Not all sanctuaries are created equal: variation in protected area selection by wintering mallards

Abstract

Public lands managed for wildlife frequently provide various forms of sanctuary to increase residency times and allow access to energetic and other habitat resources for waterfowl. The influence of sanctuary type and disturbance regime on resource use and fine‐scale movements of waterfowl has not been investigated extensively using currently available transmitter technologies. We examined mallard (Anas platyrhynchos) use of various types of waterfowl sanctuary and non‐sanctuary areas in the Mississippi Alluvial Valley region of eastern Arkansas, USA, during winters of 2019–2021. We deployed 105 global positioning system transmitters on mallards at 4 closed‐access spatial sanctuaries on or adjacent to Dale Bumpers White River National Wildlife Refuge. We used hourly transmitter locations to examine mallard use of public sanctuary areas, public hunt areas, and private lands using integrated step selection analysis. Public sanctuary areas provided varying levels of protected status, public hunt areas allowed for varying levels of hunting intensity by duck hunters, and private lands were open to waterfowl hunting and other forms of private uses but may or may not have been hunted at any specific frequency. Mallards selected spatial sanctuary and avoided public hunt areas, other sanctuary types, and private lands during the day. In contrast, mallards selected for private lands over spatial sanctuary at night. Mallards tended to avoid areas that allowed duck hunting or used them during the night when risk of harvest mortality was removed. After the hunting season closed, mallards began using areas that previously allowed duck hunting during the day, suggesting that risk was the primary factor influencing site use. Moreover, mallards were 1.6 times more likely to use public daily hunt areas and 2.1 times more likely to use private lands potentially open to hunting during the day than spatial sanctuary 2 weeks after the close of duck hunting season in February. Spatial sanctuaries appear more effective in influencing mallard use than temporal sanctuaries or inviolate sanctuaries, which are commonly used by state and federal agencies. Partial daily, daily, or activity‐specific (e.g., no hunting past noon, no hunting 3 days/week, no waterfowl hunting) closures to encourage mallard use of temporal sanctuaries do not appear to reduce the perceived harvest‐related risk to mallards enough for them to view these areas as accessible or significantly increase their use.