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1.
Rimgaudas Treinys Asko L?hmus Darius Stonius Saulis Skuja Eugenijus Drobelis Bronius ableviius Saulius Rumbutis Deivis Dementaviius Vladas Narueviius Antanas Petraka Danas Augutis 《Journal of Ornithology》2008,149(1):75-81
Recent trends in the European Black Stork Ciconia nigra population are geographically distinct: range expansion and adaptation to human activity dominate in western and central
Europe, while declines—probably induced by landscape change—are reported in the east. We studied the large Lithuanian Black
Stork population in the transition zone to explore whether, and how, the detrimental influences of recent Baltic landscape
changes are balanced by the West European tendency of behavioural adaptation to human activity. Based on monitoring in sample
plots, the current population was estimated at 650–950 pairs, indicating a significant decrease (possibly over 20%) during
the last two decades. In comparison to the Latvian and Estonian populations, however, this decline is smaller, and the reproductive
success remains at a high level [66% breeding success and 2.99 ± 0.97 (SD) fledglings per successful attempt, 2000–2006];
this north–south gradient suggests a climate-mediated impact of habitat degradation in the Baltic countries. The storks are
also nesting closer to forest edges and in younger stands than 15–30 years ago, which has probably reduced the nest-tree limitation,
as indicated by an increased use of large oaks. Thus, habitat degradation and adaptation seem to be taking place simultaneously
in the Lithuanian Black Stork population, as was expected from its geographical location. In general, our study supports the
view that, whenever possible, species conservation strategies and the use of indicator species should be geographically explicit. 相似文献
2.
Toni Mingozzi Giampiero Masciari Giuseppe Paolillo Brunella Pisani Manuela Russo Alessandro Massolo 《Biodiversity and Conservation》2007,16(12):3519-3541
Loggerhead turtle Caretta caretta nesting in Italy had been reported to be limited to the Pelagian Islands and only sporadically elsewhere. As presence of
loggerhead turtle nests had occasionally been reported (1988–1999) along about 200 km of the Ionian coast of Calabria, we
carried out a project to assess the actual state of the nesting population between 2000 and 2004. We divided the coastline
in two sectors (A: 52 km, and B: 146 km) that were monitored from mid-June to end of July for a total of n = 174 monitoring days and 1,813.6 km patrolled on foot with different intensities (extensive versus intensive). In sector
B, through extensive monitoring we did not find any emergence tracks, but in sector A by intensive survey (2002–2004: one
survey/3.64 days) we detected 3–8 nests/year. In total, 25 nests (both observed and reported), were recorded in our study
area, and an assessment of a total of 15–16 nests/year was suggested. These figures, within the national scenario depicted
from the review of known nesting events in the last 40 years (88 records concerning more than 143–144 nests), show that loggerhead
turtle nesting has been underestimated in Italy, due to inadequate monitoring protocols, and that nesting is more frequent
than expected (at least 30–40 nests/year). Conservation strategies in Italy should then focus not only on the reduction of
mortality at sea, but also include large-scale actions to preserve scattered (but regular) nesting events. 相似文献
3.
Jean-Marc Paillisson Sebastien Reeber Alexandre Carpentier Loic Marion 《Biodiversity and Conservation》2006,15(11):3469-3480
In this study we investigated the interplay between water level management, floating macrophytic vegetation and nesting whiskered
tern (Chlidonias hybridus) during 8 years (1995–2002) at a shallow macrophyte-dominated lake in western France. The specific question was to see if
slight increases in the water regime of the lake (three scenarios), as part of a restoration programme, affect the timing
of nesting and occupation of colonies by whiskered terns by way of changes in biomass of waterlily (Nymphaea alba) beds where colonies always establish. During the study period, egg-laying dates were progressively delayed up to 40–50 days
(mid-May to early July) in relation to late appearance of suitable waterlily biomass (R
2 = 0.67, p = 0.01) associated with high spring water levels (1.10–1.25 m vs. 0.95 m). Simultaneously some nesting attempts were observed
in sub-optimal habitats (adjacent wet grasslands) in high flooding conditions leading either to poor breeding success or colony
desertion. We concluded that there is a need for compromise between the experimental water levels used to control waterlily
biomass and the nesting requirements of the whiskered tern population in this lake of international importance (260–510 pairs
in 1995–2002, ≥ 1% Ramsar level). 相似文献
4.
