Neoromicia robertsi, Goodman, Steven M., Taylor, Peter J., Ratrimomanarivo, Fanja & Hoofer, Steven R., 2012

Goodman, Steven M., Taylor, Peter J., Ratrimomanarivo, Fanja & Hoofer, Steven R., 2012, The genus Neoromicia (Family Vespertilionidae) in Madagascar, with the description of a new species, Zootaxa 3250, pp. 1-25 : 11-20

Neoromicia robertsi sp. nov.

Neoromicia melckorum Bates et al., 2006 Neoromicia capensis Goodman, 2011

Holotype. UADBA 43677, adult male, body preserved in formalin and subsequently transferred to 70% ethanol; skull removed, cleaned, and previously illustrated ( Bates et al. 2006, their Figure 9C; baculum removed and cleared ( Bates et al. 2006). The skull and mandible are in fine condition ( Figure 4 ). Original field number Richard B. Jenkins (RBJ) 105. The holotype was used in the morphological and molecular comparisons.

Type locality. Madagascar: Province d’Antananarivo, Anjozorobe, Amboasary, 18°24.295'S, 47°56.699'E ( Figure 1 ). Animal was captured on 25 September 2002 in a clearing surrounded by relatively intact montane forest.

Referred specimens. UADBA 43678 (RBJ 118) and FMNH 213931 (RBJ 119, formerly UADBA 43679), Madagascar: Province de Toamasina, Parc National de Mantadia, between PK 9 and PK 10, 18°48.941'S, 48°25.633'E ( Figure 1 ). These two individuals were captured in an open agricultural area with some banana trees. The baculum of FMNH 213931 has been previously illustrated ( Bates et al. 2006, their Figure 8C). The skull of UADBA 43679 appears to have been lost.

Etymology. This species is named after the late Austin Roberts, who conducted systematic research on African mammals at the Transvaal Museum in Pretoria ( Brain 1998; Monadjem et al. 2010). A portion of his career was devoted to the study of southern Africa bats, including small vespertilionids, and he provided important insights into sorting out their generic affiliations.

Diagnosis. Medium-sized member of the genus Neoromicia , with a single upper premolar and a distinctly long dark chocolate brown dorsal and ventral pelage; the upper ventrum has a bi-colored appearance with certain hairs being more lightly colored. The soft parts, including the patagium, uropatgium, ear, and tragus are blackish-brown. The ears have long hair on the proximal one-half of the dorsal surface. The outer margins of the tragus run largely in parallel, and towards the distal tip curve inwards and terminate with a rounded margin. The tragus has a deep notch at the base along the posterior border. While certain external measurements overlap with populations of N. matroka , N. robertsi can be distinguished from all Malagasy members of the genus by its larger and non-overlapping cranio-dental measurements. The greatest skull length of the holotype is 14.3 mm and one of the paratypes is 14.6 mm. In N. robertsi , there is a distinct diastema between the 2nd upper incisor and the prominent upper canine, the upper tooth rows are positioned largely in parallel, and the 2nd upper incisor, which is approximately one-half the height of the 1st upper incisor, has a distinct single cusp on the posterior edge. Based on molecular genetic characters, N. robertsi forms a distinct clade from other Malagasy members of this genus and is the sister species to N. malagasyensis . Further, bacular characters support this relationship; whilst lateral and dorsal shape is reminiscent of N. capensis , total length (2.8 mm, n = 2) is larger and does not overlap at all with the smaller N. capensis (c. 2.1 mm) (Taylor et al. in prep.).

Description. External characters. A moderately large Neoromicia with a tail less than 40% of total length (Table 3). The three specimens of N. robertsi comprising the type series (UADBA 43677, 43678, FMNH 213931) have notably shaggy dark chocolate drown dorsums and ventrums, longer than, slightly darker, and more saturated than typical N. matroka . The ventrum fur of N. robertsi , particularly the outer fur of the upper portion of the chest, often has a slightly lighter sheen, which gives the impression of being bi-colored and in N. matroka these accents are not present. The surfaces of the patagium and uropatgium are a distinct blackish-brown, similar to N. matroka and N. malagasyensis .

