The Wonderful Watery World of the Watershed
Did you know that the type and number of water creatures can tell a lot about the health of the watershed? The Sugar River and its tributaries are home to many different macroinvertebrates. These are living things that do not have a backbone and are large enough to see without a microscope. As part of our WAV Level 1 water quality monitoring, we do biotic measurements to gauge macroinvertebrate species diversity in the watershed.
The best way to collect these tiny critters is to use a net and place them in a shallow white pan filled with water. Plastic dishpans work well. Many of these creatures eat small plants and decaying organic matter in the water, though some are predators, and many are food for larger animals in the water. Worms, like bloodworms, midge larvae, and blackfly larvae, are very tolerant of pollution and can live in almost any freshwater. Others, like various mayfly and stonefly larvae, need water that is clean of chemical and particulate pollutants, including sediments, and their presence indicates very clean systems. Two common macroinvertebrates found in our local waters are scuds, small invertebrates that swim on their sides, are related to shrimp, and grow up to a quarter of an inch, and crayfish species that range from half an inch to 6 inches in length.
Freshwater mussels are present in the Sugar River, and because they filter their food from the water, they can be used as biological indicators of water quality. Biologists collect mussels found in the water, note the species, size and number of each, and replace them in the water. Some species are more tolerant of pollution than others, so depending on the species that are found, mussels can tell us a lot about what is happening in the water.
Fish species prey upon the macroinvertebrates and smaller fish in the river. Common native species in the Sugar River include bluegill, catfish species, crappie, catfish species, largemouth, smallmouth and rock bass, walleye, drum, and even northern pike and muskies. For all your fisher folk, refer to posted creel limits when fishing and be sure to have a fishing license for Wisconsin or Illinois, depending on where in the watershed you plan to try your luck.
Reptiles and Amphibians
Reptiles, turtles, and snakes use the Sugar River to hibernate, hunt food, swim, and bask in the sun. The two local species of venomous snakes, the Massasauga and Timber Rattlesnakes, tend to live in sparsely-populated areas around the Wisconsin and Mississippi Rivers, so chances are low that you will encounter one of these. The Common Water Snake is often seen swimming in the water searching for fish and crayfish to eat, or basking in the sun. These snakes, which are dark to copper-colored, are harmless but have a quick temper. Have no fear - the Sugar River is too far north for copperhead or water moccasins! 
If you go in search of other snake species, you may encounter Eastern Hognose snakes, Fox snakes, Milk snakes, several species of Garter snakes, Northern Redbelly snakes, small Little Brown Snakes, and, of course, Northern Water snakes.
Many turtles, both aquatic and land species, call the Sugar River watershed home. Turtles you are likely to see on and around the river include snapping turtles, painted turtles, and softshell turtles. Turtles tend to lay their eggs early in the summer, and the young hatch in the fall. You are likely to see turtles basking in the sun on warm days, or floating with their heads and nostrils out of the water, but be cautious if you want to get up close for a good look. Turtles are shy and will retreat quickly under the water if they feel threatened. Most turtles are omnivores that usually eat more animal material when they are young and growing more quickly, and turn more to plant foods as their growth slows. Some, like snapping turtles, prefer animal-based food their entire lives.
The Blanding's Turtle has a protected status in our area. You will notice them as they have a common practice of sticking their head up and out of the water showing off their bright yellow throat. This coloration helps them blend in with flowering water lilies. The Sugar River watershed is also home to the Ornate Box Turtle, an endangered species in the state. Ornate Box Turtles are a land species with a high-domed shell that closes completely to protect them. They prefer the sandy soils of the region to search for food and dig winter burrows.
Amphibians and reptiles are common sights in the watershed in the warmer months, both in the water and on the land. Listen for smaller tree frogs as early as late March. Frog and toad species, in the order in which they call in the spring, include wood frog, chorus frog, spring peeper, northern leopard frog, pickerel frog, American toad, Eastern grey treefrog, Blanchard’s cricket frog, green frog, and bullfrog. 
Salamanders are nocturnal amphibians, so look for these carefully. In the watershed, there are blue-spotted salamanders, Eastern tiger salamanders, and central newts.