Bunomys penitus (Miller and Hollister, 1921)

Musser, Guy G., 2014, A Systematic Review Of Sulawesi Bunomys (Muridae, Murinae) With The Description Of Two New Species, Bulletin of the American Museum of Natural History 2014 (392), pp. 1-313 : 209-237

Bunomys penitus (Miller and Hollister, 1921)

Rattus penitus Miller and Hollister, 1921a: 72 . Rattus sericatus Miller and Hollister, 1921a: 73 .

HOLOTYPE: USNM 218686 , the skin and skull of an adult male (original number 3109) collected January 21, 1917, by H.C. Raven. Measurements (external, cranial, and dental) and other relevant data are listed in table 40. The stuffed skin is an intact standard museum preparation. Both cranium and mandible are complete, all incisors and molars are present (fig. 73).

TYPE LOCALITY: Gunung Lehio (01 ° 33 9 S, 119 ° 43 9 E), 6000 ft (1830 m; locality 40 in the gazetteer and on the map in fig. 51), westcentral mountain block, Propinsi Sulawesi Tengah, Indonesia .

EMENDED DIAGNOSIS: Among the largest in physical size ( LHB 5 155–242 mm, WT 5 95–170 g, ONL 5 39.3–46.1 mm) of the species in Bunomys and further characterized by the following combination of traits: (1) a long muzzle, broad head, and stocky body; (2) dorsal fur thick, lustrous, brownish gray speckled with buff, ventral fur grayish white, digits white, dorsal carpal and metacarpal surfaces typically white, ranging from grayish white to grayish brown in some samples; (3) claws on front feet short and somewhat delicate, long ungual tufts forming dense cover over front and hind claws; (4) tail shorter or slightly longer than length of head plus body ( LT / LHB 5 88 % –102 %), dark glossy gray to brownish gray on the dorsal surface, glossy white on the ventral surface (5) white tail tip common (98 % of 293 specimens) and when present is long relative to tail length (mean 5 21.0 %, range 5 3 % – 68 %); (6) testes small relative to body size (range 5 9 % –13 %); (7) shape of sperm head similar to that of B. chrysocomus but slightly wider with a shorter apical hook and spermatozoan tail; (8) robust skull with a long and wide rostrum, narrow and sloping zygomatic plate, long bony palate and incisive foramina, and large ectotympanic bulla relative to skull size; (9) molars large relative to size of skull and mandible; (10) large labial cusplet sits next to or partially merged with cusp t 6 in 30 % of sample, cusp t3 occurs frequently on second upper molar (62 %) but not on third molar (5 %); (11) anterolabial cusp present on second lower molar in about half of sample but absent from third lower molar; (12) anterior labial cusplets typically infrequent on first lower molars (8 %), posterior labial cusplets typically present on first and second molars in all or most of sample (97 % –100 %); and (12) karyotype, 2N 5 42, FNa 5 58, FNt 5 60 (females) or 61 (males).

GEOGRAPHIC AND ELEVATIONAL DISTRI- BUTIONS: Samples of Bunomys penitus come from two major mountainous regions (see gazetteer, the map in fig. 50, and table 5). Most specimens have been collected from the west-central mountain block in Sulawesi’s core where they were taken on ridges and peaks covered by lower and upper montane rainforest formations between 1285 and 2287 m: Gunung Kanino, Gunung Nokilalaki, Gunung Lehio, Rano Rano, Mamasa region (which includes Gunung Gandangdewata), Pegunungan Quarles, Gunung Rantemario, and Pegunungan Latimojong.

The other sample is from montane forest habitats between 1500 and 2000 m on Pegunungan Mekongga, the highest mountain complex on the southeastern peninsula of Sulawesi (highest point is 2500 m).

What other mountainous regions may harbor populations of B. penitus is unknown.

The range of B. penitus on the southeastern peninsula may be more expansive than is indicated by samples at hand. Northeast of Pegunungan Mekongga and south of Danau Towuti are ridges high enough (1500–2100 m) to support lower montane forests, but these

TABLE 58 Results of Principal-Components Analysis of Bunomys andrewsi , B. chrysocomus , and B. coelestis Samples of B. andrewsi from Lombasang (southwestern peninsula), B. chrysocomus from Sadaunta (west-central region), B. coelestis from Gunung Lompobatang (southwestern peninsula), and a subfossil from Batu Ejaya II (southwestern peninsula) are compared. Correlations (loadings) of five mandibular molar log-transformed variables are based on 59 specimens; see figure 72.

highlands have not been surveyed for small mammals.

Pegunungan Pompangeo rises to more than 2500 m east of Danau Poso in the eastern sector of Sulawesi’s core, and would also be a place to look for B. penitus .

Gunung Tambusisi, at the western end of the mountainous backbone along the eastern peninsula, has yielded Bunomys prolatus and Maxomys wattsi from its montane forests, but no B. penitus (see the account of B. prolatus ). Whether B. penitus is absent from mountain forests covering higher elevations on Gunung Tambusisi and highlands east of there on the eastern peninsula or is replaced by B. prolatus or additional undescribed montane species of Bunomys can be determined only by careful trapping surveys.

SYMPATRY WITH OTHER BUNOMYS: In the west-central mountain block and on Pegunungan Mekongga, B. penitus is sympatric with B. chrysocomus ; both species have been collected in the same trapline (see account of B. chrysocomus ). With that exception, no other species of Bunomys has been found occupying the same montane habitat as B. penitus (table 5).

In addition to B. chrysocomus , other species of Bunomys occur in the west-central mountain block and on the southeastern peninsula, but their ranges are elevationally parapatric to that of B. penitus . In the northern part of the west-central mountain block, B. andrewsi and B. karokophilus , n. sp., inhabit tropical lowland evergreen rain forest, but are absent from montane forest formations. In the southern portion of the block on Gunung Gandangdewata in Pegunungan Quarles, B. penitus is sympatric with three other Bunomys but not elevationally syntopic: B. andrewsi has been collected in tropical lowland evergreen rain forest at 1600 m, B. penitus in montane forest at about 2000 m, and B. torajae higher at 2500 and 2600 m. On the southeastern peninsula, B. andrewsi is found in lowland habitats adjacent to Pegunungan Mekongga, but not in montane forests.

DESCRIPTION: One of the most handsome of the species of Bunomys , B. penitus was described in 1921 by Miller and Hollister from five specimens collected at about 6000 ft on Gunung Lehio in the mountainous central region of Sulawesi (locality 40 in the gazetteer and on the map in fig. 51). The Latin, penitus , means ‘‘internal,’’ ‘‘within,’’ ‘‘inward,’’ ‘‘inner,’’ or ‘‘interior’’ (Brown, 1956: 436, 597) and the authors (who provided no etymology) were likely referring to the provenence of the sample in that it came from the core or ‘‘interior’’ of the island.

Defining traits of ‘‘ Rattus penitus ’’ were provided by Miller and Hollister (1921a: 72) in their diagnosis that was based on five specimens:

A mountain member of the chrysocomus group with long, soft, cinnamon-flecked fur; sides dark like upperparts; belly grayish buff; feet scantily haired with grayish or whitish, toes whiter. Entire underside and terminal third of tail above, whitish. Skull with extraordinarily enlarged rostrum, which is thickened throughout, and only very slightly tapering toward end; antorbital plate weak and sloping, without squarish angle.

