1. North American subspecies of tundra swan having a soft whistling note
   - whistling swan

Type of: Cygnus columbianus, tundra swan

• popularity contest
• popularization
• popularize
• popularizer
• popularly
• populate
• populated
• populated area
• population
• Population Commission
• population control
• population growth
• population profile
• population scientist
• population shift
• populism
• populist
• Populist Party
• populous
• Populus
• Populus alba
• Populus balsamifera
• Populus canescens
• Populus deltoides
• Populus grandidentata