Temporal dynamics of grouse populations at the southern edge of their distribution

摘要: Studies of grouse conducted at northern latitudes have shown that tetraonids frequently exhibit cyclic fluctuations in abundance but little is known about the dynamics species southerly edge their range. Hunting statistics from four based on 30 yr data collected 210 hunting areas were examined Dolomitic Alps province Trentino. These summed to represent 18 time series discrete mountain groups. Analyses identified cycles ca 5 minority rock ptarmigan Lagopus mutus and hazel Bonasa bonasia populations. only showed significant negative autocorrelation half cycle period classified as phase-forgetting quasi-cycles. Cycles not found black Tetrao tetrix or capercaillie urogallus. Correcting for effort restrictions tended increase proportion populations exhibited no difference strength second order density dependence. A linear first density-dependent autoregressive model described most with exception a where non provided best fit. We compare findings studies Finland suggest possible reasons reduced tendency southern Europe.