Congratulations to Erin Talmage for winning the April 2021 Photo-observation of the Month for the Vermont Atlas of Life on iNaturalist. Erin’s image of a North American Medicinal Leech feeding on Wood Frog eggs in the Birds of Vermont Museum’s pond garnered the most faves this month.
As surreal as this scene looks, predation of wood frog eggs by leeches is actually a relatively common occurrence! Because the egg masses of wood frogs and other frog species in the northeast lack the protective, gelatinous outer layer of spotted and jefferson salamander egg masses, they are more vulnerable to predation by a host of aquatic predators from leeches, to newts, to aquatic insects. While vernal pools are an attractive egg-laying site for many of Vermont’s amphibians due to their lack of fish predators, they are by no means a completely safe nursery for frog and salamander eggs, as evidenced by Erin’s amazing photograph. Wood Frogs combat this inevitable predation by laying an overwhelming number of eggs consisting of 800 to 2,000 embryos per egg mass, certainly more than any leech could eat in one sitting!
Visit the Vermont Atlas of Life on iNaturalist where you can vote for the winner this month by clicking the ‘fave’ star on your favorite photo-observation. Make sure you get outdoors and record the biodiversity around you, then submit your discoveries and you could be a winner!