Almost Invisible

Frog Hidden Object Game Wins Photo Contest

Tonality: This Southeast Asian rice field frog (Fejervarya limnocharis) is barely distinguishable from the bark of the tree it sits on. With its gray-brown color, the frog is almost perfectly camouflaged in this environment. This camouflage protects the approximately four-centimeter-long tiny creature from predators while simultaneously stalking its prey undetected and catching them from behind.

Southeast Asian rice-field frog (Fejervarya limnocharis). © Sritam Kumar Sethy/CC-by 4.0

Whether it's a peppered moth, a sloth, or a snail: camouflage through mimicry is a sophisticated and widespread strategy of nature. Animals adopt a coloration or shape that resembles the plants or substrate in their habitat. This allows them to blend in visually with the background and thus be optimally camouflaged.

This also applies to the frog pictured here: "The frog's camouflage serves a dual purpose: It helps it evade predators such as snakes and birds, while also providing perfect cover for the prey it stalks. With patience and precision, it hunts small insects, millipedes, and worms, relying not on speed but on invisibility and timing," says Sritam Kumar Sethy of Berhampur University in India, who took the photo.

With this image, the student won second place in the "Colourful Strategies" category in this year's photo competition organized by the journals BMC Ecology and Evolution and BMC Zoology. The competition aims to highlight "the beauty, struggles, and survival strategies" of living things on Earth. Each year, a panel of judges selects photos from biologists around the world and sorts their subjects into four categories: Collective Social Behavior, Life in Motion, Colorful Strategies, and Science in Action.

Perfect Camouflage?

"The textures in this image are beautifully captured. As you look at the picture for a while, the frog's features gradually become more detailed, captivating the viewer," says jury member David Ferrier of the University of St. Andrews about this hidden object puzzle.

However, despite its sophisticated camouflage strategy, the frog is not immune to all dangers and predators. It is a popular food source for people in Thailand, Laos, Cambodia, and other Southeast Asian countries where the amphibian is native.

Source: 2025 BMC Ecology and Evolution and BMC Zoology Image Competition, doi: 10.1186/s12862-025-02423-6