著者

Kaoru FUJITA Go FUJITA Hiroyoshi HIGUCHI

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.22, no.1, pp.67-79, 2023 (Released:2023-01-26)

参考文献数

74

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Inspired by ecologists R. H. MacArthur and E. O. Wilson, who pioneered the use of islands as ideal model systems for researching the formation and maintenance of biodiversity, we studied two sympatric passerine bird species on a volcanic archipelago, in Japan. We focused on the occupancy and co-occurrence of Varied Tit Sittiparus varius and Cinereous Tit Parus cinereus, both members of the Parus guild, on the Izu Islands. Their populations range from being stable, and co-occurring, to being temporally unstable (with local extinctions, invasions, and species replacement) and even totally absent. Using results from several surveys carried out on the islands over the last 60 years, and our own contemporary surveys, we tested the ecological drivers of inter-island occupancy through occasional dispersal of these two species. We found that both species had positive relationships with island size and vegetation diversity, while Cinereous Tit exhibited a negative associating with distance to the mainland (Honshu, Japan). Cinereous Tit was also negatively correlated with Varied Tit, but their co-occurrence was positively associated with island size, connectivity, and vegetation diversity. We suspect that resource constraints play a significant role in the distributions of the two species on the islands. Varied Tit is dominant over Cinereous Tit, but Cinereous Tit is able to utilize a wider range of habitats and resources. We also discuss the potential for a competition-colonization trade-off for the two species on the islands.

著者

Andrey BUSHUEV Ekaterina ZUBKOVA Anvar KERIMOV

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.20, no.2, pp.213-222, 2021 (Released:2021-07-31)

参考文献数

41

被引用文献数

1

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The Scarlet-backed Flowerpecker Dicaeum cruentatum (Dicaeidae, Passeriformes), a sedentary species of Southeast Asia, is among the smallest passerine birds (5–6 g). Despite its very small size, it feeds mainly on plant foods, such as berries, nectar, and green seeds. We found that in conditions of likely food shortage Scarlet-backed Flowerpeckers were able to greatly reduce their metabolic rate at a relatively high ambient temperature (26–28°C). This is within the thermoneutral zone of most tropical birds, although slightly cooler than the normal lower critical temperature of flowerpeckers. In this state, the resting metabolic rate (RMR) of three individual, free-living Scarlet-backed Flowerpeckers from Vietnam averaged 1.57 mL O2/g*h, which was 3.4 times lower than their non-torpid RMR, measured at the same ambient temperature (Ta=~27°C) and 2.5 time lower than their basal metabolic rate (BMR) measured at Ta=~31°C. We did not measure the body temperature (Tb) of these individuals, but the dramatically low oxygen consumption provides evidence of torpor, an energy-saving physiological state, which is very rare among passerine birds. The skin Tb of active flowerpeckers, just before nocturnal RMR measurements, averaged 41.1°C (their cloacal Tb was 41.2°C), while in resting non-torpid birds at night the skin Tb averaged 36.3°C. Our report is the first quantitative evidence of torpor in the family Dicaeidae.

著者

Eugenia V. BRAGINA Irina V. BALAN Nadezhda V. KUZNETSOVA Mikhail P. PARILOV Jonathan C. SLAGHT

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.21, no.1, pp.53-62, 2022 (Released:2022-01-31)

