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991.
Primatology in China 总被引:2,自引:2,他引:0
China is one of the countries with the greatest diversity of nonhuman primate species: 22 species with 30 subspecies, in 6 genera and 3 families. Primatology in China started in 1862, but fruitful study began only in the 1950s. More than 2,000 academic papers have been published, covering systematics, evolution, ecology, etho-ecology, conservation, reproduction and neuroscience. We review primatology in China over the past century, concentrating mostly on systematics, etho-ecology, conservation and reproduction. We aim to share this information with international colleagues and to seek possibilities for collaboration in the future. 相似文献
992.
S. Libants A. M. Kamarainen K. T. Scribner J. D. Congdon 《Molecular ecology resources》2004,4(2):300-302
We describe the cloning and characterization of seven microsatellite loci from [CA]‐ and [GA]‐enriched partial genomic libraries of Blanding's turtle, Emydoidea blandingii, and their use in two other species of freshwater turtle, Chrysemys picta and Chelydra serpentina. These loci will be used in a long‐term ecological study of the reproductive success of these co‐occurring freshwater turtle species. 相似文献
993.
Feeny revisited: condensed tannins as anti-herbivore defences in leaf-chewing herbivore communities of Quercus 总被引:2,自引:0,他引:2
Abstract. 1. Community level oak–tannin–insect patterns have been largely unexplored since Paul Feeny's ground‐breaking research. Two hypotheses were tested for Quercus velutina and Q. alba in the Missouri Ozarks: abundance and richness of leaf‐chewing herbivores are negatively correlated with foliar condensed tannin concentrations and variation in condensed tannin concentrations explains variation in herbivore community structure. 2. In 2001, foliar condensed tannins in the understorey and canopy of these two oak species were quantified simultaneously with censuses of herbivores in May, during leaf expansion, and in June and August, when leaves were fully expanded. Thirty‐eight of the 134 species encountered had densities sufficient to be analysed individually (n = 10). Of those, Acronicta increta (Noctuidae) and Attelabus sp. (Curculionidae), both oak specialists, were negatively correlated with condensed tannins in the canopy of Q. alba. One additional specialist, Chionodes pereyra (Gelechiidae), was marginally negatively correlated with condensed tannins in the understorey of Q. velutina. Understorey species richness of May Q. velutina herbivores was negatively correlated with condensed tannins, as were total canopy insect density and species richness of August herbivores on Q. alba. 3. Principal component analysis (PCA) of insect abundances indicated that understorey and canopy Q. velutina and Q. alba had different communities of leaf‐chewing insects. Furthermore, condensed tannin levels contributed significantly to variation in PCA scores for Q. velutina, explaining 25% of the total variation. 4. Overall, these results indicate that specialists were more likely than generalists both to correlate negatively with condensed tannins and to occur in lower tannin habitats; abundance and richness of both early and late season fauna correlated negatively with tannins; and species were more likely to correlate negatively with condensed tannins when feeding on Q. alba than on Q. velutina and when feeding in the canopy than in the understorey. Future studies of tannin–insect interactions should manipulate leaf quality in combination with manipulations of other factors that likely influence community structure. 相似文献
994.
We examined feeding of blue catfish, Ictalurus furcatus, and flathead catfish, Pylodictis olivaris, collected from floodplain lake, secondary (side) river channel, and main river channel habitats in the lower Mississippi
River (LMR), U.S.A. We described the feeding ecology of two large river catfish species within the context of whether off-channel
habitats in the LMR (i.e., floodplain lakes and secondary channels) potentially provided energetic benefits to these fishes
as purported in contemporary theory on the ecology of large rivers. We used diet composition and associated caloric densities
of prey consumed as indicators of energetic benefit to catfishes. Differences in diet among habitats were strong for blue
catfish, but weak for flathead catfish; consumed foods generally differed among habitats in caloric (energy) content. Caloric
densities of consumed foods were generally greatest in floodplain lakes, least in the main river channel, and intermediate
in secondary river channels. Strong between-year variation in diet was observed, but only for blue catfish. Blue catfish fed
disproportionately on lower-energy zebra mussels in the main river channel during 1997, and higher-energy chironomids and
oligochaetes in floodplain lakes during 1998. Results suggested that although off-channel habitats potentially provided greater
energetic return to catfishes in terms of foods consumed, patterns of feeding and subsequent energy intake may vary annually.