Miller and Hollister (1921a: 73) remarked of ‘‘ Rattus penitus ’’ that ‘‘This large-snouted member of the chrysocomus group is very different from all the related forms ….’’

After 1921, Miller and Hollister’s generic and specific combination was listed in most treatises and checklists published in the 1930s and early 1940s ( Tate, 1936; Ellerman, 1941). An exception was Sody (1941) who placed penitus in his newly described Frateromys , the genotype being F. fratrorum . Later, Ellerman (1949) and Laurie and Hill (1954) treated penitus as a subspecies of Rattus adspersus . By the 1980s, penitus had been transferred to Bunomys ( Musser and Newcomb, 1983) and has been associated with that genus ever since ( Corbet and Hill, 1992; Musser and Carleton, 2005; the present and past nomenclatural associations of penitus are summarized in table 4.

Bunomys penitus is, in body size, the largest member of the B. fratrorum group (LHB 5 155–242 mm, LT 5 138–190 mm, LHF 5 38–45 mm, LE 5 23–29 mm, W 5 95–170 g, ONL 5 39.3–46.1 mm), has a broad head, long rostrum, chunky body, beautiful, soft, and luxuriant fur, and a moderately long white-tipped tail (see the portrait of the species in fig. 6). The lustrous dorsal fur of adults is long (up to 25 mm) and very soft to the touch. Brownish gray speckled with buff is typical along the head, back, and rump (a result of the mixture of dark gray underfur, overhairs that are dark gray for most of their lengths and tipped brown and buffy bands, all intermixed with blackish guard hairs); sides of the body are paler—grayish brown. Because the guard hairs extend only slightly beyond the layer of overhairs, the surface of the fur feels smooth and looks even. The proximal portion of each forearm is encircled by dark gray. Sides of the muzzle are white.

The short (10–15 mm long) ventral coat is also soft and either grayish white or dark grayish white (tips of the gray hairs are unpigmented). On a few animals the underparts are grayish buff (the hairs are tipped with buff instead of being unpigmented) or a richer buffy gray. White patches (hairs are unpigmented for their entire lengths) occur on the chest, stomach, and inguinal region of many specimens in the sample. The contrast between dorsal and ventral coats is evident but not sharply demarcated. White tips of the hairs have altered to cream in older stuffed skins held for decades in museum collections, such as the specimens in USNM collected by H.C. Raven.

Ears (pinnae) are large and appear naked but are covered in short, fine, and unpigmented hairs. In life, the ears have a rubbery texture and are pigmented with gray and brown hues; gray, dark gray, grayish brown, and brownish gray marked the ears the freshly caught rats I examined. The dried ears of stuffed museum skins have lost the rubbery texture of the live animal and dry to dark brown with no hint of the actual range in hue and tone.

The tail ranges from slightly shorter to longer than the combined length of head and body (LT/LHB 5 88 % –102 %; see table 41), and is bicolored except for the white tip. The entire ventral surface is glossy white in all animals I studied (best appreciated in freshly caught rats) and the white envelops all surfaces of the tail tip in 83 % –100 % (mean 5 98 %) of the specimens surveyed where the tip forms 3 % –68 % (mean 5 21.0 %) of the total tail length (table 8). Behind the white tip, coloration of the dorsal surface and sides vary. The hues and tones I recorded from freshly caught rats are blackish gray (rare), dark glossy gray, grayish brown, and brownish gray (most common); two rats have a mottled gray dorsal covering between base of the tail and the white tip.

Front and hind feet are long and slender. Digits are white, and specimens in about 60 % of the sample have white dorsal metacarpal and metatarsal surfaces; in the rest of the sample, these dorsal areas are white suffused with pale gray, dark gray, or pale brown. A few animals have white front feet and grayish or brownish hind feet. The naked palmar and plantar surfaces are either unpigmented or show gray tones. Claws are unpigmented, those on the front digits are very short relative to lengths of the digits and appear weak; a few ungual hairs spring from the base of each claw. Claws on the hind feet are longer and nearly completely concealed by long and dense tufts.

Females have four teats, arranged in two inguinal pairs. The scrotal sac of males is gray and sparsely haired (appears naked), and the testes are small relative to body size (9 % –13 %; table 9). Spermatozoan morphology is described by Breed and Musser (1991).

The juvenile coat covering upperparts of the head and body is duller and darker than that of the adult fur—a muted grayish brown (lacks buffy overhair tips). It is dense, fine, and very soft to the touch. Underparts are grayish white as in the adults, but the hairs are finer and shorter. White patches are prominent on the chest and inguinal region. Ears are dark gray or grayish brown. Front and hind feet are pigmented as in the adults. The tail pattern is also similar: glossy white over the ventral surface and around the tip, glossy dark gray or grayish brown on the dorsal surface and sides behind the tip.

The large skull of B. penitus with its long and wide rostrum and narrow zygomatic plate is distinctive (figs. 52–54, 73; tables 42, 61, 62). Among members of the B. fratrorum group, only B. karokophilus , n. sp., possesses as narrow a zygomatic plate (see table 42). Other noteworthy traits of B. penitus are its relatively narrow interorbital region, long and broad incisive foramina, long palatal bridge, wide mesopterygoid region, and large ectotympanic bullae. Each dentary is similar in shape to those of other members in the B. fratrorum group, with the exception of its longer incisor sheath anterior to the molar row.

Large molars with simple occlusal patterns are typical of B. penitus (figs. 74, 75; table 10). On the first upper molar, a large labial cusplet sits adjacent to or is partially merged with cusp t 6 in 30 % of the sample (fig. 75), a configuration not present in other species of the B. fratrorum group or in members of the B. chrysocomus group. Cusp t3 is present on the second upper molar in 62 % of the sample, but is rarely seen on the third molar (5 %), although when present is often large (fig. 75). As in other species of Bunomys , an anterior labial cusplet is generally absent from the first lower molar, but a posterior labial cusplet typically forms part of the chewing surfaces of both the first and second lower molars (figs. 74, 75). An anterolabial cusp is present on the second lower molar in about half the sample (55 %) but absent from the third molar in all specimens surveyed (fig. 74; table 11).

KARYOTYPE: 2N 5 42, FNa 5 58 for both sexes, FNt 5 60 for females and 61 for males, comprised of seven pairs of metacentric chromosomes, two pairs of subtelocentrics, and 11 pairs of acrocentrics; the presumed sex chromosomes of the female are acrocentrics, the male has an acrocentric and a submetacentric (table 12).

COMPARISONS: Samples of B. penitus were compared with those of B. torajae , B. fratrorum , and B. andrewsi in the accounts of those three species; contrasts between B. penitus and B. karokophilus , n. sp., will be addressed in the account of the latter. Here

TABLE 59 Descriptive Statistics for Cranial and Dental Measurements (mm) Derived from All Population Samples for Bunomys chrysocomus , B. penitus , and B. prolatus Mean ± 1 SD and observed range (in parentheses) are listed.

