Animals have evolved a variety of adaptations to care for the body surface, such as grooming behavior, which keeps the integument clean, parasite-free, and properly arranged.  Despite extensive research on the grooming of mammals, birds, and arthropods, the survival value of grooming has never been measured directly in natural populations.  We monitored grooming and survival in a population of marked American kestrels (Falco sparverius) on San Salvador Island, Bahamas. We found a strong association between time spent grooming and survival over a two-year period.  The quadratic relationship we show is consistent with stabilizing natural selection on grooming time.  To our knowledge, this is the first evidence for a correlation between grooming time and survival in a natural population.  Grooming time may predict the survival of many animal taxa, but additional studies are needed to determine the shape and strength of the relationship among birds, mammals and arthropods.

Data from this field study are availble here as csv files.  See publication for more information about data collection methods.