August 20, 2017

Dall Sheep Bio

DALL SHEEP (Ovis dalli dalli) INHABIT THE MOUNTAIN RANGES THROUGHOUT MUCH OF ALASKA and are found in relatively dry country that has the special combination of open alpine ridges, meadows and steep slopes that also offer very rugged escape terrain. Dall sheep primarily use the open ridges, meadows and slopes for feeding and bedding. There they feed on a variety of plants including grasses, sedges, mosses and lichens. When, and if, danger approaches they will often flee to the ledges and crags of the escape terrain to elude predators. Sheep are very loyal to their home ranges but will often travel within that relatively small home range to bedding and feeding areas and between winter and spring ranges.

Male Dall sheep are called rams and are distinguishable by their massive curling gold or tan colored horns. Dall sheep horns grow continually throughout the sheep’s life with the majority of the growth occurring in the spring, summer and early fall of each year. In the late fall and winter horn growth slows considerably in part due to body chemistry changes during the rut, or breeding season, which occurs in November and December, as well as the reduced availability of food during the winter months. This change in horn growth rate creates a pattern of rings, called annuli, which are spaced along the length of the horn. These annuli rings can help to accurately determine the age of a ram.

A rams horns grow in a circular manner when viewed from the side, while at the same time grow in either a converging or diverging manner when viewed from the front or back. Converging horns, when viewed from the front, tend to grow inwards towards the face while diverging horns tend to grow outwards, away from the face and “flare” to the sides. Typically, rams horns reach half a circle (half curl) between two and three years old, three quarter curl in four or five years, seven-eighths curl in six or seven years and full curl by age seven or eight. Throughout most of Alaska, hunters are required to harvest Dall sheep rams that have achieved full curl, are at least eight years old or are “broomed” on both sides (have both horn tips broken off). Generally speaking, a twelve year old ram is considered very old and most rams die, either through predation or natural causes, between ages eight and eleven. The average size for a full curl, legal ram in Alaska is approximately 33 inches.

Female Dall sheep, called ewes, have shorter, more slender and slightly curved horns. Rams and ewes can be difficult to distinguish until they are about three years old, after which the continued horn growth of the rams makes them easily recognizable. Beginning at about age three, ewes usually give birth to a single lamb in late May or early June and within a week of birth the lambs are feeding on vegetation and are generally weaned by October.

Sheep have a very well developed social structure or hierarchy and generally the rams do not associate with the ewes and lambs except during the breeding season. The classic horn clashing that has helped to make sheep of many species famous is not a result of fighting over specific ewes for breeding, but is a way that rams, and occasionally ewes, establish the bands social order and an individual sheep’s place in that order, which in turn helps them to organize a breeding order. Though rams are capable of siring offspring at eighteen months of age, most of the successful breeding is done by the older, more dominant full curl rams.

Dall sheep are relatively short, stocky animals and generally have an adult live ram weight of between 200-250 pounds; a carcass weight of approximately 120 pounds and a boned-out carcass weight of 80 pounds. Dall sheep meat has an excellent flavor and I consider it the finest wild game meat I have ever had the pleasure of eating. When considering a Dall sheep hunt, the most important factor is a hunter’s mental and physical condition. Dall sheep are considered by many to be one of North America’s ultimate big game trophies due in part to the fact that it can require a great deal of physical and mental fortitude to harvest these monarchs of the mountains!

– Henry Tiffany with portions excerpted from the Alaska Department of Fish & Game Wildlife Notebook Series