B. penitus requires comparison with two members of the B. chrysocomus group, B. chrysocomus and B. prolatus .

Bunomys penitus and B. chrysocomus: Voucher specimens record the sympatry of B. chrysocomus and B. penitus on Gunung Kanino, Gunung Lehio, and Gunung Latimojong in the west-central mountain block, and Pegunungan Mekongga on the south-

eastern peninsula (see table 20 and the account of B. chrysocomus ). The two species are not difficult to distinguish. Adult B. penitus average larger in body size, with longer appendages (tail, hind foot, and ear) and greater mass than the smaller-bodied B. chrysocomus (table 74). Bunomys penitus is grayish, the upperparts are soft and silky, dense (up to 25 mm long), and brownish gray; underparts are grayish white; the rhinarium is unpigmented and sides of the rostrum are white; tops of front and hind feet are either solid white or tinged with gray; and the tail is glossy brownish gray along the dorsal surface until the last 5–118 mm (3 % – 68 % of the tail length, mean 5 21.0 %), which is white as is the entire ventral tail surface— nearly every specimen surveyed exhibits a white tail segment (98 % of 293 specimens; table 8). Bunomys chrysocomus is dark brown, the dorsal coat is soft and thick but not silky, and not as long (12–15 mm thick) as that in B. penitus , and is dark brownish gray speckled with buff; the rhinarium and sides of the rostrum are dark brown; the ventral coat is grayish white and washed with rust or buff in a few specimens; metacarpal and metatarsal surfaces are grayish white to brown; the tail is brown over its upper surface, whitish speckled or mottled with brown along the ventral surface (rarely white), and most specimens lack a white tip—when present it is short (1 % –25 % of the tail length, mean 5 6 %) and found in only 20 % of the sample containing 396 specimens (table 8). Bunomys penitus has short, delicate claws on the front digits; B. chrysocomus has much longer claws, both absolutely and relative to body size.

Relative to body size, the testes are small in B. penitus (9 % –13 %) but large in B. chrysocomus (22 %; table 9), and this contrast is obvious in freshly trapped adult males. Shape of the spermatozoa is similar in the two species, but that of B. penitus has a wider head, shorter apical hook, and shorter spermatozoan tail ( Breed and Musser, 1991).

Both species have a 2N of 42, but different fundamental numbers (FNa 5 58 and FNt 5 60–61 for B. penitus and FNa 5 56 and FNt 5 58 for B. chrysocomus ; table 12).

Bunomys penitus has a large skull and massive molars compared to B. chrysocomus , but the latter has a broader zygomatic plate and bony palate. The magnitude of differences in cranial and dental dimensions tabulated in tables 59 and 74 in the form of descriptive univariate statistics can be visually examined in the cranial images (figs. 99– 101), and viewed in the scatter plot of specimen scores projected onto first and second principal components (fig. 76, upper graph). In that ordination, separation of scores along the first axis for the larger B. penitus (the aggregation on the right side) and smaller B. chrysocomus (the cloud on the left) is facilitated by the large and positive correlations (r 5 0.65–0.96) for all variables except breadths of zygomatic plate and bony palate, which are negative, reflecting the greater magnitude of most variables for B. penitus but its narrower zygomatic plate and bony palate as compared with B. chrysocomus (table 60).

The two species exhibit minor topographic differences on occlusal molar surfaces. There is no large labial cusplet adjacent to cusp t 6 in all the specimens of B. chrysocomus I examined (present in 30 % of the sample of B. penitus ). Cusp t3 on the second upper molar occurs far more frequently (62 %) in the sample of B. penitus , but is relatively uncommon (17 %) in the large sample of B. chrysocomus (table 10). Just the reverse is the case for the anterior labial cusplet on the first lower molar, which is found in about half (52 %) of the B. chrysocomus sample, but is rarely seen (8 %) in the sample of B. penitus (table 11). On the second lower molar, an anterolabial cusp is nearly standard for B. chrysocomus (90 %) and is also found on the third lower molar of that species in 65 % of the sample; the comparable cusp occurs in only about half of the sample of B. penitus and is absent from the third lower molar of all specimens surveyed for this trait.

Bunomys penitus and B. prolatus: The species of Bunomys living in montane habitats on Gunung Tambusisi, at the western margin of the eastern peninsula, is B. prolatus , not B. penitus , and the former may replace the latter in montane forest formations in the mountain backbone of the eastern arm. Alternatively, B. prolatus may occur on some highlands and B. penitus on others, or both may inhabit the same montane forests—survey of those eastern peninsular highlands for small mammals has been scanty. Both species are characterized by large body size and lush gray pelage; those traits along with what may be an interesting displacement pattern of their geographic distributions warrants comparing them.

Certain external aspects of B. penitus and B. prolatus are similar. Both have brownishgray or grayish-brown upperparts, the fur is thick, long, and soft, the underparts of both are grayish white, and each has a long muzzle and large ears. Bunomys penitus , however, is a physically larger animal as evidenced by its average longer head and body and longer hind foot (compare measurements for B. prolatus in table 19 with those for B. penitus in table 41). Bunomys penitus has a much longer tail, not only absolutely (means 5 162.5–169.1 mm for two samples of B. penitus ; mean 5 132.4 mm for B. prolatus ), but also relative to length of head and body (range of means 5 88 % –93 % in B. penitus , 79 % in B. prolatus ). While the tail in nearly every specimen of B. penitus has a long white terminal segment, is brownish gray or paler on the dorsal surface behind that unigmented tip, and pure white along the ventral surface, only one of seven examples of B. prolatus has a short white tip (table 8), and the undersurface ranges from all white through white speckled with brown to brown nearly indistinguishable from the dorsal surface. Finally, the small and delicate front claws in B. penitus are unlike the robust and elongate front claws typical of B. prolatus (fig. 36).

All but two of the cranial and dental dimensions I measured average greater in the sample of B. penitus compared with that of B. prolatus (table 59). Bunomys prolatus has a wider interorbital region, and the ectotympanic bullar capsule is about the same length in both species, reflecting the close resemblance between the two in size of pinnae (see the values for B. prolatus listed in table 19 and for B. penitus in table 41).

Specimen scores projected on first and second principal components coalesce into two discrete aggregations along the first component (fig. 76, lower graph), providing a multivariate summary of size differences between the two species in cranial and dental measurements, as indexed by the moderate to large and positive correlations among nearly all variables (r 5 0.25–0.84; table 60). Compared with B. prolatus , B. penitus has a larger skull, more prominent rostrum, more spacious mesopterygoid fossa and incisive foramina, and larger molars, all attributes that can be seen when the cranial images of B. prolatus in figures 37–39 are compared with the cranial portrayals of B. penitus in figures 52–54.

Proportional interplay among the variables is indicated by the postion of scores along the second axis. The upper cloud of scores for B. prolatus separated from the lower and larger constellation for B. penitus reflects the relatively wider interorbit of B. prolatus compared with B. penitus ; its relatively longer rostrum, diastema, and postpalatal region; wider zygomatic plate and more spacious bony palate, but weaker molars, as indicated by the moderate to high

TABLE 60 Results of Principal-Components Analysis Comparing All Population Samples of Bunomys penitus with Those of B. chrysocomus , and B. prolatus Correlations (loadings) of 16 cranial and two dental log-transformed variables are based on 185 B. penitus , 232 B. chrysocomus , and eight B. prolatus ; see figure 76.

positive or negative loadings for these variables (table 60).

Frequencies of certain molar cusps differ in the two species. Every one of the four examples of B. prolatus lacks cusp t3 on the second upper molar (eight comprise the sample, but occlusal surfaces of four are too worn to determine presence or absence of certain cusps and cusplets), but the comparable structure characterizes 62 % of the large sample of B. penitus (table 10). None of the examples of B. prolatus show a labial cusplet adjacent to cusp t6 (present in 30 % of the sample for B. penitus ; fig. 75). An anterolabial cusp is present on the second lower molar in each of the four B. prolatus , and is also seen on the third lower molar in three of the four specimens; only 55 % of the sample of B. penitus exhibits the cusp on the second molar, no specimen shows the cusp on the third molar (table 11).