参考文献数

30

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Red-crowned Grus japonensis (IUCN status: Endangered) and White-naped Antigone vipio (IUCN status: Vulnerable) cranes are both rare, with wild populations of ~3,000 and ~6,000 individuals, respectively. Since 1991, the Rare Bird Reintroduction Station at the Khingansky State Nature Reserve, Russia, has been rearing and reintroducing chicks of both species to bolster wild populations. The station uses two different chick-rearing methods: (1) the "parent-reared" method, in which chicks are raised in enclosures by natural parents and stay with them until their release into the wild, and (2) the "semi-wild" method, a modification of hand-rearing, in which cohorts of 2–7 chicks spend most of their time together in an enclosure but are guided on daily excursions outside the enclosure, under supervision of a keeper from a distance of 30–50 m. We have assessed and compared apparent survival of crane chicks reared under these methods. Of the 165 juveniles released into the wild from 1991–2019 (104 Red-crowned; 61 White-naped), no difference was found between apparent survival of parent-reared and semi-wild chicks. Six-month apparent survival of Red-crowned Cranes was 84.2% (95% confidence interval: 75.3–90.3%); for White-naped Cranes -89.5% (95% CI: 83.9–93.3%). Both parent-reared and semi-wild chicks were later observed in mated pairs with their own offspring (17 chicks in total), coupling with either other reintroduced birds or with wild individuals. We conclude that both the parent-reared and semi-wild methods had similar outcomes with respect to apparent survival. However, since the semi-wild method is less costly with respect to time (i.e., more juveniles can be released annually using this method) we recommend that it be used whenever possible to bolster these Endangered and Vulnerable populations.

著者

Wieland HEIM Aleksey ANTONOV Ilka BEERMANN Simeon LISOVSKI Martha Maria SANDER Steffen HAHN

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.21, no.1, pp.121-126, 2022 (Released:2022-01-31)

参考文献数

45

被引用文献数

6

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East Asian songbirds are known to migrate along two major corridors: from mainland Eurasia via China to South-East Asia, and from Japan and easternmost Russia through chains of islands in the Pacific to Indonesia and the Philippines. We successfully tracked the hitherto unknown migration of a Blue-and-white Flycatcher Cyanoptila cyanomelana breeding in the Russian Far East. The bird spent five months on Mindoro Island in the Philippines during the non-breeding season and migrated through Taiwan, the Chinese east coast, and the Korean peninsula. Thus, we provide the first direct evidence for songbird migration from mainland Russia to the Philippines.

著者

Masaharu HAYAKAWA Mieko SUZUKI-MATSUBARA Kazumi MATSUBARA Satoshi KANAZAWA Takashi FUJII Wataru KITAMURA Ryoh Alexander MUROFUSHI Akihiko MORIYAMA

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.21, no.2, pp.155-163, 2022 (Released:2022-08-13)

参考文献数

21

被引用文献数

1

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Little Tern Sternula albifrons sinensis was been categorized as Endangered Class II by the 2020 Ministry of the Environment's Red List in Japan. For an effective conservation program for the taxon, the unit of conservation needs to be understood. In this study, we investigated genetic and morphological diversity as a clue to clarify the units to be protected. Blood samples were collected from 47 individuals in four different breeding sites in Japan (Tokyo, Chiba, Fukuoka, Okinawa). The nucleotide sequences of the control region of mitochondrial DNA were used to analyze their genetic diversity and structure. Basic morphological features were also compared. Nucleic acid base substitution, deletion, or insertion were identified at 30 sites of the 1029-bp sequence alignment of the control region, leading to identification of 30 different haplotypes. Genetic diversity was high in the four breeding populations, and haplotype frequencies showed no indication that specific genotypes were present at extreme frequencies. This suggests that the population of Little Tern nesting in Japan has been maintained without recent bottleneck events. The haplotype network formed two major haplotype groups from the 30 haplotypes. Haplotypes of one group were abundant in the Tokyo, Chiba, and Fukuoka populations. In contrast, those of the other group were frequent in the Okinawa population. Pairwise haplotype analysis between populations also revealed that the genetic variations at Okinawa differ from those of the remaining three populations. Furthermore, the Okinawa population showed different morphological characteristics compared to the Tokyo/Chiba populations. These results collectively suggest that the population of Little Terns in Japan is divided into at least two different populations.

