Table 1. Comparison of the potential advantages and disadvantages associated with two primary acoustic survey methods, mobile driving transect surveys and stationary point surveys, recommended to survey bats (Loeb et al., 2015).
Stationary surveys are further separated into survey methods in which a single detector is strategically located (‘single strategic’) and multiple detectors are spatially replicated across the landscape (‘spatially replicated’). The effectiveness of these survey methods at detecting species richness and rare species were tested in Everglades National Park, Florida, USA.
| Survey method | Advantages | Disadvantages |
|---|---|---|
| Mobile driving transect surveys | - Allows estimates of bat abundance - Enables sampling of a large spatial area in one night - Allows sampling of areas that may be inaccessible for other survey techniques (e.g., private lands) - Low equipment cost (e.g., requires only one detector) |
- Introduces spatial sampling biases (e.g., some bat species may avoid or be attracted to roads) - Provides limited spatial sampling (sampling is restricted to locations & habitats where roads are constructed) - Provides limited temporal sampling (e.g., transects are typically surveyed only a few hours per night) - Introduces temporal sampling biases (areas along the transect are sampled only briefly) - Labor intensive (e.g., requires an individual to drive throughout the duration of the survey) |
| Stationary point surveys | - Low investment of labor (equipment is left to sample many hours after deployment) - High temporal sampling replication (equipment can record all night for multiple nights) |
- Does not allow estimates of bat abundance - Provides limited spatial sampling (only one location is sampled per detector) |
| Single strategic | - Enables purposeful maximization of bat detections (e.g., if detectors are placed near water or other areas expected to have high bat activity levels) - Low investment of labor (equipment is left in one place permanently) |
- Provides limited spatial sampling (does not capture landscape heterogeneity) |
| Spatially replicated | - Provides spatial replication (captures landscape heterogeneity) | - Labor intensive (requires deployment of equipment at multiple sites) |