Sturnus Cineraceus Research Articles

Relationship between communal roosts of Grey Starlings and surrounding environment in urban area

The aim of this study is to grasp the distribution of grey starling’s communal roosts formed in urban areas and to clarify the surrounding environmental characteristics preferred by them. First, I investigated the distribution of grey starling’s communal roosts in Japan. I defined the roosts in densely inhabited districts as "urban roost," and grasped their distribution and characteristic trends. Next, I performed a wide-area analysis of the relationship between urban roosts in Osaka and land use around them. Finally, I performed a narrow-area analysis of the relationship between five urban roosts in Osaka and their surrounding spatial components. The majority of the 349 (1950-2019) urban roosts were located on the side of roads, in front of stations of commercial areas, and in the roadside zelkova serrata trees. Additionally, in relation to spatial components, more urban roosts were located in areas with middle-high-rise residential buildings. In addition, it became clear that it is important for grey starlings to be near buildings higher than the roosts as a microscopic spatial component.

Spatial analysis on the distribution of communal roosts of gray starlings (Sturnus cineraceus) and surrounding land uses in the Tokyo 23 special wards

Spatial analysis on the distribution of communal roosts of gray starlings (Sturnus cineraceus) and surrounding land uses in the Tokyo 23 special wards

高知県宿毛市におけるムクドリとギンムクドリの異種間つがいによる繁殖事例

高知県宿毛市におけるムクドリとギンムクドリの異種間つがいによる繁殖事例

大阪市中心部の街路樹と越冬期の鳥類の出現状況の関係

I investigated birds from 15 January to 24 February 2004 along 8 wooded streets in central area of Osaka, Japan, in order to determine which environmental factors of wooded street are important as habitat of birds in winter. Eight species of 218 individuals were recorded at 2 times observation of the streets. I used a satellite image to identify the distribution of vegetation in my study area. The normalized difference vegetation index (NDVI) of each grid cell was calculated. The value of NDVI that indicated the threshold value for vegetation cover were 0.3 and more, based on the ground-truthing from December 2003 to February 2004. The proportion of vegetation cover within 50 m from a recording point was calculated in each bird species. The average vegetation cover proportion of Hypsipetes amaurotis and Sturnus cineraceus was more than 25 %, while that of Passer montanus was around 5 %. Almost all individuals of species except Passer montanus were significantly recorded in buffer areas within 100 m, 200 m, 300 m and 400 m from the edge of 2 ha and more woodlot.

都市緑地における樹林地の構造と鳥類の利用について

We examined how vegetation structure and human activities influenced avian fauna in wooded open spaces in urban areas. Canonical Corresponding Analysis (CCA) revealed that factors such as coverage of lawn, pressure of human-utilization, and coverage of deciduous trees were important to determine avian fauna. Areas covered with lawn and used by people tended to hold characteristic fauna in which such species as grey starlings, dusky thrushes and white wagtails were dominant. In particular, grey starlings showed the same tendency in both wintering and breeding seasons. Although abundance of these species decreased as lower layers became too dense, it was also confirmed that lower vegetation layers of intermediate coverage contributed to maintain some species such as black-faced bunting, pale thrushes, Japanese bush warblers, and oriental turtle doves, which has already been known in previous studies. In breeding season, spatial variation in avian fauna could not be explained by these factors well, which may be caused by the absence of the species that tend to use specific vegetation structures such as lower vegetation layers. On the other hand, the area of wooded open space and surrounding land uses influenced avian fauna in some extent.