著者

Shota DEGUCHI Yousuke UEDA Masumi HISANO

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.21, no.2, pp.133-143, 2022 (Released:2022-08-13)

参考文献数

60

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Many bird species with heterogeneous distribution are at risk of extinction. It is essential to identify and elucidate environmental factors explaining such distribution patterns to develop effective conservation strategies for those species. Yellow Bunting Emberiza sulphurata is an endangered migrant bird species exhibiting heterogeneous breeding distribution in Japan. Here we clarify the spatial distribution and the altitudinal range of the Yellow Bunting breeding range, and detect environmental factors (e.g., climate and topography) influencing their distribution pattern using an extensive dataset from the national breeding birds survey of Japan. The presence of Yellow Bunting during the breeding season (1997–2002) and six environmental factors (temperature, snow depth, elevation, tertiary layer, landslide area and forest edge density) were analyzed using maximum entropy models (MaxEnt). We found that Yellow Buntings were present in a higher proportion of survey grids in northern Honshu (the main island of Japan) than elsewhere in the country, and they mainly occurred in areas below 700 m above sea level. Moreover, the elevation of the occupied grids decreased with latitude. Temperature and snow depth were of greater importance (0.380 and 0.350, respectively) than other factors in explaining the breeding distribution of the Yellow Bunting. Our study highlighted the location of the core areas of the Yellow Bunting's breeding distribution, and demonstrated that lower temperature and deeper snow cover are the critical determinants of those areas. There may be abundant prey and fewer avian competitors, such as resident bird species, in colder regions, and more frequent snow avalanches and water from melting snow may establish the marshy and bushy habitat preferred by Yellow Buntings. These findings are essential for developing effective conservation strategies for the endangered Yellow Bunting. As past mass-trapping may have also influenced the heterogeneous distribution of the Yellow Bunting, this is an important avenue for future research from a different perspective.

著者

Ming-Tang SHIAO Mu-Chun YAO Mei-Chen CHUANG

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.21, no.2, pp.165-176, 2022 (Released:2022-08-13)

参考文献数

54

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In heterogeneous landscapes, birds may mistime their breeding attempts relative to local food abundance. How birds cope with this challenge has been little studied. In this study, we compared the provisioning behavior and nestling condition of the Green-backed Tit Parus monticolus nesting in a landscape mosaic comprised of native mixed-oak forests and exotic Japanese Cedar Cryptomeria japonica plantations. Parent birds in the larvae-poor plantations time their breeding as they do in the larvae-rich forests and have clutches of similar size. We found that parent birds were flexible in adjusting their criteria for prey choice on the basis of larval abundance. In early spring, in cedar plantations where larval abundance was low, male parents maintained constant nearby feeding trips to the early broods, just as they did in the mixed-oak forests, but reduced their dietary specialization on larvae, while female birds increased their provisioning frequency. Combining both parents' efforts, the early brood nestlings raised in the cedar plantations received food deliveries more frequently and with a higher proportion of non-larval prey than their counterparts did in the mixed-oak forests. In contrast, during late brood rearing, when larvae were abundant, both parents in the plantations foraged heavily on larvae at the expense of other prey, just as they did in the mixed-oak forests. We found that parent birds reared heavier nestlings as the contribution of large larvae to the diet increased. Moreover, the nestlings during early broods in the plantations had lower body weights than their counterparts in the mixed-oak forests. We suggest that the provisioning flexibility of Green-backed Tits helps them gather food for raising nestlings when their breeding attempts are less synchronized with the larval food supply in their habitat. As a result, they can breed successfully in the exotic cedar plantations.

著者

Yuji OKAHISA Yoshinori KANEKO Hisashi NAGATA Kiyoaki OZAKI

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.21, no.2, pp.145-154, 2022 (Released:2022-08-13)

