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A number of small items came to light over the summer, so I am putting them into one column. The ecologist who has been conducting a small mammal study here since 1983 did not continue his work in 2022. He said he had the strength to do the trapping, but not to deal with the MN D.N.R. special permit people. He will be here in late summer or fall of 2023 to pick up the small mammals a number of us have been accumulating for him since the fall of 2021.
Last year I mentioned the migration and major decline of monarch butterfly populations. Overall, monarchs have declined by 85% since the 1990’s. The eastern populations, which over-winter in Mexico, occupied only 7 acres of habitat last winter. The western populations, which over-winter in California has declined by 99 percent. Overall, monarch populations are less than half what they need to be to avoid extinction. The International Union for Conservation has declared them to be endangered and has placed them on its Red List of Threatened Species.
Introduction of exotic animals into the wild has been a problem for many decades. Much of this has been via the pet trade where fish and other species are released by their owners when they no longer want to keep the animals, cannot find someone to take them, or think they are doing a kindness by letting them live free. This has become a major problem in Florida (especially in the Everglades) where large pythons have become very abundant and are disrupting the ecosystem and consuming the food resources of native species. The University of Florida reports that pythons are known to consume 24 species of mammals, 47 species of birds and 2 reptile species.
The first removal of pythons from the Everglades was in 1979. The Conservancy of Southwest Florida started removing pythons in 2013 and has removed 1,000 pythons from 100 square miles of that area. The total weight of the pythons removed is over 26,000 pounds. Burmese pythons caught in Florida are usually 6 to 9 feet long. This year they caught a female that was nearly 18 feet long and weighed 215 pounds. A necropsy of the snake found that its last meal was an adult white-tailed deer. That puts it in the category of being dangerous to humans, especially children.
How they catch these snakes is very interesting. They capture male pythons, fit them with radio transmitters, release them and track their movements. The males seek out large reproductive females; the researchers follow the radio signals and find the females and their nests. By focusing on large females, they not only remove her, but also all of her eggs. Hopefully that can eventually get them under control, but it must be a continuing program as there is no way to completely eliminate the snakes.
Another species that causes a great deal of damage where it has become established is feral (wild) hogs. Minnesota D.N.R.’s Conservation Volunteer had an excellent article on them in the May-June 2022 issue. They are extremely invasive: they eat nearly anything dead or alive – including agricultural crops. They reproduce prolifically and cause soil erosion through severe habitat damage to streams, wetlands, and upland vegetation. Cropland damage is estimated at $1.5 billion by the approximately 6 million feral hogs in the U.S.
Females can give birth at 6 months of age and have two litters of 4 to 12 piglets per year. Population control is extremely difficult as they are also very intelligent and quickly learn how to avoid danger from humans, especially hunters. Many southern states have severe wild hog problems, but so do some northern states such as Michigan.
Minnesota has had a number of incidents of feral hogs, but has been successful (so far) in eliminating all of the hogs involved. The Minnesota Feral Swine Working Group (MN D.N.R., MN Board of Animal Health, and U.S.D.A. Wildlife Services) meet regularly to stay up to date on the matter and recommend actions. When it comes to feral hogs, elimination is the only way to prevent them from becoming established. U.S.D.A. Wildlife Services is very effective in getting all of them.
In Minnesota it is illegal to possess, release, or allow feral swine to run at large (Minnesota Statute 97A.56). Violators are subject to fines. It is also illegal to shoot wild hogs in Minnesota. Shooting some only makes them more wary and elusive which results in it being far harder for authorities to eliminate them all. All sightings need to be reported so they can be dealt with appropriately.
In some states, hunting of wild hogs has become popular. This compounds the feral hog problem. Hunters are not willing to put in the effort necessary to kill them all. When it gets less likely to see them in an area, hunters switch to different areas where they will have better chances of success; this makes it very easy for the remaining hogs to repopulate the area. Even worse, sometimes hunters have introduced larger breeds of hogs that are even more dangerous to humans. All hogs can be very dangerous when angered, but some breeds are especially so. Also, all hogs grow tusks which can be quite sharp and inflict serious wounds. Tusks are usually cut off when hogs are raised in captivity.
I grew up in a farming community where nearly every farmer raised, at least some, hogs. All visitors were told to never get into the hog pen, especially if a sow had piglets. I never knew a farmer to go into the pen when feeding the pigs. They always stayed outside of the fence and poured the feed through the fence and into a trough just inside the fence.
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