Initial and long-term use of inserts by red-cockaded woodpeckers
Artificial cavities have become a standard management technique for red-cockaded woodpeckers (Picoides borealis). Seventy cavity inserts were installed in our study sites on the Angelina National Forest in eastern Texas from 1990 to 1995. Eighty-two percent of the inserts were used for at least one year. It is still too early to make a direct comparison, but it is likely that inserts will remain usable as long as natural cavities do. Inserts installed in 1990 and 1991 were 20.5 cm in height, whereas inserts installed from 1992 to 1995 were 25.5 cm in height. Larger inserts (25.5 cm) appear to remain usable for a longer time than smaller inserts (20.5 cm). Newer unused inserts are more likely to become active for the first time than older unused inserts. Similar to unused inserts, active cavities (naturally excavated and inserts) that have become inactive are less likely to be reactivated the longer they are inactive. Newness and recency of cavity use and red-cockaded woodpecker activity appear to be important factors in the attractiveness of inserts and naturally excavated cavities.