Quail With Pomegranate Jus

Combine shallots, Worcestershire sauce, pepper, 2 tablespoons pomegranate juice, 2 teaspoons tarragon, and 1/8 teaspoon salt in a large bowl. Add quail, tossing gently to coat, then marinate, covered and chilled, at least 2 hours and up to 4 hours.
Remove quail from marinade, scraping off shallots and reserving marinade, then pat quail dry with paper towels and sprinkle with remaining 1/4 teaspoon salt.
Heat 2 tablespoons butter in a 12-inch heavy nonstick skillet over moderately high heat until foam subsides. Cook 4 quail, turning over once, until browned and just cooked through, about 5 minutes total. (Quail will be rare.) Transfer cooked quail to a serving dish and keep warm, loosely covered with foil. Cook remaining 4 quail in remaining 2 tablespoons butter in same manner, transferring to serving dish.
Add reserved marinade to skillet and cook over moderately high heat, scraping up any brown bits with a wooden spoon, until shallots are just softened, about 4 minutes. Stir in remaining 2 tablespoons pomegranate juice and season with salt, then spoon over quail. Sprinkle with pomegranate seeds and remaining teaspoon tarragon.
To juice a pomegranate, cut in half crosswise, then use a manual or electric juicer. Alternatively, remove seeds from pomegranate and pulse seeds in a food processor until juicy, then transfer seeds to a sieve and drain, pressing on and then discarding solids.