Gizzard Spirurid Nematode Acuaria skrjabini in Japanese Tree Sparrows and a Gray Starling from Tokyo

Gastrointestinal helminths were collected from 49 Japanese tree sparrows (Passer montanus saturatus) in Tokyo, Japan. In 16 sparrows, 1-9 (average, 3.5) gizzard spirurid nematodes (Acuaria skrjabini Ozerskaya, 1926) were found embedded in the mucosa of the gizzard. In addition, Capillaria sp., Platynosomum passeri Yamashita et Tsumura, 1962, and a hymenolepidid cestode were collected from 1, 2, and 1 sparrows, respectively. A sexually mature A. skrjabini female and 3 males were found also in a young gray starling (Sturnus cineraceus) that was found dead in the same area after failure to leave the nest. Starlings are a new host record for this spirurid species. Until this study, this gizzard spirurid species has not been recorded in this country or the Far East region.

Kinematic parameters of the walking of herons, ground-feeders, and waterfowl

The kinematic gait characteristics of six species of birds in three groups were compared. The groups studied were herons (Gray Herons and Little Egrets), ground-feeders (Domestic Pigeons and Gray Starlings), and waterfowl (Pintails and Black-headed Gulls). The results showed that the relative stride frequency was greater in the waterfowl than in the other species. Complementary to this, the amplitude of the movements was smaller in the waterfowl than in the others. These differences between the waterfowl and the other species might be caused by their morphological and/or physiological adaptation to swimming. Another possible cause for these differences was the magnitude of head bobbing, as the ground-feeders and herons, which walk with head bobbing, showed a large relative stride length and excursion angle, while the waterfowl, which do not head-bob, walk with a relatively short stride length and small excursion angle. Moreover, the relative magnitude of head movement during walking was especially large in Little Egrets, which showed an especially large relative stride length and excursion angle. These parameters may have some mechanical relationships with each other.

Floaters as intraspecific brood parasites in the grey starling Sturnus cineraceus

The breeding season of the grey starling Sturnus cineraceus is divided into two periods: the early and late breeding season. The birds that breed in each season are referred to as early and late breeders, respectively. In this study, the late breeders mainly consisted of new immigrants that did not breed in the early season. This suggested that these new immigrants were probably floaters in the early breeding season. Because intraspecific brood parasitism occurred frequently, it is possible that the parasites were floaters without nesting boxes. To check for the presence of floaters, two field experiments were conducted and floaters were captured with traps. With additional nesting boxes provided during the breeding season, all new boxes were quickly occupied by floaters from the period of incubation to hatching in the early breeding season, but were not occupied by floaters during the egg laying period of the late breeding season. The addition of boxes before the start of the breeding season significantly decreased the parasitic rate and number of parasitic eggs per nest. There was a positive correlation between the relative occupancy of nesting boxes and the parasitic rate. The removal of boxes again increased the parasitic rate. As for the capture of floaters with traps, the number of trapped birds per day was also related to the relative occupancy of nesting boxes. The floaters trapped between incubation and nesting periods of early breeders became the late breeders. Judging from these results, many floaters were present from the incubation to hatching periods of early breeders, and were probably intraspecific brood parasites.

Parasitism strategy of the grey starling, Sturnus cineraceus: Selection based on host characters and nest location

The strategy used by the intraspecific brood parasite, the grey starling, Sturnus cineraceus (Temminck) and the degree to which this strategy reflected the sources of mortality for parasite eggs were examined. Approximately 74% of all parasite eggs failed to produce young that survived to fledglings. Most of this mortality was due to two factors: (i) laying in a nest that had been deserted by a host during its nesting cycle (19%); and (ii) mismatched timing of laying in the host’s nesting cycle (38%). It is important for parasites to select a suitable host in order to avoid this mortality and increase their reproductive success. However, grey starlings did not select hosts on the basis of nest location, host characteristics, or laying date. Lack of attention to these factors implies a failure on the part of the grey starlings to recognize cues that could direct them to select host nests that would provide the best environment for their eggs. Although some egg loss and egg replacement occurred before clutch initiation by hosts, no evidence was found that parasitic birds removed host eggs after clutch initiation by hosts. These results suggest that parasites did not adopt a successful strategy for enhancing the survival rate of their own eggs.

