See the Paper: Waterfowl pond preference and behavior during fall migration through southeastern Minnesota

Background

Waterfowl are larger aquatic birds like ducks and geese. They are important to Minnesota ecologically, culturally, and economically, and wetlands are crucial habitat for them to maintain healthy populations. Many waterfowl are migratory, and during a migratory season, it is valuable to know where birds are and what habitat they are using. Climate change is projected to significantly alter the way waterfowl migrate because many species time their migration based on temperature changes rather than daylight signals. Climate change also leads to varied environmental conditions that affect how wetlands are providing resources. Long-term monitoring of wetlands and waterfowl presence is useful to help managers understand how wildlife is using the landscape. 

A St. Olaf student continued a migratory waterfowl monitoring project in 2021 in order to assess how birds were using two wetlands in the St. Olaf Natural Lands. 

The Study

Sophia Rice (Class of 2022, B.A. Biology) studied two ponds: Big Pond and Baseball pond. 

During the month of October and the first week in November, Rice counted the number and species of birds entering and exiting the pond surveyed that day. Rice also recorded the behavioral states of the birds at different times in order to determine if ponds were used for different purposes over the course of the season. 

The Findings

Rice observed four species of waterfowl during the study: Canada goose (Branta canadensis), mallard (Anas platyrhynchos), wood duck (Aix sponsa), and hooded merganser (Lophodytes

cucullatus). All four species were observed at Big Pond, and only Canada geese and mallards were seen at Baseball Pond. Statistical analyses did not find a significant difference in the behaviors displayed by the birds between each pond (i.e. how often birds spent foraging, preening, etc.), nor did they find a significant difference in how many birds were observed at each pond. Geese did leave and join ponds more frequently than mallards. 

With these findings, Rice concluded that both ponds were important habitat for these migratory waterfowl, and despite differences in size, vegetation, and edge habitat, birds relied on both. Rice also noted that different years of this study faced different environmental conditions (low water levels, varied temperatures, etc.) and therefore understanding how this affects birds is imperative. For example, a study in 2019 found that geese and mallards were using Baseball Pond much more frequently because Big Pond was at a severely low water level. 

Relevance

Monitoring both bird behavior and environmental conditions is critical in order to understand how best to support both wetland ecosystems and waterfowl populations in the future. Overall, multiple wetland options should be considered and maintained to increase the resilience of these birds in a changing climate. 

Citation

Rice, S. 2021. Waterfowl pond preference and behavior during fall migration through southeastern Minnesota. St. Olaf College Local Ecology Papers. https://wp.stolaf.edu/naturallands/files/2022/03/Rice_view_PDF-1.pdf