Snowy Egret

Snowy egrets are large fishing birds that stay year-round in San Diego’s wetlands. In the winter, the chilly waters can become dangerous without a way to conserve heat. The thinness of the snowy egret’s legs would usually result in more heat loss since there is less mass to store the thermal energy. To combat this, egrets have a special way to regulate their body heat: countercurrent exchange. They have two veins in their legs running antiparallel, one the travels from the heart down to the feet (arterial) and the other traveling in the opposite direction (venous). The arterial blood is warmer, and as it flows, it exchanges heat with the colder venous blood. The now warmed venous blood travels back up to the heart, heating that vital organ. This special heat regulation allows both the heart and the legs to stay warm in the chilly waters. In buildings requiring lower energy heating systems, this antiparrallel pattern can be mimicked to ensure more efficient heat distribution.

Fishing in wetlands, snowy egrets have adapted to maximize their hunting prowess. The signature S-shaped neck acts as a powerful spring when the egret swiftly extends it to stab. This particular bend in the neck is also highly aerodynamic: it reduces air resistance as the egret flies. Robots, drones, and other technologies specializing in locomotion through the air may take direct inspiration from this S-shape to create an aerodynamic design capable of rapidly extending itself for whatever specified purpose.

Sources:
https://www.ornithology.org/adaptations/countercurrent-exchange
https://www.allaboutbirds.org/guide/Snowy_Egret/id
https://www.audubon.org/magazine/more-you-ever-wanted-know-about-heron-necks