Brain size in Hylarana guentheri seems unaffected by variation in temperature and growth season. Supplementary Table S1

Brain size
varies dramatically between vertebrate species. Two prominent adaptive
hypotheses – the Cognitive Buffer Hypothesis (CBH) and the Expensive Brain
Hypothesis (EBH) – have been proposed to explain brain size evolution. The CBH
assumes that brain size should increase with seasonality, as the cognitive
benefits of a larger brain should help overcoming periods of food scarcity via,
for example, increased behavioral flexibility. Alternatively, the EBH states
that brain size should decrease with seasonality because a smaller brain
confers energetic benefits in periods of food scarcity. Here, to test the two
adaptive hypotheses by studying the effects of variation in temperature and
growth season on variations in overall brain size and the size of specific
brain regions (<i>viz</i>. olfactory nerves, olfactory bulbs, telencephalon,
optic tectum and cerebellum) among <i>Hylarana guentheri </i>populations.
Inconsistent with the predictions of both the EBH and the CBH, variation in
temperature and growth season did not exhibit correlations with overall brain
size and the size of brain regions across populations. Hence, our data do not
provide support for either the EBH or the CBH to explain brain size variation in
<i>H. guentheri</i>. Furthermore, brain size variation did not differ between
males and females in this species. Our findings suggest that both the variation
in temperature and growth season did not shape the variation in brain size in <i>H.
guentheri</i>.