Amphibian Egg Mass Surveys

One of the things I do in my spare time (for self-serving fun and career development as well as stewarding my planet) is volunteer with Northwest Trek and Washington Department of Fish and Wildlife conducting amphibian egg mass surveys. No, I don’t go door to door asking questions about egg masses. I go to a pond and look for the eggs that several species of amphibians left behind following breeding.

            First, what is an amphibian? It’s a critter that leads a double life as both a terrestrial and aquatic animal. Unlike a reptile like an alligator that must surface to breathe, amphibians can breathe above or below water. The word amphibian comes from the Latin amphi bios meaning two lives.

            There are 27 species of amphibians in Washington, but WDFW only has us looking for the eggs of 8. They are Oregon spotted frog (state endangered, federally threatened), red-legged frog, American bullfrog (invasive to the Northwest), Pacific tree frog, western toad (candidate for listing as federally threatened or endangered), Northwestern salamander, long-toed salamander, and rough skinned newt.

            The pond I survey is in Eatonville. In and around, I have found eggs, tadpoles, or adults of four of those species. There were Northwestern salamander, Pacific tree frog, and red-legged frog egg masses; adult Pacific tree frogs, a red-legged frog, and American bullfrogs; and some tadpoles that were too fast to be able to identify.

American bullfrog

Red-legged frog

Pacific tree frogs

            To conduct a survey, I go into the pond with my partner Roger and slowly walk around looking for eggs. It seems like a challenge at first, but the egg masses are very obvious in most cases. Northwestern salamander egg masses are a huge solid ball of jelly, about the size of a grapefruit. They are likely to be attached to a pond lily stem. Pacific tree frog masses are smaller balls of jelly attached to smaller aquatic plants in most cases.

Northwestern salamander egg mass

Pacific tree frog egg mass

            When we find egg masses, we mark the location on a GPS and take a picture. It also gets logged on a tracking sheet. Last March the batteries in either the GPS or camera died and the spare batteries in our pack were also dead. It was a little frustrating switching batteries from one device to the other, especially because that was the day a river otter was helping us. It would’ve been great to get a shot of that little guy! As a consolation, we found a pile of his poo.

River otter scat

            Gently cleaning our waders before and after conducting a survey is a thoughtful way to help prevent the spread of invasives from one pond to another. It can also help reduce the spread of chytrid fungus, which causes disease in amphibians.

            The data we collect gets sent to the state to help biologists determine habitat conditions and species trends. Amphibians are an indicator species (species that can indicate trouble in an ecosystem by absence or presence) because their thin skin makes them very sensitive to environmental changes. By identifying trouble early on, biologists can analyze and correct the situation.

            Now you have a glimpse inside the working world of a nature guy. I’ll be back in the pond for a third season of egg mass surveying, starting this week. Weather permitting, of course. Don't forget to like Nature Minute on Facebook!