60 yrs of data show shift in winter range

[cajunwannabe]

No surprise to me.

https://www.usgs.gov/news/national-n...pecies-midwest

By Communications and Publishing June 3, 2024
RESTON, Va. — The autumn and winter ranges of three species of economically important dabbling ducks have shifted since the 1960s according to new research co-authored by scientists from the U.S. Geological Survey, Ducks Unlimited and the U.S. Fish and Wildlife Service.

Published today, the new study used 60 years of band recovery data from the Central and Mississippi Flyways of North America to determine that blue-winged teal winter distributions shifted westward and southwards and that mallard and northern pintail distributions shifted eastward and northwards by 60 to several hundred miles.

“This research was in direct response to public concern that duck winter ranges had shifted northward,” said Lisa Webb, Southern Regional Supervisor for the USGS Cooperative Research Units Program and study co-author. “It was made possible by over half a century of work and investment by numerous waterfowl banders and supporting agencies in the United States and Canada.”

A graphical abstract for a study on shifting duck ranges. For help interpreting this figure, please contact ewebb@usgs.gov
Sources/Usage: Public Domain. View Media Details
The study results showed that while the winter ranges of mallards and northern pintail did, indeed, shift northward during the months of December and January, the scale of the shifts were small compared to the overall geographic distributions of these species during those months. Furthermore, there was no evidence of complete abandonment of large wintering regions. And while the general trend of northward shifts in winter ranges was confirmed, the authors caution that summarizing shifts across species, months or subpopulations may hide finer-scale patterns that would be important to habitat conservation and population management.

“The data that allowed us to answer this important question came from one of the longest-term community science efforts in North America,” said study lead author Bram Verheijen. “We are grateful to the thousands of waterfowl hunters that enabled this study by reporting waterfowl band recoveries.”

To determine if and in what directions the duck species’ ranges had shifted, the authors first created duck distributions based on locations from over 350,000 banded ducks recovered during autumn and winter months. Then they compared the overlap of duck distributions for the three species between the 1960s and the present day.

“Sound science is the foundation of responsible waterfowl conservation and management,” said Ducks Unlimited Senior Waterfowl Scientist and study co-author Mike Brasher. “This study is another tool that Ducks Unlimited and our partners will use to guide our hunter-supported conservation efforts across the U.S. Through their 60 years of band reporting, waterfowlers have enabled us to scientifically study the dynamic migration habits of our ducks. And hunter support will also lead us to discover more efficient ways to improve the landscape.”

The purpose of the study was to determine if, where and how much the ducks’ ranges had shifted, not why, so follow-up research is already underway to uncover the causes.

“A wide variety of factors, including loss and degradation of breeding habitat, changing land use, climate change, and ever-evolving agricultural practices are likely all affecting migration patterns of ducks and geese," said USFWS Wildlife Biologist and study co-author Heath Hagy, who is also a project leader for the USFWS Habitat and Population Evaluation Team. "The causes of the changes are complex, vary by species, and manifest themselves differently across breeding areas such that no single factor can be blamed directly for the changes.”

Waterfowl are economically and culturally important, with over 1 million hunters contributing approximately $700 million to local and regional economies annually. Potential shifts in regional autumn and winter waterfowl distributions, and the subsequent effects on recreational opportunities, could impact conservation and management of these species and their habitat at the continental level.

Read the study “Long-term changes in autumn-winter harvest distributions vary among duck species, months, and subpopulations” for full details on the range shifts.

[Sasha and Abby]

Not surprising at all. Farming practices have changed and birds simply don't have to chase food.