Picky Tongues: Dietary Variety and Species Size in Local Anurans

Zach Moning, Leo Sack, and Willis Okech

Research Question and Hypothesis

• We asked the question, “How does species size affect the eating habits of anurans?”

• Our hypotheses1. We believe that larger frogs will

have a more diverse diet than that of smaller species

2. We believe that larger frogs will grow in biomass more rapidly than smaller species

Relevance

• Some anurans are plentiful and invasive, many others are disappearing

• Amphibians are bio-indicators; they are like canaries in a coal mine

• If smaller frogs have less diverse diets, they are in greater danger of extinction

Research Design

• We worked with Blanchard’s Cricket Frogs, Northern Green Frogs, and Northern Leopard Frogs

• The specimens were separated into sections of aquaria

• Four types of food were offered (worms, meal worms, crickets, and guppies)

• We recorded the biomass and diet of each frog

Methods

• Every other day, each potential type of food was offered to each frog

• On feeding days, the uneaten food that remained was counted and recorded

• The aquaria were cleaned on feeding days to the best of our abilities

• Every week the frogs were weighed for biomass

Data CollectionEach frog had a designated data sheet for food, and one data

sheet was used to record all of the frogs’ biomasses

Problems

• Financial and time constraints made feeding and cleaning consistently difficult

• Most of the Blanchard’s Cricket Frogs refused to eat in captivity and died. The rest were released in a display of MERCYMERCY.

• Several Northern Green Frogs died under mysterious circumstances

• Some inaccurate measurements plagued our weight data

Rest in peace

Problems (cont.)

• The divisions of the tanks were not fool-proof; guppies, worms, and even frogs occasionally crossed over

• The mealworm bin and fish tank suffered from a mite infestation

• Crickets don’t like water. Amphibians do. Crickets are dumb, and apparently need Prozac.

• Worms burrowed in some of the tanks

Results:Results:

This test compares the average total food eaten by species. There is no significant difference.

This test shows the preferred type of food and compares said preferences between species

This figure shows the difference in weight gain between the two species

Conclusions

1. Green Frogs and Leopard Frogs ate similar amounts of food, despite the latter being generally larger

2. The preferences for food type of the two species were significantly different

3. Species size does not appear to affect relative growth

4. We found no evidence to suggest that species size affects diversity of diets in anurans

Frogs are still neat

For further information, see these sources:

• Davis, Jeffrey G.; Menze, Scott A. In Ohio's Backyard: Frogs and Toads. Columbus: The Ohio Biological Survey, 2002.

• Amphibian Care Sheets http://www.amphibiancare.com

• Frog Web http://www.frogweb.gov

• See our final report online for a complete list (to be posted soon)