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Loon research at Big Mantrap

Dr. Darryl Heard prepares a sedated adult male for the surgically implanted GPS unit. (Steve Maanum / For the Enterprise)1 / 2
The captured chicks receive color-coded leg bands. One loon was recently tracked to Leech Lake. You can follow the Mantrap adventures online at On the site's map, follow the "M" loons. M9 is the one that has migrated to Leech Lake.2 / 2

Loons have always been one of my favorite photo subjects. I spend countless hours each spring and summer documenting their habits.

Their welfare is important to me so I strive to photograph them in ways that will not cause them stress.

Wildlife photography, when properly used, can help uncover facts about lead to new and better management techniques.

In July Kevin Kenow (research wildlife biologist), Steve Houdek, Luke Fara (biological technicians), and Dr. Darryl Heard (veterinarian) stopped in Park Rapids with the sole intention of capturing loons.

They had just spent a few nights on lakes in Tamarac National Wildlife Refuge where they captured three adult males, two adult females, and three chicks; now they were hoping to add to that number.

Mantrap Lake was chosen as one of the capture sites because of the very active loon nesting program that has been conducted by a group of lake residents for a number of years. Lyle Laske and Arlis McGinnis are two members of that group and they assisted Kevin and the research team that night, as did Rob Naplin (DNR area wildlife manager) and Pam Perry (DNR non-game division).

I went along to photograph the various phases of the adventure. It's all part of their research project that will track the migration routes of loons from Minnesota, Wisconsin, and Michigan.

We know that some of our loons migrate to the Atlantic coast and some migrate to the Gulf of Mexico, but what routes do they take and what do they encounter along the way?

Outbreaks of type-E botulism in the Great Lakes have been recorded since the 1960's and it has resulted in the deaths of fish and the birds that eat fish. The reasons for the outbreaks and the actual locations where the birds are being exposed to it are not clear.

One of the goals of Kevin's research project is to gain a better understanding of this toxin and how it is being spread through the Great Lakes food web.

The capturing takes place at night. As Kevin and Steve headed out in the research boat.

Luke and Darryl stayed behind to prepare their mobile lab for the examinations and surgeries that would take place. Adult males received a surgically implanted GPS unit that will provide valuable data for the scientists.

The GPS unit will be inside the loon, but the antennae will be visible from the outside.

Adult females received geo-locator tags on their legs that will provide information about location, tag temperature, and dive depths. Although they are not as accurate as the satellite transmitters, they will still give approximations of migration routes and wintering locations.

Body mass is measured on all captured birds and standard measurements are taken on the adults. Blood samples are collected from most birds and, when possible, a fat sample is collected from the adult males during the surgery procedure.

The samples are analyzed for mercury and other metals, and in some cases they are checked for oil and dispersant residue.

The night on Mantrap was very productive. Fourteen loons were captured. Five males were sedated before they received their surgically implanted tracking devices, three adult females were given geo-locator tags, and six chicks now wear leg bands.

Young loons don't return to their northern breeding range until their third spring so the first few years of their lives are spent in the coastal areas. These loons may provide valuable information on the possible effects of contaminants in the Gulf waters.

A website has been established where anyone can track the movement of these adult males. It is www. on the loon study.