Table 1 Nest box use by the boreal owl in Europe, North America, and Asia; the state, locality, elevation, period, the number of boxes, nests, box-years, and the nest box occupancy (expressed as the proportion of occupied nest boxes of checked boxes). The way how authors described their results varied hugely. Therefore, we present the information on the number of boxes, nests, and nest box occupancy from long-term studies either as a sum counted for the entire study period (marked as ‘Total’) or a yearly mean (marked as ‘Mean’) with minimum (‘Min’) and maximum (‘Max’) values.
From: Forest structure determines nest box use by Central European boreal owls
State | Locality | Elevation | Period | No. of boxes/ year | No. of box-years | No. of nests | Nest box occupancy (%) | References | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Total | Min | Max | Total | Mean | Min | Max | |||||||
Canada | Southern Yukon | 1984–96 | 13–105 | 573 | 6 | 1 | |||||||
Canada | Alberta region | 470–920 | 2016 | 169 | 169 | 4 | 2 | ||||||
USA | Alaska | 90–150 | 1995–97 | 36 | 108 | 29 | 27 | ||||||
USA | Alaska | 200–650 | 2005–06 | 91, 108 | 199 | 23 | 12 | ||||||
USA | Alaska | 110–690 | 2015 | 200 | 200 | 27 | 14 | ||||||
USA | Rocky Mts. | 1700 | 1985–88 | 45 | 180 | 3 | 2 | ||||||
USA | Idaho | 1520–2140 | 1988–90 | 283–450 | 1016 | 4 | |||||||
USA | Rocky Mts. | 1995–01 | 250–450 | 1 | |||||||||
China | Lianhuashan Mts. | 2003–07 | 67 | 335 | 4 | 7 | 6 | 10 | |||||
Sweden | Västerbotten | 1980–84 | 500 | 2500 | 525 | 4 | 201 | 21 | 1 | 40 | |||
Sweden | Västerbotten | 1981–82, 1984–85 | 44–149 | 330 | 5 | 99 | 30 | 6 | 66 | ||||
Sweden | Västerbotten | 1998–99 | 300 | 600 | 84 | 15 | 22 | ||||||
Sweden | Västerbotten | 2006–07 | 273, 275 | 548 | 47 | 9 | 2 | 15 | |||||
Finland | Kauhava region | 30–120 | 1966–85 | 35–450 | 4577 | 352 | 2 | 63 | 8 | 2 | 22 | ||
Finland | Kauhava region | 30–120 | 1966–08 | hundreds | 677 | 104 | 15 | ||||||
Czech Rep. | Ore Mountains | 730–960 | 2000–03 | 100 | 400 | 72 | 10 | 26 | 18 | 10 | 26 | ||
Czech Rep. | Šumava Mts. | 500–1300 | 1984–05 | 211 | 4448 | 316 | 7 | ||||||
Czech Rep. | Šumava Mts. | 500–1100 | 1992–02 | 395 | 250 | 6 | 4 | 8 | |||||
Czech Rep. | Šumava Mts. | 400–1378 | 1978–02 | 5006 | 299 | 6 | |||||||
Czech Rep. | Krkonoše Mts. | 1985–86 | 40, 60 | 100 | 1 | 1 | 0 | 2.5 | |||||
Switzerland, France | Jura Mts. | 1000–1600 | 1985–14 | 64–116 | 2550 | 425 | 2 | 39 | 17 | 3 | 55 | ||
Germany | Kaufunger Wald | 250–580 | 1965–84 | 60 | 1200 | 76 | 6 | ||||||
Germany | Harz Mts. | 450–850 | 1979–91 | 250 | 3250 | 390 | 12 | ||||||
Germany | Olpe | 430–580 | 1981–10 | 4–64 | 1034 | 187 | 0 | 20 | 18 | 0 | 56 | ||
Italy | Cansiglio Highland | 1989–20 | 80–100 | 2400 | 93 | 4 | |||||||
Serbia | Kopaonik National Park | 800–2017 | 2011–13 | 63 | 189 | 9 | 5 | ||||||