The ear length in the holotype of N. robertsi is 13 mm, which is the same measurement as in the two paratypes (Table 3), and in general falls within the range of N. matroka and N. malagasyensis . The dorsal surface of the pinna of N. robertsi , particularly the lower proximal half is furred, which is distinctly less developed in N. malagasyensis and mostly naked in N. matroka . Neoromicia robertsi has notably dark blackish-brown pinna and tragus, the later representing less than 50% of the length of the former. The main body of the tragus in N. robertsi has the two outer margins running mostly in parallel for approximately two-thirds of the proximal length and then turns medially, curves slightly, and terminates with a rounded margin ( Figure 5 A). Further, there is a distinct notch at the base of the tragus along the posterior border. In comparison, N. matroka has a tragus length about 60% that of the ear length, the crescent-shaped tragus terminates as a rounded sickle-shape, and the notch at the posterior base of the structure is less developed than in N. robertsi ( Figure 5 B). In N. malagasyensis the tragus length represents between 50-65% the ear length, the tragus is slightly more crescent-shaped than in N. robertsi , but not as prominent as in N. matroka , and lacks a distinct notch at the base along the posterior border ( Figure 5 C).

On the basis of external measurements of the type series of N. robertsi , this species seems to show sexual dimorphism in size, with the single female specimen being notably larger than the two males in total length, tail length, and forearm length. The two males have an average forearm length of 34.5 mm and the female measures 38 mm, as compared to 31.9 mm and 33.9 mm, respectively, in N. matroka from the Central Highlands (OTU 1, Table 3). On average, based on two specimens, N. malagasyensis is smaller than the other two Malagasy members of this genus.

Cranio-dental characters. Dental formula in Neoromicia robertsi , as in other members of the genus, is I 2 /3 C 1/1 P 1/3 M 2/3, comprising the adult dentition of 32 teeth. Neoromicia robertsi is easily distinguished from other Malagasy members of this genus based on its notably larger cranial measurements (Table 4). Of the two skulls available of this taxon (both males), the greatest skull length of UADBA 43677 (holotype) is 14.3 mm and FMNH 213931 is 14.6 mm. These measurements are larger and do not overlap with the average greatest skull length of N. matroka from the Central Highlands (OTU 1) of 12.9 mm and in N. malagasyensis of 12.8 mm. Further, with the exception of postorbital width, the different cranial measurements of N. robertsi are larger and non-overlapping with those of N. matroka and N. malagasyensis . In N. robertsi , the supraorbital ridge is notably more inflated than N. matroka and N. malagasyensis .

Neoromicia robertsi is easily distinguished from other Malagasy Neoromicia based on its notably larger upper and lower dental measurements (Table 5). Of the two skulls available of this taxon (both males), the length of the complete cranial tooth row of UADBA 43677 (holotype) and FMNH 213931 are both 6.0 mm. These values are notably larger and do not overlap with the average length of the complete cranial tooth row of male N. matroka from the Central Highlands (OTU 1) of 5.1 mm and in N. malagasyensis of 4.7 mm. The upper tooth rows in N. robertsi are largely in parallel, while in N. matroka and N. malagasyensis are more of an arc shape and converge anteriorly.

In N. robertsi , the 2nd upper incisor, which is approximately one-half the height of the 1st upper incisor, has a distinct single cusp on the posterior margin, as compared to N. matroka , which has a more complicated bicuspid 2nd incisor ( Figures 6 A and 6B). The incisors in N. malagasyensis are distinctly different with the 2nd upper incisor without a distinct secondary cusp and the 1st upper incisor being about two-thirds the length of 2nd ( Figure 6 C). Further, in N. capensis , including the holotype (BMNH 97.9.1.32), the 2nd upper incisor is a peg-like tooth with no clear secondary structure ( Figure 6 D). The diastema between the 2nd upper incisor and the upper canine is most prominent in N. robertsi as compared to the other Malagasy members of this genus.

Male baculum characters. The baculum of N. robertsi is typical of the genus Neoromicia , with strong ventral deflection of the tip, but diagnostically larger than any described species.

Natural history, distribution, and conservation status. Neoromicia robertsi is only known from two localities in central eastern Madagascar, where it occurs in sympatry with N. matroka ( Figure 1 ). The specimens of N. robertsi from the Parc National de Mantadia were obtained at an elevation between 900 and 1000 m, and the holotype from Anjozorobe, between 1200 and 1300 m. These two sites are both associated with partially degraded habitats, one of which is in close proximity to a forested zone. Hence, N. robertsi does not appear to be a forest restricted species, but has not been found roosting in a synanthropic context, which is known for N. matroka (Goodman 2011) .

