Disturbing Waterfowl Die-Off Study Concluded By Montana FWP

There is an element of good news-bad news to this, but still a pretty sad conclusion.

Fans of Montana waterfowl hunting and viewing, be assured that a pretty extensive study was done to get a handle on what was being found on a popular Montana river. It appears heavy competition for food was a contributing factor.

Montana Fish, Wildlife and Parks tells us that in late February, they collected mallard, geese and shorebird carcasses from Afterbay to about three miles downstream along the Bighorn River Fishing Access Site. After extensive testing, Montana FWP has concluded that the death of a large number of waterfowl on the Bighorn was caused by starvation.

With all the recent concerns about bird flu in Montana and elsewhere, the collected carcasses were transported to FWP’s Wildlife Health Lab in Bozeman for Highly Pathogenic Avian Influenza testing. All carcasses tested negative.

Following these negative results, the waterfowl carcasses were sent to the U.S. Geological Survey’s National Wildlife Health Center in Wisconsin for further testing and investigation. No evidence of infectious diseases was detected. Emaciation and starvation were the only consistent ailments found in all sampled carcasses.

And what might be classified as good news-bad news? Well, besides the fact flu was not a factor, FWP’s mid-winter waterfowl surveys for the Bighorn River, conducted in early January, showed higher than average waterfowl numbers, which likely led to more competition for the limited food in the area. Added to that was early 2025's extreme cold temperatures and large amounts of snowfall in the region, making the search for food even more challenging.

As usual, lots of nature's moving parts.