Table 1. Output from mixed models investigating the grooming behaviour of adult dwarf mongooses at the evening refuge.

All models contained treatment (conflict, control) as a fixed effect (the reference level in the table is ‘conflict’), with Individual ID nested within Group ID as random effects. The first model (generalised linear mixed model (GLMM) with a binomial error distribution and logit-link function) examined (a) whether an individual was involved in a grooming bout (Yes or No). Subsequent models focussed on those individuals that did participate in grooming, examining (b) the proportion of time spent grooming (GLMM with a beta error distribution and logit-link function), (c) the rate of grooming interactions (GLMM with a Poisson error distribution, log-link function, and log(duration) as an offset term to account for differences in the time available for grooming), and (d) the log-transformed mean grooming-bout duration (linear mixed model (LMM) with a Gaussian error distribution). Significant fixed effects shown in bold; variance ± SD reported for random effects is shown in italics.

	Effects	Estimate ± SE	df	χ2	p
(a) Individual involvement in grooming
Random effects	Group ID	0.919 ± 0.959
	Individual ID in Group	<0.001 ± <0.001
Minimal model	(Intercept)	1.267 ± 0.497
	Treatment (Conflict)	1.106 ± 0.488	1	5.401	0.020
(b) Proportion of time spent grooming
Random effects	Group ID	0.187 ± 0.433
	Individual ID in Group	0.065 ± 0.255
Minimal model	(Intercept)	–1.544 ± 0.190
	Treatment (Conflict)	–0.697 ± 0.164	1	15.873	<0.001
(c) Rate of grooming bouts
Random effects	Group ID	<0.001 ± 0.018
	Individual ID in Group	0.195 ± 0.442
Minimal model	(Intercept)	–1.317 ± 0.102
	Treatment (Conflict)	–0.296 ± 0.105	1	8.010	0.005
(d) Mean grooming-bout duration
Random effects	Group ID	0.047 ± 0.217
	Individual ID in Group	0.067 ± 0.258
Minimal model	(Intercept)	3.257 ± 0.104
	Treatment (Conflict)	–0.167 ± 0.083	1	3.958	0.047