在Java中欺骗单一继承？

public interface Flyable {
    void fly();
}

public class Animal {
    private String name;
    private int age;

    public Animal(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }
}

public class Bird extends Animal implements Flyable {
    public Bird(String name, int age) {
        super(name, age);
    }

    @Override
    public void fly() {
        System.out.println("I can fly!");
    }
}