andfrekvens

Andfrekvens, literally “duck frequency” in Danish, is a term used in ecology and ornithology to describe the frequency or occurrence of ducks in a given area or time period. It can refer to the rate at which ducks are observed in field surveys, the relative abundance of duck species in a community, or the frequency of duck vocalizations in audio recordings. In field monitoring, andfrekvens is often expressed as sightings per unit effort (for example, ducks observed per hour of surveying) or as a proportion of observations relative to other waterfowl.

Measurement methods include point counts and transect surveys, roost counts, harvest data, and automated acoustic or radar monitoring. Calculation commonly involves adjusting raw counts for effort and detection probability to produce an index of presence or an estimate of abundance.

Interpretation: andfrekvens helps track population trends, seasonal migration timing, and habitat use, and supports management decisions such as hunting quotas and habitat restoration. However, it is sensitive to detectability biases, weather, water levels, and observer skill, so results are often reported with confidence intervals and, where possible, detection corrections.

Relation to other concepts: it relates to population density, occupancy, and relative abundance. It should not be confused with biomass or absolute population size unless coupled with robust sampling and modeling.

See also: waterfowl surveys, occupancy modeling, bird acoustics.