Common Whitethroats Curruca communis show a continuum of residency
duration but a high degree of between-years site fidelity at
non-breeding grounds in Nigeria
Abstract
The non-breeding period represents a significant part of an
Afro-Palearctic migratory bird’s annual cycle. Decisions such as whether
to remain at a single site and whether to return to it across years have
important effects on aspects such as survival, future breeding success,
migratory connectivity, and conservation. During this study, we
colour-ringed > 300 Common Whitethroats Curruca communis
and undertook daily resightings to understand site persistence and the
degree of site fidelity throughout three non-breeding periods (November
– April) in Nigeria. The probability of detecting a colour-ringed
Whitethroat when it was present, was 0.33. Site persistence varied
widely across individuals (1 – 165 days) and did not differ
significantly with sex or year, though first-year birds remained for
significantly shorter periods than adults. We believe that shorter
residencies are likely due to the use of multiple stationary
non-breeding sites rather than low winter survival. A minimum of 19% of
individuals returned to the study site the following year and shifted,
on average, 300 meters, suggesting that Whitethroats have a relatively
high degree of between-years site fidelity at a very fine scale. An
individual’s previous residency duration did not seem to determine its
residency duration the following year. We suggest that spatial fidelity
is high and constant through years, but temporal fidelity is not, and
individual residency patterns vary, probably according to yearly and
seasonal conditions. Our results highlight the complexity of the annual
cycle of a single species and the importance of carrying out in situ,
small scale research throughout a migrant’s annual cycle over several
years.