First here are a couple of quotes from some predator identification articles. A link to the article follows the quote.
Skunks
•Skunks kill few adult birds, When skunks kill poultry, they generally kill only one or two birds and maul them considerably. Crabb (1941) observed that spotted skunks help control rats and mice in grain storage buildings. They kill these rodents by biting and chewing the head and foreparts; the carcasses are not eaten.
•Skunks are serious nest robbers. Eggs are usually opened at one end; the edges are crushed as the skunk punches its nose into the hole to lick out the contents. The eggs may appear to have been hatched, except for the edges. When in a more advanced stage of incubation, eggs are likely to be chewed in small pieces. Eggs may be removed from the nest, but rarely more than 3 feet (1 m) away.
•Most rabbit, chicken, and pheasant carcasses found at skunk dens are carrion that have been dragged to the den sites.
Weasels
•Weasels and mink have similar feeding behaviors, killing prey by biting through the skull, upper neck, or jugular vein.
•In poultry houses, they often kill many birds, eating only the heads of the victims. Predation by rats usually differs in that portions of the body are eaten and carcasses are dragged into holes or concealed places. One farmer suggested that weasels and mink attack hens underneath the wing.
•While eating large muskrats, make an opening at the back or side of the neck. As the mink eats away flesh and pieces of the adjacent hide, the ribs, head, and hindquarters are pulled out through the same hole and the animal is skinned. Similar feeding behavior by weasels occurs when they eat small rodents.
•Weasels eat eggs by breaking in at the ends. (openings 1/2 to 3/4 inch (1.5 to 2.0 cm) in diameter). Close inspection of shell remains frequently will disclose finely chewed edges and tiny tooth marks.
http://icwdm.org/inspection/livestock.asp
Skunks
Skunks do not kill many adult birds. In general, when a skunk attacks a flock, it kills only one or two birds and mauls others considerably. Also, skunks love eggs. Usually, a skunk opens an egg at one end and punches its nose into the hole to lick out the contents. Eggs that have been eaten by a skunk may appear to have been hatched, except that the edges of their openings are crushed. A skunk may remove eggs from a nest but rarely carries them more than 1 meter (3 feet) away.
Weasels
The least weasel has been referred to as the smallest living predator. It is long and slender, with a long neck, a narrow head, and short limbs. Least weasels weigh only about 30 to 55 grams (1 to 2 ounces) and are usually 165 to 205 millimeters (6-1/2 to 8 inches) long, with much of that length being tail. They are seldom seen and rarely trapped. They are active day and night and in winter and summer, and they do not hibernate. When a least weasel kills, it wraps its body and limbs around its prey and kills with a bite to the base of the skull. Least weasels can squeeze through holes as small as 1/4-inch in diameter. Consequently, they typically can get through chicken wire. Because a weasel must eat food equal to four times its body weight each day, weasels are voracious eaters.
http://articles.extension.org/pages...mall-and-backyard-poultry-flocks#.VDQPcxEtCUk
Hayley, if you read it, they do not say weasels always without a doubt 100% of the time kill every chicken anywhere around. They often kill many, not always kill them all. While certain species of predators often follow similar behavior, not every predator of that species always acts the same way. Or sometimes they hear you or another threat approaching and don’t finish what they start. Treat these things as clues to what it might be, not as absolute proof of what it was.
Skunks are mostly scavengers but most scavengers will kill when they have a good opportunity. These critters are living animals. Words like often and mostly need to be noticed when thinking about them. FluffyChickens6 saw the skunk. How much proof do you need that the problem there was a skunk?