GEOGRAPHIC VARIATION: Population samples of B. penitus come from two highland regions: the west-central mountain block in Sulawesi’s core (Gunung Kanino, Gunung Nokilalaki, Gunung Lehio, Rano Rano, Mamasa Area, Pegunungan Quarles, and Pegunungan Latimojong) and Pegunungan Mekongga, the mountain complex on the southeastern peninsula of Sulawesi. In the west-central mountain block, gene exchange is likely prevalent among populations where montane habitats are continuous in particular stretches of high ridges and peaks, but interrupted among montane patches separat- ed by tropical lowland evergreen rain forests in intermontane valleys and river gorges. Some degree of phenetic variation among samples should be expected in this extensive mountainous landscape.

In relation to samples from the west-central mountain block, that from the Mekongga range is isolated on the southeastern peninsula of the island. Certainly some phenetic differences should be expected between populations in the core and those on the southeastern peninsula. One of my aims in assessing geographic variation among population samples of B. penitus was to determine whether those samples from Pegunungan Mekongga represented a separate species.

There is geographic variation in some of the characters I examined, but the magnitude of difference is not great. No appreciable qualitative variation among available populations of B. penitus is evident in external traits, at least that I could detect. Whatever the montane provenance of a sample, individuals of comparable age are similar in physical size and look closely similar in other external traits from sample to sample: a thick, soft, and silky brownish-gray dorsal coat; dense grayish-white underparts; relatively large, rubbery grayish-brown ears; white feet, lightly suffused with gray in some individuals; a slender tail that is coequal with length of head and body, the proximal threefourths of its dorsal surface grayish brown or paler, the distal segment and entire ventral surface pure white.

I examined skulls in all the population samples and did not detect any qualitative

TABLE 61

Descriptive Statistics for Cranial and Dental Measurements (mm) Derived from Population Samples of Bunomys penitus from the West-Central Mountain Block

Mean ± 1 SD, and observed range (in parentheses) are listed.

traits that were associated with particular geographic regions or any pattern indicated by descriptive statistics for cranial and dental measurements (tables 61, 62). A similar picture was generated by results from quantitative analyses of cranial and dental variables using one multivariate technique, but two other multivariate approaches produced a more revelatory pattern.

A scatter plot of specimen scores projected on first and second principal components produced no apparent pattern reflecting covariation among the variables correlated with geography (fig. 77, upper graph). Scores for specimens in the large samples from Gunung Kanino and Gunung Nokilalaki in the west-central mountain block are spread along both axes and overlap nearly every score for specimens from other collection sites in that mountain block (Rano Rano, Gunung Lehio, Mamasa Area, and Pegunungan Latimojong) as well as scores for the sample from Pegunungan Mekongga on the southeastern peninsula. Ordinations (not

TABLE 62

Descriptive Statistics for Cranial and Dental Measurements (mm) Derived from Population Samples of Bunomys penitus from the West-Central Mountain Block and Southeastern Peninsula

Mean ± 1 SD, and observed range (in parentheses) are listed.

illustrated here) bounded by the combinations of first and third, and second and third components showed similar patterns of specimen scores. Covariation in most variables is responsible for the dispersal of scores along the first axis (r 5 0.31–0.76), with breadths of zygomatic plate and mesopterygoid fossa most influential (table 63). Rath- er than identifying significant intraspecific geographic variation or separate clusters possibly indicating the presence of more than one species, the spread of scores, signifying both size (first component) and shape (second axis) factors, more likely reflects individual variation as well as the range of variation in variables due to age within my young to old adult categories.

A fuzzy pattern of geographic variation emerged from results of discriminant-function analysis where individual specimen scores from the population samples are projected on first and second canonical variates (fig. 77, lower graph). The large cluster of scores for Gunung Kanino and Gunung Nokilalaki also contains nearly all points for specimens collected elsewhere in the west-central moun- tain block. Two outliers are the five specimens from Gunung Lehio, with a slightly longer postpalatal region and narrower zygomatic plate compared with the other samples from

TABLE 63 Results of Principal-Components and Discriminant- Function Analyses Performed on All Population Samples of Bunomys penitus Correlations (loadings) of 16 cranial and two dental log-transformed variables are based on 185 specimens ; see figures 77 and 78.

the mountain block, and the three specimens from Pegunungan Latimojong that show an average wider skull (indicated by zygomatic breadth) and zygomatic plate along with longer incisive foramina (see tables 61 and 62). The significance of these average differences is unclear because the samples from Gunung Lehio and Pegunungan Latimojong are so small relative to the very large series from Gunung Kanino and Gunung Nokilalaki.

Scores representing the sample from Pegunungan Mekongga on the southeastern peninsula (N 5 11) lie to the left relative to position of the scores for the other samples in the ordination, all of them from the westcentral mountain block (fig. 77). An overall smaller skull, both shorter (measured by occipitonasal length) and narrower (indexed by zygomatic breadth and breadths of inter- orbit and braincase) shorter basicranium (postpalatal length), smaller bullae, and shorter molar row characterizes the sample from Pegunungan Mekongga compared with those collected in the west-central region (see the univariate descriptive statistics in table 62); breadth of braincase and lengths of bulla and molar row are especially forceful in spacing the scores along the first canonical variate, with those for Pegunungan Mekongga at one end of the spread and the points representing Gunung Kanino and Gunung Nokilalaki at the opposite (fig. 77, table 63).

Lengths of head and body, tail, and hind foot also average shorter in the sample from Pegunungan Mekongga compared with those series collected in the west-central mountain block (table 41). The contrast in these cranial and external variables suggests underlying partial genetic isolation between populations living in the two mountainous landscapes.

Cluster analysis resulted in a pattern of montane variation that for most samples mirrored the relative position of their highland collection sites (fig. 78). The clustering pattern based on squared Mahalanobis distances unites first the samples from Gunung Nokilalaki and Gunung Kanino (which is a high ridge leading to Nokilalaki) within a cluster comprised also of Rano Rano (highlands just east of Kanino and Nokilalaki), Gunung Lehio (west of the latter three locations and across the valley of the Sungai Miu), and the Mamasa Area (to the south of those four places)—all part of the westcentral mountain block. Those five are linked to Pegunungan Mekongga on the southeastern peninsula. Pegunungan Latimojong, in the southern part of the west-central mountain block, connects to the sample from Pegunungan Mekongga rather than to samples from the west-central mountain block. I do not know whether this last link reflects a real phenetic relationship or is an artifact of sample size.

Compared with samples from the westcentral mountain block, that from Pegunungan Mekongga differs by its average shorter and narrower skull, shorter basicranium, smaller bullae, and shorter molar row as reflected in the tables of summary statistics (table 62) and results of discriminant-function analysis (fig. 77; table 63) described above. These distinctions, plus the isolated geographic position of the Mekongga population relative to those occurring in the westcentral mountain block, prompted me to run an additional principal-components analysis that employed only two samples: one containing the combined six population samples from the west-central mountain block, the other consisting of the smaller sample collected on Pegunungan Mekongga. Results might reveal a sharper pattern of cranial and dental differentiation between samples from the two mountainous regions and better test whether the samples from the west-central mountain block and that from the mountain range on the southeastern peninsula represent two species rather than one.

