Comments on the Taxonomic Status of Apodemus Peninsulae, With Description of a New Subspecies From North China

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UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY

Volume 9, No. 8, pp. 337-346, 1 fig. in text, 1 table

August 15, 1956

Comments on the Taxonomic Status of Apodemus peninsulae, with Description of a New Subspecies from North China

J. KNOX JONES, JR.

UNIVERSITY OF KANSAS LAWRENCE 1956

UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

Editors: E. Raymond Hall, Chairman, A. Byron Leonard, Robert W. Wilson

Volume 9, No. 8, pp. 337-346, 1 fig. in text, 1 table Published August 15, 1956

UNIVERSITY OF KANSAS Lawrence, Kansas

PRINTED BY FERD VOILAND, JR., STATE PRINTER TOPEKA, KANSAS 1956

26-3854

Comments on the Taxonomic Status of Apodemus peninsulae, with Description of a New Subspecies from North China

J. KNOX JONES, JR.

In the past several years the United States National Museum has received a large number of mammals from central and southern Korea through the auspices of the Commission on Hemorrhagic Fever of the Armed Forces Epidemiological Board. Among these Korean collections are more than a hundred specimens of a murine rodent originally described as "Micromys speciosus peninsulae" by Oldfield Thomas but currently placed in the genus Apodemus. In attempting to ascertain the specific relationships of this mouse I have examined, through the generosity of Dr. David H. Johnson, Acting Curator of Mammals, most of the other Oriental specimens of the subgenus Sylvaemus in the U. S. National Museum and it is on this combined material that the following comments and description are based.

Three general groups of the genus Apodemus are presently known to occur on the mainland of northeast Asia. One is the distinctive Apodemus agrarius, lone representative of the subgenus Apodemus. The others, both in the subgenus Sylvaemus and closely resembling each other, are represented by a small animal that is currently regarded as conspecific with Apodemus sylvaticus and a larger animal of which the Korean mouse, peninsulae, is representative. The oldest trivial name applied to the large Sylvaemus is major of Radde, 1862, in the combination [Mus sylvaticus] vrt. major. This is, however, twice preoccupied (see Ellerman and Morrison-Scott, 1951:566). The next available name is peninsulae of Thomas, 1907, which was applied to mice from central and southern Korea (type from Mun'gyong, 110 mi. SE Seoul, Korea), and was originally proposed as a subspecies of the insular Japanese species, Apodemus speciosus. G. M. Allen (1940:949), who recognized peninsulae as a monotypic species, was the first investigator to make the important distinction that it was not conspecific with the Japanese speciosus, although Hollister (1913:1-2) and Miller (1914:89) had previously used the combination Apodemus peninsulae, evidently with the same thought in mind.

a. Apodemus flavicollis flavicollis (Melchior), Lolland, Denmark, adult , No. 141691 USNM, ×2.

b. Apodemus flavicollis flavicollis (Melchior), Mauseklippe, Germany, young , No. 112895 USNM, ×10.

c. Apodemus peninsulae peninsulae (Thomas), Central Nat'l Forest, near Pup'yong-ni, 200 m., Korea, subadult [Female], No. 300650 USNM, ×10.

d. Apodemus peninsulae peninsulae (Thomas), 6 mi. S Yongdongp'o, Korea, adult , No. 299554 USNM, ×2.

In comparing the ventral views of skulls note especially the size and location of incisive foramina and posterior palatine foramina as well as the breadth of mesopterygoid fossae. In comparing the left maxillary tooth-rows note especially the size of M3 and the reduced posterointernal cusp on Ml in A. peninsulae.]

More recently, Ellerman (1949:32) and Ellerman and Morrison-Scott (1951:566) have arranged peninsulae as a subspecies of Apodemus flavicollis under the assumption that all the members of the subgenus Sylvaemus on the eastern Asiatic mainland are subspecies of one or another of the species of western Europe, A. flavicollis or A. sylvaticus. Ellerman (in Ellerman and Morrison-Scott, 1951:564) states: "The majority of the forms I distribute in a somewhat arbitrary manner between sylvaticus, average smaller skull, and flavicollis, average larger skull; occurring together nearly throughout the Palaearctic. I feel fairly sure that there are some errors of judgment in my arrangement, and equally sure that there is no other way to define species in this very large and difficult group." I have compared the specimens of peninsulae available to me from central and southern Korea with specimens of A. f. flavicollis from Denmark, Germany and Sweden and find, although the two are similar in many ways, that peninsulae differs from flavicollis in several important characters: Mammae 1-2=6 in flavicollis, and 2-2=8 in peninsulae; incisive foramina reaching level of alveoli of M1, or nearly so, in flavicollis, but ending conspicuously short of that level in peninsulae; posterior palatine foramina large in flavicollis and opposite a point where M1 and M2 meet, but small in peninsulae and situated farther back on the palate, opposite M2. Moreover, peninsulae lacks the characteristic buffy throat patch of flavicollis, has a much reduced posterointernal cusp on the M1, a relatively (frequently actually) larger M3 and, on the average, a broader mesopterygoid fossa. In view of these differences, all of which appear to be constant, I consider peninsulae specifically distinct from flavicollis. Throughout its known geographic range (see below) peninsulae is evidently confined to wooded terrain, either scrub or brush types or forested areas, and the vernacular name wood mouse, therefore, seems appropriate for this species.

