Got a question for Ask MDC? Send it to AskMDC@mdc.mo.gov or call 573-522-4115, ext. 3848.
Q: I was at Klepzig Mill last February, and we noticed five or six crayfish climbing up a waterfall from a lower pool. The rock face was nearly 6 feet tall. Do crayfish climb like this for spring mating or for some other purpose?
MDC’s staff have observed this same crayfish behavior firsthand. Former MDC Scientist Bob DiStefano, now retired, also witnessed the same event during the spring at Rocky Falls, Missouri’s tallest waterfall near the Current River.
“It is now apparent to me this phenomenon is actually a real and reoccurring natural event for crayfishes, at least in our Ozark streams,” DiStefano said, noting that most of the reports have occurred in spring.
Why these crayfish are on the move remains a mystery to science — for the time being. DiStefano thinks the movement might be linked to feeding or reproduction, or both. It’s possible egg-carrying females “migrate” to ensure their progeny are dispersed for the purpose of genetic mixing.
“We have some telemetry tracking data from some Ozark stream crayfish in the St. Francis River drainage, showing that they do move fairly good distances,” DiStefano said. “I have also heard reports of large numbers of crayfish crossing roads at low-water stream crossings, appearing to migrate upstream. But honestly, I don’t have a confident opinion of what we’re observing. There are so many cool and fun natural events going on that we don’t even know about yet.”
Q: Three times over the course of our four-day float on the Eleven Point River last January, I encountered otters swimming alongside my canoe, dolphin-like, occasionally doing flips. It seemed they might be begging for food. Do river otters beg for food on this river?
Of all the mammals, otters are particularly playful and curious. When in the water they tend to be the most relaxed mammal, since few if any other predators can catch them.
“I have heard of otters approaching canoes and kayaks out of curiosity since they likely would not view boats as a risk. But I have not heard of otters begging for food,” MDC Scientist Nathaniel Bowersock said. “My guess is your float was well timed with these otters patrolling their usual fishing spots, and you both were using the same parts of the river at the same time.”
During winter, otters feed almost exclusively on fish. However, crayfish make up a large portion of their diets during other seasons. While the fishing habits of otters do not endear them to anglers, it must be realized otters eat rough as well as game fish and take many other kinds of food, including mussels, frogs, turtles, aquatic insects, and other small animals. They use their whiskers to feel around underwater to find food. Research suggests that they have minimal impacts on fish populations in large streams, rivers, and lakes but may impact fish populations in small streams and ponds. If you are experiencing difficulties with river otters, please contact MDC for guidance on how to better control them.
For more information about Missouri’s North American river otters, visit short.mdc.mo.gov/4kS.
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This Issue's Staff
Editor – Angie Daly Morfeld
Associate Editor – Larry Archer
Photography Editor – Ben Nickelson
Staff Writer – Kristie Hilgedick
Staff Writer – Joe Jerek
Staff Writer – Dianne Van Dien
Designer – Marci Porter
Designer – Kate Morrow
Photographer – Noppadol Paothong
Photographer – David Stonner
Circulation – Marcia Hale