In an ordination bounded by first and second principal components, the usual pattern of scores representing two morphologically closely related but different species consists of two slightly overlapping and obliquely oriented elliptical clouds in which the major axes (regression lines) of the spreads are phenetically discrete—the regression lines of the second principal component on the first are clearly separate and their Yintercepts are significantly different between the two species (see Voss et al., 1990; Voss and Marcus, 1992). This is the pattern illustrated in the principal components ordination comparing samples of B. chrysocomus with the morphologically similar B. coelestis (fig. 42); other examples are provided by Carleton and Martinez (1991), Carleton and Musser (1995), Carleton et al. (1999, 2006, 2009), Carleton and Byrne (2006), Carleton and Arroyo-Cabrales (2009), Carleton and Stanley (2012), Musser et al. (1998), and Voss et al. (2002) for Mexican, Central American, South American, and African muroids; by Anderson and Gutiérrez (2009) for South American heteromyid rodents; and by Musser et al. (2010) for Sulawesi squirrels. No such dual ellipsoidal patterns characterize the distribution of scores for the two samples of B. penitus (fig. 78, lower graph). The two regression lines are essentially horizontal (their slopes statistically the same; ‾ 0.004 versus 0.023, F 5 0.039, P 5 0.844), overlap for much of their lengths, and their Y- intercepts are not significantly different (0.000 versus 0.001, F 5 0.210, P 5 0.885). Statistically, there is a single major linear axis of one large assemblage of scores, reinforcing the interpretation of a single species showing geographic variation in some cranial and dental variables.

This pattern of variation contrasts with that characterizing other murid groups occurring in the Mekongga region having counterparts in the west-central mountains. Taeromys arcuatus , Taeromys microbullatus , Maxomys n. sp., Margaretamys christinae , and Rattus salocco , for example, are known only from Pegunungan Mekongga (see table 81), and their counterparts in the westcentral mountain block are two new species of Taeromys , Taeromys callitrichus , Maxomys dollmani , Margaretamys parvus and M. elegans , and Rattus facetus , respectively (documented in manuscripts in prep.).

Present samples of B. penitus provide one pattern of variation in cranial and dental variables among highland populations; that picture may be altered or substantiated after study of material from unsampled highlands and larger series from some of those places recorded here. Aside from the samples from Gunung Kanino and Gunung Nokilalaki, the other population samples are small, three to seven useable intact specimens in those from Rano Rano, Gunung Lehio, Mamasa Area, and Pegunungan Latimojong, and 11 in the Pegunungan Mekongga lot (tables 61, 62). Larger series from these latter five places would allow sorting of specimens into age groups and comparing sets of similar relative age, which would provide sharper resolution of any intersample variation. The pattern revealed here does provide a hypothesis that can be tested with measurements of external and cranial variables from more and larger samples, and eventually with results from analysis of DNA sequences.

NATURAL HISTORY: Summarized here are my observations covering habitat and diet derived from the animals collected along my transect that culminated on Gunung Kanino and Gunung Nokilalaki in the cool and wet primary tropical lower and upper montane rain forests.

Habitat: Mean ambient air temperatures ranged from 58.4 ° to 64.8 ° F on Gunung

TABLE 64

Microhabitats at Trap Sites in Which a Portion of the 288 Specimens of Bunomys penitus Were Collected on My Transect in Central Sulawesi, 1973–1976

Descriptions of the trapping sites are summarized from my field journals (in Mammalogy Archives at AMNH). See landscapes in figures 79–83.

Place and date Microhabitat

Gunung Kanino Primary tropical lower montane rain forest (1285–1616 m)

(October 27– On wet ground beneath decaying tree trunk that is part of an old treefall lying on forest floor and

November 23, densely covered by rattan rosettes, climbing bamboo, shrubs, herbaceous vines, and rotting limbs

1973; January and branches; small trees emerge above the tangle and the ground is carpeted with decaying leaves.

17–February Many B. penitus caught in traps set in damp runways beneath rotting tree trunks lying on the forest

16, 1975) floor, on steep slopes or ridgetops, and in runways in the space beneath moss-covered tree roots, especially those of chestnut ( Castanopsis acuminatissima ).

2 ft off ground on top of a large decaying trunk lying on a hillside next to stream.

Damp runway beneath wet, moss-covered decaying trunk lying on terrace above stream; forest wetter here than on ridges.

On leaf-covered ground in runway below ridgetop; trap set in open area next to a tree on a small flat. In front of hole in base of chestnut-trunk complex growing on terrace; chesnut base is closed, not an open hollow like so many, and has other openings to the inside, which is honeycombed with passages.

In runway along side of huge, decaying moss-covered dammar trunk ( Agathis philippinensis ) lying in dammar area of oak-chestnut forest on ridge.

On wet, decaying, moss-covered trunk spanning streamlet draining very wet and forested muddy hillside above Sungai Salebeka.

In oak-chestnut forest on top of ridge; placed in runway leading to burrow under root system of short understory tree.

On ground beneath stilt roots of chestnut cluster on ridge in oak-chestnut forest.

Inside hollow, decaying, moss-covered base of old chestnut treefall on wet, fern-covered depression between ridges.

On decaying trunk spanning Sungai Tokararu and 2 ft above water surface. Here the stream is about 4 ft wide, its cut bank is 8 ft wide and 2 ft high, and its terrace flat and 30 ft from slope to slope. Trunk (10–12 in. diameter) lies across terraces, is densely covered with thick moss (1 in. deep), from which are growing gingers, ferns, an oak-leaf fern, small shrubs, and tiny plants; no path is worn in moss. Terrace is wet and muddy. Caught the squirrel Hyosciurus heinrichi in same spot.

Gunung Nokilalaki Primary tropical lower and upper montane rain forest (1740–2287 m)

(December In mossy runway beneath root of tree growing along top of sloping ridge.

7–30, 1973; In wide runway beneath long, decaying and moss-covered trunk lying down slope below ridgetop.

February Other B. penitus were caught in similar microhabitat configurations—runways beneath or

22–May 15, alongside decaying sections of trunks or large limbs lying on the forest floor, usually bordered by

1975) sedges, ferns, and monocot shrubs.

Trap in front of burrow leading between decaying roots on hillside; extending from the roots are runways along decaying, moss-covered trunks that are lying at either side of the roots.

On steep, washed, and muddy slopes above head of a stream. Rattans and herbaceous shrubs are the prevalent ground cover.

In well-used runway beneath long, rotten, and moss-covered trunk lying downslope about 20 ft from top of ridge. In same spot, the ground squirrel Hyosciurus heinrichi was caught during the day and the rat Rattus hoffmanni at night.

On ground beneath large eroded roots of live canopy tree growing next to ravine on steep slope; several B. penitus were caught on flats and ridges in similar situations.

A few B. penitus were taken on mossy ledges that extend along vertical or steeply sloping sides of ridges just below the ridgetops.

In runway at end of decaying, moss-covered, large trunk that is part of an old treefall. Runway extends up into main jumble of limbs and branches and connects with other passages, some of which run alongside the main trunk. Sedges and moss provide ground cover surrounding the decaying pile of moss-enclosed trunks, limbs, and branches; B. penitus were regularly trapped beneath other old treefalls now covered with dense moss and decaying into the wet forest floor. On ground beneath eroded roots of tree growing on steep slope.

