Brandon Güell's Image

Brandon Güell (Costa Rica/USA) wades through murky water to document a rare frog breeding frenzy.

Plagued by mosquitoes, Brandon waded chest-deep into the murky water. At dawn, after torrential rain, thousands of female gliding treefrogs arrived at the pool to lay their eggs on overhanging palm fronds. They had been attracted by the calls of the waiting males, which were ready to fertilise their eggs once laid.

These spectacular mass breeding events occur in only a few remote locations, just a handful of times a year and are hard to predict. Brandon had been up at four in the morning for days in anticipation of catching one.

A huge mass of eggs is created, with each female laying around 200 eggs. The eggs are green when freshly laid but soon turn translucent, revealing the developing embryos inside. Most of the embryos will die due predation, fungal infection or increased dry spells resulting from climate change. Any surviving tadpoles drop into the water below and continue to mature.