Altitudinal distribution and seasonal life cycle of drosophilid flies (Diptera: Drosophilidae) in central Japan,with reference to their biogeographic features

Altitudinal distribution and seasonal life cycle of drosophilid flies (Diptera) were studied on the southwestern slope of Mt. Higashi-Kagonoto in Tomi and at Ishi-no-yu in Shiga Heights, Nagano, central Japan. Collections of flies were carried out from early spring to late autumn using traps baited with fermenting banana. Based on the present results and previous faunal reports from central Japan, major native drosophilid species collected in this study were classified into migratory (5 species), high-altitude (6), mid-altitude (14) and low-altitude (14) species. The migratory species are assumed to perform extensive seasonal migration between low- and high-altitude areas. Among these native species, Drosophila alpina (a high-altitude species) and D. moriwakii (a mid-altitude species) are assumed to pass only one generation in a year, while the others pass two or more generations. Five of the six high-altitude species are assigned as the Palearctic elements, while four of the five migratory species and 12 of the 14 low-altitude species are assigned as the Sino-Japanese elements. The mid-altitude species consist of approximately equal numbers of the Palearctic and Sino-Japanese elements. Among the high-altitude species, D. alpina and Hirtodrosophila makinoi are also distributed in high-altitude areas in Hokkaido, northern Japan. The other high-altitude species and most of the mid-altitude species generally occur in low-altitude areas in Hokkaido or the further north. The Sino-Japanese elements occurring at high and mid altitudes in central Japan are also distributed at high altitudes in southern and southwestern China.     

Seasonal Altitudinal Movements of Golden Takin in the Qinling Mountains of China

Abstract: We studied seasonal movements of golden takin (Budorcas taxicolor bedfordi), a large, social, forest-dwelling ungulate, by radiotracking and field surveys during 1995–1996 and 2002–2005 at Foping National Nature Reserve on the southern slope of the Qinling Mountains, China. Takins inhabited forests and subalpine meadows at an altitudinal range from 1,360 m to 2,890 m. Our results showed that golden takins had a complicated seasonal movement pattern and underwent altitudinal migration 4 times each year. Takins occupied a high-altitude range during summer, stayed at low-altitude ranges for short periods during spring and autumn, and resided at an intermediate-altitude range during winter. Changes in plant phenology may have caused seasonal movements. Reserves for takin conservation should incorporate lower altitude habitats than those takins use in spring and autumn, and seasonal movements by takins should be protected from disturbance by human activities. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):611–617; 2008)     

Small-scale altitudinal effects on reproduction in bank voles

Elevation gradients and corresponding changes in environment have the potential to affect seasonal reproduction and mortality and hence the seasonal age structure of animal populations. This has been frequently shown in mammals and birds on larger geographic scales, but evidence for small-scale gradient effects is scanty. We studied such small scale altitudinal effects on the proportions of juveniles in a population of bank voles (Myodes glareolus) in a forested habitat along an elevation gradient of 355 m. This was done by regular live trapping in different altitudes over a two-year period. We also measured altitudinal differences in ambient temperatures and vegetational parameters in order to shed light on the underlying mechanisms of such purported differences in age structure. As could be expected for a seasonal breeder, the proportion of juveniles showed an initial increase in spring, an optimum in summer and a subsequent regression in early autumn, reflecting the seasonal pattern of reproduction. In addition, there was evidence for altitudinal effects on the occurrence of juveniles, which was decreased in higher altitudes, assumingly driven by altitudinal differences in onset and/or intensity of annual breeding activity. This altitudinal gradient in juvenile occurrence was partly explained by corresponding differences in ambient temperatures. Furthermore, there was good support that the higher abundance of herbs in lower altitudes played an important role in explaining the altitudinal differences in the proportion of juveniles. In conclusion, our study strongly supports the existence of altitudinal small-scale gradient effects on reproductive parameters in a small rodent, most probably due to the action of altitude-related factors such as microclimate and vegetational parameters.     