TABLE 64

(Continued)

Place and date Microhabitat

Beneath pile of decaying sections of trunk and limbs lying on nearly vertical slope; entire jumble is covered with moss and surrounded by sedges, gingers, and shrubs.

On damp ground beneath part of a rotten, moss-covered trunk lying on ridgetop in gingers, ferns, sedges, rattan rosettes, and small shrubs. The rat Melasmothrix naso was caught in same spot during the day.

On ground on wet leaf litter beneath roots and rocks, all covered with thick wet moss on slope of ridge. Other B. penitus were encountered nearby in mossy runway along wet rocks covered with moss on steep muddy slope.

In mossy runway beneath decaying moss-covered trunk lying on edge of summit; this runway is continuous with one in which the rat Tateomys macrocercus and the ground squirrel Hyosciurus heinrichi were caught.

Among roots of standing trunk base (15 ft high, 4 ft diameter) of a large oak ( Lithocarpus sp. ) in which the main trunk broke and fell long ago and is now decaying on the forest floor; very wet short forest near summit.

Kanino (1440 m), and 57.5 ° to 64.8 ° F at 1730 m on Gunung Nokilalaki and 51.0 ° to 56.6 ° F on the summit (see table 3 relative humidity and rainfall patterns are also listed). A portion of the trapping sites are described in table 64 (the descriptions are selected to cover the range of microhabitats trapped and not to document where every rat was taken).

During about two months at different times camped on Gunung Kanino (October 27–November 23, 1973, and January 17– February 16, 1975) and longer on Gunung Nokilalaki (December 7–30, 1973; February 22–May 15, 1975), we collected 288 Bunomys penitus . This was the most frequently trapped murid in these montane habitats, followed by Paruromys dominator (201 examples), Rattus hoffmanni (92 specimens), Maxomys musschenbroekii (73 individuals), and Margaretamys elegans (40 specimens); see figure 103. And except for the lower edge of lower montane forest between 1274 and 1555 m where we trapped both B. penitus and B. chrysocomus , the former is the only representative of Bunomys in montane habitats on Gunung Kanino and Gunung Nokilalaki, ranging from the lower boundary of lowland montane forest at 1274–1300 m all the way to the summit of Gunung Nokilalaki at 2287 m.

Bunomys penitus is nocturnal and terrestrial; we never trapped any examples on substrates above ground level.

Gunung Kanino forms a highland mass attached to the southwestern shoulder of the higher ridge forming Gunung Nokilalaki. Its northwestern margin is defined by the Sungai Tokararu, which drains into Danau Lindu (see area at right in the distribution map in fig. 51). The base of Kanino is mantled by lowland tropical evergreen rain forest where our camp at 1150 m was located on a terrace above the Sungai Tokararu. Upslope at (1296–1311 m), the lowland forest transitions sharply into lower montane formations defined by the beginnings of chestnuts ( Castanopsis acuminatissima ) and Calophyllum that form extensive groves covering the slopes and terraces up to about 1800 m (fig. 79). Here the chestnuts are dominant and form most of the canopy with mature trees attaining 80–100 ft high, some reaching about 125 ft. They are spaced 15 to 20 ft apart. The ground is mossy but also thickly covered with leathery-brown chestnut leaves forming a dry litter that crackles under foot. Here Calophyllum is also abundant, both as young trees throughout the understory and as scattered canopy trees; they outnumber the scattered oaks ( Lithocarpus glutinosus and L. elegans ) and the forest could be described as a chestnut-calophyllum climax. This ratio changes with altitude and oaks become as abundant as Calophyllum (chestnut-oak- Calophyllum climax) and then exceed it in numbers as the latter and chestnuts become scattered and rare, with the oaks, primarily Lithocarpus havilandii , growing on higher slopes above the chestnut, where they form extensive groves in places, all the way to the summit of Gunung Nokilalaki. Stands of the conifer dammar ( Agathis philippinensis ) along with a variety of other canopy as well as understory trees contribute to the lower montane forest composition (see legend to fig. 79). Bunomys penitus was frequently encountered in these chestnut-oak- Calophyllum groves between 1300 and 1600 m, 49 % of all specimens trapped in lower and upper montane forest (see fig. 103 and the trapping sites described in table 64).

Although most B. penitus were caught in either chestnut-oak- Calophyllum forest or higher in upper montane habitats near the summit of Gunung Nokilaki, we also found them at intervening elevations, even in ridgetops covered by short forest dominated by Tristania and Pandanus (fig. 80). Generally, every line of traps set at different elevations in montane forest yielded examples of B. penitus .

About 39 % of the 288 B. penitus were trapped between 2000 m and the summit of Gunung Nokilalaki in densely mossy, cool, and wet upper montane forest (see figs. 81– 83, 103; also see the descriptions of this forest provided in Musser, 1982). Near and on the summit, all the rats were trapped in runways—usually damp and either muddy or carpeted with moss—beneath isolated decaying trunks, under tangles of trunks, limbs, and branches formed from old treefalls, inside rotting stumps, and within spaces among moss-covered roots of living trees (table 64).

The montane habitats in which B. penitus were collected lack the floristic species diversity found in tropical lowland evergreen rain forest (see Natural History in account of B. chrysocomus ). We collected samples from about 150 species of trees, and while some of these also occur in lowland forest most are found only in montane habitats. Except for six species of rattans ( Calamus and Daemonorops ), only the solitary palm Areca vestiaria was seen scattered in the forest at high elevations. There are fewer kinds of shrubs, pandans, gingers, and ground ferns; tree ferns are scattered through the forest from the beginning of lower montane forest to the summit of Gunung Nokilalaki.

Diet: Bunomys penitus consumes invertebrates, small vertebrates, some fruit, and a variety of fungi (table 13) and can be viewed primarily as an invertebrate and fungal predator. I kept up to 15 adults captive for several weeks in the camps on Gunung Kanino and Gunung Nokilalaki and offered them a range of foods. Invertebrates and fungi were the items most voraciously consumed. All were picky about fruits, accepting only seeds of oaks ( Lithocarpus ). Back at the museum I extracted the contents from 97 stomachs, which fell into the following categories: (1) six were empty except for matted hair ingested during grooming; (2) one contained unidentifiable remains; (3) 16 contained only bait (ranging from stomachs distended with bait to stomachs nearly empty except for remnants of bait, usually raisin and bacon fragments); (4) four were filled with arthropods and snails but no fungi; (5) six held remains of fruit and no fungi; (6) 64 held fungal remains only or fungi mixed with bait, arthropods, snails, or fruit in different combinations.

Below I present the foods eaten by B. penitus drawn from my observations of captive animals and study of the contents extracted from stomachs.

Earthworms —All the captive rats consumed earthworms (2–3 inches long) and handled them in a manner similar to that described for Bunomys chrysocomus (see that account). Each rat would aggressively grab the worm with incisors, and quickly transfer it to the front feet. The rat placed one end of the worm in its mouth, cutting it into segments while it pulled the worm through its front feet until entirely consumed, a process taking 20–30 seconds.

Only one of the 97 stomachs contained short unchewed segments of a small earthworm and this low frequency may be related to where the earthworms occur in montane forest and the ability of B. penitus to obtain them. We occasionally saw an earthworm crawling over open muddy ground after a hard rain, but we found most of them living beneath thick layers of moss covering decaying trunks, limbs, and smaller branches. Some we located beneath the bark of fallen trees not yet densely mantled with moss; rotting pieces of oaks ( Lithocarpus ) provided the most abundant earthworm accumulations. Except for the occasional earthworm squirming on muddy ground, which B. penitus could snatch up quickly, most would have to be excavated from beneath thick moss, which would be more difficult for the rat because its front claws are short and appear weak, at least as compared with the elongate front claws of B. chrysocomus and the montane species of Melasmothrix and Tateomys , all aggressive earthworm predators.