参考文献数

48

被引用文献数

2

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An increasing number of reintroduction programs have been set up in recent years in an attempt to reintroduce once extinct species to their indigenous ranges and create self-sustaining populations. However, the released individuals often experience low mating success and fecundity. Appropriate rearing in captivity is considered essential for the successful post-release reproduction of captive-reared individuals. Low post-release mating success and fecundity are also issues in reintroduced Crested Ibis Nipponia nippon populations on Sado Island. These phenomena may be caused by the effects of hand-rearing in captivity, yet temporary hand-rearing is necessary when captive breeding, because rescuing embryos from mortality is essential due to the abnormal behavior of parent birds in captivity. Therefore, the establishment of rearing methods that temporarily protect embryos or chicks while limiting the negative effects of hand-rearing on breeding after release is needed. To overcome these challenges, we tested how captive rearing methods impact post-release courtship behavior, mating success, and fecundity of the ibis. By combining detailed rearing history in captivity with long-term post-release monitoring, we demonstrate that the initiation of parental rearing before the chicks' eyes open is the critical factor leading to increased pseudocopulation frequency and mating success in captive-born male ibis. Based on these results, not hand-rearing the chicks beyond the day after hatching would reduce the impact of hand-rearing on reproduction after release. Rearing methods that take into account the nestling period should be implemented to enhance the efficiency and reduce the cost of avian reintroduction projects.

著者

Hanaka ISHII Masanori YAMAJI Haruki NATSUKAWA Tomohiro ICHINOSE

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.21, no.2, pp.227-234, 2022 (Released:2022-08-13)

参考文献数

39

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The Daurian Redstart Phoenicurus auroreus has expanded its breeding distribution in recent years and now breeds in Japan, previously only part of its wintering range. We analyzed the breeding habitat selection of the population at the nest and territory scale in the Kirigamine Highlands, Nagano, Central Japan. At the nesting scale, the birds chose buildings frequently occupied by humans, while at the territory scale, they avoided sites in larger built-up areas. Our findings demonstrate that the breeding habitat selection of Daurian Redstart is influenced by environmental factors at both nest and territory scales.

著者

Katsumi TAMADA

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.21, no.2, pp.215-225, 2022 (Released:2022-08-13)

参考文献数

41

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Rural areas provide various habitats for birds, and some studies have revealed habitat associations in rural bird communities in Japan. Previous studies have primarily focused on waterbirds or the habitat values of abandoned farmland, thus little is known about the importance of cultivated land for rural bird communities. Therefore, in this study, I clarified the characteristics of the avifauna in a rural area of the Ishikari Plain in Shinshinotsu Village, Western Hokkaido, and examined habitat utilization of cultivated land by eight major grassland species; Bull-headed Shrike Lanius bucephalus, Eurasian Skylark Alauda arvensis, Black-browed Reed Warbler Acrocephalus bistrigiceps, Siberian Rubythroat Calliope calliope, Stejneger's Stonechat Saxicola stejnegeri, Chestnut-eared Bunting Emberiza fucata, Black-faced Bunting E. spodocephala, and Common Reed Bunting E. schoeniclus. I conducted bird surveys along three 2-km line-transect routes among rice fields with some wheat, non-wheat crop fields, and weedy areas from April to October from 2016 to 2018. I recorded a total of 51 species of three general types: grassland birds, residential birds, and water birds. Rice fields in this study areas were flooded during early to mid-May to mid to late August, however species-specific habitat utilization analyses revealed that a small number of Eurasian Skylark, Stejneger's Stonechat, and Chestnut-eared Bunting inhabited the rice fields during study periods other than the flooding season. A relatively large number of Eurasian Skylark was observed in wheat fields and non-wheat crop fields throughout the study period, and Stejneger's Stonechat and Chestnut-eared Bunting were temporarily observed in those habitats. The other five species only rarely observed in rice, wheat, or non-wheat crop fields, but all eight species were observed in weedy areas. The characteristics of the avifauna in this rural area of Western Hokkaido proved to be quite different from previous studies conducted in the Kanto Region of Honshu. For the conservation of biodiversity and birds in rural areas, it is necessary to investigate the avifaunal characteristics of various regions of Japan.

