The Bat Fauna of Nopporo Forest Park, Hokkaido
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Mammal Study 29: 191–195 (2004) © the Mammalogical Society of Japan Short communication The bat fauna of Nopporo Forest Park, Hokkaido Mark Brazil1,* and Naoko Sasaki2 1 Mark Brazil, Environmental Systems Faculty, Rakuno Gakuen University, 582-1 Midorimachi, Bunkyodai, Ebetsu-shi, Hokkaido 069-8501, Japan 2 Naoko Sasaki, Sakura Mansion #3, Sakuragaoka 6-15-28, Kushiro, Japan Thirty-five bat species, out of a world total of 925–977 and Sasaki (2003). species, have been recorded in Japan, although two of Of the 17 bat species previously reported from them (Pteropus loochoensis and Pipistrellus sturdeei) Hokkaido, at least nine (Rhinolophus ferrumequinum, are presumed extinct there (Corbet and Hill 1991; R. cornutus, Myotis frater, M. macrodactylus, M. ikon- Kuramoto 1996; Maeda 2001). Surprisingly, more than nikovi, Vespertilio superans, Nyctalus aviator, Murina half (17) of Japan’s extant bat fauna has been recorded leucogaster and M. ussuriensis) are wide-ranging and from Hokkaido, Japan’s northernmost island, although known to occur from central and western Hokkaido the status and distribution of many of these species is still (Maeda 1994), and were thus considered as potentially poorly known. In Hokkaido most species are thought to occurring in NFP. use hollow trees and tree cavities as roosts (Maeda 1984, A further five species (Myotis daubentoni, M. mystaci- 1986, 1994, 1996). Mature lowland forest, supplying nus, Eptesicus nilssonii, Plecotus auritus, Barbastella cavity needs, is, therefore, a very important habitat for leucomelas) are wide-ranging further north and/or east Hokkaido’s bats. in Hokkaido, but have not yet been reported from as far Although Hokkaido supports more than half of southwest as the Ishikari Plain/Sapporo area, thus they Japan’s surviving bat species, relatively little research were considered unlikely to occur in NFP. The three had been conducted there on this mammalian group until remaining species (Myotis nattereri, Pipistrellus savii, recently. Basic bat faunal research has recently been Tadarida insignis) are either too rare or too local to other conducted on Rebun Island (northern Hokkaido), and in regions of Hokkaido to be at all likely in the NFP area, Kutchan, Asahikawa, Bihoro, Shari, and Nemuro areas thus, taking into consideration the known ranges of spe- (Maeda et al. 1993; Uno et al. 1997; Sato and Maeda cies in Hokkaido, as many as nine species might possibly 1999; Bat Research Group 1998, 2001; Dewa 2001; occur in NFP assuming that their habitat requirements Dewa and Kosuge 2001; Kondo 2001; Dewa 2002). No are met there. The aim of this research was to establish previous bat research has been conducted in Nopporo and confirm first of all whether bats occur within NFP, Forest Park (NFP), however, despite this being an then to locate and identify them where possible and to internationally renowned and important relict of once obtain basic data on their status and distribution within widespread lowland mixed forest, close to the city of NFP. Sapporo, and where the flora, avifauna, butterfly fauna, and terrestrial mammal fauna have received considerable Study area and methods attention (e.g. Brazil 1987; Murano 1999). The only prior data on bats from the NFP area relates to two The study area, Nopporo Forest Park (NFP) is a 2,051 specimens of one species, the Lesser Tube-nosed Bat ha lowland forest patch, designated as a prefectural natu- Murina ussuriensis, first obtained from inside the cen- ral park since 1968, within the administrative boundaries tennial tower on 1 September 1972, then a juvenile was of Sapporo, Ebetsu, and Kita-Hiroshima cities (Murano found on 15 July 1995 (Kadosaki 1981; Asakawa and 1999). NFP consists of a mixture of Sakhalin Fir Abies Harada 2000). The presence of M. ussuriensis within sachalinensis, Japanese Yew Taxus cuspidata, Yezo NFP was also confirmed by a photo-survey by Hirakawa Spruce Picea jezoensis, Japanese Elm Ulmus davidiana, *To whom correspondence should be addressed. E-mail: [email protected] 192 Mammal Study 29 (2004) Katsura Cercidiphyllum japonicum, and various other by skull analysis (it proved to be M. ikonnikovi see deciduous tree species, although as much as 40% of the below). total area consists of coniferous forestry plantation. Mist netting was conducted on 15 occasions from 28 NFP is surrounded by farmland and development, thus June until 24 October 2002, with nets set at a total of 40 today NFP represents an increasingly isolated island of locations within NFP. lowland forest habitat. NFP has a mixture of coniferous and broad leaf trees, and still retains a large number of Results sizeable mature deciduous trees, some of which provide potential cavities for bats, in hollow