Influence of resource selection on nonbreeding season mortality of mallards. Issue 7 (19th July 2022)

• Record Type: Journal Article
• Authors: Palumbo, Matthew D.; Petrie, Scott A.; Schummer, Michael L.; Rubin, Benjamin D.; Benson, John F.
• Is Part Of: Journal of wildlife management. Volume 86:Issue 7(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-07-19
• Subjects: Anas platyrhynchos -- Cox‐proportional hazard -- Global Positioning System -- Kaplan‐Meier -- known‐fate -- Lake St. Clair -- resource selection -- survival -- waterfowl hunting; Wildlife management -- Periodicals; Zoology -- Periodicals; 333.954
• DOI: 10.1002/jwmg.22292
• Languages: English
• ISSNs: 0022-541X

Abstract

Abstract: Relationships between individual resource selection strategies and fitness are difficult to quantify at large spatial scales. These links are important for understanding the potential effects of management on population‐level processes. We modeled the degree to which selection of specific landscape features altered mortality risk of female mallards ( Anas platyrhynchos ) during the non‐breeding season. We used individual resource selection estimates from adult female mallards equipped with Global Positioning System (GPS) backpack transmitters ( n = 56) in the Lake St. Clair region of southwestern Ontario, Canada, in August of 2014 and 2015. We determined the fate of individuals between August and January and used time‐to‐event analyses to model survival over 158 days. Furthermore, we investigated how diurnal and nocturnal resource selection and year were related to mortality risk. The survival rate for the adult female mallards was 0.57 (95% CI = 0.42–0.77). Resource types were combinations of land class types (e.g., water, marsh, flooded agriculture, supplemental feeding areas, and dry agriculture) important to mallards and varying levels of risk from anthropogenic disturbance ranging from inviolate refuges to publicly accessed areas where we predicted mortality risk to be greatest. Our results suggest that water that the public can access (i.e., public water) influenced mortality risk during multiple seasons. Specifically, selection of public water by female mallards reduced mortality risk diurnally during the non‐hunting period (hazard ratio = 0.68, 95% CI = 0.48–0.96) but increased mortality risk during the first half of the hunting period (hazard ratio = 1.54, 95% CI = 1.08–2.20). Our research highlights that individual selection strategies by ducks within this landscape can influence mortality risk. Abstract : Mallards maximize fitness by balancing risks with access to necessary resources. In areas where waterfowl hunting is popular, increased access to preferred resources with reduced risk from anthropogenic disturbances is important for management.