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1.
A quintessential urban estuary is the lower Passaic River in northeastern New Jersey, USA. This system is environmentally degraded and its ecosystem is functionally limited. Birds in this river are of particular interest for ecological assessment and environmental management because they are conspicuous, ecologically important, and their habitat requirements encompass the full range of ecosystems associated with the estuary. In this article, we present the results of a 1-year seasonal bird survey of the lower 6 miles of the Passaic River. We contrast our survey results with those from other waterways in the region that have stressor issues similar to the Passaic (i.e., contaminants, pathogens, physical disturbance, etc.), but which have substantially more wetlands habitat available for birds (i.e., fewer habitat constraints). Our objective was to evaluate the influence of habitat availability or constraints on bird use in such systems. The results of our survey and comparison to conditions of other regional waterways demonstrate that the lack of wetland and associated shoreline habitat in the lower Passaic River is likely the primary constraint on bird use of the system. Future investigations of individual stressors in this region should identify the habitat constraints in the decision matrix for judging management options.  相似文献   

2.
I analyzed temporal variation in hybridization between the southwestern toad (Bufo microscaphus) and Woodhouse's toad (Bufo woodhousii) along the Virgin River in southwestern Utah and northwestern Arizona. Bufo woodhousii is largely restricted to the floodplain of the Virgin River from southern Nevada to the vicinity of St. George, Utah. By contrast, B. microscaphus is confined primarily to the tributaries of the Virgin River, only occupying the Virgin River proper exclusive of B. woodhousii along its upper reaches east of La Verkin Creek. As in all other zones of sympatry for these bufonids, behavior and morphology provide clear evidence of hybridization at a number of sites along the Virgin River. Analysis of morphology and behavior indicates that the distribution of these taxa and their hybrids is largely unchanged relative to that documented forty years ago by Blair (1955). Comparisons of morphological hybrid index scores reveal slight shifts in relative numbers of parental taxa at only one site. Hybridization between these anurans has been relatively stable geographically, and may be related to the nature of the riparian habitat available for breeding.  相似文献   

3.
T. E. Weaks 《Hydrobiologia》1982,97(2):97-103
Phytoplankton was sampled from the lower 60 miles portion of the Guyandotte River where three active coal dredging operations presently exist and five more permits are pending. Comparisons were made with phytoplankton from a similar stretch of the Mud River, a stream of minimal mine drainage and no coal dredges along its entire course.Diatoms were the predominant planktonic algae on both streams. The number of all phytoplankton species was 24% higher for the Mud River than for the Guyandotte River. Equitability and species diversity indices plus the distribution of mine water indicator algae show that the Guyandotte River is heavily polluted with domestic wastes and mine drainage. No correlation could be established for turbidity, specific conductance, or pH and locations of dredging operations, when the data were analyzed for differences among sampling stations.Step-wise discriminant analysis was used to compare the two streams and the biological, physical, and chemical variables. Based on coefficients for canonical variables, conductivity and pH are the two most influential variables in separating the two streams. Analysis of variance indicates that the canonical means of the stations on the Guyandotte River are significantly different from the Mud River stations.  相似文献   

4.
《Behavioural processes》1997,39(3):291-294
Two young White Storks were tracked by satellite during a part of their first migratory journey from the nest colony (settled in Piedmont, NW Italy) to the wintering ground in Western Africa. Both birds left westward, but only one of the two birds provided reliable data which allowed the reconstruction of its migratory route along the coasts of France and Spain up to Morocco. A new aspect of the journey is that the bird did not pass from Europe to Africa at Gibraltar, the storks' known western route. Despite the storks' tendency to avoid flying over large stretches of sea, the tracked bird crossed the Alboran sea from De Gata Cape (Spain) to Tres Forcas Cape (Morocco), thus flying about 120 km over the open sea.  相似文献   

5.
《Annales de Paléontologie》2017,103(2):141-147
A small bird with a shorebird-like beak and a very long hind toe is described from the Early Eocene of Messel in Germany. Vanolimicola longihallucis, gen. et sp. nov. is one of the few candidate species for a “wading bird” from Messel, that is, a bird that may have foraged along the shoreline of the ancient lake. A few features indicate a relationship to charadriiform birds and Jacanidae (jacanas) in particular, but charadriiform affinities are only weakly supported. In the preserved skeletal elements, V. longihallucis also resembles the taxon Songzia from the Early Eocene of China, which is considered to be a representative of the Ralloidea (rails and allies). A potential biogeographic significance of the new Messel fossil is strengthened by similar fossils from the North American Green River Formation.  相似文献   

6.
《Plains anthropologist》2013,58(50):1-45
Abstract

The Glenrock Buffalo Jump, 48C0304 is part of a Late Prehistoric period buffalo procurement complex in central Wyoming along the south side of the North Platte River. Operation of the jump required controlled movements of buffalo herds for as far as one to three miles before they were finally stampeded over a bluff 40 feet high. The effective width of the bluff was small and as a result the herd had to be under control during the final stampede as well as the initial drive.

