Long-term changes in autumn-winter harvest distributions vary among duck species, months, and subpopulations.

Autor: Verheijen BHF; Missouri Cooperative Fish and Wildlife Research Unit, School of Natural Resources University of Missouri Columbia Missouri USA., Webb EB; U.S. Geological Survey, Missouri Cooperative Fish and Wildlife Research Unit, School of Natural Resources University of Missouri Columbia Missouri USA., Brasher MG; Ducks Unlimited, Inc. Memphis Tennessee USA., Hagy HM; U.S. Fish and Wildlife Service, Habitat and Population Evaluation Team Bismarck North Dakota USA.
Jazyk: angličtina
Zdroj: Ecology and evolution [Ecol Evol] 2024 Jun 03; Vol. 14 (6), pp. e11331. Date of Electronic Publication: 2024 Jun 03 (Print Publication: 2024).
DOI: 10.1002/ece3.11331
Abstrakt: Our aim was to describe shifts in autumn and winter harvest distributions of three species of dabbling ducks (blue-winged teal [ Spatula discors ], mallard [ Anas platyrhynchos ], and northern pintail [ Anas acuta ]) in the Central and Mississippi flyways of North America during 1960-2019. We measured shifts in band recovery distributions corrected for changes in hunting season dates and zones by using kernel density estimators to calculate 10 distributional metrics. We then assessed interannual and intraspecific variation by comparing species-specific changes in distributional metrics for 4 months (October-January) and three geographically based subpopulations. During 1960-2019, band recovery distributions shifted west- and southwards (blue-winged teal) or east- and northwards (mallard and northern pintail) by one hundred to several hundred kilometers. For all three species, the broad (95% isopleth) and core distributions (50% isopleth) showed widespread decreases in overlap and increases in relative area compared to a 1960-1979 baseline period. Shifts in band recovery distributions varied by month, with southward shifts for blue-winged teal most pronounced in October and northward shifts for mallard and northern pintail greatest during December and January. Finally, distributional metric response varied considerably among mallard subpopulations, including 2-4-fold differences in longitude, latitude, and overlap, whereas differences among subpopulations were minimal for blue-winged teal and northern pintail. Our findings support the popular notion that winter (December-January) distributions of duck species have shifted north; however, the extent and direction of distributional changes vary among species and subpopulations. Long-term distributional changes are therefore complex and summarizing shifts across species, months, or subpopulations could mask underlying finer-scale patterns that are important to habitat conservation and population management. A detailed understanding of how species distributions have changed over time will help quantify important drivers of species occurrence, identify habitat management options, and could inform decisions on where to focus conservation or restoration efforts.
Competing Interests: There are no conflicts of interest that we know of for this manuscript.
(© 2024 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)
Databáze: MEDLINE
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