Complex effects of testosterone level on ectoparasite load in a ground squirrel: an experimental test for the immunocompetence handicap hypothesis

Table 2 Results of conditional model averaging, based on negative binomial generalized linear mixed-effects model on tick load of male or female Daurian ground squirrels (Spermophilus dauricus)

Model/factors	Estimate	Standard error	Z value	P value	VIF
Male
Intercept	3.69	0.37	8.69	< 0.001	NA
Treatment (testosterone)	0.98	0.33	2.43	0.016	1.12
FleaLoad_after	0.041	0.024	1.41	0.16	1.39
TickLoad_before	0.0024	0.010	0.19	0.85	1.10
Body weight	− 0.0027	0.0070	0.31	0.76	1.33
Female
Intercept	3.35	0.57	5.62	< 0.001	NA
Treatment (testosterone)	0.18	0.39	0.43	0.67	1.69
FleaLoad_after	0.013	0.049	0.24	0.81	1.39
TickLoad_before	0.0083	0.0053	1.42	0.16	1.51
Body weight	−0.0054	0.0035	1.38	0.17	1.29

TickLoad_after: tick load recorded in the first round of ectoparasite check. FleaLoad_after: flea load recorded in the second round of ectoparasite check. Variance inflation factor (VIF) for each explanatory factory is indicated. Significant terms marked by bold

ISSN: 1756-3305