Sand and nest temperatures were monitored during the 2002–2003 nesting season of the green turtle, Chelonia mydas, at Heron Island, Great Barrier Reef, Australia. Sand temperatures increased from ∼ 24°C early in the season to 27–29°C in
the middle, before decreasing again. Beach orientation affected sand temperature at nest depth throughout the season; the
north facing beach remained 0.7°C warmer than the east, which was 0.9°C warmer than the south, but monitored nest temperatures
were similar across all beaches. Sand temperature at 100 cm depth was cooler than at 40 cm early in the season, but this reversed
at the end. Nest temperatures increased 2–4°C above sand temperatures during the later half of incubation due to metabolic
heating. Hatchling sex ratio inferred from nest temperature profiles indicated a strong female bias. 相似文献
5.
Xingyi Gao Weikang Yang Jianfang Qiao Jun Yao Kefen Xu 《Frontiers of Biology in China》2008,3(4):385-391
This article presents the distribution and status of bustards, which are listed as first-category protected animals according
to the survey results during 1990–2002 in China. The Chinese populations of Otis tarda dybowskii are breeding in south-west of Heilongjiang Province, western Jilin Province, east and middle Inner Mongolia, north Ningxia
Hui Autonomous Region, and Gansu Province. A few can winter in the south breeding-range. Its winter-range lies from the south
to the Yellow River, as far as to Guizhou Province and Jiangxi Province. Its population number is about 200–300 or 500–800.
The Chinese populations of O. t. tarda are breeding in the north and west of Xinjiang. It is unclear about its winter-range, which is presumed to be in south Asia.
Recently we found individuals wintering in Chabuchaer and west Xinjiang. The population number is about 2000–3000. The habitat
in breeding range includes steppe, grassland, desert grassland, and farmland. The habitat in winter range is the beach of
rivers and lakes, meadows, meadow-grassland, and wheatland. The Chinese populations of Chlamydotis undulata macqueeni are breeding in the fringe of the Jungar Basin, the banks of the Ulungur River, Balikun and south Turpan Basin in Xinjiang,
west Inner Mongolia, and west Gansu. NortheastMulei in eastern Jungar Basin of Xinjiang is the main breeding-range in the
world. The bird uses desert and desert grassland as its habitat. Its winter-range is west Asia and south Asia. Its population
number is about 2000. The Chinese populations of Tetrax tetrax are breeding in north Xinjiang, and China is located on the east border of its breeding-range. Its habitat is grassland and
semi-desert, and its winter-range lies in south Asia. Its population in China is very scarce. In addition, we analyzed the
causes of their endangerment and put forward protection tactics of Chinese Bustards.
__________
Translated from Arid Zone Research, 2007, 24(2): 179–186 [译自: 干旱区研究] 相似文献
6.
The quality of running waters is reflected in the composition of benthic diatom assemblages. The biological assessment of
changes in the composition, and thus of changes in water quality, was carried out in the lowland mid-sized Bzura River, Central
Poland, over the period of 30 years. The benthic diatom material consisted of samples collected in two investigation periods,
in 1972 and in 2003–2004. The methods applied were three diatom indices, IPS — Specific Pollution Sensitivity Index, GDI —
Genetic Diatom Index and TDI —Trophic Diatom Index, and the OMNIDIA computer program, which are commonly used in Europe. The
aim of the study was demonstrating the process of restoration that occurred in the river. The Bzura was included to the most
polluted ones in Poland till 1996. Since 1998 a gradual improvement in water quality has been observed, which is caused by
a number of biological-technical measures, mostly a proper organization of sewage management in most cites located on the
river. In 1972 the IPS classified Bzura water into Water Quality Class IV-V, while in 2003–2004 it reached much higher values,
i.e. Class III–IV. On the basis of the GDI Class III was determined in the whole river in 2003–2004, while its values indicated
Class III–IV in 1972. The trophic index, TDI attributed Bzura water to the eutrophic to hypereutrophic zone in 2003–2004,
and to one degree better water, i.e. from the mesoeutrophic to eutrophic zone, in 1972. 相似文献
7.
