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1.
布氏田鼠对主要贮草种类的选储嗜好 总被引：2，自引：0，他引：2
布氏田鼠 (Ｍｉｃｒｏｔｕｓｂｒａｎｄｔｉ)为内蒙古典型草原区的主要害鼠 ,其危害主要表现在与牲畜争夺牧草资源[1,3 ,5,6,9] 。该鼠属不冬眠种类 ,冬季主要以洞群贮草仓库中的贮草为食 ,因此 ,研究其秋季集群的贮草习性 ,对于分析和了解该鼠的越冬生态特征具有一定的意义。有关布氏田鼠的贮草习性 ,已有一些报道[4 ,7] 。研究表明 ,在羊草 冷蒿 隐子草草场 ,布氏田鼠的越冬贮草以蒿属 (Ａｒｔｅｍｉｓｉａ)植物为主 ,其中冷蒿 (Ａ .ｆｒｉｇｉｄａ)与黄蒿 (Ａ .ｓｃｏｐａｒｉａ)占贮草比例超过 90 % [2 ] ,但上述研究均未涉及布氏田鼠… 相似文献
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Brief AC electroshock caused significant elevations in plasma cortisol, glucose, osmolality, and chloride levels in rainbow trout within 15min, but plasma protein was reduced at 3h. Circulating granulocytes had declined by 15min, but other haematological features remained unchanged. Thus, AC electrofishing would not be suitable for monitoring physiological conditions in trout if short delays are encountered before blood is sampled. 相似文献
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Nino Maag;Malcolm D. Burgess;Marta Maziarz;Shannon Lüpold;John W. Mallord;Richard K. Broughton;Andrew Cristinacce;Raphaël Arlettaz;Sandro Carlotti;Joan Castello;Tony Davis;Michael Gerber;Alex Grendelmeier;Christopher J. Orsman;Michael Riess;Pablo Stelbrink;Tomasz Wesołowski;Zephyr Züst;Gilberto Pasinelli; 《Journal of avian biology》2022,2022(10):e03033
Differences in population trends across a species' breeding range are ultimately linked to variation in demographic rates. In small songbirds, demographic rates related to fecundity typically have strong effects on population trends. Populations of a forest songbird, the wood warbler Phylloscopus sibilatrix, have been declining in many but not all regions of the European breeding range. We investigated if clutch size, hatching rate, nest survival and number of fledglings vary across Europe, and if nest survival is related to differences in the regionally dominant nest predator class (birds versus mammals). From 2009 to 2020, we monitored 1896 nests and used cameras at a subsample of 645 nests in six study regions: the United Kingdom (mid-Wales, Dartmoor, the New Forest), Germany (Hessen), Switzerland (Jura mountains) and Poland (Białowieża National Park). Number of fledglings was lowest in the New Forest (1.43 ± CI 0.23), intermediate in Jura (2.41 ± 0.31) and Białowieża (2.26 ± 0.24) and highest in mid-Wales (3.02 ± 0.48) and Dartmoor (2.92 ± 0.32). The reason for low reproductive success in the New Forest, Jura and Białowieża was low nest survival, and large clutch sizes in Białowieża did not compensate for high nest losses. High reproductive success in mid-Wales and Dartmoor was due to high nest survival and large clutch sizes. Overall predation rates were similar everywhere despite variation between the regions in the dominant nest predator class. Unsuccessful nests in mid-Wales were mainly predated by birds; in Dartmoor, the New Forest, Hessen and Jura similarly by birds and mammals; and in Białowieża exclusively by mammals. Regional reproductive success does not match the population trends recently reported for the wood warbler in the six study regions (i.e. high reproduction ≠ positive trend). Annual survival may be a decisive factor, but it is difficult to quantify for a nomadic species such as the wood warbler that rarely returns to the same breeding locations. 相似文献
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Beldomenico PM Telfer S Gebert S Lukomski L Bennett M Begon M 《The Journal of animal ecology》2008,77(5):984-997
1. Pathogens have been proposed as potentially important drivers of population dynamics, but while a few studies have investigated the impact of specific pathogens, the wealth of information provided by general indices of health has hardly been exploited. By evaluating haematological parameters in wild populations, our knowledge of the dynamics of health and infection may be better understood. 2. Here, haematological dynamics in natural populations of field voles are investigated to determine environmental and host factors associated with indicators of inflammatory response (counts of monocytes and neutrophils) and of condition: measures of immunological investment (lymphocyte counts) and aerobic capacity (red blood cell counts). 3. Individuals from three field vole populations were sampled monthly for 2 years. Comparisons with individuals kept under controlled conditions facilitated interpretation of field data. Mixed effects models were developed for each cell type to evaluate separately the effects of various factors on post-juvenile voles and mature breeding females. 4. There were three well-characterized 'physiological' seasons. The immunological investment appeared lowest in winter (lowest lymphocyte counts), but red blood cells were at their highest levels and indices of inflammatory response at their lowest. Spring was characterized by a fall in red blood cell counts and peaks in indicators of inflammatory response. During the course of summer-autumn, red blood cell counts recovered, the immunological investment increased and the indicators of inflammatory response decreased. 5. Poor body condition appeared to affect the inflammatory response (lower neutrophil and monocyte peaks) and the immunological investment (lower lymphocyte counts), providing evidence that the capacity to fight infection is dependent upon host condition. 6. Breeding early in the year was most likely in females in better condition (high lymphocyte and red blood cell counts). 7. All the haematological parameters were affected adversely by high population densities. 相似文献
7.
