No detectable effects of lightweight geolocators on a Palaearctic-African long-distance migrant

摘要: Tracking devices are used in a broad range of species for questions, but their potential effects on study debated. Outcomes earlier studies equivocal: some find negative behaviour and life history traits, while others do not. Contrasting results might be due to low sample sizes, temporal scale (no repetition the over multiple years) limited response variables considered. We investigated geolocators variables: body condition, physiological states, reproductive performance and, ultimately, annual apparent survival medium-sized Palaearctic-African long-distance migrant, Eurasian Hoopoe Upupa epops, combined period (2009–2014) individual years. 1 year after deployment geolocator found no differences states several components between individuals with without when data were combined. Also, did not differ control birds. did, however, years possibly related environmental stochasticity or chance events lower sizes. argue that tracking should interpreted generalized great caution suggest future conducted Future also apply capture–recapture models estimate survival, rather than focus solely return rates.