Seasonal migration patterns of female sika deer in eastern Hokkaido,Japan

Fifty-seven female sika deer (Cervus nippon yesoensis), captured at the wintering area in the Shiranuka Hills in eastern Hokkaido, Japan, were radio-tracked during 1997–2001 to examine the factors affecting seasonal migration at the individual-landscape level. Ten of the 57 deers migrated between low-altitude summer home ranges and intermediate-altitude winter home ranges (the upward migrants). Twenty-nine migrated between high-altitude summer home ranges and intermediate-altitude winter home ranges (the downward migrants). Twelve used the intermediate-altitude home ranges all year round (the non-migrants). The remaining six were unknown. The summer home ranges of deer were widely scattered over an area of 5734km². Migration distances ranged between 7.2 and 101.7km. Deer showed high site fidelities to their seasonal home ranges. The upward migrants wintered in areas of less snow, higher quality of bamboo grass, and more coniferous cover than their summer home ranges. The downward migrants wintered in areas of less snow, higher quality of bamboo grass, higher winter temperature, and more southern slopes, but less coniferous cover than their summer home ranges. The non-migrants used year-round ranges with little snow, high quality of bamboo grass, and sufficient coniferous cover. We suggest that snow cover and bamboo grass are the factors affecting seasonal migration of the population and that coniferous cover is another factor for the upward migration.     

白马雪山黑白仰鼻猴(Rhinopithecus bieti)垂直迁移

2000-2001年间,在白马雪山国家级自然保护区南任村附近,通过在四个山坡每隔海拔100米的样带(宽5.0米)内搜集黑白仰鼻猴的粪便来研究猴群不同季节的垂直迁移模式。同时,通过在每个地区山脊上和山沟内搜集2.5米宽垂直样带内的粪便,来研究猴群不同季节对山脊和山沟的选择性。结果表明:猴群在海拔3500-4300米的区域活动。虽然猴群全年集中利用3900-4200米的林带;但是具有季节性差异:夏季最高(4200米),依次是秋季(4100米)和冬季(4000米),夏季最低(3900米)。另外,冬季山沟中的粪便多于山脊说明猴群在沟中停留时间长,这与沟中少风且温度高有关。不同海拔带上的粪便密度和松萝量间正相关,这意味着食物资源的垂直分布是影响猴群垂直迁移的重要因素。春季,猴群会下到低海拔采食嫩芽/叶,而冬季则下到低海拔处躲避首次大雪,这很可能导致猴群集中利用第二个海拔带。     

Seasonal variation in the migration strategies of the green lacewing Chrysoperla carnea species complex

Abstract.  1. Insect migration strategies are generally poorly understood due to the propensity for high-altitude flight of many insect species, and the technical difficulties associated with observing these movements. While some progress has been made in the study of the migration of important insect pests, the migration strategies of insect natural enemies are often unknown.
2. Suction trapping, radar monitoring, and high-altitude aerial netting were used to characterise the seasonal migrations in the U.K. of an assemblage of aphid predators: three green lacewings in the Chrysoperla carnea species complex.
3. Chrysoperla carnea sens. str . was found to be very abundant at high altitudes during their summer migration, and some individuals were capable of migrating distances of ≈ 300 km during their pre-ovipositional period. In contrast, high-altitude flights were absent in the autumn migration period, probably due to a behavioural adaptation that increases the probability that migrants will encounter their over-wintering sites. The other two species in the complex, C. lucasina and C. pallida , were much rarer, making up ≈ 3% of the total airborne populations throughout the study period.
4. The summer migration of C. carnea sens. str . was not directly temporally associated with the summer migration of its cereal aphid prey, but lagged behind by about 4 weeks. There was also no evidence of spatial association between aphid and lacewing populations.
5. The results show that to understand the population ecology of highly mobile insect species, it is necessary to characterise fully all aspects of their migration behaviour, including the role of high-altitude flights.     

Altitude, migration, and fertility in the Andes

In order to examine the relationship between hypoxia and reduced fertility of high Andean populations, a sample of 241 females living in the low-altitude Tambo Valley of Peru was studied. 63 of the subjects were born in the low-altitude valley, 121 were migrants from high altitudes, and 57 were migrants born in low altitudes. The rate of abortion was low among high-altitude subjects before they migrated, but became greater after migrating. It was found that the high-altitude populations had almost twice as long parity intervals than the low-altitude populations. Compared to migrants born at low altitudes, the high-altitude-born subjects who migrated to low altitudes had higher fertility rates. The results of the study are consistent with the hypothesis that high altitudes, through anoxia, have a lowering effect on fertility. Of the several possible explanations which might account for the increase in fertility of downward migrants on migration from high to low altitude (migration, socioeconomic factors, acculturation, seasonal male emigration from high altitude, and removal of hypoxia stress), altitude appears to be the most significant.     