Spatial, seasonal and species variations of harmful algal blooms in the South Yellow Sea and East China Sea 总被引:12,自引:0,他引:12
DanLing Tang BaoPing Di Guifeng Wei I-Hsun Ni Im Sang Oh SuFen Wang 《Hydrobiologia》2006,568(1):245-253
The occurrences of harmful algal blooms (HABs), in terms of frequency and area in the Chinese coastal waters, have been increasing
since 1980s and caused considerable economic losses. In the present study, we have analyzed spatial and seasonal characteristics
of HAB events in the southern Yellow Sea and East China Sea along Chinese coast from 1933 to 2004. With a total 435 HAB records,
the most frequent HAB occurrence area (FHA) is off the Yangtze River mouth and another two FHA areas are located south of
the Yangtze River estuary along about isobaths of 30–60 m coastal water in the East China Sea. The time of HAB occurrence
shifted during our study period: from autumn (August–October) before 1980s to July–August in 1980s, during May–July in 1990s,
and May–June for the period of 2000–2004. Causative species were found to be different: Noctiluca scintillans and Skeletonema costatum were dominant causative species prior to 2000; and Prorocentrum donghaiense Lu was dominant from 2000 to 2004 and also caused large blooms in May. Trichodesmium sp. caused many HABs in autumn (August–October) prior to 1980s with only one HAB between 1980 and 2004. The changes of the
dominant HAB species may have affected the timings of HAB occurrence, as well as the increasing HAB-affected areas in recent
years. 相似文献
8.
Piotr Zduniak 《Journal of Ornithology》2010,151(1):45-50
This paper examines how flooded river valley conditions affect reproductive success of Hooded Crows Corvus cornix nesting in the biotope considered as primary for this species. The main goals of the present study were to determine the
nesting period that most influences the breeding output and to investigate the factors influencing reproductive efficiency
of the studied population. Mean survival rate of the whole nesting period (53 days––from egg laying to fledgling) was 0.371
(95% CL: 0.338–0.403), while mean survival for the incubation period (to day 21) was 0.850 (0.827–0.875) and mean survival
rate for the nestling period was 0.499 (0.460–0.538). The study has shown that the most critical period in the breeding cycle
is the first half of the nestling stage, especially from hatching to day 5. Furthermore, the study demonstrated how water
conditions affect reproduction in untypical wetland species. Similarly to many other waterbirds, in the studied population
of the Hooded Crow, water level positively influences its reproduction. 相似文献
9.
10.
Shigeru M. Shirai Ryoji Kuranaga Hideki Sugiyama Masahito Higuchi 《Ichthyological Research》2006,53(4):357-368
We analyzed patterns of genetic diversity in the sailfin sandfish (Arctoscopus japonicus), focusing on population subdivisions within the Sea of Japan. We observed 270 specimens from nine sampling sites in 1999–2000,
i.e., seven sites in the Sea of Japan and two sites from the Pacific coast of Hokkaido. An additional site (30 specimens)
was sampled from eastern Korea in the spawning season of 2004 for comparison. Forty haplotypes, compiled into three haplogroups
(A–C), were detected based on the comparison of a 400-bp sequence of the anterior part of the mitochondrial control region.
In accordance with previous hypotheses from morphological and molecular analyses, genetic discontinuity between the Sea of
Japan and the Pacific coast of Hokkaido was conspicuous. Within the Sea of Japan, eight sampling sites were not genetically
uniform, and most of the variations among sites were detected between eastern Korea [the “eastern Korea” (EK) population:
distributed from the Korean Peninsula to Mishima, Yamaguchi Prefecture] and the other sites along the coast of Japan [the
“western Japan” (WJ) population: from Oki Islands to western Hokkaido] (Φ
CT
= 0.096, P = 0.0183). The WJ population, having lower genetic variability, showed significant departure from neutrality, indicating
influences through a recent population expansion. The period of the expansion can be estimated to have begun on the order
of 104 years ago. We consider that the present Japan Sea populations have been formed through the invasion of a small ancestral
stock to the Sea of Japan and its population expansion during the last glacial period or later. On the other hand, we failed
to detect distinct evidence of a population expansion in the EK population. Haplogroup C, detected in a high frequency in
this population, was estimated to have mixed with haplogroup A after rapid differentiations of the latter. Therefore, the
EK population, strongly influenced by such a mixture, might possess haplogroup C in a higher frequency and a different haplotype
composition from the WJ population. 相似文献
11.
