Spring migration dates of Teal (Anas crecca) ringed in the Camargue
Simon G; Arzel C; Guillemain M; Mondain-Monval J-Y
https://urn.fi/URN:NBN:fi-fe2021042716076
Tiivistelmä
The policy of the
European Commission prohibits hunting of migratory birds while they travel to
their breeding grounds. To date, spring migration dates of ducks have mainly
been determined using bird counts, but the validity of this sometimes disputed
method has never been tested. We used ring-recovery data from close to 9,000
teal Anas crecca ringed in the Camargue, southern France, to determine the
onset of spring migration. This method makes it possible to avoid potential
biases linked to duck counts, and was used to test the validity of spring migration
dates inferred from such counts. Depending on the type of analysis (intra- or
inter-annual recoveries), teal appeared to start migrating from the Camargue
during the first or second 10-day period of January, with no significant differences
between years, and no effect of the bird’s age or sex. However, when taking
potential winter dispersion into account, we suggest that a conservative estimate
for the onset of spring migration is the first 10-day period of February. Migration
dates inferred from ring-recovery analyses were consistent with earlier results
from duck counts, and provide a firm basis for policy making related to
hunting. Though ringing data should be preferred when available, our study suggests
that determining migration dates from bird counts may be a reliable method for
teal, and potentially for other dabbling and diving ducks as well.
Kokoelmat
- Rinnakkaistallenteet [19207]