What is the recommended duration for an evening bat watch when confirming for infestation?

The recommended duration for an evening bat watch is 1 hour, as this timeframe allows for sufficient observation to assess bat activity and verify potential infestation. An hour provides a practical window during which you can effectively document the number of bats emerging from roosting sites and gain insights into their behavior and patterns. This duration typically coincides with the time after sunset when bats are most active, ensuring that observations are made during peak moments of emergence.

Other shorter durations, such as 30 minutes, may not capture the full extent of bat activity, possibly leading to inaccurate assessments. On the other hand, significantly longer durations, like 90 minutes or 2 hours, might not be necessary and could result in diminishing returns on data collection as the bats’ foraging behavior stabilizes after initial emergence. Therefore, one hour strikes a balance between thorough observation and efficiency, making it the best choice for confirming bat infestations.