Lead Poisoning and Montana's Loons

Lead is cheap with a long tradition of use in fishing tackle. Many western societies have eliminated it in paints, gasoline, solders and in shot for waterfowl hunting. Despite this, lead products continue to be used for angling.

Although lead is toxic to all wildlife, birds hold lead objects in the gizzard rather than passing it through their system, making them particularly at risk. Lead poisoning is a leading cause of mortality in adult common loons. One recent New Hampshire study found that between 1989 and 2012 nearly half (48.6 percent) of the adult loon mortalities were from lead. In New England, another study revealed that between 1987 and 2000, of the 522 dead loons collected, 222 had died from lead poisoning. It doesn't take much lead to kill a loon either. Most of the lead objects found in these dead birds were less than 2.5 centimeters long and less than 25 grams.

Loons ingest lead tackle in a variety of ways. They can ingest a fish that has swallowed lead jigs or sinkers. Loons have also been documented stealing fish on a line. Loons also pick up and swallow gravel to help digestion and may pick up lead sinkers by mistake. The largest pebble found in a loon's stomach was 23 millimeters.

Once ingested, the lead sinker/tackle goes into the loon's gizzard. The acid and grinding action of the gizzard quickly erodes the lead.

As the lead breaks down it passes into the bloodstream and poisons the loon. The bird becomes uncoordinated and soon can't fly, dive or catch prey. This progresses to weakness, tremors, gasping and muscle paralysis. A loon in late stage poisoning may hide among aquatic vegetation or pull themselves up on shore. They may stay behind while other loons migrate. Soon it becomes emaciated and dies within two to four weeks after swallowing the lead.

Lead poisoning is diagnosed with the help of x-rays which reveal the lead the loon was carrying. Analyzing blood, liver or kidney tissue will confirm the cause of death. If you see a dead loon, please contact the Montana Loon Society or the Common Loon Working Group.

Eliminating lead tackle under 25 mm in size would go a long way towards protecting loon populations. Many Eastern states have laws prohibiting the use and sale of certain lead sinkers and gigs that have a total weight of one ounce, which is 28 grams.

Inexpensive alternatives such as steel, brass, tin, ceramic, glass, granite and bismuth exist. Some alternatives are harder and smoother and less likely to get hung up on rocks. Some are denser providing a smaller profile. Some have a lower melting point, which allows for finer detail. Some make more noise and act as a fish attractant. Ask your local store to carry lead-free tackle, then experiment to find what works best for your type of fishing.

Go through your tackle box and remove old lead tackle. Dispose of it properly at household hazardous waste collection sites. Never throw old tackle in the water or on shore. To insure that future generations hear the call of the loon we need to safeguard the environment. Even if you don't fish, share this information with family and friends who do. Just tell them to "Get the lead out!"

Blackfoot/Clearwater (Ovando/Seeley Lake) Loon Report

In 2017, Loon Ranger Keeley Benson surveyed thirteen lakes in the Blackfoot/Clearwater region. The Clearwater had four nests that produced six chicks with two chicks each on Placid and Rainy lakes and one chick each on Seeley and Clearwater. Summit Lake was the disappointment as it has regularly produced chicks for the past few years. Lake Alva also remained "off-line" for chicks, which has been the case for several years.

In the Blackfoot, three lakes often have nesting pairs. Upsata Lake was the only one that produced chicks in 2017, hatching two chicks that survived until July Loon Day. We credit that success in part to Barry Gordon, the new caretaker at Upsata Lake Lodge, which is now a new Private Lands Office for US Fish and Wildlife Service.

After losing Salmon Lake's loons in the Clearwater Drainage system to the west, Upsata is now the most southern loon lake in Montana and as such, is an important linkage lake for loons to the south.

For his work, Gordon received the 2017 Volunteer of the Year Award. MLS President Lynn Kelly said, "Barry's help with assembling the new buoys for the Clearwater/Blackfoot area and for his care of Upsata Lake loon's area are very much appreciated. It's great to have new people stepping up the plate for the cause of loons."

Swan Geographic Area

In 2017, 17 lakes were surveyed by Loon Ranger Alissa Anderson. Four known nests were found but only two chicks hatched and survived on Loon Lake (Ferndale). Chicks may have hatched at Pierce and Loon Lake (Kraft Creek), but then were predated. Van Lake had no eggshells, so that nest failed before hatching.

Six other lakes received loon foraging use including: Swan, Meadow, Lindbergh, Shay, Cygnet, and Crystal. In this area four unbanded adults were confirmed and six banded.

2017 Clearwater/Blackfoot Loon Chick Count at a Glance

To quickly see how our Blackfoot and Clearwater loon neighbors faired last year, take a look at the included chart. Bumps and dips naturally occur in loon numbers. Nationally, one in four nests fails naturally. In Montana, flood years are a major cause in the drop in chicks, but not all areas flood the same year. It is only cause for concern if numbers drop and drop without bounce-back.

Even with these dips and rises on local lakes, chick numbers in Montana have remained roughly the same with an average forty-one chicks per year, which is considered a viable loon population. 2017 was a slightly above average year with 48 chicks that survived in the state until the July Loon Day count and are assumed to have migrated in autumn.