The parasite communities of the rabbitfish, Siganus rivulatus, were used to track multi-annual changes in the northern Gulf of Aqaba, Red Sea, in an environment subjected to ongoing anthropogenic
impact. Parasitological data from these fish were collected from 1998 to 2000, with spring and fall samplings at three locations:
at a coral reef (OBS), at a sandy beach area (NB) and at a mariculture cage farm (FF). These data were compared with data
from 1995–1997 as well as data collected during 1981–1985 at the coral reef sampling site. The data analyses indicate that
the ratio between heteroxenous and monoxenous parasite species declined significantly at all sites between 1995–1997 and 1998–2000.
During the same period, the species richness of monoxenous parasites increased significantly at all sites. The species richness
of heteroxenous parasites decreased significantly at the coral reef site, but remained steady at the other two sites. This
coincided with a significant increase in the prevalence of monogeneans at the OBS and FF sites and a significant decrease
in the prevalence of digeneans at the FF and NB sites. The decline in the abundance of the latter, specifically of Opisthogonoporoides sp. and Gyliauchen sp., was even more significant when compared with the 1981–1985 data. The prevalence of other gut helminths, namely the digenean Hexangium sigani and the nematodes Cucullanus sigani and Procamallanus elatensis, however, showed a significant increase over the same period. Analysis of the species richness and diversity indices of the
parasite communities did not reveal conspicuous differences. These, however, did become apparent when heteroxenous and monoxenous
members of particular taxa were analyzed separately. Therefore, when using parasite assemblages to detect ecological changes,
it is essential to analyze not only at the community level, but also to consider separate components of particular parasitic
groups.
Communicated by H. von Westernhagen, A. Diamant 相似文献
12.
Barbara Urban-Malinga Aleksander Drgas Anetta Ameryk Agnieszka Tatarek 《Polar Biology》2009,32(2):243-252
Intertidal meiobenthos of Hornsund—the southernmost fjord of Spitsbergen—was investigated between July and September 2005.
Mean total meiofaunal densities ranged between 4.3 and 328 ind. 10 cm−2. Nematode assemblages were impoverished in terms of the number of genera when compared with those from the western Spitsbergen
coast (11 vs. 25–28 genera in total, respectively). It is suggested that severe environmental conditions in the southern part
of Spitsbergen overcome the adaptation skills of many nematode species and hamper the establishment of a diverse community.
Comparatively high nematode numbers on a beach subject to heavy macroalgal wrack input contrast sharply with numerically poor
communities in sparse-wrack beaches (up to 315 vs. 31 ind. 10 cm−2, respectively). It is suggested that the wrack input to the Arctic beach may substantially influence the richness and composition
of the intertidal meiobenthic community. Nematode assemblages were dominated by extreme colonizers: Geomonhystera disjuncta and rhabditids. Their relatively high densities in beach sediments recorded at the beginning of July indicate their ability
to recover rapidly after the winter period and to effective (re)colonization of the intertidal habitat just after the ice
melt. Average concentration of rhabditids and monhysterids associated with macroalgal wrack deposited on the upper shore was
as high as 52 × 103 individuals per gram of the substrate. It is hypothesized that nematodes can play a substantial role in the wrack decomposition
in the Arctic intertidal. 相似文献
13.
