Assets/Score.cs(12,34): error CS0122: `BirdMovement.dead' is inaccessible due to its protection level

using UnityEngine;
using System.Collections;

public class Score : MonoBehaviour {

static int score = 0;
static int highScore = 0;

static Score instance;

static public void AddPoint() {
	if(instance.bird.dead)**ERROR**
		return;
	
	score++;
	
	if(score > highScore) {
		highScore = score;
	}
}

BirdMovement bird;

void Start() {
	instance = this;
	GameObject player_go = GameObject.FindGameObjectWithTag("Player");
	if(player_go == null) {
		Debug.LogError("Could not find an object with tag 'Player'.");
	}
	
	bird = player_go.GetComponent<BirdMovement>();
	score = 0;
	highScore = PlayerPrefs.GetInt("highScore", 0);
}

void OnDestroy() {
	instance = null;
	PlayerPrefs.SetInt("highScore", highScore);
}

void Update () {
	GetComponent<GUIText>().text = "Score: " + score + "

ERRORHigh Score: " + highScore;ERROR
}
}
Writes can not determine
help
version of the Unity Unity 5.1.1f1 (64-bit)

In Bird movement say public bool dead if it private or instead of birdmovement Bird say public birdmovement Bird and move up