著者

Golusu Babu RAO Santhanakrishnan BABU Goldin QUADROS

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.21, no.2, pp.199-213, 2022 (Released:2022-08-13)

参考文献数

75

被引用文献数

7

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The Indian coast and its adjacent wetlands host large congregations of shorebirds, including winter and passage migrants of high conservation priority, along the Central Asian Flyway. Identifying crucial wintering and stopover sites and seasons is an important step toward conserving shorebirds and their habitats along the Indian coast. We assessed spatial and temporal patterns of shorebird composition from January 2015 to December 2016 at seven estuaries along Maharashtra's Sindhudurg district, which is located on India's west coast, a coastal zone of international importance for shorebirds. Three potential shorebird habitats –mangroves, mudflats, and sandy beaches – were selected at each of the estuaries chosen for the study. We established three vantage points, one each in the mangrove, mudflat, and sandy beach areas, to count birds during low tide. The total count method was followed to count birds, and occasional photograph-based counts were also made when flock size was big or the flocks kept changing. We recorded 31 species of migratory shorebirds, of which 68% wintered and 32% used the Sindhudurg coast as migratory stopover site. We found significantly high richness and abundance of shorebirds during winter and in the mudflats. nMDS was used to determine species composition of shorebird across habitats and months and revealed distinct patterns of composition in five unique phases: arrival, wintering, early departure, departure, and breeding. Our results revealed that the species composition of shorebirds is not homogenous across sites and months, and is largely driven by the habitat heterogeneity of estuaries, seasonality, and anthropogenic disturbances. These results provide baseline information on shorebirds along a stretch of India's west coast and highlight the importance of mudflats and non-protected coastal wetlands for shorebirds.

著者

Noriko Kondo Shigeru Watanabe Ei-Ichi Izawa

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.9, no.1, pp.83-91, 2010-06-25 (Released:2010-07-10)

参考文献数

58

被引用文献数

16

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We investigated whether vocal communication in wild Large-billed Crows (Corvus macrorhynchos) is governed by a temporal rule as an evidence for vocal exchange. In order to examine this potential temporal rule, we analyzed the intervals between two single-note ka calls produced sequentially by two crows in gregarious situations. Two different individuals sequentially uttered ka calls at approximately 0.2–0.8-sec intervals. Such a specific time window was not observed in a simulation of ‘imaginary’ flocks, in which multiple crows independently emitted ka calls at their own pace, similar to the calls of solitary crows in the wild. These results suggest that the specific time window of inter-call intervals between different crows is not an incidental phenomenon in a crowded situation, but rather a specific event that follows a temporal rule organizing vocal communication of two crows. Our findings provide the first evidence of vocal exchange using ka calls that are organized following a precise temporal pattern in Large-billed Crows.

著者

Martyna PACZUSKA Artur GOLAWSKI

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.20, no.1, pp.115-118, 2021 (Released:2021-02-09)

参考文献数

22

被引用文献数

1

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The Smooth Newt Lissotriton vulgaris is a hibernating amphibian, whose winter activity in central and eastern Europe is very rarely observed. We found seven Smooth Newts in late November and early December in eastern Poland in larders of the Great Grey Shrike Lanius excubitor. The amphibians had probably been caught by the shrike while it was looking for a suitable overwintering site. Increasing numbers of winter records of Smooth Newts may be expected in eastern Europe in connection with climate warming; analysis of the diets of certain avian species may be helpful in this respect.

著者

Canchao YANG

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.20, no.1, pp.101-107, 2021 (Released:2021-02-09)

参考文献数

26

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The adaptive mate choice theory is believed to provide a general explanation of sexual selection. Females are thought to choose males based on direct benefits or because they have perceivably good genes based on visual indicators of male quality, involving adaptive qualities acted on by natural selection in the current environment. However, a recent hypothesis, called "Beauty Happens" has been proposed based on Darwin's "Really Dangerous Idea," an idea that has been criticised, to explain sexual selection in animals, including human beings. Accordingly, it has garnered widespread attention and evoked controversial debate. Here, I review the Beauty Happens hypothesis and clarify the arguments that focus on the sexual autonomy and aesthetic perception of females. I found that, in the case of sexually dimorphic birds, unambiguous evidence is absent in support of the adaptive mate choice theory. Although the Beauty Happens hypothesis is logically feasible, aesthetic perception could possibly evolve and develop on the basis of sexual autonomy and resource-independence in females. Therefore, aesthetic radiation among females may lead to beauty radiation in males, and female mate choice as a selection process may act independently of natural selection, favouring good-to-pass-on genes rather than good genes. However, the Beauty Happens hypothesis seems to be more applicable when explaining the behaviour of sexually dimorphic birds than other animal taxa. I suggest that the mechanisms of female mate choice and intrasexual competition in males may lead to biological evolution, depending on the degree of autonomy of females in different animal species.

