Search

The breeding and wintering bird fauna at Ooyamazawa were monitored by point counting every year from 2010 to 2017. The abundance of bird species that feed in bushes, including the Japanese Bush Warbler (Cettia diphone) and Siberian Blue Robin (Luscinia cyane), decreased. On the contrary, the other bird species that feed in habitats other than bushy understory did not decrease significantly. In Ooyamazawa, deers have serious impact on the understory vegetation. Thus, deer browsing likely affected the number of birds using the understory vegetation.

The Fukushima-Daiichi Nuclear Power Plant (F1NPP) accident is an IAEA level 7 event, the same as that of Chernobyl, while the amount of radionuclides released is not comparable. Radioactivity attributed to the F1NPP accident was detected 250 km away from the F1NPP. Although we have not yet systematically studied the effect of radionuclides on the environment and wildlife, one of three Japanese Bush Warblers (Cettia diphone), captured in Akaugi district in August 2011, was observed to have a conspicuous lesion near the cloaca, which is rare in Japan. All of the birds' feathers were strongly contaminated. Further study is needed to determine the significance of this result. We emphasize the importance of continuing assessment of the effects of the F1NPP accident on wildlife.

Island and mainland populations of birds often differ in their breeding biology because of differences in ecological conditions. We studied the breeding biology of Japanese Bush Warblers Cettia diphone on Hahajima in the Ogasawara (Bonin) Islands group. Based on observations of four nesting attempts, clutches consisted of three or four eggs, which is smaller than on the mainland. Males fed the chicks, although the frequency was fairly low. Brood sizes declined during the nestling period due to starvation. Neither such male behavior nor starvation, have been reported on the main islands of Japan or on their small peripheral islands. These features of their breeding biology may have resulted from food scarcity and strong intraspecific competition on the island.

The dawn chorus is a period of peak singing activity of many songbirds. Numerous studies have sought to understand this widespread phenomenon, and many hypotheses have been proposed to explain the dawn chorus. The social dynamics hypothesis proposes that dawn singing plays an important role in the announcement of territorial occupancy and the regulation of social relationships between males; it predicts that the dawn chorus vocal behavior varies with changes in social relationships. In this study, we tested the influence of territorial insertions and the number of neighbors, on the intensity of the brownish-flanked bush warbler (Cettia fortipes)’s dawn singing. We found that simulated territorial insertions (playback) caused the males to increase their dawn singing significantly the next day, and males that had many neighbors exhibited more intense dawn singing than did males with few neighbors. Our study provides evidence that dawn singing plays an important role in the announcement of territorial occupancy and the regulation of the social relationships between the males.

Wildlife, mainly 69 bird (Aves) species, has been observed in Abukuma Mountains, northeastern Fukushima Prefecture, which is the most radioactively contaminated area, over the seasons since July 2011. However, it is still unclear whether the changes in the bird community have been caused by the radioactive contamination and/or by changes in human activity, adding to the natural dynamics. The aerial dose rate at the survey area was initially estimated to be more than 100 μSv/h (mainly 137Cs, 134Cs, and 131I), which decreased in the summer of 2014 to 0.1–20 μSv/h (mainly 137Cs and 134Cs). Radioactivity in wild habitats is heterogeneous among the microhabitats and is dynamic through time and seasonal conditions. Microhabitat radio-heterogeneity was clearly indicated by the 2-month-long measurement with 200 dosimeter badges in this study. The ecological factors related to free living (in-situ) wildlife in the highly contaminated area of Fukushima are discussed.

The distributions of the Little Cuculus poliocephalus and Oriental C. saturatus cuckoos differ throughout Japan. In Honshu, the Little Cuckoo parasitizes mainly the Japanese Bush Warbler Cettia diphone and lays reddish mimetic eggs. The Oriental Cuckoo mainly parasitizes the Eastern Crowned Leaf Warbler Phylloscopus coronatus and lays whitish eggs. However, in central Hokkaido, where no Little Cuckoos breed, Oriental Cuckoos parasitize Japanese Bush Warblers as their main hosts, in whose nests they lay reddish eggs. Anecdotal evidence suggests that they also parasitize Eastern Crowned Leaf Warblers, laying reddish eggs, but this has not been confirmed. Here, we report the first complete evidence in which an Oriental Cuckoo chick, which hatched from a non-mimetic reddish egg, was raised by Eastern Crowned Leaf Warbler hosts in Hokkaido.