K van Oers A W Santure I De Cauwer N EM van Bers R PMA Crooijmans B C Sheldon M E Visser J Slate M AM Groenen 《Heredity》2014,112(3):307-316
Linking variation in quantitative traits to variation in the genome is an important, butchallenging task in the study of life-history evolution. Linkage maps provide a valuabletool for the unravelling of such trait−gene associations. Moreover, they giveinsight into recombination landscapes and between-species karyotype evolution. Here weused genotype data, generated from a 10k single-nucleotide polymorphism (SNP) chip, ofover 2000 individuals to produce high-density linkage maps of the great tit (Parusmajor), a passerine bird that serves as a model species for ecological andevolutionary questions. We created independent maps from two distinct populations: acaptive F2-cross from The Netherlands (NL) and a wild population from the United Kingdom(UK). The two maps contained 6554 SNPs in 32 linkage groups, spanning 2010 cM and1917 cM for the NL and UK populations, respectively, and were similar in size andmarker order. Subtle levels of heterochiasmy within and between chromosomes wereremarkably consistent between the populations, suggesting that the local departures fromsex-equal recombination rates have evolved. This key and surprising result would have beenimpossible to detect if only one population was mapped. A comparison with zebra finchTaeniopygia guttata, chicken Gallus gallus and the green anole lizardAnolis carolinensis genomes provided further insight into the evolution ofavian karyotypes. 相似文献
8.
Michael W. Shiflett Kristy L. Gould Tom V. Smulders Timothy J. DeVoogd 《Developmental neurobiology》2002,51(3):215-222
The hippocampal formation (HF) of food‐storing birds is larger than non‐storing species, and the size of the HF in food‐storing Black‐Capped Chickadees (Poecile atricapillus) varies seasonally. We examined whether the volume of the septum, a medial forebrain structure that shares reciprocal connections with the HF, demonstrates the same species and seasonal variation as has been shown in the HF. We compared septum volume in three parid species; non‐storing Blue Tits (Parus caeruleus) and Great Tits (Parus major), and food‐storing Black‐Capped Chickadees. We found the relative septum volume to be larger in chickadees than in the non‐storing species. We also compared septum and nucleus of the diagonal band (NDB) volume of Black‐Capped Chickadees at different times of the year. We found that the relative septum volume varies seasonally in food‐storing birds. The volume of the NDB does not vary seasonally. Due to the observed species and seasonal variation, the septum, like the hippocampal formation of food‐storing birds, may be specialized for some aspects of food‐storing and spatial memory. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 215–222, 2002 相似文献
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Previous research has shown heightened recruitment of new neurons to the chickadee hippocampus in the fall. The present study was conducted to determine whether heightened fall recruitment is associated with the seasonal onset of food-storing by comparing neurogenesis in chickadees and a non-food-storing species, the house sparrow. Chickadees and house sparrows were captured in the wild in fall and spring and received multiple injections of the cell birth marker bromodeoxyuridine (BrdU). Birds were held in captivity and the level of hippocampal neuron recruitment was assessed after 6 weeks. Chickadees showed significantly more hippocampal neuronal recruitment than house sparrows. We found no seasonal differences in hippocampal neuronal recruitment in either species. In chickadees and in house sparrows, one-third of new cells labeled for BrdU also expressed the mature neuronal protein, NeuN. In a region adjacent to the hippocampus, the hyperpallium apicale, we observed no significant differences in neuronal recruitment between species or between seasons. Hippocampal volume and total neuron number both were greater in spring than in fall in chickadees, but no seasonal differences were observed in house sparrows. Enhanced neuronal recruitment in the hippocampus of food-storing chickadees suggests a degree of neurogenic specialization that may be associated with the spatial memory requirements of food-storing behavior. 相似文献
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1. Snowshoe hare ( Lepus americanus Erxleben) populations were studied in south-west Yukon during the low phase of the 10-year population cycle. Food availability and predator abundance were manipulated in a factorial design to determine the importance of each factor in hare dynamics during this phase.
