As a Midwest girl who has always loved tropical frogs, this trip through Costa Rica’s rainforests is an exciting new experience. I have lost count of the number of species of frogs and toads I have seen over the last ten days. But one has emerged as my favorite species, the blue-jeans or strawberry poison dart frog (Oophaga pumilio).
The strawberry poison dart frog parents have some unique parenting habits. Once the eggs are fertilized the male watches over the eggs until they hatch. The female then returns to load the tadpoles onto her back and transports them to small pools of water high up in the canopy. She continues to care for her developing tadpoles by feeding them unfertilized eggs until they develop into adults. The tadpoles live on only unfertilized eggs delivered by their mother, a highly unique diet for tadpoles.
One day last week while traipsing through the rainforest in the pouring rain, I had a thought; does acid rain have the potential to harm my beloved poison dart frogs? This thought blossomed into my independent research proposal, which is looking at the possible connection between increases in the acidity of rain and the decreases in frogs populations. My research into the topic suggested it was possible for two main reasons. First, poison dart frogs use small pools of rain water as a nursery for their young. This means that tadpoles are potentially exposed to highly acidic conditions that could slow their growth and development. Second, frogs use their skin to breath, which leaves them exposed to environmental changes such as increasing acidity.
As frog populations around the world have begun to decline, it is rapidly becoming important to understand all of the factors effecting frogs. The chytrid fungus may be the most well known threat to frogs but there are still many mysteries surrounding it and acid rain may be one piece of that puzzle.