Comparing diel activity patterns of wildlife across latitudes and seasons: time transformations using day length

(1) Camera trapping allows scientists to study activity patterns of animals under natural conditions. However, comparisons of activity patterns across seasons or latitudes can be biased, because activity is often attuned to sunrise and sunset, the timing of which varies with latitude and season. Existing transformation methods to solve this problem have limitations. (2) Here, we explore whether and how activity patterns can be transformed more accurately using two alternative ‘double anchoring’ transformations – equinoctial and average anchoring – that anchor activity time to two chosen anchor points during the study period. (3) Using simulated noisy datasets mimicking species with either crepuscular, diurnal or cathemeral activity patterns, we compared the ability of different transformation methods to extract the latent pattern and activity levels under different study conditions. We found that average anchoring best retrieved the original diel activity pattern and yielded accurate es...