Publications by authors named "Hiroyoshi Higuchi"

A thorough understanding of the development of complex plumages in birds necessitates the acquisition of genetic data pertaining to the mechanism underlying this phenomenon from various avian species. The oriental honey-buzzard (), a tropical summer migrant to Northeast Asia, including Japan, exemplifies this aspect owing to the diversity of its ventral coloration and intra-feather barring patterns. However, genetic polymorphism responsible for this diversity has not been identified yet.

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We satellite-tracked the eastern buzzard () wintering in Japan to delineate both northward and southward migration routes, destinations, and stopover behavior. Twenty-two buzzards were captured and fitted with functional platform transmitter terminals. For these buzzards that departed from the capture sites, we observed a total of 65 northward migrations during 2008-2016 and a total of 55 southward migrations during 2008-2015.

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Flying over the open sea is energetically costly for terrestrial birds. Despite this, over-water journeys of many birds, sometimes hundreds of kilometres long, are uncovered by bio-logging technology. To understand how these birds afford their flights over the open sea, we investigated the role of atmospheric conditions, specifically wind and uplift, in subsidizing over-water flight at a global scale.

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The Japanese sparrowhawk is a small raptor that breeds in Northeast Asia. The species consists of the widespread and mostly migratory subspecies that is common in East Asia, including Japan, and the resident and endangered subspecies which inhabits the Ryukyu and Yaeyama Islands in Okinawa, southern Japan. Given the minimal knowledge about the migration of the species, in this study we sought to compare the genetic variation of the populations breeding in Japan with those migrating through Southeast Asia.

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Understanding migration ecology of Eurasian wigeons () is crucial for effective population management, mitigating conflicts with human, and habitat conservation. The objectives of the present study were 1) to determine their migration patterns of Eurasian wigeons in the East Asian flyway, and 2) to identify the key breeding and stopover sites. From 2007 to 2016, a total of the 64 wigeons, which wintered in Japan, were equipped with satellite transmitters.

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Individual consistency in migration can shine light on the mechanisms of migration. Most studies have reported that birds are more consistent in the timing than in the routes or stopover sites during migration, but some specialist species showed the opposite patterns, being more consistent in spatial than temporal aspects of migration. One possible explanation for this contrast is that specialists rely on particular food or habitat resources, which restrict the migratory routes they can take, leading to high spatial consistency.

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The intestinal microbiome is known to affect host health through various effects on nutrition and immunity. The oriental honey buzzard (OHB) is a raptor that feeds on bees and wasps. Due to its restricted diet, we reasoned that the OHB may have a unique microbiome.

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Flapping flight is relatively costly for soaring birds such as raptors. To avoid costly flight, migrating raptors generally avoid flying over water. As a result, all but one of the global raptor migration flyways are largely over land.

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Migratory birds can be adversely affected by climate change as they encounter its geographically uneven impacts in various stages of their life cycle. While a wealth of research is devoted to the impacts of climate change on distribution range and phenology of migratory birds, the indirect effects of climate change on optimal migratory routes and flyways, through changes in air movements, are poorly understood. Here, we predict the influence of climate change on the migratory route of a long-distant migrant using an ensemble of correlative modelling approaches, and present and future atmospheric data obtained from a regional climate model.

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The basic structure of a bird feather may be adapted to suit a variety of functions on different parts of the body and in different species. In Oriental honey buzzards (Pernis ptilorhynchus), a species which often preys on the larvae of bees and wasps, it is thought that the bird's integument may provide protection against the stings of these insects. We investigated the structure of Oriental honey buzzard feathers from the face, head, and neck using light and scanning electron microscopy.

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Migration through the Eastern Palearctic (EP) flyway by tundra swans (Cygnus columbianus) has not been thoroughly documented. We satellite-tracked the migration of 16 tundra swans that winter in Japan. The objectives of this study were 1) to show the migration pattern of the EP flyway of tundra swans; 2) to compare this pattern with the migration pattern of whooper swans; and 3) to identify stopover sites that are important for these swans' conservation.

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Age-related variation in demographic rates is now widely documented in wild vertebrate systems, and has significant consequences for population and evolutionary dynamics. However, the mechanisms underpinning such variation, particularly in later life, are less well understood. Foraging efficiency is a key determinant of fitness, with implications for individual life history trade-offs.

