Using acoustic indices to estimate wolf pack size

摘要: Abstract Acoustic indices were recently developed for biodiversity evaluation by measuring the acoustic heterogeneity generated animals in natural environments. Some of these focus on species diversity a community studying frequency and temporal variations signals. We explored possibility using to estimate population size specific species. More precisely, objective was grey wolf packs testing six indices: H, Hf, Ht, M, AR, ACI. The relationship between averaged values number howling wolves studied based artificial solos choruses created from howls extracted recorded captivity. Then, 16 real used test predictions index calculated previously considered as references. Finally, we three biases that might influence thus chorus estimates. All positively correlated with size, although large standard deviations observed. Moreover, Ht reached plateau at 7–8 wolves. overestimated or underestimated. However, ACI most accurate close actual value. M AR also had good predictive power, especially made relatively small overestimates may be explained several sources bias related composition choruses. Indeed, influenced audio file duration, signal-to-noise ratio (SNR), overlap howls, but not same manner each index. In particular, significantly duration their decreased increased. Excluding all affected adding background noise. H Hf SNR decreased, opposite trend occurred Only four other greater extent when more overlapped. promising ACI, they provide an innovative census tool estimating pack size. Our results are encouraging further research is needed obtain effective tool. Several recommendations directions studies discussed.