Studies on Ambrosia pollen concentrations were carried out in Lublin in the period 1995–2004. The effects of a number of meteorological factors were analysed. In the first period of the study, the gravimetric method was used (1995–1999), while in the second period, the volumetric method was applied. The results show an increasing trend in the amount of airborne pollen. The Ambrosia pollen season in Lublin lasts from August to October. Over a period of 5 years, the highest number of pollen grains was recorded in September (53%), followed by August (44%) and October (3%). There were wide variations in annual totals. The annual total pollen counts was 167–1180 grains, with the peak value in 2002. Maximum daily pollen concentrations (56–312 pollen grains m−3) were recorded in the first half of August and in the first half of September. On the days when high Ambrosia pollen concentrations occurred, the temperature was above 21°C and the winds were mainly from the southeast, south and east. Maximum intradiurnal concentrations of pollen grains occurred in the afternoon hours. These results indicate, to some degree, that Ambrosia pollen is transported for long distances before descent. 相似文献
14.
A population of booted eagles (Hieraaetus pennatus) consisting of 21–29 pairs was studied for 7 years (1998–2004) in a forested mountainous region of southeastern Spain. The average egg-laying time was 25 April (earliest 31 March, latest 26 May). Sixty-eight percent of territorial pairs produced eggs, and 81% of reproductive pairs successfully raised at least one offspring. Mean clutch size was 1.91 eggs, and 84% hatched. The survival rate of chicks was high, with only 17% dying. The major known cause of nestling mortality was predation, mainly by the Eurasian eagle owl (Bubo bubo). The mean number of flying offspring was 0.91 per territorial pair, 1.29 per reproductive pair and 1.65 per successful pair. All population breeding parameters analysed were density independent, but most showed a significantly negative relationship with mean laying date. 相似文献
15.
Rapid phase-shift reversal on a Jamaican coral reef 总被引:5,自引:0,他引:5
Joshua A. Idjadi Sarah C. Lee John F. Bruno William F. Precht Laurie Allen-Requa Peter J. Edmunds 《Coral reefs (Online)》2006,25(2):209-211
Many Caribbean reefs have experienced a phase-shift in community structure, the principle features being a decline in coral cover and an increase in macroalgal biomass. However, one Jamaican reef—Dairy Bull on the north shore near Discovery Bay—is once again dominated by scleractinian corals and several key species have returned. Living coral cover at 6–8 m depth at Dairy Bull has doubled over the past 9 years and is now ~54%. The absolute cover of Acropora cervicornis was <1% in 1995, but increased to ~11% by January 2004. During this time the cover of macroalgae decreased by 90%, from 45 to 6%. We speculate that long-lived colonies of Montastraea annularis may have facilitated the recovery of this reef by providing structural refugia. 相似文献
16.
Long-term effects of nutrient enrichment on a population of brown trout inhabiting a small, alpine lake in north-central Sweden
have been studied for nearly 20 years. The study took place between 1981 and 1999 starting up between 1982 and 1987 with full
nutrient enrichment of phosphorus and nitrogen in a ratio by weight of 1:8, followed by a period of reduction by half between
1988 and 1994, and thereafter no enrichment at all. Growth of the brown trout population was low before the application of
nutrients. Fertilization promoted the development of zooplankton in great abundance, which gave rise to abundant food for
the trout. Already during the first year of nutrient addition the average 4+ and 5+ fish had increased in weight by nearly
50% and in length by about 30%. Maximum growth was reached 5–6 years later—weight by about 175% and length by about 50% higher
than before application. The slope of the growth curves for fish of ages 2+ to 5+ increased significantly from 1981 to 1987,
and so did the size-variation with a high proportion of the fish reaching larger size. After each change in nutrient treatment
the mean weights of 5–6-year-old trout were maintained for about 3 years. Five years after termination of fertilization growth
was nearly back to the original state. Although badly needed, long-term studies of fish populations like this are few in the
literature. 相似文献
17.
The development of Gryllus argentinus Sauss. was studied under stable laboratory conditions: the temperature of 26°C, the air humidity of 60%, and the photoperiod
of 12h light: 12 h dark. The life cycle of Gryllus argentinus includes four stages: egg, pronymph, nymph, and adult. The duration of embryonic development is 18 days. The depth of egg
bedding in the peat is 9.63 ± 0.12 mm (n =145), the clutch containing 2–4 eggs. A female can lay over 1100 viable eggs during the entire oviposition period. Nymphal
development includes 9 instars and lasts 97 days. The duration of nymphal instars (days) is: I—5; II—6; III—6; IV—6; V—8;
VI—10; VII—13; VIII—14; IX—29. The duration of the adult life is 51 days in males and 69 days, in females. In the imaginal
ontogenesis of males and females, three periods can be distinguished: pre-reproductive, reproductive, and postreproductive.
