Personalized 1st Bird Day Long Sleeve T-Shirt. IT'S MY BIRD-DAY 1st birthday Long Sleeve T-Shirt - White with a cute little blue bird, yellow and red bird house, butterflies, clouds and number 1. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL