Table 1.

Mean values (± standard error, SE) and associated t-test results for bank vole autumn density, PUUV spring seroprevalence, and weather variables in the two study periods in the 1980s and 2000s. Significant differences (p < 0.05) are highlighted in bold. Winter represents December–March

Variables	1980s (mean ± SE)	2000s (mean ± SE)	T	df	p
Bank vole autumn density	3.9 ± 1.3	4.5 ± 1.1	− 0.344	11.83	0.737
Bank vole spring density	0.7 ± 0.2	1.1 ± 0.3	− 1.141	13.98	0.273
PUUV spring seroprevalence	28.6 ± 4.9	32.1 ± 5.9	− 0.566	11.24	0.583
PUUV spring seroprevalence with spring density > 0.69	26.4 ± 0.9	45.4 ± 3.3	− 5.501	5.55	0.002
November rain (mm)	86.6 ± 3.4	21.1 ± 4	− 2.463	13.98	0.027
Number of rainy days in November	1.7 ± 0.6	5.1 ± 1.2	− 2.634	12.97	0.021
November temperature (°C)	− 6.3 ± 1.0	− 2.8 ± 0.9	− 2.580	11.73	0.024
October rain (mm)	72.2 ± 12.4	41.4 ± 9.3	1.972	10.34	0.076
Number of rainy days in October	9.2 ± 1.7	7.1 ± 1.4	0.935	10.76	0.370
October temperature (°C)	1.7 ± 0.5	2.0 ± 0.4	− 0.361	11.66	0.725
Winter rain (mm)	8.4 ± 2.8	13.3 ± 5.0	− 0.851	13.15	0.410
Number of rainy days in winter	1.5 ± 0.4	3.1 ± 1.2	− 1.268	11.15	0.231
Winter temperature (°C)	− 9.6 ± 0.6	− 7.2 ± 0.6	− 2.965	12.83	0.011