Throughout the many years that I have been tying flies or teaching tying classes, I have been asked a plethora of questions regarding what types of materials I use and why. One specific question that I have had to answer more than once, that I think would help beginner tiers is what are most common tailing materials I used in the patterns I tie and why. Of course the tailing materials are dependent on the style of fly you are planning on tying but I will substitute different materials called for in patterns for my top four tailing fibers.
Squirrel Tail is the first material in my tailing list. This natural fiber a durable material that is super easy to work with. The hair in general is fine, soft and barred in color. Squirrel tails are a durable fly tying material that is easy for tiers of all experience levels to work with. All you need is a sharp pair of scissors and a hair stacker to create some cool tails for your favorite nymph or wet fly patterns.
Calf Tail (or kip tail) is the second material on my list. This fiber is a crinkly, wavy, fine type of hair that is well suited for creating semi-stiff tails for your flies. Calf tail should be the hair you reach for when you need a material that is semi-stiff, fine, but is still capable of pushing some water. Calf tail when used in dries is a material that allows them to balance on the water's surface when tied in conjunction with a bushy hackle.
Bucktails are as good as materials get for tailing. Bucktail is a stiff hair that keeps its shape but still moves some in the water. It is also durable, versatile, easy to work with, and comes in a variety of colors. Widely used in streamers (from trout to saltwater), bucktail is essential for large minnow patterns.
The last of my fantastic four tailing materials is Moose Mane. This special material has a hollow core that allows each hair to float, naturally lending it to use in dry flies. Soft, but still durable, moose mane can be used to create mayfly tails, or extended bodies (or tails) for your favorite dries. A popular choice by many tiers, moose mane is key material when tying many productive fresh and saltwater patterns.
With these four materials in your kit for tying flies, you will have your bases covered to catch a variety of fish. Don't be afraid to try new things and substitute different tail materials to suit your needs.