The neotropical otter is covered in a short, dark grayish-brown pelage. The bovids show great variation in size and pelage colouration. Specimens in worn pelage varied to yellowish-brown and reddish. The greyish brown of the upper-parts of the pelage is interspersed with silvery hair. These primates do not appear to show any sexual dimorphism in relation to pelage coloration. Their pelage (coat) is any shade from fawn to rufous, typically rather orange. The golden tiger has a pale golden pelage with a blond tone and reddish-brown stripes. In preparation for winter most populations moult into a white (or largely white) pelage. It has a thick and woolly pelage that varies in colour depending on the subspecies. Occasionally, colour mutations such as albinos and white spots throughout the pelage occur. Such variation depends largely on the amount of guard hairs relative to regular pelage. The ground colour of Siberian tigers' pelage is often very pale, especially in winter coat. The color of the pelage is unique among martens, being bright and variegated. The summer and winter pelages are distinctive with the winter pelage being much darker. The sitatunga is almost indistinguishable from the nyala, except in pelage and spoor.