RACCOON

Under Construction May 2011

RACCOON

Procyon lotor

GUARD HAIR

Length: 40-60mm (Brown 1942), 50mm (Mayer 1952), Longest mane hairs 50mm (Adorjan and Kolenosky 1969), 74mm max (Moore et al 1974), 110mm max (Furskin 2006), 50-65mm (ASM #1)

Diameter Range: 100-268 microns (Brown 1942), 180 microns max (Mayer 1952), 154 microns (Moore et al 1974), minimum shaft diameter just above the root averages about 46% of the maximum shaft width (Tumlison 1983), 70-110 microns (Furskin 2006), 65-90 (ASM #1)

Medullary Index: 0.38 ave MI<0.4 and ill-defined cells (Brown 1942). 0.35-0.47 (ASM #1).

Medulla: Continuous, looks amorphous in the proximal region near the root and then becomes vacuolated as it moves away from the root end. Impression that medulla is “froth” with various sized bubbles.  Sometimes medulla looks to have two transparent cells side by side across the width. The cells are rounded in some locations and wedge-shaped in others. The cells are surrounded by air, appearing an opaque black mass that forms straight lines at the perimeters of the medulla (ASM #1). A second guard hair showed a very different-looking medulla. This fiber showed a continuous medulla with a straight perimeter and many tiny cells are clustered close together throughout. The cells have an indistinguishable shape and are difficult to focus on, though slightly easier to see them in polarized light (ASM #1).   Hicks (1977) reports a medulla that is amorphous at the base and then vacuolated at the tip.

Color: Hairs never entirely white.  In cross section, there is a narrow zone of pale yellow in the periphery on darkly pigmented hairs that is diagnostic (Mathiak 1938).  Hair often banded, white at the base, then dark brown in the midshaft with a light-colored tip.  Pigment granules crowded toward medulla.  ASM samples were light beige at the base, then dark grey band, light beige band and a black tip.

Scales:  The scales have a slightly curved top ridge overall and there are subtle undulations on this ridge, giving the appearance of a wavy line. There are two to three scales per the width of the fiber. (ASM #1) Snake-like diamond petal shaped scales near the base, turning more irregular and rough-edges in the middle, the closely spaced with very rough edges at the tip.

 

UNDERFUR

Length: 20-30mm and kinky (Brown 1942), 20-25mm (Adorjan and Kolenosky 1969), 20-25mm (ASM #1)

Diameter Range: 20-60 microns (Brown 1942), 10-25 microns (Furskin 2006), 10-35 microns (ASM #1)

Medullary Index: 0.41 (Brown 1942)

Medulla:  Usually absent, when present it is fragmentary (Brown 1942). Uniserial ladder (Furskin 2006). Fragmentary in some samples and absent in others (ASM #1).  Generally lacking or fragmental  (Mathiak 1938)

Color: Present in the cortex but absent in the medulla.  Brown says it is usually stained a deep rich brown.  Base usually free of pigment and stain. (Brown 1942). Streaky brown (ASM #1). Dark grey or brownish-grey (Adorjan and Kolenosky 1969)

Scales: Flower petal-like with each individual scale having one point. Scales were measured at 32.5 microns from tip to tip on one sample.  These sharp petals are unusual for rodents, although a few underfur hairs with stacked crowns can usually be found in the raccoon sample as well.

Macro Qualities: 2.5 -3.1 feet long, 4-6 rings on tail (Forsyth 1999) Sheared raccoon is brown like beaver but no belly stripes  (Bachrach 1953). Guard hair is brown-gray or yellow-gray with dark tips. Some guard hairs are white.  Underfur is gray or gray-brown.  Skin is 40-70cm long and tail is 20-40cm long (Furskin 2006).  Color bands not distinct, but blending.. Black tip on a back hair less than one half inch long and hair not wavy at the base like the hair on a coyote tail might be  (Stains 1958).  Mane hairs are curved, other guard hairs tend to be wavy (Adorjan and Kolenosky 1969).  Fresh water habitats give preferred dark colors, and salt water habitats give reddish brown coloration (Samet 1950).

Cultures: For example, the fur industry produced a lot of men’s fashion coats from raccoon in the 1920’s, and “Davy Crockett” style caps in the 1950’s.

Notes: ASM #1 from the ASM education collection pelt ring, ASM #2 is from the Cargille Reference Set F-5 commercial furs.  Introduced into Alaska in the 1930’s for the fur trade. 

Troubleshooting: To distinguish from canidae, the light band right before the white tip should be more than 11mm long, while the maximum shaft length of the hair should be less than 50mm.  Differs from Lynx because of its compound medulla, while the lynx has bigger vacuoles in the medulla? (Mayer 1952)  Raccoon has distinctly banded guard hair, white near the base, then a brown band, and then a light tip.  The underfur is also an important clue for raccoon.  In some samples there is no medulla, and in others the medulla is very interrupted if it appears at all.  The scale pattern of the raccoon underfur has a prominent spiky pinecone look as well.  Medullary index in the rodents tends to be 0.6 to 0.9, and a narrower medulla might be a useful clue for the beaver and the raccoon, whose medulla is in the 0.3 to 0.4 range. 

Range: Very small but stable populations in Southwest Alaska.

Names: Order Rodentia (the rodents)

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