Seed dispersal of Chinese tallow-tree Sapium sebiferum by Birds

Fruit of the Chinese tallow-tree Sapium sebiferum have white sarcocarp and dehiscence in autumn. The sarcocarp dries on the branch soon after the dehiscence. We observed eight bird species eating the fruit of S. sebiferum. Two species of crows Corvus corone and C. macrorhynchos, the Grey Starling Sturnus cineraceus and the Brown-eared Bulbul Hypsipetes amaurotis swallowed the fruit and excreted the seeds. The Tree Sparrow Passer montanus, the Great Tit Parus major and the Oriental Greenfinch Carduelis sinica took only a small part of the sarcocarp and left the seeds on the branch.The Turtle Dove Streptopelia orientalis took a lot of fruits and digested the seeds.The Tree Sparrow, the Great Tit, the Oriental Greenfinch, and the Turtle Dove are not seed dispersers, but a kind of seed parasite or predator.

Efficacy of common protection devices in preventing night-time damage of cabbage crops by Spot-billed Ducks in Japan

Data from the Japanese Ministry of Agriculture, Forestry and Fisheries indicate wildfowl damage to vegetable crops is common in Japan, but specific details on the problem and the effectiveness of alleviation methods do not exist. A flock of up to 99 Spot-billed Ducks ( Anas poeciloryhncha ) roosted on a river during the day at Kawagoe City, central Japan. At night some or all of this flock fed on cabbage ( Brassica oleracea Capitata group) crops nearby. Farmers deployed numerous scaring devices in the area to prevent crop damage. We grouped these into four categories: (1) monofilament lines; (2) monofilament lines in conjunction with either scarecrows, flags, and illegal mist nets; (3) flags, and flags in combination with scarecrows, and mist nets; and (4) exclusion nets, and tested the relative efficacy of these methods over 73 fields. Considering only presence or absence in fields of damaged plants, the relative effectiveness of the four categories were ranked from most to least effective as: nets > monofilament lines and others monofilament lines = flags and flags plus others. The proportions of cabbage plants damaged per field were lowest in fields protected by nets. The amount of material removed from damaged plants did not differ significantly between the categories. Crop value depends on a combination of factors, notably yield (number of plants per 10 kg), monthly changes in sale price, and plant quality. In 1996 a poor yield, slow growth rate, and poor quality plants as a result of duck depredation could have caused economic losses of 68.2% or more in some cases. Deployment of nets over the crop using metal frame supports is a costeffective protection method, but nets must be adequately supported and maintained. Although effective, nets are not favoured by farmers because they are difficult to maintain. They are also hazardous to nontarget birds in the area such as Gray Starling ( Sturnus cineraceus ), Dusky Thrush ( Turdus naumanni ), Rufous Turtle Dove ( Streptopelia orientalis ) and Skylark ( Alauda arvensis ) which die if accidentally entangled in the mesh. We therefore discuss alternative crop protection strategies which can be considered.

Intraspecific nest parasitism and anti-parasite behavior in the grey starling,Sturnus cineraceus

I studied intraspecific nest parasitism in the grey starlingSturnus cineraceus in 1992 and 1993. The population in this study consisted of 290 nests (157 nests in 1992 and 133 nests in 1993) in which the clutches were completed before May 10 in the year studied. Twenty-nine nests in 1992 and 32 nests in 1993 contained at least 1 parasitic egg. Hatching success per nest of parasitized nests was slightly higher than that of non-parasitized nests. However, fledging success per nest of parasitized nests was significantly lower than that of non-parasitized nests. Thus parasitism appeared to reduce the reproductive success of hosts. Hosts exhibited a few behaviors that minimized the potential cost of brood parasitism. These behaviors included throwing out the parasitic egg and nest guarding. Hosts threw out parasitic eggs before the onset of laying, but they never did so to parasitic eggs laid after that period. The nest guarding level was low during the hosts’ laying periods, and one observed nest was parasitized during this time. Thus, nest-guarding behavior was not effective as an anti-parasite behavior. Grey starlings do not appear to adopt strategies effective in reducing parasitism.

