| Common Moorhen, plains pocket mouse found at refuge |
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By Joel Stottrup The Common Moorhen and a plains pocket mouse are among species that have recently grabbed the attention of Sherburne National Wildlife Refuge staff members, along with various insects. Even a wetland plant, the monkeyflower, has drawn attention for the same reason. None of these species had been noticed at the refuge until the last couple of years. Staff members at the refuge keep a list of wildlife sighted there and it becomes a big deal when they can add new names to it, says Ann Sittauer, manager of the 30,700-acre refuge near Princeton. “We found so many in a short period of time,” Sittauer exclaimed. “It’s unusual to find new species (meaning new to the location), especially mammals.” The plains pocket mouse, roughly five inches long, is a peach-colored mouse that dwells underground. For a long time it had only been found in Arden Hills. Also significant, she said, is that the plains pocket mouse was found at several places on the refuge. That means, Sittauer said, that it has a thriving population in Sherburne Refuge oak savanna habitat. Also the fact that “charismatic mega fauna,” or attention-getting big animals, have been found at the refuge is significant, Sittauer said. When the U.S. Fish & Wildlife Service established Sherburne National Wildlife Refuge in 1969, she said, bald eagles, swans, wild turkeys, coyotes and gray wolves (also known as timber wolves) weren’t seen there. But all of those have been seen on the refuge since, she said. The number of nesting pairs of bald eagles has increased greatly over the years at the refuge, according to annual reports by staff members. Sherburne Refuge wildlife biologist Lizzy Berkley noted that the plains pocket mouse is listed as rare, and that the Common Moorhen isn’t usually found this far north. A pair of Common Moorhens with chicks were found at the refuge. Finding more species that are new to the refuge is great because it “adds to the biodiversity,” and is indicative of the health of the refuge’s habitat, Berkley added. “Any new species we find,” she said, “helps us key into how we’re doing with the habitat management at the refuge.” Nongame wildlife specialist Liz Harper was the one who discovered that the plains pocket mouse species was on the refuge while working on a DNR survey of what it calls Species of Greatest Conservation Need. Harper said this species of mouse was actually found during survey work last year and then again this year. The plains pocket mouse inhabits the Great Plains and intermountain basins from Minnesota, southwest to Texas and southern New Mexico. It is mainly distributed east and southeast of the state of Wyoming, but has also been found in the southeastern part of Wyoming, where it is still considered rare. “They’re actually very cute,” Harper said of the plains pocket mouse. “They are very small and have external cheek pouches for storing food.” The refuge’s Anoka sand plain soil makes for good burrowing for the animal, Harper said. She noted that the mouse has separate underground chambers for food and nesting and that they mostly stay underground. They can be predated underground by bull snakes and western hog nose snakes at the refuge, Harper noted. The Common Moorhen’s markings The Common Moorhen, meanwhile, is the most widely distributed member of the rail family, according to the Cornell Lab of Ornithology. It inhabits marshes and ponds from Canada to Chile, from northern Europe to southern Africa and across Asia to the Pacific, according to Cornell. The Common Moorhen has long toes, making it able to walk atop floating vegetation and its body has contrasting colors. The beak has a yellow tip, otherwise the rest of the beak is a bright red. It has yellow legs, and most of its body is dark feathered, with some striking white touches on the wings and tail. The Common Moorhen has a wide range of gargling sounds and sometimes will hiss when threatened. The birds seen at Sherburne Refuge months earlier, have long since headed south to a warmer clime. Two other new finds at the refuge this year, said Harper, are the Northern Barrens Tiger Beetle and a species of jumping spider. Harper said the DNR had no record of those two existing in the Sherburne Refuge before. Minnesota lists both as species of special concern. Monkeyflower, a surprise Refuge biologist Berkley noted that this is the first year that the refuge has had a wetland health evaluation survey. “Basically we want to measure the macro invertebrates and vegetation in the refuge’s wetlands,” Berkley said, “and get an idea of how much of each species there is.” Surveyors then place the data into a model and come up with an index of biological integrity, Berkley continued. The higher number that results, she said, the healthier the wetland is rated. Macro invertebrates include water bugs, snails, dragonfly larvae, and fairy shrimp. Although they can be seen by the naked eye, microscopes are needed to identify them, she noted. Berkley also talked about the monkey flower, a wetland plant with some light purple flowers, recently found at the refuge. The idea is to see how the wetlands are as habitat and if the refuge needs to adjust its management such as how it lowers and raises its water impoundment gates, Berkley said. “It’s nice to get baseline data,” she said. “It is really needed.” Another professional who has been working recently at the refuge, in this case as part of a DNR project to understand how to manage a healthy oak savannah, is DNR regional plant ecologist Hannah Texler. Texler, reached by phone on Monday, said that part of that project is planting vegetative plots to try to understand the quality of the vegetation and observe the animals that live in it. The oak savanna that is found at Sherburne Refuge is “incredibly rare,” and is classified, by a group called Nature Serve, as “globally imperiled,” Texler said. In order to keep the oak savanna maintained, she said, it has to have prescribed burns, something the refuge staff does by rotating the areas of the refuge that receive fire once about every four years. Dragonflies and damselflies And it isn’t known how many species of dragonflies and damselflies are at the refuge, but a group began trying to track them at the refuge last year as part of the Minnesota Odonata Survey Project. Project staff members organized a workshop on Aug. 9, 2008, at the refuge in which 16 people came out to collect and record odonata, which refers to dragonflies and damselflies. Dianne Rowse, who is a former interim coordinator for the project, said last week that nine kinds of dragonflies and the same number of damselflies were found at the refuge during the workshop. “There was a pretty good list of specimens to collect in one day,” said Rowse. Both dragonflies and damselflies have six legs and three body parts. Dragonflies are robust, big and chunky and when they rest their wings stick straight out, Rowse noted. Damselflies, she noted, are more needle like and petite and their wings fold over their back when they rest. Between the dragonflies and damselflies found that day, five made the record book for Sherburne County, meaning they were documented in the county for the first time, according to Rowse. Rowse described dragonflies as “just beautiful,” and “just incredibly built.” It is until you put them under a dissection- type microscope that their parts become more understandable, she said. She noted that their bodies are engineered very well, having legs with long spines that trap mosquitoes and other bugs. She also has found the damselflies beautiful, noting one type called a rainbow bluet that she says has “all colors of the rainbow” and are only found in a couple counties. In order to encourage the numbers of dragonflies and damselflies, the wetlands have to be protected, Rowse said. One way, she said, is if someone has property with wetlands, they should leave tall grass around the wetland as a buffer to keep chemicals from flowing into the water. Rowse, who works in park service in Carver County, was asked if she has noticed any trends in the population of dragonflies. There was an “incredible number” of dragonflies eight years ago but not as many since, she answered. It appears multiple agencies are interested in such facts. Rowse noted that the Odonata project got support from multiple agencies. They included the U.S. Fish and Wildlife Service State Wildlife Grants Program and the Fish Heritage Enhancement Fund through the Minnesota DNR’s Division of Ecological Resources. Comments (0)
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