From the report: "The 2020 adult population estimate is 4,115, and the chick population estimate is 893 chicks. The adult population estimate is 235 fewer loons than the 2015 survey (4,350 loons), but is well within the standard error of +/- 347 loons. The chick population estimate is 59 more chicks than the 2015 survey (834 chicks), but is also well with the standard error of +/- 141 chicks."

- Bookwood Historical Collection, Star Lake

2020 Wisconsin Loon Population Survey Results

The LoonWatch Wisconsin Loon Population Survey has been conducted every 5 years since 1985 on the same lakes. A total of 258 lakes are a part of the survey, and we try to recruit volunteers to survey as many of those lakes as possible. This stratified selection of lakes was randomly chosen based on size class to represent all the lakes that loons might occupy during the breeding season. Volunteers count the total number of loon adults and loon chicks observed on the lake during the required timeframe.

A total of 152 volunteers helped LoonWatch survey 157 lakes throughout 27 northern Wisconsin counties for the 2020 Wisconsin Loon Population Survey. They took part in a significant long term survey that occurs only once every five years, and their participation was vital to making the survey a success.

Volunteers headed out the morning of July 18th, 2020, and in the middle of a pandemic, they surveyed their chosen lakes between 5:00a.m. and 10:00a.m. on a steamy 90°F + day. Early that morning, a severe thunderstorm raced across a substantial swath of northern Wisconsin. Fortunately, almost all of the volunteers waited out the storm to venture onto their survey lakes. Thanks to them, we finally have the statistically analyzed results.

The 2020 adult population estimate is 4,115, and the chick population estimate is 893 chicks. The adult population estimate is 235 fewer loons than the 2015 survey (4,350 loons), but is well within the standard error of +/- 347 loons. The chick population estimate is 59 more chicks than the 2015 survey (834 chicks), but is also well with the standard error of +/- 141 chicks. The standard error is a measure of the variability of a statistic.

Our loons face numerous threats: habitat loss, lead poisoning, monofilament line entanglement, human harassment, water quality degradation, Great Lakes botulism outbreaks, and climate change. All of these factors have an impact on our loon population in Wisconsin. That’s why it is critical that we continue this long-term population survey.

A big thank you goes out to all the volunteers for the great work they did on that early July morning. Support LoonWatch. LoonWatch is a program of the Sigurd Olson Environmental Institute at Northland College.