中天山地区草地地表辐射收支演变规律

地表辐射对研究地表能量平衡及气候形成机制具有重要意义。利用中天山乌拉斯台地区陆气相互作用观测站2018年5月至2019年4月地表辐射数据,分析了中天山草地不同时间尺度和不同天气条件下的地表辐射与反照率变化特征。结果表明：(1)地表辐射月平均日变化除大气长波辐射较弱外,其余分量均呈单峰型,极值大小及时间存在差异,太阳总辐射与净辐射最大日峰值均出现在6月,为920.9与603.3 W/m~2,大气与地表长波辐射分别出现在7月和8月,为327.5 W/m~2与471.7 W/m~2,而反射短波辐射则出现在2月,为520.6 W/m~2。(2)太阳总辐射、反射短波辐射、大气与地表长波辐射年曝辐量分别为6860.62、2101.72、7171.25、10089.69 MJ/m~2;就季节变化而言,反射短波辐射曝辐量在冬季明显高于其它季节,其它分量则均表现为夏季>春季>秋季>冬季。(3)不同月份地表反照率日变化均呈“U”型曲线,年均值为0.393,最大与最小月均值分别出现在12月与8月,为0.760与0.217。这种变化体现在季节上则为冬季>秋季>春季>夏季。(...     

Moult Strategies Affect Age Differences in Autumn Migration Timing in East Mediterranean Migratory Passerines

Adult passerines renew their flight feathers at least once every year. This complete moult occurs either in the breeding areas, just after breeding (summer moult), or, in some long-distance migratory species, at the non-breeding areas, after arrival to the southern wintering area at the end of autumn migration (winter moult). The aim of this study was to relate moult strategies with the DMD, the difference in median migration date, through Israel, between juveniles and adults. Our data on autumn migration timing in juveniles and adults was based on ringing data of 49,125 individuals belonging to 23 passerine species that breed in Europe and Western Asia and migrate through Israel. We found that DMD was associated with moult timing. In all species that perform a winter moult, adults preceded juveniles during autumn. Among migrants who perform a summer moult, we found evidence of both migration timing patterns: juveniles preceding adults or adults preceding juveniles. In addition, in summer moulters, we found a significant, positive correlation between mean breeding latitude and DMD. Although previous studies described that moult duration and extent can be affected by migration, we suggest that moult strategies affect both migration timing and migration strategy. These two moult strategies (summer or winter moult) also represent two unique migration strategies. Our findings highlight the evolutionary interplay between moult and migration strategies.     

Changes in nonspecific immunity factor in some Equidae, Camelidae and Capridae species

Plasma lysozyme activity changed during the 2 years of the investigation period. In some species (e.g. ponies and goats) there are only seasonal fluctuations with the highest levels during summer and autumn in ponies and during winter in goats. In two Camelidae species, guanacos and llamas, only, downward trends were found, whereas in donkeys, both types of changes: seasonal variations with the maximal level during autumn and an upward long-term trend were found.     

The influence of weather on the flight altitude of nocturnal migrants in mid‐latitudes