著者

Chao-Chieh CHEN Jane-Chi WU Bruno Andreas WALTHER Po-Jen CHIANG

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.19, no.2, pp.135-144, 2020 (Released:2020-07-29)

参考文献数

35

被引用文献数

2

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Detecting different bird species requires different and appropriate surveying methods. We tested a new detection method for the Tataka Area in Yushan National Park, Taiwan, which is an important alpine stopover site for migratory landbirds. Numerous migrant species have previously been reported from this area during bird counts and banding operations. However, these traditional survey methods are incapable of detecting nocturnal migrants. Therefore, we applied acoustic monitoring devices to survey the flight calls of nocturnal migrants in the Tataka Area in order to identify the species and estimate their detection rate. We set up acoustic recorders at five recording stations twice a month during September, October and November, and once in December 2014. We identified 18 nocturnal migrant taxa from 801 hours of recordings. The Black-crowned Night Heron Nycticorax nycticorax was the most frequently recorded species, followed by thrushes (Turdus spp.) and the Brown Shrike Lanius cristatus. Passages of nocturnal migrants occurred during every hour of the night, but with a significantly higher detection rate during the period from 2000 to 2300. Detection rates also varied significantly among months and recording stations. Significantly higher detection rates were recorded in September and October than in November and December. The recording station on a ridge detected significantly fewer birds than the other four recording stations situated in or near valleys. This suggests that nocturnal migrants use lower-lying stream valleys in order to pass over mountain ridges at the lowest possible point. This study provides the first evidence to demonstrate that, besides landbird migrants, many shorebird species and even kingfishers migrate through alpine areas at night when they pass over Taiwan Island during autumn migration.

著者

Akira Chiba Rhyuhei Honma

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.9, no.2, pp.123-130, 2010-12-25 (Released:2010-12-25)

参考文献数

23

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In the course of our fieldwork study at Hyo-ko Waterfowl Park, a local preserve in Niigata Prefecture, Japan, we found a male presumed wild hybrid between a Eurasian Wigeon Anas penelope and a Falcated Duck A. falcata in 2007; another or possibly the same individual was found again in 2009. The bird shared morphological traits with both species, although it was biased toward the Falcated Duck. Occasionally, the bird joined courting parties of Eurasian Wigeon, followed Wigeon females or competed with Wigeon males, and also showed courtship displays, e.g. Grunt-whistle, Head-up-tail-up, and Burping call, all of which were more like those of the Falcated Duck than those of the Eurasian Wigeon. Thus, the hybrid bird was sexually active to a considerable extent, but it remains unknown whether or not it actually formed a pair bond with a female of either parent species.

著者

Takashi Yamamoto Hiroyoshi Kohno Akira Mizutani Hanako Sato Hiroki Yamagishi Yutaka Fujii Miku Murakoshi Ken Yoda

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.16, no.1, pp.17-22, 2017 (Released:2017-03-01)