Bird songs in island populations have often been reported to be simplified, in that island birds have a smaller number of song types and song-element types compared to mainland birds. However, there is less information on the characteristics of acoustic structure in island songs. I investigated song structure of one mainland and three island populations of Japanese bush warblers, Cettia diphone, and found that island songs had an acoustically simple structure. The frequency-modulated (FM) portions of the songs were shorter and had fewer frequency inflections in the insular populations than in the mainland population, while the number of FM notes, the frequency range of these notes, and the song repertoire sizes of males did not differ between the islands and the mainland. I also investigated whether the song complexity is related to sexual selection pressure using the degree of sexual size dimorphism as a proxy for the latter. The degree of dimorphism in body mass was larger on the mainland. Thus, weakened sexual selection on islands is a possible factor in the formation of simple songs. Further studies related to male–male competition and female choice on islands are required.

SummaryThe Timor Bush Warbler Locustella timorensis was first collected by Georg Stein on Mount Mutis, West Timor in 1932, but there have been no confirmed field observations since. Here we report on the discovery of a new population of bush warbler on Alor (9 September 2009), which prompted a search for, and subsequent rediscovery, of the nominate Timor Bush Warbler (20 December 2009) in Timor-Leste. We also undertook the first bush warbler searches in the mountains on Atauro Island, and the first ornithological exploration of the mountains of Pantar and Wetar islands. On Alor, at least 13 male bush warblers were heard singing from shrub and grass beneath woodland and forest edge at 859–1,250 m. On Timor, at least 40 males were heard during December, April and July from tall grassland below Mount Ramelau (1,720–2,100 m), Timor-Leste. The song structure of the Alor and Timor birds is similar, and close to Javan Bush Warbler L. montis of Java and Bali, as well as to recordings of Russet Bush Warbler L. mandelli of mainland Asia and Benguet Bush Warbler L. seebohmi from the Philippines. The song of the Alor bird is substantially higher pitched (mean min/max 3,233–4,980 kHz) than the Timor bird (2,928–4,761 kHz) and both are substantially higher pitched than Javan birds. Recordings of Russet Bush Warbler from mainland Asia are higher pitched than songs of all insular taxa, and the song of Benguet Bush Warbler is of a similar pitch to the Timor bird. Recent molecular studies have found that divergences between Javan Bush Warbler and the Russet Bush Warbler are slight, and the high degree of song similarity of the Alor and Timor populations to Javan Bush Warbler places them close to the Benguet Bush Warbler complex. The Timor Bush Warbler is recognised as ‘Near Threatened’ by IUCN, but this will require re-evaluation. On Alor, suitable habitat is extensive and under little threat, but grassland in the uplands of West and East Timor is intensively grazed and regularly burnt. Further field surveys are needed on both Timor and Alor to capture birds, clarify taxonomic relationships using molecular approaches, and further define habitat use and conservation status. Bush warblers were not recorded from Pantar, Atauro and Wetar islands.

We analyzed the structure and variation of the songs of the Brownish-flanked Bush Warbler (Cettia fortipes), a species common in southeastern Asia, including southwestern China, site of our study. During the breeding season of 2009, we investigated the possibility of distinguishing individuals by song. Most Brownish-flanked Bush Warblers we studied had a unique song repertoire composed predominantly of two song types. Whether singing spontaneously or in response to playback, the birds deliver the two types alternately. We defined type alpha as a song consisting of two notes, type beta as a song consisting of three notes. Both song types varied from individual to individual. Discriminant analysis revealed that the songs of individual Brownish-flanked Bush Warbler songs were distinct; rates of correct classification were 98% for the alpha song and 99% for the beta song.