Snails —Managing snails was similar to the behavior described for B. chrysocomus (see that account). A snail was grabbed with the incisors, transferred to the front feet, turned over several times and eventually bitten into until enough shell was removed, so the soft body was exposed and could be extracted. Once accessible, the rat pulled away a bit of the flesh, ingested it, bit away more shell, pulled and ingested more of the tissue, and proceeded in this manner until the entire snail was consumed. The pieces of shell bitten off were always discarded. I never found fragments of the shell in stomachs, usually only an operculum along with partly digested tissue remains of the snail. Indications of snails were found in two of the 97 stomachs (semidigested tissue and operculum in one, maserated tissue, operculum, and fragment of radula in the other).

In the montane forest habitats on Gunung Kanino and Gunung Nokilalaki, snails seemed less common than in lowland rainforest environments and to average much smaller in size. I did locate snails within wet moss, sometimes crawling over wet leaf litter, here and there beneath decaying bark, and crawling up stems and onto leaves of sedges and other low ground cover.

Insects and other arthropods —Moths, cicadids, cockroaches, and beetles were provided and all consumed by the captive rats. Moths and cicadids were aggressively pulled from my fingers and quickly manipulated so the head was at the rat’s mouth. It then bit the insect’s head and proceeded to voraciously consume head, thorax, and abdomen—wings and legs were discarded.

Large adult beetles were always accepted, even those up to two inches long. The rats were selective, eating only the abdomen and soft parts of the thorax, and discarding everything else. Small beetles were totally ingested and were represented in the stom- achs surveyed by elytra, wings, antennae, legs, along with abdominal and thoracic filamentous tissue. Beetle larvae were also consumed. A favorite were the large larvae (up to 4 inches long and K inch wide) I extracted from rotting wood; all the rats voraciously devoured these grubs.

Nine of the 97 stomachs held remains of insects and other arthropods: macrolepidopteran caterpillars, adult and larval beetles, cockroaches, and geophilomorph centipedes.

Remains of rhinotermitid termites, which I regularly found in stomachs of Bunomys chrysocomus and B. andrewsi that were trapped in tropical lowland evergreen rain forest, were absent from the stomachs of B. penitus . And I did not find any in stomachs of B. chrysocomus collected in lower montane forest on Gunung Kanino. The termites are either rare or may simply not occur in montane forest habitats. My helpers and I took apart many pieces of tree trunks and limbs in various stages of decay lying on the forest floor. We encountered earthworms along with adult and larval beetles but never termites (see the account of B. andrewsi where I provide an inventory of invertebrates, which includes termites, found in similar situations in lowland rainforest habitats).

Fruit— The meaty seeds of Lithocarpus were the only fruit consistently accepted by captive rats but only after I had extracted the seed from the hard shell. Of the 97 stomachs I emptied, nine contained remains of fruit, mostly fig ( Ficus ), a fruit with large oblong and dark brown seeds, and one with large flat hard and orange seeds.

Stomachs rarely contained only fruit. The content of a stomach from a rat trapped on Gunung Nokilalaki is illustrative. It was full with remains of a fig; another fruit with large, hard, and dark brown oblong seeds; fruit pulp, some bait; one small centipede, and several macrolepidopteran larvae.

Fungi —Different species of fungi form a significant part of the diet of Bunomys penitus , which is indicated not only by results from feeding trials but also by the prevalence of fungi in the stomachs I examined. I offered a variety of fungi to the captive animals. The two kinds of jelly or ear fungi so readily consumed by Bunomys karokophilus , n. sp. (see that account), the purplish Auricularia delicata (identified as karoko by the local people) and white Auricularia fuscosuccinea (Class Agaricomycetes, Order Auriculariales , Family Auriculariaceae ) were consistently accepted and eaten. A shelflike gilled fungus Panellus pusillus (Order Agaricales , Family Trichyolomataceae ), which I found attached only to decaying leaf shafts and stems of rattan decaying on the forest floor, was readily accepted and consumed. Seven kinds of stalked gill fungi with caps were offered to the rats and all were eaten. These mushrooms ranged in size from delicate fruiting bodies with a stalk 2 inches long and cap K inch wide to larger species with caps 3 inches in diameter and stalks reaching 3 inches. Cap and stalk of the smaller mushrooms were consumed, most of the cap of the larger mushrooms were eaten (sometimes a rat would eat only the soft underside of the cap) but the tough stems were left. I also found several kinds of shelflike jelly fungi other than Auricularia growing on rotting and wet wood and all these were consumed by the rats.

Not all the kinds of fungi offered the rats were accepted. Woody bracken fungi were ignored, as were puffballs, and a large stalked gilled mushroom with a thick brown and yellowish cap.

Of the 97 stomachs I cut open, 64 (66 %) contained either only fungi or fungi mixed with remains of invertebrates and fruit in different combinations. Of these 64, 45 (70 %) contained remains of a shelf fungus resembling Auricularia delicata but darker in color and rubbery rather than gelatinous in texture; of those 45, 16 held only the karoko -like fungus and some of these stomachs were distended with it.

The fruiting bodies of A. delicata form small and somewhat rubbery capsules (10 mm long, 5 mm wide) or broad and thick earshaped lobes (up to 50 mm wide) that grow on wet and decaying wood. The top surface is smooth and purplish or purplish brown, the undersurface white and irregularly ribbed and veined. The inside is gelatinous. Individual lobes may spread across the same wet and decaying tree trunk or limb, but usually several lobes form a cluster originating from a single point of attachment (see the account of B. karokophilus , n. sp., for a broader description of the fungus). The karoko -like fungus so prevalent in the stomachs of Bunomys penitus is dark brown, and tougher in consistency than A. delicata . In most stomachs, it appears as chewed rubbery lobes attached to a thick and tough (like hard rubber) translucent core. Fragments of the woody holdfast adhering to the core were in some stomachs, and slivers of wood and bits of moss occurred along with the fungus in other stomachs. Unfortunately, I have yet to identify this karoko -like fungus.

The combination of the karoko -like fungus with other items is illustrated by a stomach from a rat collected on Gunung Kanino: few segments of a small earthworm, remains of a snail (including the operculum and fragment of radula), fragment of cockroach leg, large rubbery chunks of the karoko -like fungus, and a few pea-sized globular fungi.

The other 19 of the 64 fungus-containing stomachs held remains of the two species of Auricularia , the Panellus , and several kinds of pink and yellow jelly fungi that I have not identified.

Overview— Bunomys penitus is mycophagous, incorporating a variety of ear, jelly, and gilled fungi in its diet, and is also an aggressive and agile predator of insects, centipedes, earthworms, and snails.