No precise details are known about the reproductive ecology of N. robertsi . The pair obtained on 8 November 2002 at Mantadia (UADBA 43678, FMNH 213931) included a male with relatively large testes and, based on the form and shape of the mammae, a female that recently gave birth and lactated. The holotype (UADBA 43677) was an adult male.

Bioacoustic information of animals that can be definitively identified as N. robertsi is not available. Kofoky et al. (2009) made recordings of hand-released individuals of Neoromicia at Mantadia and Anjozorobe, sites N. matroka and N. robertsi are known to occur, and based on the forearm length of released individuals it is not possible to determine which species was involved. Neoromicia at these sites had an average frequency of maximum energy of 41.5 kHz (range 39.2-44.3 kHz); average maximum frequency of 69.2 kHz (range 60.3-88.2 kHz); average minimum frequency of 37.7 kHz (range 35.5-39.3 kHz); average duration of 5.7 ms (range 3.8-8.0 ms); and average interpulse interval of 109.9 ms (range 65.2-196.7 ms), as compared to N. malagasyensis near Isalo where these values were 45.7 kHz (range 41.4-51.0 kHz), 79.8 kHz (range 60.3-100.0 kHz), 40.5 kHz (range 32.4-45.5 kHz), 4.9 ms (range 3.6-6.3 ms), and 34.2 ms (range 34.2-94.4 ms), respectively. Thus, while it is not apparent if differences exist between N. matroka and N. robertsi in bioacoustic parameters, N. malagasyensis shows some divergent aspects in their echolocation calls.

An older mummified specimen (MNHN 1882.1964) was obtained by Jean Auguste Lantz in the “interieur de Madagascar C. est, mai 1881 ” at a locality that cannot be properly read from the specimen label but appears to be “Ambohiramiane”. The skull still remains in the specimen, but based on the coloration of the notably long pelage, the partially furred proximal portions of the upper surface of the ears, and a forearm length of 34 mm, it may be referable to N. robertsi .

In total, we have examined over 60 specimens of N. matroka , as compared to three specimens of N. robertsi . The disproportional number of specimens of the former species may be in part associated with its broader distribution and use of buildings for day roost sites, providing easier access to field collectors. However, based on current information, N. robertsi has a limited distribution and appears notably less common than N. matroka . Further, information is needed to assess its distribution and population size, in order to properly evaluate its conservation status.

Figures

FIGURE 1. Map of localities mentioned in text associated with the known distribution of Neoromicia robertsi sp. nov., N. matroka, and N. malagasyensis. Note that N. robertsi occurs sympatrically with N. matroka at two localities. Color codes associated with elevational zones depicted on map: light gray—sea-level to 200 m, medium gray— 201 – 900 m, and dark gray—> 900 m.

FIGURE 4. Different views of skull and mandible of Neoromicia robertsi sp. nov. (UADBA 43677, RBJ 105), holotype from Province d’Antananarivo, Anjozorobe, Amboasary. Pictures include dorsal view of cranium (upper row, left), ventral view of cranium (upper row, right), and lateral view of cranium and mandible (lower row). (Photograph taken by J. Weinstein, Field Museum image number Z 94555 _ 09 d.)

FIGURE 5. Tragus of right ear of different species of Malagasy Neoromicia: A) N. robertsi sp. nov. (UADBA 43677, RBJ 105), holotype, from Anjozorobe; B) N. matroka (FMNH 209119), from Ankazobe; and C) N. malagasyensis (FMNH 175989), from near Parc National de l’Isalo.

FIGURE 6. Lateral view of the right anterior portion of skull of three different species of Malagasy Neoromicia: A) N. robertsi sp. nov. (UADBA 43677, RBJ 105), holotype, Anjozorobe, with relatively unworn teeth; B) N. matroka (FMNH 194153), Ankazobe, which has relatively unworn teeth and closely matched the holotype (BMNH 97.9.1.32); C) N. malagasyensis (FMNH 175988), from near Parc National de l’Isalo, with slightly worn teeth; and D) N. capensis (FMNH 195629), Marloth Park, which closely matched the lectotype (BMNH 49.8.16.21), South Africa, although with notably worn teeth. Skull images adapted and modified from Bates et al. (2006).