Q. I've heard loons mate for life and always go back to the same lake. Is that true? At our cabin, sometimes I see 12 to 20 loons together in the middle of the lake. Do you know what they're doing?
A. Loons often pair with the same mate as in previous years, but not consistently enough that you could call it mating for life. Bird banding records show they do often go back to the same lake year after year. In fact, DNR wildlife educator Jan Welsh says they're probably more loyal to the lake than to the mate. Loons gather in groups in late summer in preparation for fall migration.
Q. I saw a kingfisher land on a tree with a small crappie in his beak. First he took it by the tail and slammed it on the tree limb. Then he took it by the head and did the same. Was he tenderizing it for young ones?
A. Good guess, but probably not. Kingfishers commonly beat a fish on a tree branch or rock after they catch it. This immobilizes the prey, making it easier to eat.
Q. Has an environmental study ever been done to determine if antibacterial soaps damage our environment? Do they affect the sewage treatment process?
A. A number of studies have looked at possible environmental impacts of antibacterial chemicals in soaps, toothpaste, kitchen cleansers, and other products. Some people worry the chemicals could cause problems such as killing soil bacteria and increasing antibiotic resistance in bacteria that infect people, but there is no consensus on the issue at this time.
Excessive use of antibacterial products can harm the bacteria in septic systems, according to the University of Minnesota Extension Service. Tim O'Donnell, senior information coordinator for Metropolitan Council Environmental Services, says the concentration of antibacterial soaps in municipal wastewater appears to be too small to affect the municipal wastewater treatment process, but the industry continues to follow the issue. "It's probably best to use the minimum amount necessary, and apply a little extra, environmentally friendly 'elbow grease' when needed," O'Donnell recommends.
Q. I collect slugs, but they die after a day or so. What do slugs eat? How long do they live? Are they related to leeches?
Rosie Richardson, age 4
A. Most slugs eat plants and decaying stuff on the ground. They can live up to a year. University of Minnesota extension entomologist Jeff Hahn thinks your slugs may be dying due to lack of moisture. He suggests that next time you catch a slug, place it in a container with leaves and a little soil and keep it all damp (but not wet).
Slugs and leeches are related, but not very closely. Slugs are mollusks, like snails. Leeches are annelids, like earthworms.
Q. In several small lakes I catch large bluegill in the fall but only small ones in the summer. The lakes are connected to larger bodies of water. Are these bluegills migrating from the larger waters?
A. They're likely moving in from deeper water, either in the small lakes or the larger ones, says DNR aquatic education specialist Roland Sigurdson. During the hot days of summer after spawning, big bluegills like to hang out at depths of 10 to 12 feet near some type of structure. In fall they move to shallower sheltered spots, usually 8 to 10 feet deep.
Q. I have been told red squirrels castrate gray squirrels. If true, why?
A. This is not true. The legend that red squirrels castrate gray ones has been around a long time. It probably arose because gray squirrels retract their testicles into their abdominal cavity when it's not breeding season, so they might look like they're castrated.
Q. In my acute care clinic in late August, I see a lot of patients with hornet stings. Many seem to become infected or have a flare of inflammation. Do hornets feed on carrion or have traits that cause their stings to become infected?
A. Yellowjackets, paper wasps, and baldfaced hornets don't usually eat carrion, says University of Minnesota extension entomologist Jeff Hahn. In summer they mostly feed on fruit juices and catch insects to feed young. In fall, paper wasps, yellowjackets, and baldfaced hornets aren't often seen. However, aggressive German yellowjackets do gather food from picnics, trash, and fallen fruit in fall. Hahn doesn't know of any research regarding yellowjackets transferring germs. But, he adds, it's reasonable to expect that they could pick up bacteria and later spread them to humans.