Merlin

Royal Tern Identification

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The Four Keys to ID

  • Size & Shape

    A large tern, slender and long winged. The head is fairly large and often has a ragged crest at the back. Royal Terns have a substantial body, a long, forked tail, and short legs. The bill is long and daggerlike.

    Relative Size

    Larger than a Ring-billed Gull (but with shorter legs), smaller than a Caspian Tern.

    Relative Sizecrow sizedcrow-sized
    Measurements
    • Both Sexes
      • Length: 17.7-19.7 in (45-50 cm)
      • Weight: 12.3-15.9 oz (350-450 g)
      • Wingspan: 49.2-53.1 in (125-135 cm)

Regional Differences

Royal Tern’s New World populations are all grouped together as subspecies maximus. The Royal Terns that nest on the central-west coast of Africa are subspecies albididorsalis. However, the South American and African birds are very similar to one another. They are smaller and slimmer than Royal Terns in North America, with longer wings and longer, thinner, paler bills.