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1.
We determined how the presence of heterospecific individuals in the vicinity of a focal individual affects the behavior of
two critically endangered species of cranes on their wintering grounds at Cheolwon in the Korean Demilitarized Zone. The red-crowned
crane, Grus japonensis, is larger than the white-naped crane, Grus vipio, and it dominates the white-naped crane in aggressive interactions. We showed that the dominant species increases foraging
activity in the presence of the subordinate species presumably because of scrounging of food from the subordinate. Because
interspecific interactions may affect avian endangerments these behavioral findings should be taken into account when managing
winter refuges for the two endangered crane species. 相似文献
2.
3.
以往关于动物警戒行为的研究多以经典随机独立模型为基础,然而,近期一些理论和实证研究则向该模型发出了挑战。根据警戒行为同步性程度的不同,集体警戒可能存在基于模仿的同步警戒和避免重复的协调警戒两种模式。研究了中国雅鲁藏布江自然保护区越冬黑颈鹤家庭群的警戒行为,通过独立样本t检验验证由于年龄和是否携幼所导致的个体警戒水平的差异,通过单因素方差分析比较不同类型家庭群的集体警戒水平,通过配对t检验比较集体警戒的实际观测值和独立假设下的预期值从而确定越冬黑颈鹤家庭群的警戒同步性。结果表明家庭群中的幼年黑颈鹤警戒行为时间显著低于成年黑颈鹤,但幼鹤的存在对成鹤的警戒水平没有显著影响。不同类型黑颈鹤家庭群的集体警戒水平没有差异,但并未如预期表现为同步警戒。警戒行为模式是动物在特定环境中的适应性表现,越冬黑颈鹤生境中不存在落后目标策略的捕食者和高强度的捕食风险,因而可能不足以诱发以降低捕食风险为主要功能的高强度的警戒行为同步性;同时,在资源匮乏的冬季对食物获取的优先性可能也削弱了对同步警戒的需求。 相似文献
4.
We studied the oviposition performance of Fopius arisanus (Sonan) (Hymenoptera: Braconidae) attacking eggs of four fruit flies of the genus Anastrepha Schiner (Diptera: Tephritidae) under laboratory conditions. The complete process of oviposition on an individual egg of Anastrepha ludens (Loew) lasts in average 85.4 ± 2.9 s, including a tremor (25.8 ± 1.03 s) observed in the middle of this process related to
the egg’s descent. The average parasitism of A. ludens egg was 60.9 ± 7.5%, with only 1.2% of superparasitized eggs. During individual acts of oviposition, we noted that F. arisanus possesses a highly flexible ovipositor that curves easily as it searches for additional suitable eggs, which may be of particular
benefit when a female finds large clutches of eggs. The individual oviposition of F. arisanus in host fruits attacked by Anastrepha spp. varies with the egg clutch size of each fruit fly species: A. serpentina laid the biggest egg clutches (21.3 ± 1.4), followed by A. ludens (14.2 ± 0.9), and A. striata (1.0 ± 0.0) (=A. obliqua). The time spent by F. arisanus in individual ovipositions was parallel to these findings, reinforcing the idea that F. arisanus attacks several eggs in each individual insertion of its ovipositor. Neither formal oviposition acts, nor adult emergences
of F. arisanus were registered in A. obliqua. We discuss the potential of F. arisanus as natural enemy of fruit flies of the genus Anastrepha, and explore the eventual developing of its mass rearing.
Handling Editor: Torsten Meiners. 相似文献
5.
Eastern and Western Gambusia (i.e., Gambusia holbrooki and G. affinis, respectively) are considered together here because these two fish species are very closely related, similar in appearance,
similar in biology and often confused. Widely divergent attitudes have developed with regard to these fish with some viewing
them as being highly beneficial to humans through controlling mosquitoes and the diseases they harbor, and others expressing
concern about the negative impacts that these fish may have on other species with which they interact. Because of the widespread
distribution, high levels of abundance, ease of capture and captive maintenance, and divergent attitudes, a very large and
diffuse literature has developed with regard to these species. In fact, few fish species have been studied as much as or more
than these two species combined. There has, however, been no comprehensive review of their biology published to date. As it
is not possible to provide a comprehensive review of Gambusia biology in one reasonably sized document, I provide here a review of aspects of their biology at the level of species and
individual. In another review I focused instead on the levels of population and species communities and consider the impacts
that these fish have on mosquitoes and other organisms (Pyke, unpublished). As would be expected of such widespread and abundant
species, Gambusia affinis and G. holbrooki are clearly very tolerant, adaptable and variable in their biology, at both an individual and population level. Both individuals
and populations can tolerate, and often thrive within, a wide range of conditions and the abilities of individuals to do this
are enhanced if they have time to acclimate to any changes. Populations can adapt through genetic or evolutionary changes
in response to conditions that vary in space or time, and there is significant genetic variation within and between populations. 相似文献
6.
