Thrushes (Turdidae)

Eastern Bluebird (Sialia sialis) - HBW 10, p. 625

French: Merlebleu de l’Est German: Rotkehl-Hüttensänger Spanish: Azulejo Oriental
Other common names: Azure Bluebird

Taxonomy: Motacilla Sialis Linnaeus, 1758, South Carolina, USA.
Occasionally hybridizes with S. currucoides. Geographical variation slight, and level of individual variation in morphology and behaviour within and between populations remarkably high; in addition, lack of a “prealternate” moult results in very worn birds in spring and summer, confounding racial analysis and attribution; bermudensis, grata and meridionalis possibly untenable. Proposed race episcopus (S coastal Texas, in USA, S to S Tamaulipas, in NE Mexico) considered indistinguishable from nominate. Eight subspecies recognized.

Subspecies and Distribution:

  • sialis (Linnaeus, 1758) - S & SE Canada and E USA S to NE Mexico; non-breeding also N Mexico and Bermuda.
  • fulva Brewster, 1885 - SW USA (SE Arizona) S through montane C Mexico.
  • grata Bangs, 1898 - SW USA (S Florida).

     See all 8 subspecies
  • sialis (Linnaeus, 1758) - S & SE Canada and E USA S to NE Mexico; non-breeding also N Mexico and Bermuda.
  • fulva Brewster, 1885 - SW USA (SE Arizona) S through montane C Mexico.
  • grata Bangs, 1898 - SW USA (S Florida).
  • bermudensis Verrill, 1901 - Bermuda.
  • nidificans A. R. Phillips, 1991 - Caribbean slope of EC Mexico.
  • guatemalae Ridgway, 1882 - SE Mexico (Chiapas) and Guatemala.
  • meridionalis Dickey & van Rossem, 1930 - El Salvador, Honduras and N Nicaragua.
  • caribaea T. R. Howell, 1965 - E Honduras and NE Nicaragua.