We investigated bird nest predation on Miyake Island where the Japanese Weasel Mustela itatsi has been introduced. From observations of Japanese Bush Warbler nests, we estimated survival rates of 0.498 and 0.848 in incubation and nestling stages, respectively. Artificial nests coupled to an automatic image recording system showed that weasels were bird nest predators on three occasions. No other potential predators visited the nests; before the weasel introduction, nest predation was rarely reported on the island. The incidence of predation on artificial nests increased as a function of the density of predated artificial nests in the neighborhood. Other nest-site characteristics were not related to nest predation, except for height above the ground. Lower nests had slightly higher risks of predation. Hence, the fate of a nest appears to depend on whether it is located within home ranges of the Japanese Weasel. Weasels may easily find nests located within their activity ranges irrespective of thei...

In 2005, we surveyed the birds inhabiting the Tokyo University Forest in Chichibu, in western Saitama Prefecture, Japan. Special attention was given to the Bush Warbler Cettia diphone, which appeared at the study site after 22nd March. We captured seven male Bush Warblers and banded them with individually unique combinations of color rings. Six males of them maintained the same home ranges (territory) throughout the study period, and no other males were observed. The population density of the males was 19.2 individuals per km2. Although we were unable to locate an active nest to study the breeding and rearing process, juveniles were captured in August. The tarsus length of juveniles reached the size of adults earlier than the natural wing length. Thus, in the juveniles, sexual size dimorphism was evident in the tarsus length to the same extent as seen in adults. We found nests of the Japanese White-eye Zosterops japonicus, Long-tailed Tit Aegithalos caudatus, Short-tailed Bush Warbler Urosphena squameiceps, Blue-and-white Flycatcher Cyanoptila cyanomelana and Red-billed Leiothrix Leiothrix lutea. The clutch of the Short-tailed Bush Warbler was believed to have been parasitized by the Oriental Cuckoo Cuculus saturatus. We confirmed that 40 species of birds occurred in the study area during the study period.

We investigated the phylogenetic relationship and differences in the song structure between the Philippine Bush Warbler (Cettia seebohmi) and the Japanese Bush Warbler (C. diphone). We compared complete sequences of the mitochondrial cyt-b gene of C. seebohmi to those of other Cettia taxa from GenBank and found C. seebohmi formed a monophyletic group with C. haddeni and C. diphone. The phylogenetic tree also suggests that C. seebohmi is more closely related to C. haddeni than to C. diphone although this was not strongly supported due to the low bootstrap values. The estimated nucleotide differences between C. seebohmi and C. haddeni (4.37%), and between C. seebohmi and C. diphone (3.87–4.37%) were larger than the inter-subspecific difference between C. diphone borealis and C. d. cantans (2.44%). Cettia seebohmi, C. haddeni, and C. diphone diverged prior to the subspecies divergences of C. diphone. The basic structure of songs was similar in C. seebohmi and C. diphone; all songs consisted of pure ...

Artificial eggs of six different colours and control eggs of Bush Warblers Cettia diphone were introduced into nests of Bush Warblers, a host of both Little and Himalayan Cuckoos Cuculus poliocephalus and C. saturatw in Japan. All control (chocolate-brown) and artificial red eggs were accepted; all grey and all white eggs were rejected. The rejection rates of orange, pink and orange spots on grey eggs were 8%, 369; and 55%, respectively. Bush arblers are more likely to reject eggs the more dissimilar they are from their own. The results strengthen the possibility that the chocolate-brown eggs of Little and Himalayan Cuckoos may have evolved through the discriminative ability of Bush Warblers and their intolerance towards dissimilar eggs.