Bridget B. Amulike Todd K. Fuller Peter W. Houlihan Curtice R. Griffin 《African Journal of Ecology》2020,58(4):685-691
There are few quantitative estimates of numbers of Africa's endangered grey crowned cranes (Balearica regulorum), yet conservation of this species will depend on such estimates. We used line-transect distance sampling on multiple 2-km segments of an existing road network to estimate the abundance of grey crowned cranes in a portion of the Ngorongoro Crater, Tanzania, during the wet (April) and dry (August) seasons of 2016. We analysed data from 106 transects on which we observed 174 groups of 1–61 cranes (median and mode = 2). Abundance and density estimates on the areas surveyed were best modelled without group size as a covariate and indicated that mean crane densities were significantly lower in the wet season (2.4/km2) than in the dry season (20.2 cranes/km2). Even based on survey areas of different size, minimum estimated numbers of cranes in the Crater (wet season: 108–133; dry season: 362–401) likely reflect the concentration of cranes in the nonbreeding (dry) season in the perennial wetlands of the Crater and reinforce the notion of the Crater being a key seasonal habitat for crane populations in northern Tanzania, as previously suggested in the literature. 相似文献
7.
Patrick D. Danley 《Environmental Biology of Fishes》2011,92(3):275-284
Within the past 2 million years, the cichlids of Lake Malawi have diversified into well over 500 species resulting in one
of the worlds largest lacustrine fish radiations. As a result, many of the habitats within the lake support a high diversity
of species. In these highly species rich communities, male cichlids must acquire and defend a territory to successfully reproduce.
Within the rock-dwelling cichlids of Lake Malawi (mbuna), this has resulted in the formation of polyspecific leks on the heterogeneous
rocky benthos. Aggression is fairly common in these leks and has been tied not only to individual reproduction but to the
larger phenomenon of community assembly and the maintenance of biological diversity. In this study, I examined the patterns
of aggressive acts of four species within the mbuna genus Maylandia at two locations in the southern Lake Malawi. The number of aggressive acts of two sympatric species was examined at each
location. At each site, one species defends territories over bedrock and the other over cobble. The number of aggressive acts
across the four species was compared. The influence of habitat type on male aggression was examined and the targets of male
aggression were identified to evaluate several hypotheses concerning the evolution of male aggression. The results show that
aggression quantitatively varied among species, was largely directed towards heterospecifics, and was strongly influenced
by habitat type. The aggressive behavior of one sympatric species pair, Maylandia benetos and Maylandia zebra, was observed under controlled laboratory conditions. Laboratory results support field observations: the bedrock associated
species performed more aggressive acts and aggressive acts were directed equally at con- and heterospecifics. The results
of this study suggest that habitat complexity plays a larger role in shaping aggressive behavior than other suggested factors
such as competition for resources. 相似文献
8.
We studied the efficiency (proportion of the crop removed) and quantitative effectiveness (number of fruits removed) of dispersal
of Miconia fosteri and M. serrulata (Melastomataceae) seeds by birds in lowland tropical wet forest of Ecuador. Specifically, we examined variation in fruit
removal in order to reveal the spatial scale at which crop size influences seed dispersal outcome of individual plants, and
to evaluate how the effect of crop size on plant dispersal success may be affected by conspecific fruit abundance and by the
spatial distribution of frugivore abundance. We established two 9-ha plots in undisturbed terra-firme understory, where six
manakin species (Pipridae) disperse most seeds of these two plant species. Mean levels of fruit removal were low for both
species, with high variability among plants. In general, plants with larger crop sizes experienced greater efficiency and
effectiveness of fruit removal than plants with smaller crops. Fruit removal, however, was also influenced by microhabitat,
such as local topography and local neighborhood. Fruit-rich and disperser-rich patches overlapped spatially for M. fosteri but not M. serrulata, nonetheless fruit removal of M. serrulata was still much greater in fruit-rich patches. Fruit removal from individual plants did not decrease in patches with many
fruiting conspecifics and, in fact, removal effectiveness was enhanced for M. fosteri with small crop sizes when such plants were in patches with more conspecifics. These results suggest that benefits of attracting
dispersers to a patch balanced or outweighed the costs of competition for dispersers. Spatial pattern of fruit removal, a
measure of plant fitness, depended on a complex interaction among plant traits, spatial patterns of plant distribution, and
disperser behavior. 相似文献
9.
