Common loon
The common loon (Gavia immer) is a large diving bird in the family Gaviidae, measuring 66–91 cm in length with a wingspan of 104–131 cm and weighing 2.5–6.1 kg.[1][2] It features a thick, pointed bill, red eyes, and plumage that transitions from black head with white underparts and a distinctive necklace-like collar in breeding season to grayish tones in winter.[3][2] Adapted for aquatic life with dense bones aiding dives and legs set far back for swimming efficiency, it pursues small fish underwater but struggles on land, requiring long runways for takeoff.[3][2] Breeding on remote northern lakes larger than 24 hectares with islands, coves, and abundant fish, the common loon prefers clear waters in boreal forests across Canada, Alaska, and the northern United States, including Greenland and Iceland.[3][4][2] It migrates to coastal marine habitats and large southern lakes for winter, often solitary while feeding but forming loose flocks during migration.[3][2] Known for its far-carrying yodels, tremolos, and wails that evoke wilderness solitude, the species communicates territory and distress through vocalizations most active during breeding.[3] The common loon symbolizes northern wildness and is designated the state bird of Minnesota.[5] Monogamous pairs defend territories and lay 1–3 eggs (typically 2) on shore nests, with incubation lasting about 29 days and chicks fledging after 2–3 months under parental care involving substantial fish provisioning.[2] Diet consists primarily of fish supplemented by invertebrates, captured in pursuits up to several meters deep.[3][2] While globally populations remain stable and classified as least concern, regional declines occur due to mercury contamination impairing chick survival, lead ingestion from fishing tackle, habitat fragmentation from shoreline development, and reduced water clarity from climate-driven algal growth.[6][7][8] Conservation measures include lead tackle bans and monitoring programs in key breeding areas.[8][7]