Synchronization or Coordination? Context dependent anti-predator
vigilance to nature-based ecotourism
Abstract
Prey monitor surrounding dangers independently or cooperatively
(synchronized and coordinated vigilance), with independent and
synchronized scanning being prevalent. Coordinated vigilance, including
unique sentinel behaviour, is rare in nature, since it is time-consuming
and benefit-limited. Evidence does not indicate animals adopting
alternative vigilance strategies during antipredation scanning.
Considering the cooperative nature of both synchronization and
coordination, we assessed whether group members could keep alert
synchronously or coordinatedly under different circumstances,
determining whether cooperative vigilance is context dependent. Under
the framework of conservation behavior, we studied how human behaviour
and species-specific variables impacted individual and collective
vigilance of globally threatened Black-necked Cranes (Grus nigricollis)
and explored behaviour-based wildlife management. We tested both
predation risk (juveniles in group) and human disturbance (level and
distance) effects on individual and collective antipredation vigilance
of black-necked crane families. Adults spent significantly more time
(proportion and duration) on scanning than juveniles, and parents with
juveniles behaved more vigilant. Observer distance affected individual
vigilance of adults while juveniles were influenced by none of these
variables. With the number of juveniles and disturbance increased, crane
couples decreased synchronization of vigilance and they shifted to
coordination, which has so far never been reported yet. Similarly, with
observer approaching, adults shift vigilance from synchronization to
coordination. The collective vigilance shift from synchronization to
coordination as a function of observer distance could help us
determining a safe distance of c. 400m for the most vulnerable family
groups with two juveniles, so as no obvious interference with the
threatened birds by human proximity. We argue that vigilance behaviour
could be a reliable indicator in future nature-based tourist management
and decision-making, which can be derived from conservation solutions in
nature.