Dongtan (or East Tideland) on Chongming Island in China is an important wintering site of Grus monacha (hooded crane). Field observations were conducted in Dongtan in the wintering season of 2000–2001 to determine how tidal fluctuation affects the habitat use and behavior of G.monacha. Scirpus mariqueter (sea-bulrush) was the dominant species in the tidal vegetation; and its corms were the major food source for G.monacha. The corms in the outer zone (far from the dyke) were buried underground shallower than those in the inner zone (near the dyke) because of erosion by tidewater. For easy access to food, G.monacha tended to select the outer zone and the edge of tidal creeks as its foraging sites for the majority of time spent on the tideland. Regression analysis revealed that distance of the foraging sites to the dyke was correlated with tidal height. The cranes did not appear to show territorial behavior, and tended to form large-sized flocks, especially at high tide, because of the effect of the tidewater and the non-uniform distribution of food. Thus, the height of the tide is an important factor responsible for the habitat selection of G.monacha, which was also the major cause of the cranes selecting only the natural tideland at Dongtan on Chongming Island. Unfortunately, the habitats of G.monacha are limited, and even threatened, at Dongtan because the tideland is frequently reclaimed. Appropriate measures should be taken to prevent the tideland being further reclaimed, otherwise the natural wintering grounds of G.monacha will soon disappear. 相似文献
10.
Bryanne M. Hoar Douglas P. Whiteside Linda Ward G. Douglas Inglis Douglas W. Morck 《Zoo biology》2007,26(2):141-153
The enteric flora of captive whooping cranes (Grus americana) and sandhill cranes (Grus canadensis) has not been well described, despite its potential importance in the understanding of both the normal condition of the intestinal physiology of these animals and the altered colonization within disease states in these birds. Nineteen whooping cranes and 23 sandhill cranes housed currently at the Calgary Zoo or its affiliated Devonian Wildlife Conservation Centre (DWCC) in Calgary, Alberta were sampled from October 2004–February 2005 by collecting aerobic and anaerobic cloacal swabs from each bird. There were seven major groupings of bacteria isolated from both species of crane. Gram‐positive cocci, coliforms, and gram‐negative bacilli were the most prevalent types of bacteria isolated for both crane species, with Escherichia coli, Enterococcus faecalis, and Streptococcus Group D, not Enterococcus the bacterial species isolated most commonly. There was a significant difference in the average number of isolates per individual between the two crane species but no differences between age or gender categories within crane species. Campylobacter sp. were isolated from five whooping cranes. The potential zoonotic pathogen Campylobacter jejuni was isolated from one whooping crane and C. upsaliensis was isolated from a second. Three other isolates were unspeciated members of the Campylobacter genus and likely belong to a species undescribed previously. The evaluation of the enteric cloacal flora of whooping cranes and sandhill cranes illustrates that differences exist between these two closely related crane species, and highlights the potential implications these differences may have for current practices involving captive wildlife. Zoo Biol 0:1–13, 2007. © 2007 Wiley‐Liss, Inc. 相似文献
11.
S. C. Pratt 《Insectes Sociaux》2005,52(4):383-392
This paper examines the individual behavior underlying collective choice among nest sites by the ant Temnothorax (formerly Leptothorax) curvispinosus. Colonies can actively compare options, rejecting a mediocre site when it is paired with a good one, but accepting the same
mediocre design if it is instead paired with a worse site. This ability emerges from the behavior of an active minority of
workers who organize emigrations. When one of these finds a promising site, she recruits nest mates to it, but only after
a delay that varies inversely with site quality. Ants first recruit fellow active ants via slow tandem runs, but eventually
switch to speedier transports of the colony’s passive majority. Later transports grow faster still, as ants improve their
speed with experience. An ant’s choice of recruitment type is governed by a quorum rule, such that her likelihood of starting
to transport increases with the population of the new site. The size of the quorum depends on experience, with ants demanding
a larger population to launch immediately into transport than they do to switch to transport after first leading a few tandem
runs. Perception of quorum attainment requires direct contact between ants. The ants’ behavior qualitatively matches that
of T. albipennis, where models have shown that decentralized choice of the best site depends on quality-dependent recruitment delays, amplified
by a quorum rule for initiating transport. Parameter estimates for an agent-based model show significant quantitative differences
between the species, and suggest that T. albipennis may place relatively greater emphasis on emigration speed.