ECTOPARASITES, PSEUDOSCORPIONS, AND ENDOPARASITES: Fleas and ticks comprise the ectoparasites recorded from Bunomys penitus (table 14). Of the species in the six genera of fleas ( Siphonaptera ) that parasitize B. penitus , Sigmactenus sulawesiensis (Leptopsyllidae) also parasitizes four other endemic Sulawesi murines ( Bunomys fratrorum , Eropeplus canus , Maxomys musschenbroekii , and Paruromys dominator ) and the endemic tree squirrel Prosciurillus topapuensis ( Durden and Beaucournu, 2000) . Sigmactenus alticola pilosus (Leptopsyllidae) is also recorded from 14 other species of endemic Sulawesi murine rodents ( Bunomys chrysocomus , B. prolatus , and B. karokophilus , n. sp.; Margaretamys elegans ; Maxomys hellwaldii , M. wattsi , and Maxomys sp. ; Melasmothrix naso and Tateomys rhinogradoides ; Paruromys dominator ; Taeromys celebensis and Taeromys sp. ; Rattus hoffmanni and R. facetus [recorded as R. marmosurus ]) and the nonnative Rattus exulans ( Durden and Beaucournu, 2000) . In addition to Bunomys penitus , five endemic Sulawesi murids ( Rattus hoffmanni ; Bunomys chrysocomus and B. karokophilus , n. sp.; Maxomys sp. ; Paruromys dominator ) and two nonnative rats ( Rattus exulans and R. nitidus ) are also hosts for Stivalius franciscae ( Stivaliidae ; Beaucournu and Durden, 2001). Musserella, n. gen. and species # 1 ( Pygiopsyllidae ), resides not only on Bunomys penitus , but also on six other Sulawesi endemic murids ( Bunomys chrysocomus ; Rattus hoffmanni and R. marmosurus ; Paruromys dominator ; Maxomys sp. ; Taeromys celebensis ) and the nonnative Rattus exulans (Durden, in litt., 2008). Neopsylla musseri (Ctenophthalmidae) infests Bunomys penitus as well as the endemic Sulawesian Paruromys dominator and Maxomys musschenbroekii ( Beaucournu and Durden, 1999) . A female Macrostylophora sp. (Ceratophyllidae) that can not be identified to species was collected from a Bunomys penitus trapped on Gunung Nokilalaki ( Durden and Beaucournu, 2006: 224).

Dasypsyllus gallinulae klossi (Ceratophyllidae) is a bird flea that was collected from my specimens of Bunomys penitus and identified by R. Traub (1983: 184), who wrote that

The subgenus Dasypsyllus is probably the most catholic of all fleas in its host relationships, presumably infesting whatever warm-blooded animal comes within its reach, whether bird, man or other mammal. It undoubtedly has no peer in its geographic distribution, for one species … is not only Holarctic, but also occurs in the mountains of the Philippines, Indonesia and southern Asian mainland, and in the New World extends at least as far south as the mountains of Ecuador, Peru and Venezuela.

Lance Durden (in litt., 2010) provided me with additional information:

Although Dasypsyllus gallinulae is mainly a bird flea (as borne out by its morphology and by most of the host records) it has a much wider range than most other fleas. There are three recognized subspecies of this species, Dasypsyllus gallinulae gallinulae in the Palearctic, Dasypsyllus gallinulae perpinnatus in the Americas, and Dasypsyllus gallinulae klossi in Southeast Asia. I have collected D. g. gallinulae from underground small mammal nests in England so I don’t think the Sulawesi records of D. g. klossi [from Bunomys penitus ] are highly unusual. Nevertheless, morphology and most host records, tell us that this is really a bird flea.

Rhipicephalus pilans ( Acari, Ixodoidea ) larvae are the only tick recorded from Bunomys penitus . Larvae of this species also infest the native shrew, Crocidura nigripes ; the nonnative house shrew, Suncus murinus ; nonnative rats Rattus exulans and R. tanezumi (recorded as R. rattus ); whereas adults parasitize a variety of domestic mammals (cattle, water buffalo, horses, goats, sheep, pigs, and dogs) as well as humans in Sulawesi ( Durden et al. 2008).

Two species of pseudoscorpions, Magachernes sp. and Chiridiochernes sp. have been collected from the fur of B. penitus (W.B. Muchmore, in litt., 1986).

Two reports record nematodes (Nematoda) as endoparasites of B. penitus . Voucher hosts that I identified as B. penitus from the Mamasa region were found to be parasitized by the nematode Bunomystrongylus abadii (Trichostrongyloidea: Heligmonellidae ), which is host-specific ( Hasegawa and Mangali, 1996).

Bunomys penitus is listed as host for the nematode Sibulura andersoni , which also parasitizes a variety of other Indonesian murines ( Purwaningsih and Dewi, 2007; Dewi, 2008). The provenance for the host is Kendari, in the lowlands on the eastern coast of the southeastern peninsula. Bunomys penitus , however, is restricted to montane habitats and on the southeast peninsula has been found only in Pegunungan Mekongga. The host record is certainly a misidentification; B. andrewsi would be the only Bunomys occurring in the Kendari area.

SYNONYMS: One synonym applies to B. penitus .

Rattus sericatus Miller and Hollister, 1921a: 73 . HOLOTYPE: USNM 219627 (skin and skull; measurements are listed in table 41), an adult male collected December 19, 1917, by H.C. Raven (original number 3340). TYPE LOCALITY: Indonesia, Propinsi Sulawesi Tengah, Rano Rano (01 ° 30 9 S, 120 ° 28 9 E) in the west-central mountain block, 6000 ft (1830 m; locality 39 in gazetteer and on the map in fig. 51).

Miller and Hollister (1921a: 73) remarked of ‘‘ Rattus penitus ’’ that ‘‘This large-snouted member of the chrysocomus group is very different from all the related forms, with the exception of the species described next below, also a highland form, which it resembles in many features.’’

The sample of that next species also consisted of five individuals and was named Rattus sericatus by Miller and Hollister (1921a: 73) who diagnosed it as ‘‘Like Rattus penitus , but darker, and with still longer, softer pelage; feet more fully clothed with whitish hairs, sharply contrasted with dark brown of ankle. Skull with rostrum enlarged, but less thickened at end, more tapering, than in penitus .’’ ‘‘This species,’’ remarked the authors, ‘‘while obviously related to Rattus penitus , is readily distinguished by its much longer, softer pelage and the less thickened rostrum. Both species are large, high mountain forms of the chrysocomus group, with white-tipped tails.’’ The name, sericatus means having the nature of silkiness, referring to the long, soft and silky texture of the fur, a quality common to all samples of B. penitus , not just the sample from Rano Rano.

Nor is the degree of white on the feet diagnostic, the entire range from pure white dorsal surfaces to white lightly suffused with gray is found in larger population samples, those from Gunung Kanino (N 5 74) and Gunung Nokilalaki (N 5 82), for example. The rostrum averages somewhat longer and broader in sericatus compared to other population samples, but not to the type series of penitus . In both principal-components and discriminant-function analyses, scores for the holotypes of penitus and sericatus are in the same plane along the first axis; it is the relatively longer bony palate and postpalatal region of the holotype of penitus (and two other specimens) that separates it from sericatus , as reflected by the distribution of scores along the second axis (fig. 77).

There is no phenetic trait shared among the five specimens collected by Raven at Rano Rano indicating that they represent anything other than another montane population of B. penitus .

SUBFOSSILS: None.

The following account describes another member of the Bunomys fratrorum group encountered along my transect line in the west-central mountain block, an undescribed species that is found only in wet and cool streamside places in tropical lowland evergreen rain forest. In the field we called it tikus abu-abuan, the gray rat, and discovered that it eats karoko, an ‘‘ear’’ fungus.