Ermine
Plates [2], [3], [4], [9], [10] and [11]
[Putorius arcticus] subspecies kadiacensis Merriam, N. Amer. Fauna, 11:16, June 30, 1896.
Putorius kadiacensis, Preble, Proc. Biol. Soc. Washington, 12:169, August 10, 1898.
Mustela kadiacensis, Miller, U. S. Nat. Mus. Bull., 79:97, December 31, 1912.
Mustela erminea kadiacensis, Hall, Journ. Mamm., 26:179, July 19, 1945.
Type.—Male, subadult, skull and skin; no. 65290, U. S. Nat. Mus., Biol. Surv. Coll.; Kodiak Island, Alaska; April 25, 1894; obtained by B. J. Bretherton, original no. 304.
The skull lacks the basioccipital, part of the basiphenoid, the occipital region on the right side and the posterior part of the right tympanic bulla. The third, upper, left incisor is missing. Otherwise the teeth all are present and entire.
The white, winter skin is only moderately well stuffed but in a good state of preservation. The spring coat is appearing along the back. This coat is visible at only two places unless the hair be parted when the new brown pelage, which is coming in, can be seen all along the midline of the back.
Range.—Kodiak Island, Alaska. See figure [25] on page [95].
Characters for ready recognition.—Differs from M. e. arctica in hind foot less than 33 in females and in zygomatic breadth amounting to less, instead of more, than distance between last upper molar and jugular foramen irrespective of sex.
Description.—Size.—Male: One adult and 3 subadults yield average and extreme measurements as follows: Total length, 341 (318-360); length of tail, 93 (86-102); length of hind foot, 47 (44-49).
Female: An adult measures: Total length, 258; length of tail, 70; length of hind foot, 31.
Color.—As described in M. e. arctica, except that least width of color of underparts averaging 54 (40-83) per cent of greatest width of color of upper parts. Black tip of tail in 3 males in summer pelage averaging 80 (70-90) mm. which is 85 (69-96) per cent of length of tail-vertebrae.
Skull.—Male (based on 2 adults): See measurements and plates [2]-[4]. As described in Mustela erminea richardsonii except that: Weight 3.1 grams; basilar length, 42.6 (42.1-43.2); length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes averaging more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus.
Female (based on one adult, no. 98042): See measurements and plates [9]-[11]. As described in Mustela erminea richardsonii except that: Weight, 1.2 grams; basilar length, 33.0; length of tooth-rows more than length of tympanic bulla.
Comparison with arctica has been made in the account of that subspecies. Although richardsonii and kadiacensis are described as having the zygomatic breadth less than the distance between the last upper molar and jugular foramen, the zygomatic breadth is considerably more in kadiacensis than in richardsonii; consequently the two dimensions are more nearly equal than in richardsonii. Except for being slightly narrower, the skull of kadiacensis is only a slightly smaller edition of that of arctica.
Remarks.—When naming the weasel from the mainland of Alaska as new, under the name Putorius arcticus, Merriam (1896:16) wrote: "A small form of arcticus occurs on Kadiak Island. . . . It is probably worthy of recognition as subspecies kadiacensis." The informality of this description possibly was in part due to the describer's recognition of the fact that the degree of difference between arcticus and the insular kadiacensis was slight. Specimens collected after Merriam proposed the name for the weasel of Kodiak Island show the animal there to be less different from arctica of the adjacent mainland than he thought; small size is the most pro nounced distinction of kadiacensis and Merriam's male type specimen is smaller than any of the five additional males saved from Kodiak Island since that time. Even so the differences fully warrant subspecific recognition, in my opinion, although kadiacensis is not a strongly differentiated race. More adult females are needed to ascertain the norm of form and size for that sex. If the one female known is typical, the difference from arctica is more pronounced in females than in males. The lesser size of kadiacensis can hardly be credited entirely to the effect of insularity, for animals from the southern part of the mainland, on Kenai Peninsula for example, are smaller than those from central and northern Alaska and provide evidence of intergradation of a sort between kadiacensis and arctica.
Specimens examined.—Total number, 9, all from Kodiak Island, Alaska, and unless otherwise indicated in the U. S. National Museum.
Karluk, 1 (Stanford Univ.); Kodiak, 7; Kodiak Island, 1 (Field Mus. Nat. Hist.).