The generalist tick Ixodes ricinus and the specialist tick Ixodes trianguliceps on shrews and rodents in a northern forest ecosystem– a role of body size even among small hosts

Table 2 Parameter estimates of tick load in small mammals from negative binomial models. Baseline for species is Sorex araneus. Models for I. ricinus larvae were run excluding and (the best model) including body mass

	Estimate	Std. error	z	p
I. ricinus larvae
Excluding body mass
Intercept	0.4775	0.2314	2.06	0.039
Apodemus flavicollis	0.4029	0.6962	0.58	0.563
Apodemus sylvaticus	1.0826	0.3675	2.95	0.003
Microtus agrestis	−0.0725	0.3853	−0.19	0.851
Myodes glareolus	0.7528	0.3387	2.22	0.026
Sorex minutus	−2.8948	0.4927	−5.88	<0.001
Season (spring vs. fall)	−0.705	0.3618	−1.95	0.051
Including body mass
Intercept	−2.6313	0.9461	−2.78	0.005
log (body mass)	1.5014	0.4446	3.38	0.001
Apodemus flavicollis	−1.4505	0.8787	−1.65	0.099
Apodemus sylvaticus	−0.0437	0.4891	−0.09	0.929
Microtus agrestis	−2.0303	0.6912	−2.94	0.003
Myodes glareolus	−0.7295	0.5382	−1.36	0.175
Sorex minutus	−1.4236	0.6455	−2.21	0.027
Season (spring vs. fall)	−0.9547	0.3593	−2.66	0.008
I. ricinus nymphs
Intercept	−9.311	1.758	−5.30	<0.001
log (body mass)	2.36	0.616	3.83	<0.001
I. trianguliceps larvae
Intercept	0.239	0.16	1.50	0.130
Season (spring vs. fall)	1.404	0.343	4.09	<0.001
I. trianguliceps nymphs
Intercept	−7.227	1.959	−3.69	0.000
log (body mass)	1.705	0.876	1.95	0.052
Apodemus flavicollis	−3.841	1.385	−2.77	0.006
Apodemus sylvaticus	−1.140	1.090	−1.05	0.296
Microtus agrestis	−1.778	1.477	−1.20	0.229
Myodes glareolus	−0.647	1.207	−0.54	0.592
Sorex minutus	−20.20	26230.0	0.00	0.999
Location (Forde vs. Angedalen)	1.494	0.636	2.35	0.019

ISSN: 1756-3305