Biodiversity is the foundation of a healthy ecosystem. Ecosystems consist of mammals, birds, fishes, amphibians and reptiles, invertebrates, vascular and nonvascular plants, archaea, and bacteria, all interacting within their aquatic and terrestrial habitats to maintain the delicate balance of life. The diversity of species, some rare, some abundant, contributes to maintaining this balance.

The decline of many threatened and endangered species can often be traced to direct as well as indirect human impact, so it is important to assure that rare as well as common flora and fauna—and their preferred habitats—are protected from anthropogenic actions. Unique and important species can be found across the state of Illinois, often in areas threatened by human development.

The INHS Biological Surveys and Assessment Program (BSAP) helps minimize the effects of human perturbations through our field surveys, recommendations, mitigation activities, and by supporting the Natural Heritage Database and the INHS Biological Collections.

The BSAP works with the Illinois Department of Transportation (IDOT) to minimize the effects of transportation infrastructure building and maintenance on local plants and animals. Specifically, our role is to determine the presence of threatened and endangered species at sites under consideration for IDOT projects. We conduct field surveys of plants and animals at sites proposed for highway projects and natural areas statewide to ensure IDOT projects are in compliance with State and Federal environmental laws and regulations. We assess flora and fauna, including protected species and habitats, for potential impacts on natural resources so that IDOT can either reduce or eliminate adverse environmental impacts, or they can identify mitigation or remediation actions to achieve the best possible outcome during project development, design, and construction.

We also help maintain the Natural Heritage Database. Beginning in 1986, the Illinois Department of Natural Resources’ (IDNR) Division of Natural Heritage, in conjunction with The Nature Conservancy, established the Illinois Natural Heritage Database to be the central location for information on significant natural features within the state. The database houses information on 484 state and federally listed endangered and threatened species, 92 high-quality natural community types, and special features such as heron rookeries and large forest blocks. In addition, the database contains information on more than 660 areas under protection by the Illinois Nature Preserve Commission’s Nature Preserve and Land and Water Reserve programs. The database is extensively used by the INHS IDOT programs to help focus field researchers’ attention on threatened or endangered species that may be present in project areas.  In a typical year, INHS staff working on IDOT projects report hundreds of new and updated records for both state and federally threatened and endangered species to the Natural Heritage Database, including sightings of invertebrates, reptiles and amphibians, plants, fish, mammals, and birds.

Scientific collections can aid in quantifying the impacts of habitat loss, environmental contamination, biological invasions, and global climate change on our native flora and fauna. The INHS Biological Collections provide invaluable insight into changes in species composition and distribution throughout Illinois over the past 150 years. The collections act as a biological library, allowing easy access to many years of data concerning the presence or absence of state-listed species, which helps IDOT save time and money required for more extensive fieldwork. INHS oversees all aspects of collection, management, and maintenance of samples collected during IDOT biological surveys. While the INHS Biological Collections support IDOT programs, specimens and associated data collected during biological surveys are, in turn, curated into their respective collections and their databases.