Males start to emit the aggressive signal on the 6th (5–8th) day (the pre-reproductive period). They enter the reproductive
period (start to emit the calling song) on the 9th (8–13th) day. Females enter the reproductive period (become capable of
responding to the calling song and of copulation) on the 9th (8–10th) day. Oviposition starts on the day after the first copulation.
The reproductive period lasts about 40 (15–59) days in males and 58 (21–70) days in females. The post-reproductive period
starts in females at the moment of finishing the egg laying period and in males, with disappearance of reproductive behavior.
The period ends in the animal’s death. 相似文献
18.
V. A. Korovin 《Biology Bulletin》2011,38(10):980-984
The Demoiselle crane population was studied in the southern Chelyabinsk region (52°12′N; 60°21′E) during 1988–2008. Counts
of nesting pairs were annually conducted over an area of 100–130 km2 in May. The number of breeding pairs varied from 6.5 to 9.5 per 100 km2; on average, there were 8 pairs per 100 km2 during 1989–1991. In 2000–2008, the population density increased from 7.5 to 12 pairs per 100 km2, on average, 9.3 pairs per 100 km2. Demoiselle crane nesting in steppe pastures and perennial grass fields has been rarely
observed for the last decade. Now the main nesting biotopes of the species are stubble fields accounting for up to 70% of
all nidification cases documented. The decline in agricultural production in recent decades has resulted in the appearance
of long-fallow lands, in which 17 to 35% crane pairs nest. 相似文献
19.
This paper describes size composition, morphometric, and reproductive parameters of the summer generation of the amphipod
Ischyrocerus anguipes (Krǿyer, 1838) associated with the red king crab Paralithodes camtschaticus (Tilesius, 1815) in Dalnezelenetskaya Bay (southern Barents Sea, Russia). In summer 2004–2007, prevalence and mean number
of I. anguipes per host were 15.0% and 6.9 ± 1.1 specimens, respectively. The majority of amphipods were found on the host carapace (47.4%)
and the limbs (43.9%). High infestation indices and absence of negative impacts for the host indicate that I. anguipes is a facultative commensal of the red king crab. The amphipods sex ratio was significantly biased toward females (F:M = 2:1).
Females had a greater size than males. The size at 50% maturity of I. anguipes females was estimated to be 3.37 mm. The number of eggs laid is linearly correlated with the size of a female. Some differences
in biological features of symbiotic and free-living amphipods (data obtained in 1940–1950) may be explained by climatic changes
in the Barents Sea or advantages of living on the crab. 相似文献
20.
Grzegorz Lesiński 《Biologia》2010,65(4):749-753
Percentage of bats in tawny owls’ diet was compared in three periods: I — before 1976, II — 1976–1992, III — 1993–2009, by
using the published and unpublished material from Poland (only samples over 100 vertebrate prey items). This species of owl
showed an opportunistic predation on bats and took them more frequently in periods of higher abundance. Before the mass use
of toxic pesticides in Poland, in the period I bats constituted more than 2% of vertebrates in four out of five diet samples
(median 2.4%). The lowest bat abundance occurred in Poland in the 1980s and resulted in the lowest percentage of bats taken
by owls in the period II (n = 11, median 0.2%). Due to the recovery of bat populations in the period III, the percentage of bats in tawny owls’ diet
increased (n = 23, median 0.7%). In large samples (over 200 vertebrate items, n = 21) collected in central and north-eastern Poland the percentage of bats increased from 1980 to 2009 (the estimated average
value at the end of that period slightly exceeded 1%). Samples collected at the same five sites in 1975–1992 and again in
2000–2009, confirmed the increasing trend in percentage of bats captured by tawny owls noted in last years. 相似文献