Received 11 February 2005; revised 10 May 2005; accepted 20 May 2005. 相似文献
12.
白鹤(Leucogeranus Leucogeranus)是国家Ⅰ级重点保护野生动物,唯一一种极度濒危(CR)鹤类,分布和种群数量是评估其濒危程度的重要参数。无人机调查作为目前生态学研究的一个重要调查方法,为查明白鹤的越冬分布、种群数量及幼鸟比例,于2022年1月使用地面监测结合无人机调查的方法在江西、山东、安徽、湖南、湖北等地的湖泊和农田中开展越冬白鹤调查。野外调查共记录白鹤5607只,网络信息检索在调查区域外的8个地点记录白鹤9只,合计记录越冬白鹤5616只。其中江西鄱阳湖记录到越冬白鹤4813只,占总数的85.7%,主要分布在康山垦殖场、五星垦殖场和成新垦殖场;山东黄河三角洲记录到越冬白鹤625只,占总数的11.1%。安徽、湖南、湖北分别记录到越冬白鹤34,63和72只。对部分群体的白鹤幼鸟数量进行统计,4680只白鹤中,记录到幼鸟674只,幼鸟比例为14.4%,其中湖南越冬白鹤幼鸟比例最高,达28.6%,山东越冬白鹤幼鸟比例最低,为11.5%。调查刷新了白鹤种群数量,证实了山东黄河三角洲是目前除江西鄱阳湖外最重要的白鹤越冬地,缓解了白鹤越冬期过度集中的压力。基于本研究结果,我们... 相似文献
13.
Directional fidelity as a foraging constraint in the western harvester ant,Pogonomyrmex occidentalis
Jennifer H. Fewell 《Oecologia》1990,82(1):45-51
Summary Understanding the foraging behavior of an animal is critically dependent upon knowledge of the constraints on that animal. In this study, I tested whether fidelity to foraging direction acts as a behavioral constraint to foraging western harvester ants, Pogonomyrmex occidentalis. Individual P. occidentalis foragers showed strong fidelity to foraging route and direction. Directional fidelity in this population was not related to trunk trail use, food specialization, colony activity levels, or mortality risks. Directional fidelity constrained individual foraging decisions; when colonies were offered seeds of different quality in 2 directions, individuals did not switch directions to obtain the energetically more rewarding seeds. Colony-level recruitment was increased for energetically more profitable seeds, indicating that colonial responses may compensate for the constraints of directional fidelity on individual foragers. 相似文献
14.
Polystichum is one of the largest and most taxonomically complex fern genera in China. The evolutionary relationships of Chinese Polystichum and related genera, and the relationship between our Polystichum phylogeny and ecogeographic distribution, were tested by the use of DNA sequence data. Fifty-one species of Polystichum and 21 species in allied genera were sequenced for the plastid intergenic spacers rps4-trnS and trnL-F. Maximum parsimony and Bayesian phylogenetic analyses of both individual and combined data sets showed that Chinese Polystichum as commonly recognized was paraphyletic: one clade (the CCPC clade) included Cyrtomidictyum lepidocaulon, two Cyrtogonellum species, three Cyrtomium species, and a small number of Polystichum species usually occurring on limestone. A second clade, Polystichum sensu stricto, included the remainder of the Polystichum species; these often occur on non-limestone substrates. The remaining Cyrtomium species formed the third clade. Three subclades resolved within Polystichum sensu stricto (s.s.) clade do not correspond with recent sectional classifications, and we outline the issues relevant to
a new classification for the genus.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
15.
