I know this is an old story, and I probably sound like a broken record, but facing this problem every day has left me fatigued; hopefully, this post will be cathartic and result in even a few more people becoming aware of this problem.
A few weeks ago, we admitted several Canada Geese that were found weak in the same area in North Mankato. Along with these geese were several dead ones, all in the same area.
After exams and tests, we found that all the geese had lead toxicity. Radiographs (x-rays) revealed tiny lead shot in all of their ventriculi (gizzards or stomachs). The radiograph below of one of these geese shows the tiny pellets in its system (they’re the brighter white round balls):
Below is a close-up of the lead
This radiograph is odd because there are so many, uniform lead pellets in the stomach of these geese. One might think this is because hunting season recently finished and these geese have been shot; however, these metal pieces are in the gastrointestinal (GI) tract of the geese, meaning they had to eat it. If the geese had been shot, we would see metal shot in the muscles, bones, etc, but not this many in the GI tract. Also, lead only causes toxicity when it is in the GI tract because the stomach acids break it down and then it is absorbed. Lead shot lodged in a muscle or other tissue doesn’t cause lead toxicity because it doesn’t break down and enter the blood system.
To illustrate the uniqueness of these radiographs, check out the one below of a Trumpeter Swan we admitted last month with lead toxicity.
The metal in this radiograph is definitely not uniform! And check out the close-up of the metal below.
You can almost make out bent hooks, large sinkers and even a small spinner!
We admit >30 swans each fall/winter, and almost all have lead toxicity. Trumpeter Swans ingest lead fishing tackle and shot that they see at the bottom of bodies of water when they have to forage in shallow areas for food. Typically, they eat aquatic vegetation, some insects and have even been seen eating fish when vegetation is low. During the winter, when all the vegetation is gone, they end up looking on the bottom of lakes and rivers. If that body of water has been fished in, there is lead tackle sitting on the bottom. The swans see something shiny, mistake it for a minnow and eat it.
They also ingest small pebbles, or grit, to help their gizzards perform correctly. When they’re picking up small pebbles on the bottoms of the lakes and rivers, if pellets are present they just get ingested with everything else.
Canada Geese, however, are grazers. They typically eat grass and other greens found on land/shoreline. So how were these geese eating so many uniform lead shot? Was someone poisoning them? Did some shot accidentally get dumped outside? I was thoroughly confused until a former conservation officer mentioned how the waves on a river/lake can wash spent shot up on the shoreline into piles. Sure enough, check out the image below that I found online:
LEAD SHOT IN A HEAVILY USED TRAP RANGE FALL ZONE (courtesy of Nebraskalandmagazine.com http://outdoornebraska.ne.gov/blogs/2010/08/toxic-game-part-ii/)
Even though it is illegal to hunt waterfowl with lead shot, some people still do. Lead shot is still often used to shoot clay pigeons at shooting ranges, which is legal. The shot accumulates at these areas in such a concentration that any animal that grazes could accidentally eat enough to cause toxicity.
To treat our geese, we flushed the lead out of their gizzards and found not only were they impacted with grass but also sand. Geese and other birds who graze use rocks and sand to help grind the greens up in their gizzard. These geese were probably grazing on a shore line or shooting range and accidentally ingested the lead shot, mistaking it for a small rock.
Watching almost a dozen of these geese, >30 swans each winter and hearing about the dozens of bald eagles admitted each year to The Raptor Center with lead toxicity makes me wonder why it is still legal to use lead fishing tackle and lead ammunition? Fortunately, our state DNR is also concerned and is working with retailers to encourage hunters to switch to non-lead bullets. Here’s an article about the plight of Bald Eagles.
So what can you do? You can help spread the word by sharing this post via Facebook and Twitter.
Have a conversation with family and friends who hunt and fish. Ask them to use non-lead alternatives or better yet: give them the gift of non-lead items for birthdays, holidays or to celebrate the opening of the various sporting seasons.
Here’s more information on these alternatives:
Deer hunters can easily switch to copper and steel ammunition. And, in fact, copper ammunition is actually more accurate and it penetrates better than standard lead bullets. Here’s an article from WCCO on this option.
Unsure where to get non-lead ammunition? The bottom of this website has several manufacturers listed, and a simple Google search of non-lead ammunition yields hundreds of results.
If you fish, non-lead fishing sinkers are available alongside the lead fishing sinkers at your local sporting goods store for only pennies more.
More information regarding lead toxicity in Minnesota wildlife can be found on the MNDNR website.