Birds are the second largest group of invertebrates, with approximately 10,000 species. They are unique in that they have feathers, lay eggs, have bills instead of teeth, and hollow bones that make flight possible. While not all birds can fly, their respiratory and digestive systems are highly adapted for flight. Birds communicate through song, calls, and behaviors, and most species mate monogamously during one or more breeding seasons. Parrots are found in warm climates and can live between 25-100 years, with cockatoos and macaws on the longer end. Many birds like parrots mimic human speech through a structure in their throat, but they do not truly talk - they merely mimic common sounds.