Loon Research in Restoration in Minnesota

For nearly 30 years, BRI and the Minnesota Department of Natural Resources (MN-DNR) have worked to monitor and protect Common Loons (Gavia immer) throughout Minnesota. Through sustained banding efforts and a vast network of volunteers, we have been able to determine the distribution and movement patterns of loon populations, as well as their reproductive success.

BRI has also helped restore loons to the southern end of their range in the state through a novel translocation program.

Lead Investigator: David Evers

Minnesota Status Report for the Common Loon
Known as the Land of 10,000 Lakes, Minnesota boasts 11,842 lakes that are larger than 10 acres in size. Minnesota’s nearly 4,700 territorial pairs comprise the largest breeding loon population in the contiguous United States. Although the state’s loon population is healthy, current environmental threats require monitoring and action. Download Status Report.

Loon Monitoring Program

In 1994, the Minnesota Department of Natural Resources (DNR) implemented a Loon Monitoring Program. With the assistance of volunteers, the DNR annually gathers information on Common Loons on more than 600 lakes, distributed among six regions, or index areas, that include: Kandiyohi, Otter Tail, Becker, Aitkin/Crow Wing, Itasca, and Cook/Lake Counties. These regions represent different stressors that may affect loons and their habitats such as densities of roads, human population, and acid rain sensitivity.

Current Status

Reproduciton
Results from the monitoring program indicate that Minnesota’s loon population has been stable over the last two plus decades. Although the average number of chick and juvenile loons reported per pair of adults is highly variable from year to year, their numbers have also remained stable across all index areas.

Distribution
Historically, Common Loons (Gavia immer) bred throughout the state, as far south as Iowa, although they were likely uncommon in the prairies. By 1900, breeding loons were pushed north of Minneapolis. Today, breeding loons range across the northern two-thirds of the state and are beginning to return to parts of their historical range in the south-central part of Minnesota (Figure 1).

Minnesota’s nearly 4,700 territorial pairs comprise the largest breeding loon population in the contiguous United States.

Movements
Loons migrate from Minnesota in late fall. They are often observed on Lake Michigan, where they stage before migrating south. Adults leave before juveniles, so young loons arrive on the wintering grounds without prior knowledge or experience.

Band recoveries indicate that loons in Minnesota spend the winter in either the Gulf of Mexico or along the Atlantic coast. In the Gulf of Mexico they range as far west as Corpus Christi, Texas east to Tampa Bay, Florida. In the Atlantic, loons winter off the shores of Virginia and North Carolina. Recent satellite tracking showed one adult spent the winter at an inland reservoir in Tennessee.

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Loons and Lead

Loons, Lead, and Anglers
Anglers can help prevent lead poisoning in loons. A study conducted by the Minnesota Pollution Control Agency (MPCA) found that lead poisoning accounted for 12 percent of the dead adult loons with known causes of death. Inexpensive and ecologically sound alternatives to lead fishing weights are available. Through MPCA’s “Get the Lead Out!” campaign, Minnesota’s anglers are asked to consider switching from lead fishing tackle to nontoxic alternatives such as tin, bismuth, steel, and tungsten-nickel alloy.

A Campaign to Safequard Wildlife and Human Health
On April 20, 2010, an explosion on the Deepwater Horizon oil rig resulted in 168 million gallons of oil spilling into the Gulf of Mexico for more than 87 days, killing thousands of birds, fish, and marine mammals. Minnesota’s breeding loon population overwinters in the Gulf of Mexico; many of these aquatic birds were affected by the spill.

Minnesota was awarded $1.2 million as compensation for injuries to public natural resources because of this environmental disaster. Restoration of loon-years-lost (i.e., injury) is a common way for governmental environmental trustees (e.g., U.S. Fish and Wildlife Service) to compensate for such losses.

This funding will allow the MPCA and the Department of Natural Resources (DNR) to begin a three-year campaign to educate Minnesotans on the dangers lead tackle pose to breeding loons. The “Get the Lead Out!” initiative is supported by the state government, as well as lake associations, conservation organizations, and those involved in the fishing and tackle industry. Oil spill funds were also provided to the Minnesota Department of Natural Resources (DNR).

Loon Translocation

In collaboration with the Minnesota Department of Natural Resources, in 2014, five chicks were translocated from northern Minnesota (Itasca County) and released in southern Minnesota (Le Sueur County). The translocation site was on Fish Lake, west of Lakeville. An additional seven chicks in 2015 and five more in 2016 were released. Overall, 17 chicks were successfully translocated to southern Minnesota. Loon chicks started returning in 2017 based on a sighting of a color-banded loon in the release area. Further survey efforts are needed. Based on results on a loon translocation site in Massachusetts, we expect 40% (7) of the loon chicks will have returned to establish a breeding population in southern Minnesota. Learn more about our Common Loon translocaion methods here.

Recommendations for 2020

Evidence of the loon’s ability to acclimate suggests that properly designed conservation efforts can be beneficial in many instances (Evers et. al 2010). BRI led a project from 2014-2016 to restore breeding loons to southern Minnesota. Surveys in 2020 will measure that success. Over the years, BRI’s research has found the following actions to be successful or have potential for success:

Monitoring

  • Continue and expand the Minnesota Loon Monitoring Program into the south central region of the state.
  • Use standardized survey methods to collect data on the number of territorial pairs, nesting pairs, location of nests, chicks hatched, and those surviving >6 weeks of age.
  • Special emphasis should be placed on the loon restoration area near Lakeville.

Research

  • Determine survival rates, track intra- and inter-seasonal movements for adults and juveniles (using color-marked individuals and transmitters).
  • Assess effectiveness of signs and rafts.
  • Investigate risks from contaminants such as mercury in breeding, staging, and wintering areas.

Outreach

  • At visitor centers in public parks, create greater awareness of the presence and requirements of loons through the use of dioramas, exhibits, communication pieces, and video and slide presentations is needed.
  • The new National Loon Center provides an important gathering place for information dissemination.

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Photo Credits: Header photo: © BRI-Jim Paruk.