Ceratocystiopsis, Ceratocystis, Grosmannia, and Ophiostoma species were isolated from Ips subelongatus and beetle-infested Japanese larch logs collected at several areas in central and northern Honshu Island, Japan, to determine
constant associates of I. subelongatus. Ceratocystiopsis minuta, two species of Ceratocystis, three species of Grosmannia, and four species of Ophiostoma were isolated. Of the fungi isolated in the present study, G. laricis, O. brunneociliatum, and O. piceae were constant associates of the beetles. Ceratocystis fujiensis, Ceratocystiopsis minuta, and Ophiostoma sp. F were occasionally isolated with high frequencies of occurrence but were not consistent associates. Ceratocystis fujiensis was most often isolated as the leading fungal invasion in the sapwood of Japanese larch logs invaded by I. subelongatus, confirming that the fungus acts as a primary invader of sapwood in beetle-attacked logs.
Contribution No. 221, Laboratory of Plant Parasitic Mycology, Graduate School of Life and Environmental Sciences, University
of Tsukuba 相似文献
16.
17.
To clarify differences in community structures and habitat utilization patterns of fishes in Enhalus acoroides- and Thalassia hemprichii-dominated seagrass beds on fringing coral reefs, visual censuses were conducted at Iriomote and Ishigaki islands, southern Japan. The numbers of fish species and individuals were significantly higher in the E. acoroides bed than in the T. hemprichii bed, although the 15 most dominant fishes in each seagrass bed were similar. Cluster and ordination analyses based on the number of individuals of each fish species also demonstrated that fish community structures were similar in the two seagrass beds. Species and individual numbers of coral reef fishes which utilized the seagrass beds numbered less than about 15% of whole coral reef fish numbers, although they comprised about half of the seagrass bed fishes. Of the 15 most dominant species, 5 occurred only in the two seagrass beds, including seagrass feeders. Ten other species were reef species, their habitat utilization patterns not differing greatly between the two seagrass beds. Some reef species, such as Lethrinus atkinsoni and L. obsoletus, showed ontogenetic habitat shifts with growth, from the seagrass beds to the coral areas. These results indicate that community structures and habitat utilization patterns of fishes were similar between E. acoroides- and T. hemprichii-dominated seagrass beds, whereas many coral reef fishes hardly utilized the seagrass beds. 相似文献
18.
Chiara Papetti Emanuele Susana Mario La Mesa Karl-Hermann Kock Tomaso Patarnello Lorenzo Zane 《Polar Biology》2007,30(12):1605-1613
Chaenocephalus aceratus is one of the most abundant Antarctic icefish species in the Atlantic sector and has been a by-catch species in the fishery
for mackerel icefish, Champsocephalus gunnari, between the mid-1970s and mid-1980s at South Georgia, South Orkney, and South Shetland Islands. The species became the target
of the fishery in particular seasons, such as at South Georgia in 1977/78. In our paper, we report results on genetic differentiation
for 11 microsatellite loci in C. aceratus samples collected at the South Shetlands and Elephant Island. This study represents the first report on microsatellite variability
of an icefish species. Our results support the evidence from previous studies on differences in infestation patterns of parasites
that a single panmictic population of C. aceratus exists, spanning the two sampling sites separated by about 100 km. Moreover, our study indicates the presence of a significant
genetic differentiation between individual year-classes pointing out the existence of dynamic processes acting at the population
genetic level, according to recent results for broadly distributed marine species. Both small effective population size and
immigration from unsampled differentiated stocks may be at the base of the differentiation found in C. aceratus.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
D. Fiocco E. Crisetti V. Capozzi G. Spano 《World journal of microbiology & biotechnology》2008,24(6):899-902
20.
P. Lahann 《International journal of primatology》2007,28(4):895-905
Greater dwarf lemurs (Cheirogaleus major) are small nocturnal primates from the rain forests of eastern Madagascar. I investigated a population of Cheirogaleus major in a littoral rain forest of Southeast Madagascar during 2 rainy seasons to supplement the sparse information available for
the species. I collected data on morphology, group composition, sleeping behavior, home range, and social organization via
mark/recapture, radio telemetry, and focal individual observations. I identified 2 presumed family groups, and my data from
radiotracking revealed a monogamous social organization. In each group, I found an adult pair and its presumed offspring sharing
home ranges and sleeping sites together. I also observed gregarious behavior of group members during their nocturnal activity.
I found no difference in body measurements between sexes, but body mass and tail circumference increased significantly from
November to February, indicating a fatting period before hibernating. 相似文献