Our model
 results were validated with data from 14 dispersing individuals, 9 of
 which were male, for whom the timing of breeding or moult was recorded. In
 all cases, dispersal was in northward direction and timing of breeding or
 moult of dispersers more closely resembled the timing of the receiving
 than of the original subpopulation, but more so in males than in females.
 Our results support the notion of strong male-biased natal dispersal in
 monogamous waterbirds. Interestingly, despite substantial growth in the
 temperate breeding subpopulations during our study period, natal dispersal
 occurred predominantly in northward direction at both individual and
 population levels. The unidirectional long-distance dispersal observed is
 expected to result from the unique flyway structure, were subpopulations
 with large differences in population size mix during wintering.
 Additionally, we also highlight the adaptability of dispersers, showing
 that barnacle geese can adaptively switch migration on and off, and that
 plasticity in timing of breeding and moult may be larger in males than in
 females. We argue that this could be an additional explanation for the
 predominantly male-biased northward dispersal observed in barnacle
 geese. 
description: # Data from: Long-distance dispersal is asymmetrical with respect to age,
 sex and breeding latitude in a long-lived monogamous bird Dataset DOI:
 [10.5061/dryad.8sf7m0d2p](10.5061/dryad.8sf7m0d2p) ## Description of the
 data and file structure The collection of the data and the usage of the
 dataset is described in: de Vries, E.H.J., Boom, M.P., Nolet, B.A.,
 Jongejans, E. & van der Jeugd, H.P., (2025). Long-distance dispersal
 is asymmetrical with respect to age, sex and breeding latitude in a
 long-lived monogamous bird. *Journal of Animal Ecology.*  Users of the
 data file are encouraged to cite the associated paper and to contact the
 paper authors. ### Files and variables #### File:
 EH_barnacle_goose_multistate_model.RData **Description:**  Encounter
 history of barnacle geese (colour-)ringed between 1995 – 2023, used in a
 Bayesian joint live encounter - dead recovery multi-state model #####
 Variables * ch: encounter history * age: juvenile (1) and adult (2) * rt:
 ring type (1 -&gt; Coloured leg rings, 2 -&gt; metal ring, 3-&gt;
 neckband, 4 -&gt; ringed with metal ring, subsequently (after 1 year or
 more) ringed with additional coloured mark)  * sex:  female (1), male (2)
 and unknown (3) #### File: Rscript_Barnacle_goose_multistate_model.txt
 **Description:** Bayesian joint live encounter - dead recovery multi-state
 model ##### ## Access information Data was derived from the following
 sources: Ringing, recapture, resighting and dead recovery data was
 collected from the EURING Databank and the geese.org and Dutch Centre for
 Avian Migration and Demography (Vogeltrekstation) databases. Dead recovery
 data for Russia was supplemented with data collected directly from the
 Bird Ringing Centre Moscow.