Hunting constrains wintering mallard response to habitat and environmental conditions

The spatiotemporal allocation of activity is fundamental to how organisms
balance energetic intake and predation risk. Activity patterns fluctuate
daily and seasonally, and they are proximately affected by exogenous and
endogenous conditions. For birds, flight activity is often necessary for
relocating between foraging patches but is energetically expensive and can
increase mortality risk. Hunted species may have to adjust their behavior
and activity patterns to minimize anthropogenic mortality risk. We used
hourly locations from 336 GPS-marked mallards (Anas platyrhynchos) to
examine how hunting pressure affected flight activity in response to
weather conditions and habitat availability during winter in western
Tennessee, USA. Mallards were more likely to fly during crepuscular times,
particularly dusk, across winter months. Mallards conducted more flights
after shooting hours when habitat availability increased during open
hunting season; conversely, mallard flights decreased with increasing
habitat availability when hunters were present on the landscape. Mallards
were least active during periods open to hunting. However, indicators of
approaching inclement weather (i.e., increased wind speed, precipitation,
and decreasing barometric pressure) increased flights during periods open
to hunting. Mallard flights decreased at lower temperatures except when
hunting season was closed, wherein mallards increased nighttime flights.
Flight activity was directly influenced by hunting disturbance which
constrained when and how mallards reacted to environmental and habitat
conditions. An understanding of the temporal shifts in waterfowl flight
patterns can be used by natural resource managers to better manage
stakeholder satisfaction and expectations.