Intraspecific nest parasitism in the grey starling (Sturnus cineraceus)

AbstractWe studied intraspecific nest parasitism in the grey starling (Sturnus cineraceus) in 1992 and 1993. We used three criteria to detect nest parasitism: (i) the appearance of more than one egg per day while the host was laying; (ii) the appearance of extra eggs after the host completed its clutch; and (iii) the appearance of eggs which were of a different shape, size and color to other eggs in the clutch. There were 290 nests (157 nests in 1992; 133 nests in 1993) in which the clutch was completed early (clutches initiated before May 10). Twenty‐nine (1992) and 32 (1993) nests contained at least one parasitic egg. Parasitic eggs hatched if they were laid during the laying period and early in the incubation period of their host, and a few of them fledged. Fledging success of parasitic eggs was not different from that of eggs in non‐parasitized nests if parasitic eggs were laid during the host's laying period. However, fledging success of all parasitic eggs was fewer than that of eggs in non‐parasitized nests. By comparison, fledging success of parasitized nests was not a great as that of non‐parasitized nests.

Preferences and apparent digestibilities of sugars by fruit damaging birds in Japan

SummaryGray starlings Sturnus cineraceus, azure‐winged magpies Cyanopica cyana and brown‐eared bulbuls Hypsipetes amaurotis are among the main bird pests in commercial fruit orchards in central Japan. Recently Brugger & Nelms (1991) suggested that developing high‐sucrose fruit cultivars could reduce crop damage, because some pest birds lack the enzyme sucrase and can develop an aversion to sucrose. Preferences for, and digestibilities of, the monosaccharides glucose and fructose and the disaccharide sucrose by these pests species were therefore studied to assess whether this idea would be applicable in central Japan. Gray starlings and brown‐eared bulbuls were able to detect glucose, fructose, a mixture of glucose and fructose, and sucrose at a concentration of 12% w/v. Azure‐winged magpies also detected glucose and fructose, but failed to detect sucrose at the same concentration. In pairwise preference trials gray starlings and azure‐winged magpies selected the monosaccharides over sucrose, but brown‐eared bulbuls did not. To estimate the digestibility of the sugars the apparent assimilated mass coefficient, AMC*, was calculated for each species eating each sugar by measuring intake and faecal output. Monosaccharides had mean AMC*s of 0.77, 0.96 and 0.92 when consumed by gray starlings, azure‐winged magpies and brown‐earned bulbuls respectively. AMC* values for sucrose were 0.82 and 0.49 for brown‐eared bulbuls and azure‐winged magpies respectively, but gray starlings were shown to be unable to digest sucrose. As AMC* values varied from 0.75 to 0.97, consumption rates of sugars increased as digestibility decreased. Although increasing sucrose contents of commercial fruits may deter sucrase‐deficient birds such as gray starlings from depredating fruits, it may also lead to increased crop damage by species such as the azure‐winged magpie and brown‐eared bulbul which may have to consume more of the less digestible fruit in order to meet their energy requirements.

Effects of ectostriatal lesions on discriminations of conspecific, species and familiar objects in pigeons

Pigeons were trained on three visual discrimination tasks, that is (1) pigeon vs. other birds discrimination; (2) Java sparrow vs. grey starling discrimination; and (3) home cage vs. food tray discrimination. Then the ectostriatum or the Wulst was bilaterally damaged. The Wulst lesions did not cause deficits in any tasks. The ectostriatal lesions impaired the species discrimination (Java sparrow vs. grey starling) but not the conspecific discrimination (pigeon vs. other birds). Some birds showed deficits in the familiar object (the home cage and the food tray) discrimination while others did not. These results suggest dissociation between conspecific and species discriminations. The results of the familiar object discrimination indicate factor of familiarity in the conspecific discrimination.

Molecular Phylogeny of Some Passeriformes, Based on Cytochrome b Sequences.