2. Food was abundant during the low phase, and snowshoe hares were not food limited.
3. Survival of hares was higher than at any other phase of the cycle, and predators were scarce, but >75% of hare deaths resulted from predation.
4. Food addition resulted in higher hare densities and better body condition than on control sites. There were no observable effects of food addition on population rate of increase, recruitment, survival or age structure.
5. Mammalian predator reduction resulted in higher hare densities, higher survival, better body condition and an older age structure. Relative to control populations, recruitment was lower and population rates of increase similar.
6. The joint manipulation of food addition + predator reduction had greater positive effects on hare density and body condition than either single factor manipulation. Survival was better than on control sites, and the age structure was older than on control sites. Population rates of increase were similar, but recruitment was higher on the control areas.
7. We conclude that snowshoe hare dynamics at the low of the cycle are dominated by the interaction of food and predation. Risk of predation also had indirect effects on snowshoe hare age structure and body condition. 相似文献
2. Food was abundant during the low phase, and snowshoe hares were not food limited.
3. Survival of hares was higher than at any other phase of the cycle, and predators were scarce, but >75% of hare deaths resulted from predation.
4. Food addition resulted in higher hare densities and better body condition than on control sites. There were no observable effects of food addition on population rate of increase, recruitment, survival or age structure.
5. Mammalian predator reduction resulted in higher hare densities, higher survival, better body condition and an older age structure. Relative to control populations, recruitment was lower and population rates of increase similar.
6. The joint manipulation of food addition + predator reduction had greater positive effects on hare density and body condition than either single factor manipulation. Survival was better than on control sites, and the age structure was older than on control sites. Population rates of increase were similar, but recruitment was higher on the control areas.
7. We conclude that snowshoe hare dynamics at the low of the cycle are dominated by the interaction of food and predation. Risk of predation also had indirect effects on snowshoe hare age structure and body condition. 相似文献
11.
Raivo Kalle Renata Sõukand 《Botanical journal of the Linnean Society. Linnean Society of London》2013,172(2):239-253
In this ethnobotanical study, the authors provide the first quantitative analysis of the use of wild edible plants in Estonia, describing the domains and assessing the food importance of different species. The information was collected using free‐listing written questionnaires and concerned plants used by the respondents in their childhood. As part of a major study, this article covers the responses of professionals with some botanical education at vocational or university level, to ensure the greatest possible reliability without using voucher specimens. Fifty‐eight respondents provided information on the use of 137 plant taxa, corresponding to approximately 6% of the native and naturalized vascular plants of Estonia. According to use frequency, the most typical wild food plant of Estonia is a fruit, eaten raw as a snack. The results clearly signal that the majority of famine and food shortage plants had already been forgotten by the end of the 20th century, but new plants have been introduced as green vegetables for making salads. Despite changes in the nomenclature of the plants, the use of wild food plants in Estonia was still thriving at the turn of the 20th century, covering many domains already forgotten in urbanized modern Europe. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172 , 239–253. 相似文献
12.
Bonneaud C Pérez-Tris J Federici P Chastel O Sorci G 《Evolution; international journal of organic evolution》2006,60(2):383-389
Malaria parasites are a major cause of human mortality in tropical countries and a potential threat for wildlife, as witnessed by the malaria-induced extinction of naive Hawaiian avifauna. Identifying resistance mechanisms is therefore crucial both for human health and wildlife conservation. Patterns of malaria resistance are known to be highly polygenic in both humans and mice, with marked contributions attributed to major histocompatibility (Mhc) genes. Here we show that specific Mhc variants are linked to both increased resistance and susceptibility to malaria infection in a wild passerine species, the house sparrow (Passer domesticus). In addition, links between host immunogenetics and resistance to malaria involved population-specific alleles, suggesting local adaptation in this host-parasite interaction. This is the first evidence for a population-specific genetic control of resistance to malaria in a wild species. 相似文献
13.
