Projects
Maureen Donelly - Ralph Saporito

Poison frogs contain an alkaloid-based chemical defense that is sequestered from a diet of specific alkaloid-containing arthropods (including mites, ants, millipedes, and beetles). On the basis of dietary studies, ants and mites make up a significant proportion of the natural diet of the poison frog, Oophaga pumilio, at La Selva Biological Station. This observation has prompted many authors to suggest that O. pumilio (and other poison frogs) are 'dietary specialists'.

Research Idea 1 – I would like to conduct a series of controlled feeding experiments with O. pumilio to ask general questions regarding dietary preference in poison frogs. For instance, do O. pumilio prefer certain prey items (i.e., dietary specialization)? Or, are they dietary generalists?

On the same lines of ‘dietary specialization’, there is little information regarding the natural availability of arthropods that may be prey items for O. pumilio. The term ‘dietary specialization’ suggests that frogs are selectively choosing certain arthropods regardless of their availability.

Research Idea 2 – I would like to conduct a study to simultaneously examine the diet of O. pumilio (non-destructively, using a technique called stomach-flushing) and availability of arthropods in the environment.

Ants and mites do not appear to be ‘high energy’ food items, yet they are consumed in large amounts by O. pumilio. This may be related to the fact that these frogs are also obtaining alkaloids from these arthropods.

Research Idea 3 – I would like to conduct a series of experiments to examine the differences in ‘energy’ among different food items in O. pumilio. It may turn out that these frogs gain the same amount of energy from eating numerous ants and mites, as compared to less of a more ‘high energy’ food item. This experiment would employ the use of a calorimeter.