J.D. Nichols
J.E. Hines
M. S. Lindberg
Aivars Mednis
Peter Blums
2003
<p><span>1. We used up to 34 years of capture-recapture data from about 22 100 new releases of day-old </span>female<span> ducklings and </span>multistate<span> modelling to test predictions about the influence of environmental, habitat and management factors on </span>natal<span> </span>dispersal<span> probability of three species of </span>ducks<span> within the Engure Marsh, Latvia. 2. The mean </span>natal<span> </span>dispersal<span> distances were very similar (c. 0.6-0.7 km) for all three species and were on average 2.7 times greater than breeding </span>dispersal<span> distances recorded within the same study system. 3. We were unable to confirm the kinship hypothesis and found no evidence that young first-nesting females nested closer to their relatives (either mother or sister) than to the </span>natal<span> nest. 4. Young </span>female<span> northern shovelers, like adults, moved from small islands to the large island when water level was high and vice versa when water level was low before the construction of elevated small islands. </span>Movement<span> probabilities between the two strata were much higher for young shovelers than adults, suggesting that young birds had not yet developed strong fidelity to the </span>natal<span> site. Movements of young </span>female<span> tufted </span>ducks<span>, unlike those of shovelers, were not dependent on water level fluctuations and reflected substantial flexibility in choice of first nesting sites. 5. Data for young birds supported our earlier conclusion that common pochard nesting habitats in black-headed gull colonies were saturated during the entire study period. Young females, like the two adult age groups, moved into and out of colonies with similar probability. Fidelity probability of </span>female<span> pochards to each stratum increased with age, being the lowest (0.62) for young (DK) females, intermediate (0.78) for yearlings (SY) and the highest (0.84) for adult (ASY) females. 6. Young </span>female<span> tufted </span>ducks<span>, like adults, showed higher probabilities of moving from islands to emergent marshes when water levels were higher both before and after habitat management. The relationship between the spring water levels and </span>movement<span> was much weaker for young females than for adults. 7. Young </span>female<span> diving </span>ducks<span> exhibited much stronger (compared to adults) asymmetric </span>movement<span> with respect to proximity to water, with higher </span>movement<span> probabilities to near-water locations than away from these locations. 8. Local survival of day-old ducklings during the first year of life was time-specific and very low (means for different strata/states 0.01-0.08) because of high </span>rates<span> of emigration and prefledging mortality.</span></p>
application/pdf
10.1046/j.1365-2656.2003.00774.x
en
British Ecological Society
Estimating natal dispersal movement rates of female European ducks with multistate modelling
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