Fidelity to foraging sites after long migrations

1. Patterns of animal movement associated with foraging lie at the heart
of many ecological studies and often animals face decisions of staying in
an environment they know, versus relocating to new sites. 2. The lack of
knowledge of new foraging sites means there is risk associated with a
decision to relocate (e.g. poor foraging) as well as a potential benefit
(e.g. improved foraging). 3. Using a unique long-term satellite tracking
dataset for several sea turtle species, combined with
capture-mark-recapture (CMR) data extending over 50 years, we show how,
across species, individuals generally maintain tight fidelity to specific
foraging sites after extended (up to almost 10,000 km) migration to and
from distant breeding sites as well as across many decades. 4. Migrating
individuals often travelled through suitable foraging areas en route to
their “home” site and so extended their journeys to maintain foraging site
fidelity. 5. We explore the likely mechanistic underpinnings of this
trait, which is also seen in some migrating birds, and suggest that
individuals will forgo areas of suitable forage encountered en route
during migration when they have poor knowledge of the long-term
suitability of those sites, making relocation to those sites risky.