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Species designations are critically important scientific hypotheses that serve as the foundational units in a wide range of biological subdisciplines. A growing realization that some classes of data fail to delimit species under certain conditions has led to increasingly more integrative taxonomies, whereby species discovery and hypothesis testing are based on multiple kinds of data (e.g.

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Phenological events, such as the timing of flowering or insect emergence, are influenced by a complex combination of climatic and non-climatic factors. Although temperature is generally considered most important, other weather events such as frosts and precipitation events can also influence many species' phenology. Non-climatic variables such as photoperiod and site-specific habitat characteristics can also have important effects on phenology.

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Article Synopsis
  • Understanding phenological events, like flowering times, is crucial for predicting how species will react to climate change, particularly in cherry trees in Japan.
  • A study analyzed a 29-year data set on flowering times across different cherry tree species, discovering that while responses to chill were similar among species, earlier flowering trees were more affected by heat.
  • Projections indicate all cherry tree species could bloom about 30 days earlier by 2100, which could significantly impact cultural festivals in Japan and provide insights into broader ecological effects.
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Function of head-bobbing behavior in diving little grebes.

J Comp Physiol A Neuroethol Sens Neural Behav Physiol

August 2013

Most birds show a characteristic head movement that consists of head stabilization and quick displacement. In this movement, which is analogous to saccadic eye movement in mammals, head stabilization plays an important role in stabilizing the retinal image. This head movement, called "head bobbing", is particularly pronounced during walking.

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The strength and direction of phenological responses to changes in climate have been shown to vary significantly both among species and among populations of a species, with the overall patterns not fully resolved. Here, we studied the temporal and spatial variability associated with the response of several insect species to recent global warming. We use hierarchical models within a model comparison framework to analyze phenological data gathered over 40 years by the Japan Meteorological Agency on the emergence dates of 14 insect species at sites across Japan.

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As a consequence of warming temperatures around the world, spring and autumn phenologies have been shifting, with corresponding changes in the length of the growing season. Our understanding of the spatial and interspecific variation of these changes, however, is limited. Not all species are responding similarly, and there is significant spatial variation in responses even within species.

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Although the tandem duplication of mitochondrial (mt) sequences, especially those of the control region (CR), has been detected in metazoan species, few studies have focused on the features of the duplicated sequence itself, such as the gene conversion rate, distribution patterns of the variation, and relative rates of evolution between the copies. To investigate the features of duplicated mt sequences, we partially sequenced the mt genome of 16 Phoebastria albatrosses belonging to three species (P. albatrus, P.

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The Bonin Islands White-eye, Apalopteron familiare , is the sole endemic avian species surviving on the Bonin Islands. The current distribution of this species is limited to only three islands of the Hahajima Island group: Hahajima, Imotojima, and Mukohjima. Imotojima and Mukohjima, which are small satellite islands of Hahajima, are about 3.

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Wild birds, in particular waterfowl, are common reservoirs of low pathogenic avian influenza viruses, and infected individuals could spread the viruses during migrations. We used satellite telemetry to track the spring migration of the mallard ducks ( Anas platyrhynchos ) that winter in Japan. We studied their migration routes, distribution of stopover and breeding sites, and timing of migration movements.

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Single cycles of hopping and climbing were investigated in Japanese Pygmy Woodpeckers Picoides kizuki using motion analyses on video. Body movements on substrate angled from 0-90 degrees were compared for every 10 degrees. The body was inclined forward during stance phase for both small and large substrate angles, and the inclination amplitude increased when the substrate angle increased.

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Climate change is affecting plant phenology worldwide. Phenological responses vary among species, but it is not clear how responses differ among closely related species. We examined a 25-yr record (1981-2005) of flowering times for 97 trees, representing 17 species and hybrids of cherry (Cerasus sp.

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Many albatross remains have been found in the Japanese Islands and the surrounding areas, such as Sakhalin and South Korea. These remains are interesting for two reasons: numerous sites from which albatross remains have been found are located in coastal regions of the Far East where no albatrosses have been distributed recently, and there are some sites in which albatross remains represent a large portion of avian remains, although albatrosses are not easily preyed upon by human beings. We collected data on albatross remains from archaeological sites in the Far East regions during the Holocene and arranged the remains geographically, temporally and in terms of quantity.

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