trunks, or limb During 20 field visits in 2000, 2001, and 2002, echo- cavities. There are five large ponds (Osawa, Matsukawa, location calls of bats were heard in 35 areas within NFP Ogino, Hara, and Mizuho) within NFP, and these support confirming their widespread presence (see Fig. 1). Echo- considerable insect life, and this provides potential food location calls were detected at frequencies of 20 kHz, 45 for various bat species, thus given the range of habitats kHz, and 50 kHz. In 2000, bats were detected at 50 kHz available the prospects for locating bats was considered in eight areas, in 2001 in eight areas, and in 2002 in 19 good. areas. In 2002, bats were also detected at 20 kHz at one Given the paucity of information from the area, and locality (Mizuho Pond), and at 45 kHz at one locality with the aim of establishing whether bats were in fact (Sakurazawa Pond, just outside NFP) (see Fig. 1). present, a total of 20 field visits was made to NFP during Banding was attempted on 15 occasions from 28 June 2000, 2001, 2002. While walking slowly along forest until 24 October 2002. Nets were set at 40 locations, and trails and around ponds, bats were listened for with two bats were caught at 20 of them (see Fig. 2). A total of 37 Bat Detectors (Mini-3) initially set to receive only at 25 individual bats of four species belonging to two genera kHz and 50 kHz in 2000 and 2001. During 2000 and were caught: Myotis ikonnikovi (22), Murina ussuriensis 2001, research was conducted from dusk until 21:00. In (11), Myotis frater (2), and Myotis macrodactylus (2), 2002, Bat Detectors were also used while attempting none, however, was re-trapped thus only initial banding banding and continued until 23:00. On the advice of Mr data is available (see Table 1). Norihisa Kondo additional sample detection was also Skull measurements of the specimen collected from conducted in the vicinities of Mizuho and Sakurazawa NFP were made for us by Dr Kishio Maeda, who con- ponds at 20 kHz and 45 kHz, as certain species such as firmed that molar width/Condylobasal Length was 0.414 M. daubentoni and M. macrodactylus and others favour mm and Breadth Length/Brain Case Length was 0.788 areas with water and apparently echolocate at frequen- mm, and confirmed the identity of the specimen as M. cies peaking closer to either 20 kHz or 45 kHz, thereby ikonnikovi (see Table 2). increasing the likelihood of locating such species. In 2002, in order to catch and identify bats, mist nets Discussion were set across and alongside trails in NFP from dusk until 22:30 or 23:00. Each evening, on which weather The bat fauna of Hokkaido has received relatively was mild, without rain and with little or no wind, five little research attention, and the lowland forest area of nets were set (5.45 m and 9.09 m long × 4 m–5 m high). Nopporo Forest Park (NFP) none at all. Prior to this Catches were based on methods described by Mouri research project only two bat specimens, both of Murina (1988) and on experience elsewhere. The bats that were ussuriensis, had been obtained from the NFP area caught were identified to species, forearm length was (Kadosaki 1981; Asakawa and Harada 2000). measured, and they were sexed visually, weighed, aged, Given the presence of large, mature trees in NFP it and photographed. Species identification was made was suspected that these might be used by a range of based on Maeda’s (1983) key. Ageing, as either infants species such as Myotis mystacinus, M. ikonnikovi, M. or adults, was based on the degree of ossification of their frater, Nyctalus aviator, Vespertilio superans, Plecotus finger bones (see Nagorsen and Brigham 1993). Bats auritus, Murina leucogaster, and M. ussuriensis for were banded, using alloy bands provided by the Asian roosting and/or hibernating sites based on their known Bat Research Institute, and released after examination. ranges and habitat preferences elsewhere in Hokkaido One bat specimen was collected (under government (Maeda 1994). Conversely, as there are no caves in research licence No. 2-89.90) to confirm identification NFP, mainly cave-using species such as Rhinolophus Brazil and Sasaki, The bat fauna of Nopporo Forest Park, Hokkaido 193 Fig. 1. Locations in Nopporo Forest Park where bats were detected Fig. 2. Locations where bats were caught in mist nets in NFP 28 by Mini-3 Bat Detector in 2000 (■ ), 2001 ( ▲ ), and 2002 ( ○□● , , ); June–24 October 2002: ●▲ M. ikonnikovi; M. ussuriensis; ◆ M. ○□■▲● = 20 kHz; = 45 kHz; = 50 kHz. frater; ■○ M. macrodactylus; netting attempted but no bats caught. Table 1. The biometrics of bats caught in NFP in 2002. Table 2. Skull measurements of a specimen of M. ikonnikovi from NFP. Forearm (mm) Weight (g) Species Sex n Mean ± SD Mean ± SD Measurement Size (mm) (Range) (Range) Brain Case Width (BCW) 6.75 * Myotis ikonnikovi