To eat or to care? Factors shaping parental or infanticidal behaviours in male poison frogs during territory takeover.

BACKGROUND

Parental care is costly for the caregiver. Therefore, parents should be able to discriminate between their own and conspecific offspring to avoid costly misdirected care. Infanticide, the intentional killing of conspecific young by adult individuals, occurs in many animal taxa. It has been shown to have several benefits for the perpetrator, such as increasing mating opportunities, ensuring dominance, or reducing a competitor's fitness; but infanticide may also minimise risks of misdirected parental care. Previous studies in Allobates femoralis, a poison frog with parental care, have shown that males transport all tadpoles present in their territory to water bodies, regardless of whether they have sired the clutch or not. However, when taking over a new territory, males cannibalise clutches from the previous territory holder. These findings raise the question as to which factors actually shape parental care and infanticidal behaviour in male A. femoralis after territory takeover. To answer this question, we designed a laboratory experiment, in which we tested males with different territorial status and recent mating activity. We recorded tadpole transport and cannibalism and compared the occurrence of these two behaviours across our different experimental conditions.

RESULTS

We found that territory ownership, relatedness to clutches, and possibly also recent mating activity influenced parental behaviours. However, we were unable to clearly disentangle the factors influencing cannibalistic behaviours. Our results also confirmed that males use territorial recognition to discriminate between their own and unrelated offspring, and that they commit infanticide likely to avoid misdirected parental care.

CONCLUSIONS

Transport and cannibalism appear to be impacted by several factors in different ways. We found that the territorial status and relatedness to the clutch both influence parental behaviours in male poison frogs, whereas the factors influencing infanticidal behaviours remain unclear. Therefore, transport and cannibalism appear to be two independent processes, and factors influencing one behaviour do not necessarily affect the other. Further studies should investigate associated neuroendocrine changes, to better understand the mechanisms underlying parental and infanticidal behaviour in poison frogs. Our findings suggest that the decision-making processes involved in tadpole transport and clutch cannibalism appear to be more complex than previously thought.