By altering its flight altitude, a bird can change the atmospheric conditions it experiences during migration. Although many factors may influence a bird's choice of altitude, wind is generally accepted as being the most influential. However, the influence of wind is not clearly understood, particularly outside the trade‐wind zone, and other factors may play a role. We used operational weather radar to measure the flight altitudes of nocturnally migrating birds during spring and autumn in the Netherlands. We first assessed whether the nocturnal altitudinal distribution of proportional bird density could be explained by the vertical distribution of wind support using three different methods. We then used generalized additive models to assess which atmospheric variables, in addition to altitude, best explained variability in proportional bird density per altitudinal layer each night. Migrants generally remained at low altitudes, and flight altitude explained 52 and 73% of the observed variability in proportional bird density in spring and autumn, respectively. Overall, there were weak correlations between altitudinal distributions of wind support and proportional bird density. Improving tailwind support with height increased the probability of birds climbing to higher altitude, but when birds did fly higher than normal, they generally concentrated around the lowest altitude with acceptable wind conditions. The generalized additive model analysis also indicated an influence of temperature on flight altitudes, suggesting that birds avoided colder layers. These findings suggested that birds increased flight altitudes to seek out more supportive winds when wind conditions near the surface were prohibitive. Thus, birds did not select flight altitudes only to optimize wind support. Rather, they preferred to fly at low altitudes unless wind conditions there were unsupportive of migration. Overall, flight altitudes of birds in relation to environmental conditions appear to reflect a balance between different adaptive pressures.     

Can wind help explain seasonal differences in avian migration speed?

A bird's ground speed is influenced by the wind conditions it encounters. Wind conditions, although variable, are not entirely random. Instead, wind exhibits persistent spatial and temporal dynamics described by the general circulation of the atmosphere. As such, in certain geographical areas wind's assistance (or hindrance) on migratory flight is also persistent, being dependent upon the bird's migratory direction in relation to prevailing wind conditions. We propose that, considering the western migration route of nocturnal migrants through Europe, winds should be more supportive in spring than in autumn. Thus, we expect higher ground speeds, contributing to higher overall migration speeds, in spring. To test whether winds were more supportive in spring than autumn, we quantified monthly wind conditions within western Europe relative to the seasonal direction of migration using 30 years (1978–2008) of wind data from the NCEP/NCAR Reanalysis dataset. We found that supporting winds were significantly more frequent for spring migration compared to autumn and up to twice as frequent at higher altitudes. We then analyzed three years (2006–2008) of nocturnal migratory ground speeds measured with radar in the Netherlands which confirmed higher ground speeds in spring than autumn. This seasonal difference in ground speed suggests a 16.9% increase in migration speed from autumn to spring. These results stress the importance of considering the specific wind conditions experienced by birds when interpreting migration speed. We provide a simple methodological approach enabling researchers to quantify regional wind conditions for any geographic area and time period of interest.     

Water temperatures and ice cover in lakes of the Tatra Mountains

In 2000 and 2001, miniature thermistors with integrated data loggers were employed to measure lake surface water temperatures (LSWTs) and temperature profiles in high-altitude mountain lakes lying between 1580 and 2145 m a.s.l. on both the Slovak and Polish sides of the Tatra Mountains. This allowed the annual cycle of water temperatures and ice cover in these lakes to be described quantitatively, and their dependence on lake altitude above sea level to be investigated. LSWTs in the Tatra Mountains are found to decrease approximately linearly with increasing altitude from late spring to autumn. LSWT in summer can be modelled well in terms of exponentially smoothed ambient air temperature. Although the timing of ice-off is dependent on altitude, the timing of ice-on is not; the dependence of the duration of ice cover on altitude is therefore wholly due to the altitudinal dependence of the timing of ice-off. The temperature profile measurements allow quantitative characterization of summer and winter stagnation, and spring and autumn turnover.     

Spatial behaviour of adult male Alpine ibex<Emphasis Type="Italic">Capra ibex ibex</Emphasis> in the Gran Paradiso National Park,Italy

During a two year preliminary study, the spatial organization of a group of male Alpine ibexCapra ibex ibex Linnaeus, 1758 was examined in the Gran Paradiso National Park, Western Italian Alps, Italy. From December 1995 to January 1998 we measured annual, seasonal home range and home range during the rut, plus altitudinal migration of 13 radio-collared adult Alpine ibex. The small annual home range size showed a traditional use of space, confirmed by the high overlapping values between home ranges of consecutive years: the ibex used the same places from year to year. This was also true during periods of rut. Home ranges closely overlapped in consecutive ruts, while their size changed from winter to winter. Snow cover limited the movements of the ibex; winter and spring home ranges were smaller than those in summer and autumn. Mean vertical movement patterns were similar in the two years, showing the highest values in summer and the lowest in spring. Space use was never proportional to availability for each altitudinal range.     

