2020 Wisconsin Loon Population Survey Results

Dear Loon Population Survey Volunteers,

I would like to thank you all for your efforts to help with LoonWatch’s 2020 Wisconsin Loon Population Survey. A total of 157 lakes throughout 27 northern Wisconsin counties were surveyed. You took part in a significant long-term survey that occurs only once every five years, and your participation was vital to making the survey a success.

The 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.

Though it has been a while since you all headed out the morning of July 18th, 2020, I’d like to take you back to that day and the challenges we faced. In the middle of a pandemic, you surveyed a lake(s) 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. Though it was over for most of the state by 7:00a.m. I had no idea if some of you decided against going out. Fortunately, almost all of you waited out the storm, and then ventured onto your survey lakes. Thanks to you all, we finally have the statistically analyzed results.

The 2020 adult population estimate is 4,115 adult loons, 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 the loon population in Wisconsin. That’s why it is critical that we continue this long-term population survey.

Thank you all for the great work that you did on that early July morning. I hope you will consider signing up for our 2025 survey.


Erica LeMoine

LoonWatch Coordinator