Common names are lowercase, unless they contain a proper name:
Follow the spelling of common bird names in Merriam-Webster’s Collegiate or Unabridged dictionaries.
Generally do not hyphenate compound common names such as sage grouse. Follow standard Style Manual guidelines for hyphenating compounds before a noun:
Some publications may want to follow the naming convention from the American Ornithologists’ Union, which hyphenates terms like sage-grouse. National Geographic’s Field Guide to the Birds of North America, for example, follows these guidelines.