// Here we define what it means to be a bird...  We're making the attributes
// protected so that a subclass (e.g. Penguin) can change them.
public class Bird extends Animal
{
  protected double wingspan;

  // we also inherit the attributes:  isHungry, isWarmBlooded

  public Bird()
  {
    weight = 20;
    isWarmBlooded = true;
    wingspan = 30;
    System.out.println(" just created a bird");
  }

  public void feed()
  {
    super.feed();
    System.out.println(this + " eats like a bird!");
  }

  public boolean canFly()
  {
    return true;
  }
}