HOOFED MAMMALS

Under construction May 2011

HOOFED MAMMALS

ORDER ARTIODACTYLA (the even-toed ungulates)

Family Cervidae (the cervids)

Caribou/ Reindeer (Rangifer tarandus)

Moose (Alces alces)

Roosevelt Elk/ Olympic Elk (Cervus Canadensis Roosevelt)

Sitka Black-Tailed Deer (Odocoileus hemionus sitkensis)

Family Bovidae (the bovids)

American Bison ( Bison bison)

Calf/ Cattle (Bos Taurus)

Dall Sheep (Ovis dalli dalli)

Mountain Goat (Oreamnos americanus)

Muskox (Ovibos moschatus)

LENGTH: The guard hairs are usually quite large, usually over 200 microns and sometimes up to 500 microns.  However, leg hair of animals is sometimes used, and can be much shorter.  Guard hairs of hoofed animals can sometimes be quite wavy or crimped-looking in the macro view.  Long hairs are seen on the bell or fur under the neck of moose (up to 160mm), caribou (up to 120mm) and elk (up to 110mm).  Mountain goat and bison can reach 150mm, but the longest hairs are from the muskox, with lengths up to 350mm measured.

WIDTH: Hicks (1977) suggests guard hairs for artiodactyla in the 300 microns range, although among Alaskan samples taken only moose, elk and Sitka black-tailed deer were measured that large.  The moose consistently will have the widest guard hairs, possibly over 500 microns.  Anything over 400 microns wide is most likely moose.  Elk were measured up to 400 microns, and Sitka Black Tailed Deer have guard hairs reaching 380 microns wide.  Caribou hairs rarely exceed 275 microns wide, and all the bovids are narrower than 250.  Mayer (1952) reports that the family cervidae will have a maximum width of 305 microns with tip possibly having pigment granules for the last 3-4mm and family bovidae will have maximum  width 107 microns and with tip possibly having pigment granules for only the last 2mm.

MEDULLA: Most of the cervids have a honeycomb medulla.  Caribou medulla cells seem to have a distinctive “cuspy” appearance.  The cells seem to push against each other and create defined ridges, and the resulting appearance is a little like a faceted gemstone.  All the other honeycombed medullas have a much more rounded appearance and don’t seem cusp-like in appearance. 

MEDULLARY INDEX: Usually not measured on animals with a honeycomb medulla as the medulla is so wide.

SCALE: Most of the cervids have fish-scale looking cuticle layer, although sometimes the edges are smooth and sometimes they are more jagged and there is not enough sample at this time to indicate if this information gives a useful diagnostic pattern.

UNDERFUR:  Most hoofed animals have no medulla in their underfur, and a moderate amount of pigment.  Elk and muskox have some intermediate sized hairs, and their presence is especially helpful in distinguishing the elk.  Mountain goat is the only hoofed animal with a consistent uniserial ladder medulla.  Dall sheep have an interrupted medulla.  Moose underfur will be pigmented brown consistently and the medulla is interrupted or absent.  Sitka black tailed deer have a rare but notable interrupted medulla that should be represented in most samples.  All the underfur of the hoofed animals has scales like stacked crowns

COLOR:  White fur typical of Dall sheep or mountain goat.  To distinguish between them, look at the underfur.  Banding occurs on the Sitka Black-Tailed Deer, elk, and moose.  Caribou will not have stark white and black fur the way cow does.

SUMMARY: This order has the only animals with a honeycomb or bubble-pack looking medulla of polygonal cells with very little cortex present.  Having a lack of cortex and a thin cuticle leads to brittleness.  This honeycomb medulla look can be mistaken for a scale pattern, but the scale pattern when observed from a scale cast usually looks like wide blunt fish scales.  If you see a honeycomb medulla, the Alaskan mammal will usually be a deer-like animal from the Cervid family, but the Dall Sheep also has this kind of medulla and it is a bovid.  To confirm Dall Sheep, look at the underfur.  It will be totally unpigmented and have an easy-to-see interrupted medulla.  Porcupines may sometimes be mistaken for having a honeycomb medulla….look for some visible cortex, banding, and scale pattern differences.

In distinguishing the hoofed animals that do not have a honeycomb medulla, length and medulla appearance are useful.  Bison and Muskox both have long guard hairs, but the bison has a rather narrow shaft for a hoofed animal (under 100 microns).   It is also easier to see a splotchy dark-and-light pattern in the muskox medulla while the bison medulla is very dark.  Muskox medulla in the guard hair may also be off-center, and gets very narrow and disappears as it approaches the tip.  Underfur of muskox may have interrupted medulla, an intermediate sized hair, and variation in whether or not they are pigmented.  The bison underfur is uniformly pigmented with light brown and has no medulla.

Cow and horse may sometimes be used in Alaska, and have a lot of variation.  A single sample of cow or horse might have a very dark medulla in one hair and none in the hair next to it.  Underfur is generally not present, and the guard hairs are very short with the exception of mane and tail hairs. Moore et al (1974) say cow and horse may be distinguished by the wide unbroken medulla in the base of horse hair.  Caribou fur does not come very white or very black as seen in cow fur, often seen on parka piecework.  

Images upcoming

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