Anthropogenic habitats or surrogate communities are habitats that may be similar to and at least partially mimic the structure and function of natural habitats. Today's anthropogenic habitats may be inhabited by an assemblage of species that historically used structurally similar natural communities. Some examples of anthropogentic habitats are non-native grasslands, mines and gravel pits, bridges and buildings, dredge spoil islands, and agricultural fields. What does and does not constitute an athropogenic habitat can be an issue of considerable debate.
Many anthropogenic habitats have a distinct set of species that use them. For example, old mines are often used by bats, bridges are used by phoebes and cliff swallows, dredge spoil islands are used by terns and other colonial nesting birds, chimneys on houses are used by chimney swifts, and some tall buildings are used by peregrine falcons as nest sites. Other habitats such as agricultural fields and non-native grasslands are used by a wider variety of species as nesting and feeding areas. Some anthropogenic habitats are very important for wildlife and should be considered for protection (e.g., old mines). Others provide important habitat for many species and changes in management can have important effects on wildlife. For example, conversion of hayfields and pastures to agricultural row crops is believed to be a contributing factor in the decline of grassland birds in the last 30 years. Some athropogenic habitats are now important for sustaining Wisconsin's wildlife populations and should be considered when planning the management of the wildlife in the state.
The surrogate grassland community type has been fairly well defined and evaluated in Wisconsin through publications such as Managing Habitat for Grassland Birds: A Guide for Wisconsin (Sample and Mossman 1997). Some examples of surrogate grasslands are agricultural hayfields, small grains, pastures, fallow fields, and non-native grasslands. Surrogate grasslands currently represent the majority of grassland habitats in the state and are very important to the conservation of grassland Species of Greatest Conservation Need. Because of this, surrogate grasslands were specifically addressed as part of Wisconsin's Wildlife Action Plan.