Landscape genetic approaches offer the promise of increasing our understanding of the influence of habitat features on genetic structure. We assessed the genetic diversity of the endangered golden-cheeked warbler (Dendroica chrysoparia) across their breeding range in central Texas and evaluated the role of habitat loss and fragmentation in shaping the population structure of the species. We determined genotypes across nine microsatellite loci of 109 individuals from seven sites representing the major breeding concentrations of the species. No evidence of a recent population bottleneck was found. Differences in allele frequencies were highly significant among sites. The sampled sites do not appear to represent isolated lineages requiring protection as separate management units, although the amount of current gene flow is insufficient to prevent genetic differentiation. Measures of genetic differentiation were negatively associated with habitat connectivity and the percentage of forest cover between sites, and positively associated with geographic distance and the percentage of agricultural land between sites. The northernmost site was the most genetically differentiated and was isolated from other sites by agricultural lands. Fragmentation of breeding habitat may represent barriers to dispersal of birds which would pose no barrier to movement during other activities such as migration. 相似文献
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Determining the genetic structure of tropical bird populations is important for assessing potential genetic effects of future habitat fragmentation and for testing hypotheses about evolutionary mechanisms promoting diversification. Here we used 10 microsatellite DNA loci to describe levels of genetic differentiation for five populations of the lek-mating blue manakin (Chiroxiphia caudata), sampled along a 414-km transect within the largest remaining continuous tract of the highly endangered Atlantic Forest habitat in southeast Brazil. We found small but significant levels of differentiation between most populations. F(ST) values varied from 0.0 to 0.023 (overall F(ST)=0.012) that conformed to a strong isolation by distance relationship, suggesting that observed levels of differentiation are a result of migration-drift equilibrium. N(e)m values estimated using a coalescent-based method were small (相似文献
15.
Hans-Heiner Bergmann Wiltraud Engländer und Vladimir U. Arkhipov 《Journal of Ornithology》2001,142(2):129-143
Zusammenfassung In einem Vorkommen des Dünnschnäbligen Tannenhähers an der Küste des Ochotskischen Meeres im Fernen Osten Sibiriens wurde das Ernten und Verstecken von Samen aus den Zapfen der Zwergzirbelkiefer (Pinus pumila) untersucht. Der Inhalt von durchschnittlich 2,8 Zapfen, das sind etwa 80 Samen, wurde in der gefüllten Kehltasche transportiert und auf eine Anzahl unter niedriger Zwergstrauchvegetation gelegener Bodenverstecke verteilt. Die Verstecke wurden in annähernd linearer Anordnung ohne Bevorzugung einer bestimmten Himmelsrichtung angelegt. Die Versteckserien enthielten im Median 79, maximal mehr als 120 Samen, das Einzelversteck durchschnittlich 19,6 Samen. Das Ernten und Leeren eines Zapfens geschah im Schnitt innerhalb von 47 s. Für das Verstecken einer Füllung des Kehlsacks benötigten die Vögel ca. 170 s. Für das gesamte Beschaffen und Verstecken eines einzelnen Kiefernsamens errechnet sich ein durchschnittlicher Zeitbedarf von 3,26 s. Nach 20 Tagen war der Zapfenvorrat in der lokalen Kiefernpopulation erschöpft. Jeder Häher hat nach den Hochrechnungen bis zu 100.000 Samen vergraben.
Harvesting and caching capacities of Thin-billed Nutcrackers in the Russian Far East
Summary At the Ochotskian sea coast Thin-billed Eurasian Nutcrackers (Nucifraga caryocatactes macrorhynchos) harvested seeds of ripe cones of the brush pinePinus pumila in late summer. The mean number of seeds carried in their sublingual pouch was 80, which respresents the harvestable contents of 2.8 cones. These were distributed in an average of 5 caches, exclusively in the soil under low tundra vegetation. Caches were organized in nearly straight lines. Series contained a mean of 82.7 seeds, single caches a mean of 19.6 seeds. Plucking one cone and harvesting its seeds took 47 seconds on average. The caching of a complete pouchful took on average 123.4 seconds. The time invested for harvesting and caching one single seed was calculated at 3.26 seconds. Within three weeks in July, an average individual bird was calculated to have cached a total of up to 100,000 seeds.相似文献
16.
