Scat, to paraphrase a common expression, happens. Which is a good thing for Splachnum rubrum. More commonly known as red parasol moss, the plant has evolved a peculiar taste in terms of habitat requirements: It grows only in moose dung. As Minnesota's moose population has declined, the delicate moss with spore-producing capsules that resemble tiny umbrellas has been put at risk as well. Now both the moss and the moose have earned spots on the state's list of endangered, threatened, and special concern species. The list has just been updated for the first time in 17 years.
Minnesota's endangered species law requires the DNR to create and periodically revise such a list, and it prescribes three levels of concern. An endangered species is one that is at great risk of extinction within the state, either throughout or within a significant portion of its range. A threatened species is likely to soon become endangered. A species of special concern, though not at immediate risk, is considered vulnerable because of its rarity or highly specific habitat requirements. The law prohibits the taking or possession of endangered and threatened species without a permit from the DNR.
The list is a trove of rare and sometimes strangely named life forms: Roger's snaggletooth snail, spaced-out tangle moss, hairy-necked tiger beetle, purple wartyback clam. It's a testament both to Minnesota's rich natural heritage and to the impacts of an expanding human footprint on the environment. First created in 1984, the list has grown from 290 species of plants and animals to the current total of 590. Based on information from field surveys and other sources, the recent update removes 29 species that have recovered. Those species include the bald eagle, snapping turtle, and wolf. Ninety-one species had their status either upgraded or downgraded. An additional 180 species gained protection.
A species can be put at risk by any of a number of factors, including habitat degradation or loss, climate change, pollution, and persecution. The northern pocket gopher, for instance, has seen much of its habitat plowed up, and some trappers intent on removing what's viewed as an agricultural pest make no distinction between this threatened rodent and its larger, more common cousin, the plains pocket gopher.
Sometimes the cause for population decline is difficult to discover. No one's certain why moose numbers have dropped so precipitously that the iconic mammal has been listed as a species of special concern; the Minnesota DNR earlier this year launched a study to find out.
Ultimately, the list of rare species isn't only about moss, moose, or other individual rare species: It's about preservation of functioning natural ecosystems, which harbor countless organisms interacting in ways that we don't yet fully understand. Aldo Leopold, the father of conservation ecology, once compared species preservation to working on a complex mechanism such as a clock: Eliminate some of the parts and the mechanism may no longer work as intended. "If the biota, in the course of aeons, has built something we like but do not understand, then who but a fool would discard seemingly useless parts?" Leopold wrote. "To keep every cog and wheel is the first precaution of intelligent tinkering."
All of which might make one want to tread lightly in the wild. Walking through the woods of northeastern Minnesota, keep an eye out not only for the root or rock that could cause a fall, but also for the increasingly rare pile of moose dung. The list presents one more reason not to step in it.
Find Minnesota's list and the rare species guide.