Who can volunteer?
Anyone who lives or vacations on a Wisconsin lake can send us their observations.

How often do I need to monitor the loons?
We recommend that volunteers observe loon activity as often as possible on the lake—the more observations you make, the more confidence you will have in your interpretation of the summer’s events. However, useful information can come from as little as one day of observations—so don’t hesitate to join the Annual Lake Monitoring Program.

What if someone is already monitoring the lake?
We have a number of lakes with multiple observers. This is okay. It helps to ensure that someone will send us information, because sometimes people can’t get out as often as they plan to. We usually allow two volunteers on small- and medium-sized lakes, and possibly more on very large lakes and flowages. We do encourage volunteers to work together whenever possible to create a more complete picture of loon activity at a lake on one monitoring form.

Is there specific information you’re looking for?
Yes. Loon Rangers should download a monitoring form each spring, which asks for information such as when loons first arrived on the lake, if they nested or just visited the lake, if they had chicks, how many chicks they had, and if there are any threats to the loon nest site. This information is gathered throughout spring and summer, and then the volunteer returns the form to us in the fall.

What if I don’t know anything about loons, but I still want to help?
We encourage new volunteers to attend a Loon Ranger Workshop to learn about loons, receive training in loon monitoring, and to interact with experienced Loon Rangers. If you are not available for one of the workshops, however, you can still participate in the program. Volunteers may download a Loon Ranger Instruction Packet and explore our website for other information about loons to help them learn more about this northern bird.

How do I sign up?
Call or send us an email and tell us what county you are in and what lake you would like to monitor.

If you monitored your lake this summer and still need to fill out the monitoring form information, please download and print the following PDFs and return them to LoonWatch.

• Instructions for the Annual Lake Monitoring Form (Download PDF)
• Annual Lake Monitoring Form (Download PDF)

Annual Lakes Monitoring Program Reports

• 2020 report
• 2019 report
• 2018 report
• 2017 report
• 2016 report
• 2015 report
• 2014 report

Wisconsin Loon Population Survey Reports

2020 Summary
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.

2015 Summary
Wisconsin loons are doing surprisingly well, according to the results of the 2015 one-day Wisconsin Loon Population Survey. July 18, 2015 was LoonWatch’s seventh survey. Roughly 210 volunteers collected data, surveying 204 lakes in twenty-seven northern Wisconsin counties.

The analysis results show another positive outlook for Wisconsin’s loon population.  According to the results, the adult loon population is estimated at 4,350, an increase of 9.1 percent from 2010’s population estimate of 3986.7.  The chick population is estimated at 834, an increase of 37.8 percent from 2010’s estimate of 605.  Between the 2010 Gulf oil spill and 2012 botulism outbreak loons have faced extraordinary challenges over the last five years, so this is good news.

2010 Summary
July 17, 2010, marked the sixth Wisconsin Loon Population Survey. Volunteers surveyed 244 of the 258 pre-selected lakes. This is the most lakes ever visited during this survey’s 25-year history. The most lakes surveyed previously was 225 in 2005.

The analysis results are in and the outlook for Wisconsin’s loon population looks good. The adult loon population for 2010 was estimated at approximately 4,000 and chick population was estimated at approximately 600. This represents a significant adult population increase over the 3,373 adults and slight chick population decrease below the 805, estimated in 2005. Thus, 2010 had the largest adult loon population estimate since the survey started in 1985.

Why isn’t the chick population the highest as well? This appears to be primarily linked to increased territorial aggression. As the loon population grows, they are using sub-prime nesting habitat and are fighting each other for the prime nesting habitat. Both of these behaviors lead to less chick productivity. Loons who do not have a territory, often referred to as prospecting loons, will attack a loon on a prime territory in an attempt to win the territory and the mate that is there. Typically these are male on male or female on female battles, and if an intruding loon wins, it will mean that the current nest or chicks will be abandoned.

Another trend we saw in 2010 was the presence of large groups of loons on lakes. Groups of loons are typically loons that don’t have a territory or have lost their nest or chick early. These loons typically return to their territorial lake late each evening, but leave again in the morning to feed in groups. Working together to corral fish is one advantage that loons in groups have over individuals.

2005 Summary
The results indicate that the outlook for Wisconsin’s loon population looks good. The adult loon population for 2005 was estimated at 3,373 (±495) and chick population was estimated at 805 (±218). This represents a marginal adult population increase over 3,131 adults estimated in 2000 and significant chick population increase over 462 in 2000. Thus 2005 had the largest loon population estimate since the survey started in 1985.

We also look at what proportion of the loon population comes from four lake size classes. When the two smaller lake classes (25-149 acres) were combined and the two larger lake classes (150+ acres) were combined, an interesting pattern emerges over time. In 1985, 20% of the population was found on the large lakes and 80% on the small lakes. As of 2005, this ratio was about equal with approximately half of the population on small lakes and half on large lakes.

We don’t collect any other data with this survey to correlate our population numbers to lake factors that may be the cause for this shift. We can speculate that something has changed on small lakes that make them last attractive to loons or something has changed on the large lakes that make them more attractive than in the past. One is left wondering if a shift toward increased shoreline development on small lakes over the past twenty years might not be at least part of the cause. Regardless, our loon population seems to be adapting to these changes as the population seems to be doing well.

2000 Summary
During the 2000 survey, volunteers observed 223 adults and 34 chicks on 151 lakes in 25 counties. Using these data, the 2000 Wisconsin loon population was estimated at 3,131 adults and 462 chicks. The 2000 adult population estimate was significantly larger than the 1985 estimate of 2,358. The chick population estimate was the lowest on record but did not differ significantly from any of the previous surveys.

The adult common loon population in Wisconsin appears to be strong and may even be growing. Though it would be inaccurate to view the 2000 survey data as a sign that loon productivity in Wisconsin is declining overall. It is important to note that moderate to large lakes are an important component of the loon’s breeding habitat, and research by the Wisconsin DNR has found that these areas are under the greatest pressure from development and recreational use.