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Abstract. Evaluating the practicality, economic, and sampling efficiency of potential monitoring programs is a first step in validation. Thus, we established a system of nest boxes in southeast Ohio to evaluate the feasibility of using a system of nest boxes to monitor changes in southern flying squirrel (Glaucomys volans') populations. We recorded the time of box placement until first usage and types of use by flying squirrels as an indicator of presence as well as nest box occupancy trends on a month-to-month basis to assess usage patterns and productivity. Using monitoring results from 4 years, we evaluated alternative survey sampling techniques for occupancy and determined sample sizes necessary to estimate occupancy within specified relative bounds. We also studied the cost of establishing a nest box system and monitoring nest box use. At low nest box occupancy (9.4%), sample size necessary to monitor trend would be extreme (431 boxes for 30% relative bound), but sample size is not restrictive when occupancy rates exceed 17% (211 boxes to achieve 20% relative bound). Monitoring combined spring and summer litter sizes in November or December as a measure of recruitment would require a smaller effort to achieve a tighter relative bound (10%). Assumptions relating these demographic parameters to habitat change or disturbance still must be tested before the systematic placement of nest boxes can be considered the optimum approach to monitor southern flying squirrel response as measured by changes in population density or recruitment.
OHIO J SCI 101 (2):2-11, 2001
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INTRODUCTION
Monitoring distribution and abundance over time provides the empirical data needed to detect population change. The monitoring process should provide the primary feedback loop into basic ecological models used to determine the cause of population change (Verner 1986). The immediate need is to provide sufficient information to assure current management practices are not threatening long-term viability of local populations. Despite the importance of monitoring population changes in responses to habitat, adequate techniques have not been developed for many secretive species.
Southern flying squirrels inhabit a variety of forest types throughout their distribution (Dolan and Carter 1977). Habitat requirements include forest structure allowing gliding travel (Bendel and Gates 1987), snags or other natural cavities for nesting (Muul 1974; Gilmore and Gates 1985; Taulman...