Herbert, J. S., A. Chakraborty, L. W. Naylor, W. Beatty, and D. G. Krementz. Effects of landscape structure and temporal habitat dynamics on wintering mallard abundance. Landscape Ecology 33:1319–1334.
Abstract
1. The conservation of wintering waterfowl in North America requires flexibility because of constantly changing landscapes and conditions, yet a gap in knowledge still exists regarding waterfowl spatio-temporal habitat use at large spatial scales. Many mallards (Anas platyrhynchos) use the lower Mississippi Alluvial Valley (MAV) for migrating and
wintering habitat, making this an area of emphasis for improving management strategies for waterfowl and wetlands.
2. In this study, we used mallard observation data from 25 aerial surveys collected in the Arkansas portion of the MAV (ARMAV) from 2009-2016 to explain the abundance and distribution of mallards. Using hierarchical spatio-temporal models with covariate data on 2x2 km grid cells, we analyzed how covariates related to changes in mallard abundance and distribution within and among years.
3. Our analyses found mallard abundance and distribution responded positively to surface
water along with the land cover inundated by that water. For best performing models across different months and years, surface water, rice fields, wetlands and fallow (uncultivated) fields were found to have a positive influence on mallard distribution most
of the time.
4. Our models showed a strong correlated spatial pattern existed for mallard abundance
distributions across the ARMAV. We also predict mallard abundance distributions across the ARMAV.
5. Identifying regions on where to expect mallards and environmental factors that are driving the distribution changes will improve management and conservation efforts. Our analytical approach can be used outside of the ARMAV and for other species.