tattler

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun One who tattles.
• noun Either of two shorebirds of the genus Tringa found in Asia, Australia, and western North America, especially T. incana, noted for its loud cry.

from The Century Dictionary.

• noun One who tattles; an idle talker; a prattler; a telltale.
• noun In ornithology, a bird of the family Scolopacidæ and genus Totanus in a broad sense; one of the Totaneæ; a horseman or gambet: so called from the vociferous cries of most of these birds.

from the GNU version of the Collaborative International Dictionary of English.

• noun One who tattles; an idle talker; one who tells tales.
• noun (Zoöl.) Any one of several species of large, long-legged sandpipers belonging to the genus Totanus.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun One who tattles (notifies authorities of illicit behavior) or is inclined to do so; a tattletale.
• noun Either of two similar bird species in the shorebird genus Heteroscelus (Tringa in some taxonomies).
• noun A device fitted to a vehicle to measure mileage etc.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun any of several long-legged shorebirds having a loud whistling cry
• noun someone who gossips indiscreetly