Table 2 Reproductive parameters of the European Roller population of Lazio region during the study period 2010–2016
From: Nest box selection and reproduction of European Rollers in Central Italy: a 7-year study
Year | Occupied nests | No. of successful breeding pairs | Values | No. of eggs laid | No. of eggs hatched | No. of eggs not hatched | No. of fledglings | Hatching success | Fledging success | Breeding success |
|---|---|---|---|---|---|---|---|---|---|---|
2010 | 15 | 6 | Mean | 5.28 | 4.50 | 1.62 | 4.37 | 0.84 | 1.00 | 0.84 |
SD | 0.48 | 1.37 | 1.84 | 1.18 | 0.25 | 0.00 | 0.25 | |||
Total | 32 | 27 | 5 | 27 | Â | Â | Â | |||
2011 | 19 | 11 | Mean | 5.38 | 4.18 | 1.36 | 4.18 | 0.75 | 0.81 | 0.75 |
SD | 0.76 | 2.13 | 2.11 | 2.13 | 0.38 | 0.40 | 0.38 | |||
Total | 61 | 46 | 15 | 46 | Â | Â | Â | |||
2012 | 16 | 11 | Mean | 5.00 | 4.64 | 0.27 | 4.42 | 0.95 | 0.92 | 0.86 |
SD | 0.91 | 1.08 | 0.90 | 1.60 | 1.15 | 0.26 | 0.32 | |||
Total | 56 | 53 | 3 | 50 | Â | Â | Â | |||
2013 | 14* | NA | Mean | – | – | – | – | – | – | – |
SD | – | – | – | – | – | – | – | |||
Total | 32* | – | – | 23* | – | – | – | |||
2014 | 11* | NA | Mean | – | – | – | – | – | – | – |
SD | – | – | – | – | – | – | – | |||
Total | – | – | – | 46* | – | – | – | |||
2015 | 32 | 32 | Mean | 4.75 | 3.66 | 1.09 | 3.50 | 0.77 | 0.83 | 0.74 |
SD | 1.08 | 1.77 | 1.63 | 1.90 | 0.35 | 0.37 | 0.37 | |||
Total | 152 | 117 | 35 | 112 | Â | Â | Â | |||
2016 | 33 | 29 | Mean | 4.74 | 2.54 | 1.66 | 2.22 | 0.53 | 0.80 | 0.47 |
SD | 1.29 | 2.21 | 1.89 | 2.2 | 0.43 | 0.35 | 0.42 | |||
Total | 136 | 78 | 48 | 69 | Â | Â | Â | |||
Study-period | 20.00 | 17.80 | Mean | 5.03 | 3.90 | 1.20 | 3.74 | 0.77 | 0.87 | 0.73 |
8.8 | 11.82 | SD | 0.48 | 0.78 | 0.54 | 0.76 | 0.13 | 0.07 | 0.23 |