Energetic benefits associated with off-channel habitats as purported under contemporary theory (e.g., the ‘flood-pulse concept’)
may not be accrued by catfishes every year in the LMR. 相似文献
995.
Information from four archival literature sources from the late 19th century was matched to present-day plant species distribution data for the region of Turnhout (Belgium) and for 15 smaller sub-regions within this region. In the entire study area 25% of the species recorded in the late 19th century went extinct during the 20th century and the extinction rate doubled at the more detailed sub-region level. Binary survival-extinction data and continuous residuals from a linear regression between historical and present-day abundance categories were used to investigate underlying ecological factors of change including habitat preference, ecological amplitude and life strategy. Species increasing relative to the overall trend were generally correlated with nutrient-rich habitats while declining species were more associated with nutrient-poor situations. Generalist species have become relatively more common whilst habitat specialists have strongly declined, resulting in a flora with many ‘losers’ and a few tolerant ‘winners’. The winners are often competitive species while the losers are mainly stress-tolerating species and species with combined life strategies (e.g. SC, SR). Correlations between the decline of historically present habitats and extinction rates of related habitat specialist species show clear trends. We suggest the most important factors involved in changes in flora diversity and vegetation composition are habitat loss due to urbanization and habitat deterioration, mainly due to agricultural intensification. 相似文献
996.
FEEDING ECOLOGY OF THE MARINE OTTER (LUTRA FELINA) IN A ROCKY SEASHORE OF THE SOUTH OF CHILE 总被引:1,自引:0,他引:1
Gonzalo Medina-Vogel Claudio Delgado Rodriguez Ricardo E. Alvarez P. Jose Luis Bartheld V. 《Marine Mammal Science》2004,20(1):134-144
The marine otter ( Lutra felina ) lives exclusively along exposed rocky shorelines on the South American Pacific coast from Peru (6°S), to Cape Horn, Chile (56°S), and Isla de los Estados, Argentina. L. felina diet and its relationship to prey availability and energy content was assessed by spraint and prey remains analysis, direct observation, and the use of crab pots and fish traps, at four sites on the Valdivian coast in the south of Chile, between June 1999 and June 2000. Based on spraints analysis, the diet was composed of 25 species; 52% (13/25) of the species identified were crustaceans, 40% (10/25) were fish, and 8% (2/25) were mollusks. Crustaceans were found in 78% of 475 spraints, 100% of 929 prey remains, and 90.8% of prey determined by direct observation, fish in 20% of spraints and 9.0% of prey determined by direct observation, and mollusks in 2% of spraints and 0.2% of prey determined by direct observation. Observed seasonal variation in prey availability was reflected in the otter diet. Fourteen prey species were trapped; 43% (6/14) were crustaceans and 57% (8/14) fish, crustaceans were 93% of 566 trapped individuals, fish 7%. L. felina showed opportunistic feeding behavior, selecting prey seasonally according to their availability rather than to their energy input. 相似文献
997.
998.
Dispersal and population structure of two sympatric species of the mediterranean land snail genus Mastus (Gastropoda, Pulmonata, Enidae) 总被引:1,自引:0,他引:1
A. PARMAKELIS M. MYLONAS 《Biological journal of the Linnean Society. Linnean Society of London》2004,83(1):131-144
We studied the population dynamics of Mastus by investigating the effects of population structure, spatial ecology and biology of reproduction on the genetic diversity of two sympatric Mastus species endemic to the island of Crete. Over a period of 27 months, we carried out both mark–recapture and random quadrat sampling techniques in order to assess the dispersal trends, the aggregation patterns, the neighbourhood size and the habitat preferences of these species. There were 154 recorded movements for M. butoti and 114 for M. cretensis . Mean monthly dispersal was estimated at d = 0.5 m for M. butoti and d = 1 m for M. cretensis . Both species showed a random dispersal pattern but tended to aggregate in the field. Their populations were found to be highly structured owing to their highly parsimonious dispersal behaviour and the very low population densities, estimated at D = 2.07 ± 0.16 and D = 0.73 ± 0.16 individuals m−2 for M. butoti and M. cretensis , respectively. The neighbourhood size did not exceed 150 individuals for either species. The habitat occupied by each species changed during the active season, but both the immature and the adult individuals of each species seemed to prefer the same habitats throughout the active season. Partial population activation during the active season was observed in both species. We conclude that the population structure, the partial population activation and the species-specific reproductive strategies have a profound effect on maintaining the genetic diversity of the genus' populations. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 83 , 131–144. 相似文献
999.
