Data from: Estimating waterfowl breeding pair and brood densities using distance sampling with uncrewed aerial systems

Wildlife management relies on effective methods to estimate population
indices, which are crucial for understanding the status and trends of
wildlife populations and the factors that influence their persistence.
Biologists have conducted surveys of waterfowl since the 1950’s using a
combination of aerial (fixed wing aircraft) and ground-based methods to
account for imperfect detection. While some individuals may be missed by
aerial observers, ground observers are assumed to detect all individuals.
This allows for a visual correction factor to be applied to the initial
aerial count. However, the assumption that ground-observers are detecting
every individual is unlikely and can potentially lead to biased population
estimates. We conducted breeding waterfowl surveys in Wisconsin during
2022 and 2023 and recorded observations of duck pairs and broods using
uncrewed aerial systems (UAS) equipped with thermal cameras, which have
been shown to improve detection of many wildlife species. We flew UAS
surveys along transects and employed distance sampling to estimate duck
densities while accounting for imperfect detection. This can be
accomplished by recording the distance at which birds are detected and
fitting a detection function to the data, which models detection
probability and excludes the need for two independent observers. Our
overall goal was to determine if UAS distance sampling can be used to
monitor breeding waterfowl and produce reliable population metrics. The
archived datasets contain transect-based observations of waterfowl pairs
and broods collected over both years of the study, along with their
associated distances from the observation transect. Additional
observational variables are also included to support analyses in this
study.