Natural Curiosities

Q. Late last summer I watched a squirrel eat seed on our bird feeder. As he sat back on his hind legs, one leg would start to come up until he toppled over. He would start to fall off the feeder, then catch himself and start the process over again. Later, while sitting on our deck, he did not seem to have the same problem. Could he have had a reaction to the height of the feeder?

Cathleen Hauenstein
Eagan

A. More likely he was a bit tipsy, speculates DNR wildlife educator Jan Welsh. Crab apples and other fruits can start to ferment in hot weather, and the alcohol that builds up can affect birds and small mammals that eat them. The squirrel's rapid metabolism might have helped him sober up by the time he made it to your deck.

Q. My husband and I visited a state park in northwestern Minnesota last May. I found four or five ticks on me, while my husband discovered at least 20. Why did they prefer him? I was wearing dark clothing and his outfit was light-colored.

Karen de Boer
Glencoe

A. Your husband's superior success in catching ticks was probably due more to hiking style than to clothing color, says University of Minnesota entomology professor Timothy Kurtti. In shrubby or grassy areas, ticks climb to the tops of vegetation and sit there waving their forelegs around, waiting for something warm and blood-filled. Hikers who stray from the trail or tend to brush up against tall grasses and bushes are more likely to pick up ticks than those who stick to the middle of the path.

Q. When tracing a stream to its origin, how does one determine which is "top dog"? At the origin of the Mississippi, I saw two streams that could have been the origin. And where the Missouri joins the Mississippi, how did someone decide which was the Mississippi and which was the tributary?

Kenneth Jefferson
St. Paul

A. In the case of the Mississippi River, the "top dog" is Lake Itasca. According to Glen Yakel of DNR Waters and Bryce Anderson of DNR Parks, surveyor Jacob V. Brower, who in the 1890s characterized Lake Itasca and its watershed as "the greater ultimate reservoir bowl at the source of the Mississippi River," acknowledged that several small streams flow into Lake Itasca. However, he said because they were merely creeks and not rivers, the true source of the Mississippi River is Lake Itasca.

According to Yakel, when two rivers meet, the united river downstream usu-ally takes the name of the larger of the two rivers. The Mississippi River is larger by volume than the Missouri River at the rivers' confluence.

Q. What has happened to the muskrat population? In the 1940s every pond had a muskrat house. Now I see none.

Elizabeth Nelson
Minnetonka

A. Muskrat populations fluctuate with disease and weather conditions, says DNR furbearer specialist Conrad Christianson. The low levels in recent years are due mainly to drought. "They'll be back," Christianson says.

Q. A hawklike bird had been standing in the same place all day. When my wife approached the bird, it turned its head toward her and began a soft peeping. An osprey nest is nearby. Was the bird injured or had it fallen from the nest? Should we have left the bird alone, or taken it somewhere?

Dick Broen
Bemidji

A. If you see no major injury, leave an animal where it is, says DNR wildlife educator Jan Welsh. If a chick falls from a nest, the parent birds will continue to feed it. If the bird you saw had feathers, it may have been learning to fly. At this stage young birds spend a fair amount of time sitting on the ground or near the nest trying to get the hang of things.

Q. When I lived in north-central Minnesota, our garage had a motion--detector light. Several evenings I observed a big brown bat swoop in, causing the light to come on. It would then make several runs under the light, apparently catching insects. If it left for a couple minutes, the light would go out. Again the bat would come in and on would go the light. What do you think-smart bat, or just dumb luck?

Steve Palmer
Montello, Wis.

A. DNR nongame wildlife expert Steve Kittelson says he's seen swallows get to their nest in The Home Depot by swooping past the motion detector that causes the door to open. He's also seen swallows flying around a closed barn, even though it didn't have a motion detector. Because insects congregate on the sides of buildings for shelter, they might come around your garage even with the lights off.