参考文献数

42

被引用文献数

14

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There is increasing evidence showing that wind velocity affects the flight and foraging behavior of seabirds; however, few studies have examined these effects on seabirds inhabiting tropical oceans where lighter wind conditions usually prevail. The Brown Booby Sula leucogaster is an example of a tropical seabird with relatively low wing loading; strong wind conditions may be expected to impede the stability of their flight. We examined how different wind conditions affected the duration and flying behavior of Brown Booby fledglings during foraging trips by means of direct observation of nest attendance and by attaching video loggers to birds. The duration of foraging trips by fledglings decreased with increasing wind speed, and during flight, the body rotation of fledglings became greater with increasing wind speed. As expected, fledglings were buffeted by strong winds due to their relative inexperience in flight combined with their low wing loading. Fledglings were probably forced to flap against strong winds in order to adjust the stability of their bodies, offsetting the efficient use of wind for gliding. Furthermore, the height at which fledglings flew fluctuated more at higher wind velocities, which may have constrained their detection and capture of prey. In conclusion, our results indicate that the aerodynamic performance of Brown Booby fledglings is impaired by strong wind conditions, leading to poor flight stability and potentially reduced prey detection.

著者

Ivana NOVCIC

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.19, no.1, pp.107-113, 2020 (Released:2020-01-30)

参考文献数

57

被引用文献数

1

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An important property of a foraging group is its density, particularly measured as nearest-neighbor distance. This study examined whether distance to the nearest neighbor changes over short time intervals in two fast-moving foragers, Dunlin Calidris alpina and Semipalmated Sandpiper C. pusilla, while at a spring stopover site in Delaware Bay, USA. For 181 focal individuals, nearest-neighbor distance was recorded in 5-s intervals for 60 seconds. For each focal individual, measured values were compared with those recorded at the beginning and end of observations, with the mean of values recorded at the beginning and end of observations, and with the mean of values recorded at the beginning, middle and end of observations. The results of this study indicate that single-point estimates of nearest-neighbor distance may not be appropriate in fast-moving foragers such as sandpipers.

著者

R. Todd ENGSTROM Lars EDENIUS Tej B. THAPA Basu BIDARI Anil GURUNG Grzegorz MIKUSIŃSKI

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.19, no.1, pp.29-40, 2020 (Released:2020-01-30)

参考文献数

49

被引用文献数

2

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Maintaining biological diversity is an important objective at Chitwan National Park (CNP), the most visited national park in Nepal. Given human uses and manipulations of forests both in and around CNP, developing forest management guidelines that can both support human use of trees and sustain the biological diversity of the forests is a high priority. In February 2009 we measured bird communities with point counts, woodpecker abundance with playback, and collected vegetation data in Sal Shorea robusta and riverine forests in CHP and a nearby community forest to provide basic data on bird-habitat associations with an emphasis on woodpeckers. Riverine forest had over twice the density of trees per ha (many small trees), higher tree species richness, and greater basal area than Sal forest. Sal forest had more large trees than riverine forest. We detected 71 bird species during the point counts in the study forests, 18 more during playback sessions, and an additional 12 species that were more associated with adjacent habitats (e.g., wetlands or flying overhead) for a total of 101 species. Among resident species, 31% were primary or secondary tree-cavity nesters. On average for point counts, we detected 29.5 bird species (2.2 woodpeckers) on transects located in riverine forest and 23.3 bird species (1.8 woodpeckers) in Sal forests, but the difference was not statistically significant. While riverine forest had several commonly occurring species not detected in Sal forest, the opposite was not the case. The regression of woodpecker species richness against large tree density in both Sal and riverine forests was positive, but not statistically significant. As a method of sampling woodpeckers, playback resulted in approximately twice the number of individuals and species compared to detection from point counts.

著者

Natalia Tańska Rafał Czechowski Konrad Leniowski Ewa Węgrzyn

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.18, no.2, pp.183-188, 2019 (Released:2019-07-29)

参考文献数

25

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We investigated the division of provisioning between Fieldfare Turdus pilaris mates as well as synchronisation and alternation of parental feeding trips. We found that parents equally participated in provisioning of older nestlings, but males provisioned young nestlings more than their mates. Synchronisation between parents was higher during the early nestling stage, when they alternated more than during the whole nestling stage. During the early nestling stage alternation was correlated with parental share in provisioning, suggesting that alternation may ensure more equal participation of each parent in provisioning. However, we did not find an analogous relationship between alternation and provisioning during the late nestling stage.