Recruitment,growth, and vertical distribution of the endangered mud snail Cerithidea rhizophorarum A. Adams, 1855: implications for its conservation

Some fundamental natural-history traits of the endangered mud snail Cerithidea rhizophorarum were investigated for three years in an open, bare, sandy tidal flat located on the east of Shikoku Island in southwestern Japan. Our study demonstrated a highly aggregated distribution of younger snails and complicated differences in vertical migration patterns between younger and older snails that might have prevented comprehensive understanding of the precise demography of C. rhizophorarum in previous studies. From late summer, juveniles of the first-year cohorts appeared patchily at 12–16 cm lower tidal heights than snails of the oldest cohorts and reached 5.0–7.5 mm in mean shell length by the first mid-autumn. In the second year, juveniles gradually moved upward and appeared at higher tidal heights. The second-year cohorts reached 15.6–19.1 mm in mean shell length by the end of the second autumn and converged into the oldest cohorts during the third year or later. Our results suggest that C. rhizophorarum matures sexually and starts reproduction from the fourth summer at the earliest. On the other hand, older snails showed a similar seasonal migration pattern every year—downward movement in summer and upward movement in autumn—probably associated with their reproductive activity and/or a seasonal change in the maximum tidal height. For conservation of C. rhizophorarum, it is very important to preserve both the higher area as a main habitat for older snails and the lower tidal flat as the nursery ground.     

Thiol content of spruce needles at forest limits

Summary We determined the water-soluble thiol (SH) content and the osmolality of the cell sap in spruce trees of both low- and high-altitude origin that were transplanted to two test areas at different altitudes (400 m and 1700 m). There was little or no significant difference in SH content and osmotic value between trees of low- or high-altitude origin at the same altitude, but the sulfhydryl (SH) content varied with the altitude of cultivation, being higher at 1700 m than at 400 m. SH content and osmotic value were higher in winter, independent of altitude and provenance. The annual pattern of water-soluble and protein-bound SH content and glutathione reductase activity was measured in spruce trees at 1700 m; these values also peaked in winter and were lowest in summer.     

豫西山地传粉昆虫物种多样性对地貌和季节的响应

通过野外试验布设陷阱捕捉传粉昆虫,调查豫西山地春秋两季不同人为强度土地利用下的传粉昆虫多度、丰富度等,并结合实地的植被群落特征,研究传粉昆虫的多样性、群落相似性及物种重要度(重要值).结果表明: 春秋两季累计捕获传粉昆虫23275头,优势类群多为膜翅目、双翅目等.春季捕获传粉昆虫的数量约是秋季数量的1.8倍,且两个季节传粉昆虫的个体多度差异达到极显著水平.春秋季捕获的双翅目、膜翅目相对多度较高,且季节之间变化不大.鳞翅目、鞘翅目个体数量较少,其中春季捕获的鳞翅目数量极少,秋季的鞘翅目数量也偏低.丘陵的Shannon多样性指数、Pielou均匀度指数和Margalef丰富度指数要明显高于其他两种地貌类型;山地的优势度指数和物种的个体数均高于其他两种地貌类型.不同地貌传粉昆虫的多样性和优势度差异达到显著水平,丘陵传粉昆虫多样性与山地和平原均有显著差异,山地的优势度与丘陵有显著差异.季节变化对传粉昆虫群落影响较小,但群落内各物种组成之间存在一定差异.从Morisita-Horn和Sørensen相似系数来看,仅有膜翅目群落在山地和丘陵间有显著差异.春秋季的物种重要值也存在差异,春季中胡蜂科的重要值最高,寄蝇科、果蝇科次之;秋季中花蝇科重要值最高,胡蜂科次之.传粉昆虫与农作物密切相关,影响着作物生长和粮食产量.在种植作物过程中因地制宜,合理规划土地利用方式,根据不同地貌内的植被类型适当调整物种组成,保护其多样性,对维持农业可持续发展和提高生态系统服务意义重大.     

