Table 2.
Characteristics of two small rodent population peaks in northeastern Norway; first peak 2006–2007 and second peak 2010–2011
| Data | Statistic | Tundra vole | Grey‐sided vole | Lemming |
|---|---|---|---|---|
| 1st peak | Mean (SD) abundance | 4.4 (3.3) | 3.8 (2.7) | 3.5 (3.0) |
| Range | 0–11 | 0–11 | 0–13 | |
| Growth rate (95% CI) | 0.44 (0.32, 0.56) | 0.91 (0.78, 1.04) | 0.72 (0.62, 0.83) | |
| Density dependence | −0.86 (−0.95, −0.75) | −0.85 (−1.06, −0.48) | −0.59 (−0.88, −0.13) | |
| 2nd peak | Mean (SD) abundance | 9.6 (3.7) | 4.3 (3.0) | 2.8 (2.2) |
| Range | 2–16 | 0–11 | 0–9 | |
| Growth rate (95% CI) | 1.41 (1.26, 1.56) | 1.04 (0.92, 1.16) | 0.88 (0.71, 1.04) | |
| Density dependence | −0.97 (−1.00, −0.92) | −0.53 (−0.94, 0.28) | −1.08 (−1.36, −0.88) |
All statistics are based on spatial variation in numbers of individuals trapped per quadrat. Growth rate refers to seasonal growth rate within each peak; that is, quadrat‐specific growth from spring to autumn. Density dependence is calculated as the mean of the posterior of (βDD – 1) from the Bayesian state‐space model (see Supporting Information Appendix S4). 95% credible interval is given in the parentheses.