中国粮食作物的野生近缘植物及其保存概况 总被引：1，自引：0，他引：1
郑殿升 《中国野生植物资源》2006,25(5):5-7
中国的主要粮食作物约有20种,它们的多数都有野生近缘植物.目前,中国保存的粮食作物野生近缘植物资源约1.5万份,分别保存在国家作物种质资源库和种质圃内. 相似文献
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张渝华 《植物资源与环境学报》1996,5(2):63-64
延胡索（CorydalisyanhusuoW.T.WangexZ.Y.SuetC.Y.Wu）是我国的重要中药材。《中华人民共和国药典》收载的延胡索为同类中药材的法定正品。除栽培正品延胡索外,以块茎在国内产地作药用的还有同类野生中药材约10种[1,2]。该类中药材的原植物分别隶属紫堇属延胡索亚属Subgen．CapnitesDC．的实心延胡索组Sect.Pes－gallinaceusIrimisch．和薯根延胡素组Sect．LeonticoidesDe[3]。近年．人工杂交新品种的培育成功[4]又扩大了药源。近年,作者在浙江余杭超山发现一个野生延胡索居群,染色体为2n＝48,与栽培延胡索2n＝32不同。经多年… 相似文献
19.
Yanju Ma Brian A. Branfireun Keith A. Hobson Christopher G. Guglielmo 《Journal of avian biology》2018,49(3)
Mercury (Hg) is a well‐known global contaminant that persists in the environment. The organic form, methylmercury (MeHg) has been shown to adversely affect bird immune function, foraging behavior, navigation, and flight ability, which individually or together could reduce migration performance, and ultimately survival. Nestlings grow feathers at their natal site, and in North America many adult passerines undergo a complete feather molt prior to autumn migration at or near their breeding location. Body Hg is redistributed into growing feathers, and remains stable following feather growth. As flight feathers are retained in most species over the non‐breeding season until molt in the following summer, tail feathers can be used at other times and places as indicators of Hg body burden on the breeding grounds. In five migratory passerine species, we compared Hg concentrations in tail feathers that were grown prior to autumn migration and retained until the following spring. We predicted that we would observe a shift in the distribution of species‐specific feather Hg values towards lower means in the spring if Hg reduced survival over the migration and winter periods. We found reductions in mean feather Hg between autumn and spring in two long‐distance migratory insectivores (blackpoll warbler Setophaga striata; American redstart Setophaga ruticilla). Most significantly, spring‐returning blackpoll warblers, a species that undertakes long non‐stop flights to South America during autumn migration, had nearly 50 percent lower Hg concentrations than those that departed in the autumn. Our finding suggests that Hg exposure on the breeding areas could have a carry‐over effect to influence migration success and survival of insectivorous songbirds that undergo extensive and demanding migratory journeys. More investigation is needed to fully understand the relationships among Hg exposure, migration performance, and survival of songbirds. 相似文献
20.
Ciotti BJ Targett TE Nash RD Batty RS Burrows MT Geffen AJ 《Journal of fish biology》2010,77(10):2181-2209
A general mechanism relating RNA concentration and growth rate is derived from four physiological assumptions and developed into a growth index for juvenile plaice Pleuronectes platessa. The index describing instantaneous growth rates (G, day?1) in the laboratory with the lowest Akaike information criterion with small‐sample bias adjustment was a function of RNA concentration (R, ), temperature (T, ° K), body mass (M, g) and DNA concentration (D, ): G = β0 + βRR + βTT + βT2T2 + βMM + βDD + βRTRT. RNA concentration began to respond to changes in feeding conditions within 8 days, suggesting that the index reflects growth rate in the short‐term. Furthermore, the index distinguished between rapid growth and negative growth of juvenile P. platessa measured directly in laboratory and field enclosures, respectively. An application of the RNA‐based growth index at two beaches on the west coast of Scotland suggested that the growth of juvenile P. platessa varies considerably in space and time and is submaximum in late summer. 相似文献