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Today I want to celebrate more than four thousand, six hundred reasons for conservation of rivers, lakes, and wetlands in Illinois. You see, four thousand, six hundred was the estimated population of river otters last year in areas where they had been reintroduced by the Illinois Department of Natural Resources in the mid 1990s. That number led scientists to deem the river otter population “widespread and secure,” and to remove them from the list of “state threatened species.”
That’s a remarkable thing to be able to say about an animal with a history like that of the otter in our state.
At the time of European settlement, river otters were common throughout Illinois, but their numbers declined steeply during the nineteenth century, due to habitat loss and unregulated hunting and trapping. By the beginning of the twentieth century, sightings of river otters were rare, and when the species was listed as state endangered in 1989 it is estimated that there were fewer than a hundred river otters in Illinois.
How did we get from fewer than one hundred animals to more than forty-six hundred in just fifteen years? Conditions for rivers otters in Illinois had become favorable again even when numbers were at their lowest. Pollution in state waters had been greatly diminished thanks to the Clean Water Act, and that had allowed populations of fish, the otter’s main food, to rebound. In addition, beavers had come back in the state. Otters favor abandoned beaver dens for housing, preferring not to dig their own, and they also take advantage of the pools and wetlands beavers create for fishing.
Given these conditions, all the Department of Natural Resources had to do was just add otters. Between 1994 and 1997 a total of three hundred forty-six otters that had been trapped in Louisiana were released in appropriate habitat throughout Illinois. The current number of forty-six hundred otters indicates that these animals found everything they needed to make themselves at home. Besides multiplying so quickly, they have surprised biologists by taking up residence even in highly developed landscapes, including the Chicago area.
If you’re familiar with river otters, you know they are fascinating creatures. Strong, graceful swimmers, they are capable of remaining under water for three to four minutes, and traveling as much as a quarter of a mile in that time. In winter they bound through the snow and then slide on their bellies. Otters are also both curious and nearsighted, which is part of an adaptation that allows them to see well underwater, and which also explains why they sometimes come very near people and boats to investigate them.
The successful reintroduction of river otters in Illinois will allow more of us the opportunity to see them for ourselves in years to come, and that’s cause for celebration. But we should count this success as only one step on the road to the ecological recovery possible in our state.
*Credit an Illinois Department of Natural Resources Press Release for this title and the bad pun therein.
Environmental Almanac
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