We have studied in northern Japan the hitherto unidentified eggs of a species of cuckoo in the nests of the Bush Warbler Cettia diphone. The cuckoo in question appeared to be the Himalayan Cuckoo Cuculus saturatus which parasitizes mainly the Willow Warbler Phylloscopus occipitalis in southern Japan. The egg colour in this northern Cuckoo was chocolate-brown or orange-brown, similar to that of the Bush Warbler but unlike that of the southern Himalayan Cuckoo. Egg size was significantly larger than that of the southern Himalayan Cuckoo and instead similar to that of the Little Cuckoo C. poliocephalus which uses the same host species in southern Japan, to which the Little Cuckoo is confined. The shift in host species and egg colour in the northern Himalayan Cuckoo seems to be a case of character release in the absence of the Little Cuckoo.

高密度のソウシチョウの巣の存在にともなうウグイスの巣への捕食の増大という間接効果を検証するために，えびの高原（鹿児島県，宮崎県）において，ソウシチョウの巣の除去実験を行った．調査は2002年と2003年の繁殖期に，ソウシチョウの巣を繰り返し除去し，除去を行わない対照区との間で，ウグイスの巣に依存する期間の生存確率を比較した．除去の結果，2002年は巣密度の低くなった除去区では対照区より全期間生存確率は有意に高かった．2003年はウグイスの営巣数が大きく減少したため，ソウシチョウの巣を除去したにもかかわらず両地区の巣密度差が小さく，生存確率に有意差が生じなかった．本研究の結果はソウシチョウの高密度な巣の存在がウグイスの偶発的な捕食の増加を引き起こし，ウグイスの低い繁殖成功をもたらしたことを示唆している．

Background The Russet Bush Warbler Locustella (previously Bradypterus) mandelli complex occurs in mountains in the eastern Himalayas, southern China, Vietnam, the Philippines, and Indonesia. The taxonomy has been debated, with one (L. seebohmi) to four (L. seebohmi, L. mandelli, L. montis and L. timorensis) species having been recognised. Methods We used an integrative approach, incorporating analyses of morphology, vocalizations and a molecular marker, to re-evaluate species limits in the L. mandelli complex. Results We found that central Chinese L. mandelli differed from those from India through northern Southeast Asia to southeast China in plumage, morphometrics and song. All were easily classified by song, and (wing + culmen)/tail ratio overlapped only marginally. Both groups were reciprocally monophyletic in a mitochondrial cytochrome b (cytb) gene tree, with a mean divergence of 1.0 ± 0.2%. They were sympatric and mostly altitudinally segregated in the breeding season in southern Sichuan province. We found that the Mt Victoria (western Myanmar) population differed vocally from other L. mandelli, but no specimens are available. Taiwan Bush Warbler L. alishanensis was sister to the L. mandelli complex, with the most divergent song. Plumage, vocal and cytb evidence supported the distinctness of the south Vietnamese L. mandelli idonea. The Timor Bush Warbler L. timorensis, Javan Bush Warbler L. montis and Benguet Bush Warbler L. seebohmi differed distinctly in plumage, but among-population song variation in L. montis exceeded the differences between some populations of these taxa, and mean pairwise cytb divergences were only 0.5-0.9%. We also found that some L. montis populations differed morphologically. Conclusions We conclude that the central Chinese population of Russet Bush Warbler represents a new species, which we describe herein, breeding at mid elevations in Sichuan, Shaanxi, Hubei, Hunan and Guizhou provinces. The taxonomic status of the other allopatric populations is less clear. However, as they differ to a degree comparable with that of the sympatric L. mandelli and the new species, we elevate L. idonea to species status, and retain L. seebohmi and L. montis as separate species, the latter with timorensis as a subspecies. Further research should focus on different populations of L. montis and the Mt Victoria population of L. mandelli.

Song repertoire size is often cited as a classic example of a secondary sexual trait in birds. Models of sexual selection and empirical tests of their predictions have often related secondary sexual traits to longevity. However, the relationship between repertoire size and longevity is unclear. Using capture-mark-recapture studies in two populations of the brownish-flanked bush warbler Cettia fortipes, we found that males with a repertoire size of three maintained territory tenure for a longer duration than did males with a repertoire size of two. These results provide evidence that even a minimal difference in repertoire size can serve as a potential signal of territory tenure capability.

