Data from: Seasonal changes in diet and toxicity in the Climbing Mantella frog (Mantella laevigata)

Poison frogs acquire chemical defenses from the environment for protection
against potential predators. These defensive chemicals are lipophilic
alkaloid toxins that are sequestered by poison frogs from dietary
arthropods and stored in skin glands. Despite decades of research focusing
on identifying poison frog toxins, we know relatively little about how
environmental variation and subsequent arthropod availability impacts
toxicity in poison frogs. We investigated how seasonal environmental
variation influences poison frog toxin profiles through changes in the
diet of the Climbing Mantella (Mantella laevigata). We collected M.
laevigata females on the Nosy Mangabe island reserve in Madagascar during
the wet and dry seasons and tested the hypothesis that seasonal
differences in temperature and rainfall are associated with changes in the
diet and skin toxin profiles of M. laevigata. The arthropod diet of each
frog was characterized into five groups (i.e. ants, termites, mites,
larvae and other) using visual identification and cytochrome oxidase 1 DNA
barcoding. We found that frog diet differed between the wet and dry
seasons, where frogs had a more diverse diet in the wet season and
consumed a higher percentage of ants in the dry season. To determine if
these differences in diet were associated with variation in frog defensive
chemical composition, we used gas chromatography / mass spectrometry to
quantify toxins from individual skin samples. Although the assortment of
identified toxins was similar across seasons, we detected significant
differences in the abundance of certain alkaloids, which we hypothesize
reflects seasonal variation in the diet of M. laevigata. We suggest that
tThese variations could originate from seasonal changes in either
arthropod leaf litter composition or changes in frog behavioral patterns
between wet and dry seasons. Although additional studies are needed to
understand the consequences of long-term environmental shifts, this work
suggests that toxin profiles are relatively robust against short-term
environmental perturbations.