When you think of Iowa, you probably don’t immediately think of wetlands. You might think about corn, or even tallgrass prairie, but there are actually hundreds of wetlands across Iowa, including those at Whiterock Conservancy. Wetlands are very important ecosystems that provide services like flood protection, water quality improvement, recreational opportunity, and are also critical habitat for many species of fish and wildlife.
Most of the wetlands that used to be common across northern and central Iowa were drained for agricultural use, but in the past few decades, there has been a large movement to restore wetlands on Iowa’s landscape in order to create areas of high-quality habitat for wildlife such as birds. In fact, one way that scientists can determine the health of these wetland systems is by studying which birds are using the landscape; birds can be indicators of ecosystem health, and in turn contribute to the health of land by providing ecosystem services like seed dispersal, pollination, and pest regulation. Birds are also important culturally and recreationally.
This spring and summer, Whiterock Conservancy were part of a larger ongoing study through the USGS Iowa Cooperative Research Unit at Iowa State University. I am a Master’s student advised by Dr. Anna Tucker at Iowa State University, and this is what my graduate degree revolves around. I am studying birds at restored wetlands to learn which species of birds use these sites. With this information, I hope to learn which management practices (e.g., prescribed burns, invasive species removal) lead to greater diversity of birds. I am especially interested in how bird Species of Greatest Conservation Need (SGCN) use these sites; SGCN are species that have been identified as rare or in-decline in Iowa.
What does this type of work entail? My team typically starts our day around 4 A.M. to allow plenty of time to travel to our different sites, and hike to the first survey points. Surveys begin 15 minutes before dawn, so this takes careful timing. Depending on its size, each site contains 7-10 survey points. Once at the point, the surveyor stands still and quiet for two minutes, which allows birds to get accustomed to their presence and resume their typical behaviors. Once the two-minute settling period is done, the survey starts. The type of survey we do on this project is called a point-count survey, in which the surveyor stands at an exact point and identifies and counts each bird they can detect.
Several challenges come with surveying birds: most are small, fast, camouflaged, or some combination of the three. Because of this, the majority of birds on our surveys are actually identified by their sound. It takes a lot of training to do this type of bird survey; each surveyor must be able to identify over 100 species by sight and sound. Surveyors count every bird they see or hear in a 10-minute time frame. To avoid double-counting birds, they also need to be able to keep track of where individual birds are moving, whether the bird was a male or female, what distance the bird was detected at, and what time the bird was detected at. In other words, we are multi-tasking experts! This point-count method is performed at each of the 7-10 points. Because birds are most active in the morning, our surveys must finish within four hours of sunrise. Each site is surveyed three times over the course of the summer in order to detect species that weren’t detected on earlier surveys. After all bird surveys are completed, we also do a follow-up vegetation survey to record habitat characteristics such as density and composition of plants.
We detected 77 species at restored wetland areas of Whiterock Conservancy. During the breeding season, these properties are home to many common species like red-winged blackbirds, American robins, and song sparrows. We also found 25 SGCN, including dickcissel, common yellowthroat, and sedge wren. Additional surveys for this project will be conducted in summer of 2023. I look forward to learning which birds use each of these sites and identifying best management practices so they can be sustained into the future!
SGCN that use Whiterock Conservancy include bald eagle, belted kingfisher, yellow-billed cuckoo, black tern, common yellowthroat, dickcissel, blue-winged teal, grasshopper sparrow, and trumpeter swan.
Photos courtesy of Cornell Lab (Scott Heidorn, Jack & Holly Bartholmai, Benjamin Murphy, Santiago Caballero Carrera, Andrew Spencer, Martina Nordstrand, Jay McGowan, Marky Mutchler, and Frank Lehman).