武夷山不同海拔黄山松细根性状季节变化

细根作为植物吸收养分和水分的主要器官,其功能性状对森林生态系统功能具有重要影响。以武夷山黄山松为研究对象,通过对不同季节(春季、夏季、秋季和冬季)和不同海拔(1200、1400、1600、1800 m和2000 m)的黄山松细根的功能性状的测定,分析其细根性状特征随海拔和季节变化的规律。结果表明:(1)黄山松细根比根长(SRL),比根面积(SRA)均随海拔先升高后降低,其均值分别为(9.32±0.35) cm/g与(276.41±68.10) cm~2/g;根组织密度(RTD)随海拔先降低后升高,均值为(0.16±0.05) g/cm~3。根平均直径(AvgDiam)随海拔增加变化不显著,均值为(0.097±0.004) mm。SRL和SRA在海拔1600 m处达到最大,而RTD和AvgDiam的最大值出现在海拔1800 m或2000 m处。(2)SRL和SRA在夏季或秋季达到最大,RTD和AvgDiam最大值则出现在冬季或春季。季节和海拔对各细根性状都有显著影响(P0.01),但季节与海拔对根性状并没有产生显著的交互作用(P0.05)。(3)SRL与SRA间的异速生长指数是1.25,显著大于1.0(P0.01);SRL与RTD存在负等速生长关系,而与AvgDiam存在显著负异速生长关系(P0.01);SRA与RTD,以及RTD与AvgDiam间均存在显著负异速生长关系(P0.01),但SRA与AvgDiam之间不存在异速生长关系。黄山松的细根性状在1600 m处倾向于增加比根长和比根面积,而在海拔1800 m或2000 m处则倾向于增加组织密度与根直径,这与黄山松细根性状从夏秋到冬春的季节变化规律相类似。同时,相对于比根面积来说,黄山松的细根在海拔1600 m处和夏秋季节更倾向于投资比根长来增加养分的吸收。     

Trends in annual and seasonal survival of Pink-footed Geese Anser brachyrhynchus

Adult Pink-footed Geese Anser brachyrhynchus from the Svalbard breeding population were neck-banded and resighted in staging and wintering areas outside the breeding season 1990–1999. We estimated annual and seasonal survival using capture–recapture statistical models. Mean annual survival was 0.829, declining over the study period from 0.90 to 0.79. The annual cycle was partitioned into three periods: summer (1 April–30 September), including both spring and autumn migration, autumn (1 October–31 December), including most shooting, and winter (1 January–31 March). The parsimonious model selected to describe seasonal survival included a declining trend in summer survival, constant autumn and winter survival with lower survival in the severe winter of 1996, and an additive effect of sex on summer and winter survival. Monthly survival was highest during winter. Decreasing summer survival was the main contributor to the overall decline in annual survival, and was attributed mainly to increasing natural mortality on the breeding grounds. Mean annual survival based on the seasonal survival probabilities was 0.835 for females and 0.805 for males. The effect of sex was most pronounced during summer and remains to be explained.     

Seasonal patterns of food storing in the Jay Garrulus glandarius

This study investigated seasonal patterns in food consumption and food storage in six captive Jays Garrulus glandarius. In the first experiment, seasonal changes in food-storing intensity were tested by presenting acorns (oak seeds, Quercus spp.) in spring, summer and autumn. There were no significant differences between the seasons in the amount of food eaten. However, significantly more food was taken and stored in the autumn than in the spring and summer months. In the spring and summer, the acorns were stored between the doorframes, on the ledges of the aviaries and under the bark of branches. In the autumn, Jays also began to hoard underneath the plastic sheeting covering the hard-board flooring by ripping the polythene to create a hidden cache site. The length of time over which the stored food was left before retrieval increased from summer to autumn. Food storing also occurred in spring and summer but was short term. The second experiment tested whether or not there were seasonal changes in food preference by presenting birds with acorns, peanuts and mealworms in the summer and autumn. More peanuts were eaten, taken and stored in the autumn than in the summer, and, as in the first experiment, significantly more acorns were taken and stored in the autumn. In the autumn, only a few mealworms were eaten before the birds stored acorns and peanuts, whereas in the summer, birds tended to eat most of the mealworms before they began to store. As in the first experiment, items tended to be buried in the ground in the autumn and left for longer periods before retrieval. These results are discussed in relation to the demand that each food type places on the Jay's time.