Song complexity and the repertoire of the bush warbler Cettia diphone were studied in an island and a mainland population in Japan. The song complexity (number of modulations in a song) was lower in the island population than in the mainland one. On the other hand, the repertoire size (number of song types per male) was larger on the island. Founder effect probably does not influence the island song because colonization occurred a very long time ago. Sound transmission properties of the habitat and weak selection pressure for interspecific identification might have influenced the island song, but these cannot elucidate the simpler song on the island. There is a possibility that social conditions affect song complexity in the populations; the highly polygynous mating system of the mainland population yields strong selection pressure toward complex song through acquisition of mates and/or establishment of quality territories. On the other hand, variable songs on the island seem to be affected by cultural mutation.

Breeding ecology of the Short-tailed Bush Warbler Cettia squarneiceps was investigated in western Hokkaido during five seasons (1990-1994). The first arrival and first egg-laying dates were similar among years. Clutch sizes varied between 4-6 eggs, but they decreased as the breeding season progressed. The mean incubation and nestling period was 12.9±0.5 days (SD, n=18) and 10.0±0.4 days (SD, n=17), respectively. Only females incubated eggs and brooded nestlings for a long period of time. Most of the feeding of the young was conducted by males. Different (beta or gamma) males from the resident (alpha) male appeared and sometimes fed the young in 48.1% of twenty five nests observed. Some males were captured at locations far from their own nests, while there were only few cases in which a female was captured at a place distant from her mate's song area. As it was often observed that a beta male was the neighboring territory holder and his own nest was in the incubation period, it is hypothesized that some males who are emancipated from the incubation, might visit other territories to seek extra-pair copulations (EPC). We have, however, not observed mating between a female and a beta male except in the case of a widow. Within the breeding season, the females usually selected the same partner for the second brood. Main reason why the divorce rate within the season is low for the warbler in our study area is probably the high success rate for the first brood.

We compared the adrenocortical responses to acute stress in two free-living populations of bush warblers, Cettia diphone by measuring the increase in circulating levels of corticosterone in response to capture, handling and restraint over one hour. We wished to test the hypothesis that populations living in more severe habitats with shorter breeding seasons are likely to suppress the adrenocortical response to acute stresses during the nesting phase. We chose the bush warbler because males show no parental care which also has been shown to be an ecological correlate of stress modulation. Male bush warblers responded to playback of songs and long calls with aggressive behavior that was identical at the two sites (Furano, Hokkaido and Chichibu, Honshu). Plasma levels of testosterone were also similar in the two populations suggesting that they were in the same reproductive state when tested. Males of both populations showed marked increases in circulating corticosterone levels during the capture st...

Acoustic identification is increasingly being used as a non-invasive method for identifying individuals within avian populations. However, most previous studies have utilized small samples of individuals (

Japanese bush warblers, Cettia diphone , are a common species in Japan and have a poly-gynous breeding system. In the breeding ground some males have their own territories withmore than one female. Male floaters are also not uncommon in the breeding ground. Tounderstand breeding strategy in this species, exact parentage should be elucidated. In orderto obtain a tool for this purpose, we isolated 34 microsatellite loci from a genomic libraryin this species and developed primers for 12 loci. These primers were tested in the Japanesebush warbler and successfully amplified. In analyses of 49 unrelated individuals, allelicnumbers ranged from two to 22, and observed heterozygosity ( H O ) ranged from 0.27 to 0.854except for two loci (Cdi29 and Cdi35a) with H O < 0.1. Keywords : Cettia diphone , Japanese bush warblers, microsatellite, primer Received 8 August 2002; revision received 28 September 2002; accepted 28 September 2002 Japanese bush warblers ( Cettia diphone ) are distributedalong the eastern rim of the Eurasian continent and theJapanese islands and are one of the best known species inJapan because of their unmistakable songs (Hamao 1997).They are residents or short-distant migrants on Honshu(main) island in Japan. In early spring, males begin to singin wintering sites, such as bushes, parks, and backyardsof lowland areas and most of them migrate to highermountainsides and breed in bamboo bushes or grassmeadows. At the field site in Chichibu, Honshu island, weobserved their behaviour and collected blood samples forhormone measurement after capture with mist nets. Wefound that males sing from late March through August inthe breeding area and circulating testosterone is foundhigh during this period (Wada