A 646bp fragment of the mitochondrial cytochrome b gene and a 293bp fragment of the 18S ribosomal RNA gene were sequenced from 20 species of the Passeriformes, primarily of the family Muscicapidae. Phylogenetic trees of the cytochrome b gene indicated monophyly of the genus Turdus except T. dauma and close relationships among T. chrysollaus, T. obscurus and T. pallidus with a high bootstrap probability. The tree showed an early divergence of Corvus macrorhynchos from the other Passeriformes. Sturnus cineraceus was not closely related to Corvus macrorhynchos and included in the branch of Muscicapidae with a relatively high bootstrap probability. Although the trees suggested monophyly of the families Emberizidae, Ploceidae and Zosteropidae, the relationships among the families of Passeriformes were unclear. The sequences of the 18S ribosomal RNA gene were the same in the Passeriformes examined except the Tarsiger cyanurus, Monticola solitarius and Ficedula narcissina. These three species shared a single substitution at the same position, suggesting monophyly of the three species.

Distribution Pattern and Characteristics of Grey Starling Sturnus cineraceus Summer Roosts in the Eastern Kanto Area

The Grey Starling Sturnus cineraceus roosts communally in Japan. In the eastern Kanto, Grey Starlings occupy large-numbered summer roosts between June and October. Although the existence of summer roosts had been reported, the distribution pattern of summer roosts over a large area was not known. We located 14 summer roosts in the eastern Kanto and analyzed their distribution pattern using the Iδ index. Our analysis revealed that they were uniformly distributed. All of the summer roosts in our study area were occupied from late June or early July to mid-October. The Grey Starling did not seem to favor a particular vegetation type to roost during summer, which was contrasting to their preference for bamboos in winter. Since several factors are involved in the occupation and abandonment of summer roosts, it is difficult to determine the very factor directly influencing them. The uniform distribution of summer roosts might be related to the life history of the Grey Starling, and might be convenient for the starlings accompanying inexperienced young to feeding grounds.

Operant Conditioning of the Gray Starling, Sturnus cineraceus

Gray Starlings Sturnus cineraceus are one of the most notorious agricultural pests in Japan. We trained three Gray Starlings by operant conditioning to peck a response key to obtain a piece of mealworm. Birds were carefully trained to get used to the experimental situation and new schedules were gradually introduced. All the birds were successfully trained to peck the key. Two of them were further trained by an intermittent reinforcement schedule. The techniques developed here to condition the Gray Starling should be useful for further research aimed to measure aversiveness of visual or auditory stimuli for bird scaring.

繁殖期におけるムクドリの標識方法

I capture incubating or brooding Grey Starling in nesting boxes by hand. I am always careful to avoid nest desertion by ensuring that:1. Before capture, I identify that both the male and the female are involved in incubation.2. After I identify that an un-marked bird incubate more than twice, I capture the bird at least 6 days after incubation.3. If both male and female are captured, I identify that the first-captured bird is incubating before capturing the other bird.

Occurrence of Campylobacter jejuni in free-living wild birds from Japan.

Campylobacter jejuni was isolated from 44 of 313 free-living birds from Japan. The highest isolation rate was found in 30 of 87 (34%) crows (Corvus levaillanti and Corvus corone), followed by 2 of 10 (20%) blue magpies (Cyanopica cyanus), 5 of 35 (14%) gray starlings (Sturnus cineraceus), 2 of 16 (13%) domestic pigeons (Columbia livia domestica), 4 of 36 (11%) bulbuls (Hypsipetes amaurotis), and 1 of 62 (2%) eastern turtledoves (Streptopelia orientalis). One-fourth of the contents of the crop and stomach of the crows was human refuse. One-third of the crop and stomach contents of gray starlings and blue magpies consisted of insects. More than one-half of the contents of bulbuls and eastern turtledoves were seeds and plant material. These differences in food habits may be a primary factor in the varying prevalence of C. jejuni in these respective avian species.