Table 5 Parameter estimates, p-values, and marginal R² for the effect of immune challenge on variance in reproductive investment. M is the mean lnCVR effect size (positive value indicates increased variance in the treatment group), CI.lb and CI.ub are the lower and upper bounds of the 95% confidence interval. ^aIndicates moderators that were retained in the AICc final averaged model

Meta-analytic mean

0.104

0.040

0.005

0.2034

Age class

 Unclear/mixed

0.054

0.381

 − 0.067

0.175

0.028

 Old

0.225

0.087

 − 0.033

0.482

 Young

0.171

0.072

 − 0.016

0.357

Control procedure^a

 No

0.167

0.028

0.018

0.316

0.009

 Yes

0.093

0.097

 − 0.017

0.202

Source of animals

 Cultured population

0.145

0.162

 − 0.059

0.350

0.011

 Wild or immediate offspring of wild

0.117

0.033

0.009

0.224

 Wild-caught but kept in research facilities for generations

0.036

0.683

 − 0.137

0.209

Reproductive investment categories^a

 Behavioural traits

0.049

0.488

 − 0.089

0.186

0.028

 Offspring traits and success

0.024

0.782

 − 0.147

0.195

 Others

0.062

0.585

 − 0.162

0.287

 Physiological/Physical traits

0.187

0.054

 − 0.003

0.376

 Reproductive output

0.152

0.065

 − 0.009

0.313

Immune challenge type^a

 Non-pathogenic foreign bodies

0.155

0.134

 − 0.048

0.358

0.004

 Substrates of pathogenic origins

0.093

0.063

 − 0.005

0.190

Blinding^a

 No/unclear

0.103

0.066

 − 0.007

0.212

0.000

 Yes

0.108

0.144

 − 0.037

0.253

Incomplete reporting^a

 No

0.118

0.048

0.001

0.235

0.004

 Yes

0.060

0.261

 − 0.046

0.166

Log(lifespan of species) (mean centred and controlling for research effort for that species)^a

0.087

0.023

0.012

0.162

0.064