1) Mating system of individually marked Japanese Bush Warblers Cettia diphone was studied at Myokokogen (36°52′N, 138°11′E, alt. 700m), central Japan, during the 1990-91 breeding seasons. 2) Territories were maintained for short periods. Although 35 territorial males were confirmed within a census area in a breeding season, only 10-14 (x=11.7, n=9) of them were observed on each survey. 3) Intrusions into territories by non-residential males were observed frequently. These intruders never sang there. In M98's territory, 15 intrusions by floating males and five intrusions by territorial males were observed.4) In three territories, multiple females were observed breeding. In M98's territory, seven breeding attempts were made by 6 or 7 females within a season. 5) Females built nests and took the full share of parental care, including incubation, feeding nestlings, rearing fledglings, and mobbing predators. 6) Breeding failures, which might have been caused by predation, were observed frequently. There was a trend for females to leave a territory after one breeding attempt. 7) At least 21 females appeared in M98's territory, which suggests the presence of many potential mates for the male.8) Home ranges of breeding females were much smaller than male territories. Female ranges seemed to be restricted to within male territories. The ranges of females nesting in the same territories overlapped. Agonistic behavior between them was not observed. 9) Singing activity of males was vigorous throughout the breeding season irrespective of the nesting stages of breeding females. No contacts between males and nesting females, including escorting behavior of females by males, were observed.10) These results strongly suggested that the mating system of the Japanese Bush Warbler was advanced polygyny characterized by lack of pair-bonds.

Some resident birds widen their habitat ranges during the non-breeding season. Their wintering habitats may be determined not only by quality of habitats but also by their connectivity to source habitats. In this study, we extract some possible stepping-stone corridors and evaluate which corridors explain the presence/absence of four resident birds–the Bush Warbler, Long-tailed Tit, Varied Tit, and Masked Grosbeak–in possible wintering habitats in Kyoto City. Bird surveys were conducted in 18 woods (> 0.6 ha): almost all-potential breeding patches for these four species in the urban area of Kyoto. I assume the mountain forests around the city and patches in which each bird species was recorded during the breeding season to be their source habitats, and assess whether corridors connect their source and possible wintering habitats. A 15 × 15 m resolution vegetation cover ratio (VCR) map was derived from Terra/ASTER and Quick Bird images. We assumed the minimum VCR for stepping-stones to be 0.25 and created buffer zones from each stepping-stone at four distances: 50 m, 75 m, 100 m, and 125 m. Four types of corridors were extracted from the contiguous buffer zones. The maximum interval between stepping-stones was twice the distance of the created buffer. The maximum interval for suitable corridors evaluated by maximum Cohen’s kappa, maximum overall prediction success, and minimum interval for which more than 80% of the actual wintering habitats connect to the source habitats were, respectively, 200m (kappa 0.25), 200- 250 m (75% success), and 200m (89% connection) for the Bush Warbler; 100 m (0.12, 58%) and 150 m (80%) for the Long-tailed Tit; 100 m (1.0, 100%, 100%) for the Varied Tit; 100 m (0.29, 64%) and 250 m (100%) for the Masked Grosbeak. Though further analysis may be necessary, these results give us some indication regarding the size of the interval between stepping-stones necessary for planning ecological corridors.

