Urban ichnology might include the study of animal traces in city parks, gardens, and green spaces, which can be useful in the documentation of nocturnal or cryptic species, from deer and woodpeckers to insects and earthworms. It could also include the study of modern footprints in concrete sidewalks, and trace fossils in dimension stone. Anthony J. Martin has studied how the traces of beaver and deer can reveal their habits and distribution in Atlanta, Georgia (USA).