The type specimens of Apodemus praetor Miller (type from Sungari River, 60 mi. SW Kirin, Manchuria) and Apodemus nigritalus Hollister (type from Tapucha, Altai Mountains, Siberia) agree with peninsulae as concerns the above characters and differ from it only in minor external and cranial features. They are, therefore, here considered as subspecies of the latter.

Ellerman (1949:32) and Ellerman and Morrison-Scott (1951:567) regarded nigritalus, like peninsulae, as a subspecies of flavicollis. The subspecies praetor, on the other hand, has generally been regarded as a synonym of peninsulae by recent authors. Howell (1929:58) noted that the holotype was, "... a phenomenally large specimen such as is encountered occasionally in almost all groups of rodents." He ascribed the color differences noted by Miller to "seasonal" variation. The holotype of praetor is undeniably larger than the other adult specimens listed in the original description. These paratypes and other specimens of praetor available to me are approximately the same size externally and average only slightly larger cranially than specimens of peninsulae from central and southern Korea. However, the dorsal coloration of praetor is somewhat darker and duller than that of peninsulae, especially in summer pelage when praetor lacks the conspicuous bright ochraceous tinge of the Korean specimens. In addition, praetor has broader zygomatic plates with correspondingly deeper zygomatic notches and the color on the face of the upper incisors averages much more orange than in peninsulae.

In the north then, wood mice range from Korea and Manchuria westward at least as far as the Altai Mountains. For mice from the intervening Siberian areas Russian workers have used the name major which, as noted above, is unavailable. The exact relationships of the mice of these areas to previously named subspecies is unknown to me and I have not seen specimens of "Mus (Alsomys) major rufulus" of Dukelsky, 1928, the type locality of which is 75 versts (approximately 50 miles) SE Vladivostok, Siberia. It appears to be of the same species as peninsulae and judging from the original description it closely resembles praetor. Neither have I seen specimens of the Sakhalin Island mouse, giliacus, which Ellerman (1949:32) regards as a subspecies of Apodemus sylvaticus. I feel reasonably sure, however, that it will prove to be a subspecies of peninsulae. In the original description giliacus was referred to as, "Most closely allied to the Korean subspecies..." (Thomas, 1907:411).

In China the extent of the distribution of Apodemus peninsulae is also uncertain. Allen (1940:949-50) reported its occurrence from Jehol and Hopeh in the northeast, southwestward through Shansi, Shensi and eastern Kansu to Szechuan and northwestern Yunnan. Throughout most of this region it occurs with another mouse, currently regarded as conspecific with Apodemus sylvaticus, and the two kinds have been confused by some previous authors. Howell (1929:58), for instance, reported twelve specimens of peninsulae from 65-75 mi. NE Peking but my examination of these mice indicates that only four are peninsulae while the others are referrable to what is currently regarded as Apodemus sylvaticus draco. Another subspecies of sylvaticus, A. s. orestes, occurs in Szechuan and Yunnan and it is certain that some records of distribution ascribed to peninsulae from those provinces actually represent orestes (see Allen, 1940:949-50). A. sylvaticus is distinguishable from peninsulae by darker ears, blackish preauricular patches, dark eye rings, a noticeably smaller skull, incisive foramina that reach the level of Ml (or nearly so), much larger auditory bullae, and a more fully developed posterointernal cusp on M1. Too, sylvaticus typically has 1-2=6 mammae although Allen reports finding a 2-2=8 formula in some specimens. Apodemus latronum, regarded as a full species by Osgood (1932:318) and G. M. Allen (1940:950) but as a subspecies of flavicollis by Ellerman (1949:32) and Ellerman and Morrison-Scott (1951:567), also occurs in Szechuan and Yunnan. Its relatively dark color, large feet and large ears, flavicollis-like skull and large molar teeth immediately separate it from peninsulae although the two possibly have been confused in the earlier literature. Until a complete revisionary study of the Asiatic members of the subgenus Sylvaemus can be undertaken the presence of peninsulae in southwestern China must remain in question.

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