toe extending from the tarsometatarsus (foot) or finger extending from the carpometacarpus (hand) of the wing; the finger digits are extensively fused in most birds; Bald Eagles have 4 digits on each foot: first (back digit or hallux with 2 phalanges), second (inner digit with 3 phalanges), third (middle digit with 4 phalanges), and fourth (outer digit with 5 phalanges); the terminal phalanx on each toe is the talon; Bald Eagles have 3 digits on each hand: first (the alula, or the thumb or pollex, with 2 fused phalanges; sometimes labeled the first digit), second (major digit, with 2 fused phalanges + 1 unfused terminal phalanx, which articulates to help raise and lower the distal primary feathers in flight; sometimes labeled the third digit), and third (minor digit, below the second digit, with 1 phalanx, sometimes labeled the fourth digit); primary feather P7 attaches to the third digit and P8-P10 attach to the second digit, by ligaments and tendons