Fork-tailed gull

from The Collaborative International Dictionary of English v.0.48

Fork-tailed \Fork"-tailed`\, a. (Zool.)
   Having the outer tail feathers longer than the median ones;
   swallow-tailed; -- said of many birds.
   [1913 Webster]

   {Fork-tailed flycatcher} (Zool.), a tropical American
      flycatcher ({Milvulus tyrannus}).

   {Fork-tailed gull} (Zool.), a gull of the genus {Xema}, of
      two species, esp. {X. Sabinii} of the Arctic Ocean.

   {Fork-tailed kite} (Zool.), a graceful American kite
      ({Elanoides forficatus}); -- called also {swallow-tailed
      kite}.
      [1913 Webster]