Gaviiformes – Loons (divers)

This order encompasses a remarkable avian lineage represented by the iconic and highly specialized aquatic birds known as loons. These unique foot-propelled divers are renowned inhabitants of the northern hemisphere, where they navigate the frigid waters of Arctic lakes and tundra expanses with remarkable grace and efficiency.

Loons are distinguished by their dense plumage, meticulously adapted to insulate them from the intense cold of their aquatic habitats. Their plumage undergoes a fascinating transformation throughout the year, transitioning from a subdued grey-brown hue during non-breeding periods to a resplendent alternate breeding plumage characterized by bold black, white, and grey patterns, accentuated by a striking red iris. This seasonal change not only enhances their visual appeal but also serves vital functions in thermoregulation and mate attraction.

Anatomically, loons exhibit a unique foot placement, with their feet situated far back on their bodies. While this hind-positioned configuration poses challenges for terrestrial locomotion, it bestows upon them unparalleled agility and maneuverability underwater. Loons are masterful divers, capable of descending to depths exceeding 75 meters (250 feet) and remaining submerged for extended periods as they pursue their primary prey: fish.

In addition to their exceptional diving prowess, loons are highly adept navigators of their aquatic environments. They rely on a combination of keen senses, precise movements, and remarkable hydrodynamic adaptations to thrive in the complex underwater realm. Their ability to locate and capture prey with remarkable efficiency underscores their status as apex predators within northern freshwater ecosystems.

Despite their aquatic prowess, loons face unique challenges when traversing terrestrial terrain, where their hind-positioned legs limit mobility. However, these limitations are far outweighed by their mastery of the aquatic realm, where they reign supreme as formidable predators and essential components of northern freshwater ecosystems.