Plasma levels of testosterone and corticosterone were measured in free-living male bush warblers captured on their breeding ground at different times of the breeding season. Their territoriality was also estimated from their singing response to song playbacks. The pattern of change detected in the levels of plasma testosterone was different from that of “typical” monogamous species but similar to that of polygynous species. In “typical” monogamous species, plasma testosterone levels elevated during territory settlement and courtship behavior and then declined to low, stable levels during incubation. In bush warblers, plasma levels of testosterone were already high (1–2 ng/ml) upon arrival in late March and peaked (2.5–4 ng/ml) in early June. They then decreased but relatively high levels were maintained until early August. In late August the testosterone concentration was 0.03 ng/ml or less. Plasma levels of corticosterone also showed a seasonal change, being highest in May to July and declining in late August. Territoriality showed clear seasonality, reflecting the levels of circulating testosterone. Upon arrival, latency periods for responses to song playback were long and singing activity was rather low but this behavior was soon stabilized and a high degree of territoriality was maintained to late August. These results suggest that high levels of circulating testosterone and corticosterone allow males to pursue a polygynous breeding strategy, to hold a territory, and to maintain breeding activity for a prolonged period, characteristics which are likely to be adaptations to dense bushes with high rates of predation and brood parasitism of this species.

We describe a new species of Cettia from the Crown Prince Range, Bougainville Island, North Solomons Province, Papua New Guinea. By combining morphometric and molecular phylogenetic techniques, we attempt to broaden our understanding of evolutionary processes within the genus Cettia in the southwest Pacific. The new species proves to be distinct with respect to several morphological characteristics that are most probably related to a more terrestrial lifestyle than that of its congeners. Molecular data agree with morphological data in establishing that these birds are at least as distinct from the other island forms of Cettia as those forms are from each other, far exceeding intraspecific variation. These data and the restricted distribution of the population on Bougainville strongly support recognition of a new species. The application of molecular phylogenetic techniques also supports the idea that the new species and other island forms of Cettia confined to mountains on southwest Pacific islands are derived from a single common ancestor rather than being independently derived from one or more mainland forms. In addition, the relatively recent discovery of two new species of Cettia suggests that additional forms await discovery in other poorly known areas of the southwest Pacific. Our results point to the need for further molecular studies and for additional field research into the distribution and ecology of forest songbirds on islands.

Mt. Kisokoma (2, 956m above sea level) is the highest peak of the Chuo Alps, Central Honshu.Bird censuses were made throughout a year from February 1977 to February 1978 in the mid-mountain zone at 900-1, 650m altitude. Line transect method along the road is used in the census work. The total number of birds recorded was 1, 525 individuals belonging to 43 species (Table 1). The number of species and that of birds showed similar seasonal changes, i.e., maximum in the breeding season and minimum in winter. The dominant species were Pale-legged Willow Warbler Phylloscopus tenellipes, Siberian Meadow Bunting Emberiza cioides, Bush Warbler Cettia diphone, and Blue-and white Flycatcher Cyanoptila cyanomelana in breeding season and Long-tailed Tit Aegithalos caudatus, Willow Tit Parus montanus, Coal Tit Parus ater, Great Tit Parus major, and Nuthatch Sitta europaea in non-breeding season. A marked expansion of range in vertical distribution was noted for Siberian Blue Robin Erithacus cyane, Bush Warbler Cettia diphone and Blue-and-White Flycatcher Cyanoptila cyanomelana. Mixed flocks of tits were encountered in every censuses except for the three breedingmonths, and all five species of tits formed mixed flocks.

This paper deals with the status of Pale-footed Bush-warbler in Nepal with reference to its global distribution.DOI: 10.3126/on.v7i1.2577Our Nature (2009) 7:226-230

A nest of the Short-tailed Bush Warbler, Cettia squameiceps, was found again on 14 June in 1984, in the Red Pine, Pinus densiflora forest at Tomida (altitude ca. 700m), Takagi-mura, Shimoina-gun, Nagano Prefecture. Four adult warblers simultaneously attended the nest. The nest visits of each of 4 banded birds were observed for 2, 284 bird-minutes for 5 days. The food contribution of a helper of this species was very small although a helper sang well. We found a second instance of helping at the nest of this species since our discovery in 1981. The possibility that cooperative breeding occurs more or less regularly in this species is proposed.