Cindy Lee Van Dover Richard A. Lutz 《Journal of experimental marine biology and ecology》2004,300(1-2):273-307
In situ and laboratory experiments conducted over the past quarter of a century have greatly increased our understanding of the ecology of deep-sea hydrothermal systems. Early experiments suggested that chemosynthetic primary production constituted the principal source of organic matter for biological communities associated with vents, although subsequent studies have revealed many complexities associated with interactions between microbes and higher organisms inhabiting these ecosystems. A diversity of host-microbial symbiont relationships has been identified and experimental studies have revealed the exquisite physiological adaptations within the giant tubeworm, Riftia pachyptila, for the uptake, fixation, and assimilation of carbon. In vitro experiments demonstrated the unusual sulfide binding properties of tubeworm hemoglobin that prevent inhibition of the cytochrome-c oxidase enzyme system during transport of sulfide to symbiont-bearing tissues. Studies of respiration and growth of several species of vent organisms conducted over the past two decades transformed earlier views that low metabolism and slow growth are characteristics of all organisms inhabiting all deep-sea environments. Results of recent experiments suggest that metabolic rates correlate with the degree of mobility of the organisms rather than with any specific attribute of the deep-sea environment itself, and growth rates of certain vent organisms (e.g., R. pachyptila) were found to be among the highest in any marine environments. While extreme thermal tolerance has been suggested as characteristic of certain vent fauna (e.g., alvinellid polychaetes and alvinocarid shrimp), the majority of vent metazoans live at temperatures below 20 °C and additional experiments are necessary to reconcile field experiments documenting thermal tolerance in situ, thermal tolerance in vivo, and thermal sensitivity of biochemical constituents of vent organisms. Transplantation and clearance experiments, as well as in situ characterization of vent fluid chemistry, have greatly increased our understanding of organism–environment interactions. Early analyses of metazoan egg size and larval morphology, coupled with in vivo larval culture experiments, available physical oceanographic data, and genetic studies of gene flow, have contributed greatly to our understanding of mechanisms of dispersal between widely separated vent sites. The documentation of invertebrate colonization and succession of new vents following a volcanic eruption, and a series of manipulative field experiments, provide considerable insights into the relative roles of abiotic conditions and biotic interactions in structuring vent communities. Recent and emerging technological developments, such as in situ chemical analyzers, observatory approaches, and laboratory-based pressure culture systems, should provide invaluable new experimental tools for tackling many remaining questions concerning the ecology of deep-sea hydrothermal systems. 相似文献
1000.
Impact of fiddler crab foraging and tidal inundation on an intertidal sandflat: season-dependent effects in one tidal cycle 总被引:1,自引:0,他引:1
K.A. Reinsel 《Journal of experimental marine biology and ecology》2004,313(1):1-17
Intertidal sandflats inhabited by fiddler crabs are ideal systems in which to study the effects of physical and biological processes. This study addressed two questions: (1) Do fiddler crab feeding and tidal inundation have measurable effects on the sandflat over one tidal cycle? (2) Does the sandflat change over the course of a year? In field exclusion/inclusion experiments, fiddler crabs reduced sediment organic content by 40%, Chlorophyll a levels by 20% and meiofaunal density by 60% in one tidal cycle. Effects were most pronounced in the spring when organic content and meiofaunal densities were maximal. Effects of foraging were not erased by the tide and accumulated over time. The sandflat had highest levels of all variables in spring and minimal levels during summer and fall. Crabs graze the sandflat to minimum levels in the spring. Due to crab foraging, the flat is barren during the summer and fall, and recovers during the winter when crabs are minimally active. 相似文献