What do all birds have in common?

According to PawNation, all birds have feathers, lightweight skeletons, beaks, a four-chambered heart and also lay eggs. Birds are warm-blooded vertebrate that have two legs used for walking, hopping, running or perching. Birds have a unique communication system for courtship behavior, community cooperation, chick-parent recognition and territorial defense.

Birds have navigation skills that allow them to make migratory journeys depending on geographical or climatic conditions. Birds have a wishbone or furcula, which protects organs within the chest cavity from the impact of wing beats. PawNation notes that birds have an efficient and high rate of metabolism, making them highly active animals.