As part of his master's research, Coleman developed an index which relies on bird counts to evaluate the condition of wetland habitats. He is continuing that work as a doctoral student in the lab of biology professor Michael Miller. Birds turned out to be a good indicator for several reasons. Different species of birds prefer different environments. So if you find many water-loving birds and few birds adapted to drier habitats, that's an indication that the wetland environment is thriving.
Birds are also fairly easy to track.
The problem is there aren't many good records of butterflies and insects in an area. Birders also tend to keep very detailed records of what they see. Working with Professor Styer, Coleman learned to identify species commonly found in the Greater Cincinnati area. Then, he tracked bird occurrences in five Indiana and Ohio wetlands as well as three Cincinnati parks for a dry land comparison. Coleman used his own observations as well as the records of well-known birders.