Good bone preservation in much of the site allowed recovery of large samples for analysis and in addition large numbers of simple but functional tools were found in context. Marks that reflected a number of butchering operations appeared repeatedly suggesting stylized methods, and from this a model of Late Prehistoric butchering is postulated which needs further testing in other mass butchering contexts.  相似文献   

7.
In 2009, a group of practitioners took action to restore 175 miles of riparian habitat impaired by invasive plants along the Dolores River in southwestern Colorado and eastern Utah. Recognizing the magnitude of ecological, jurisdictional, and management challenges associated with this large‐scale initiative, this group of managers built trust and relationships with key partners to foster collaboration across boundaries and cultivate consensus of a variety of perspectives and forms of knowledge. What emerged was a network of individuals, organizations, and agencies dedicated to restoring the Dolores River riparian corridor while sharing information and learning from one another. This public–private collaboration, called the Dolores River Restoration Partnership (DRRP), has been successful in creating a process by which financial, technical, and human resources are shared across boundaries to restore a riparian corridor. Specifically, the DRRP developed effective planning documents, a responsive governance structure, monitoring protocols, and a shared mindset for extracting lessons learned that have been instrumental in making progress toward its shared restoration goals and addressing a wide variety of restoration challenges. The tools developed by the partnership and lessons learned from their utility are outlined in this case study as a means to inform other collaborative restoration efforts.  相似文献   

8.
Molecular tools are reshaping many traditional paradigms concerning the timeframe of avian diversification in North America. Phylogeographic studies have become essential for guiding the emerging paradigms. However, the current pool of such studies tends not to be evenly dispersed across the landscape, which limits the generality of inferences. The southeastern United States is one region where the tempo and mode of recent avian diversification is poorly understood. One phylogeographic break in particular, the Tombigbee River discontinuity, divides eastern and western phylogroups in Alabama, and, though it is known to have influenced the phylogeographic patterns of some fish and reptiles, its role in promoting recent avian diversification is not well understood. Eastern and western morphological subspecies of the yellow-throated warbler Dendroica dominica divide along the phylogeographic break created by the Tombigbee River discontinuity suggesting that this bird was also affected by this vicariance. To determine whether the phylogeographic patterns of the yellow-throated warbler are consistent with this biogeographic barrier, I analyzed mitochondrial control region sequences of 109 yellow-throated warblers from across the species' range and, from a subset of these samples, sequences from a sex-linked nuclear gene. Considerable variation was uncovered, but most of this variation was found within rather than among populations or subspecies. A shallow phylogenetic tree, star-like haplotype network, and unimodal mismatch distribution all suggested a recent expansion. Coalescent modeling indicated that modern populations are derived from a single common ancestral population and that differences among subspecies in morphology, ecology, and migratory pathways are the result of recent and rapid evolution, possibly driven by selection.  相似文献   

9.
Most large rivers in Sweden are regulated to produce hydropower. This transformation from free-flowing rivers to chains of elongate run-of-river impoundments has been shown to have consequences for aquatic, riparian and adjacent upland environments, and for the emergence patterns of aquatic insects that are important for terrestrial consumers. In this study, we investigated bird assemblages in upland-forest environments along seven large rivers (three heavily impounded and four free flowing) in northern Sweden. Bird densities were assessed by point counts in the breeding and post-breeding seasons. While we observed no significant differences in bird species richness between regulated and free-flowing rivers, cumulative densities of two feeding groups of birds (those feeding on seeds and/or large insects and those feeding on small insects) were higher along free-flowing rivers than along regulated rivers in the breeding season, consistent with known differences in aquatic-insect emergence. Further, ordination analyses showed seasonal shifts in bird assemblage structure, and that these shifts differed between regulated and free-flowing rivers and between the two feeding groups. However, the variables explaining the most variance (11?C28?%) in bird assemblage structure were related to a gradient of agricultural-to-forest land use. River regulation contributed to the model in the post-breeding season, but was of relatively low importance. Nevertheless, the observed contrasting seasonal shifts in upland-forest bird assemblage structure between regulated and free-flowing rivers suggest that regulation-induced modifications of aquatic-insect emergence and subsequent changes in prey availability to the birds are also important considerations.  相似文献   

10.
Aim To evaluate the relative effectiveness of the lower and upper sections, respectively, of the Amazon River as a barrier to bird distribution, and to evaluate ecological and taxonomic factors affecting the efficacy of the river barrier. Location Amazon River of South America between its confluence with the Napo River in the west and its delta in the east. Methods Using published distribution maps for 448 species of passerine birds occurring along the Amazon River, we evaluated whether each was distributed along one bank only (river presumed to be a barrier) or both banks (no barrier) to test the predictions that the river was more effective as a dispersal barrier: (1) along the lower, wider portion of the river than the upper, narrower portion; (2) for species inhabiting forests than open country; (3) for species inhabiting forest understorey than forest canopy; (4) for species restricted to terra firme (never inundated upland forest) than those not restricted to terra firme and (5) for certain taxonomic groups. Results Our analyses demonstrated that the Amazon River was most effective as a dispersal barrier along its lower portion and for species restricted to forests and terra firme. However, the river was not significantly more of a barrier for species inhabiting forest understorey than forest canopy. The river was most significant as a barrier to dispersal for the antbirds (Thamnophilidae) and was less significant as a barrier to species belonging to several large families including woodcreepers (Dendrocolaptidae), ovenbirds (Furnariidae), flycatchers (Tyrannidae), cotingids (Cotingidae), tanagers (Thraupidae), seed‐eating finches (Emberizidae) and blackbirds (Icteridae). Main conclusions The robust widths of Amazonian rivers are widely considered to represent impediments to dispersal and gene flow for many taxa of birds and other animals, and may have represented agents of vicariance in the diversification of species. Our study reaffirms the effectiveness of the lower Amazon River as a current barrier to bird dispersal for forest birds and provides new insights into the effects of habitat and taxonomy on the efficacy of the river barrier. Although supportive of several predictions of the river hypothesis of biological diversification, our study is limited in addressing the historical impact of river barriers as agents of vicariance in the process of diversification.  相似文献   

11.
Like many other southern African rivers, the avifaunal richness and abundance of the Orange River, southern Africa's longest, remains virtually unknown. Given that the Orange River runs through hyper-arid regions in its lower reaches, its linear oasis effect and its role as a reservoir for Red Data bird species is likely but has not been quantified. Two surveys either side of the border town of Noordoewer, in the rainy and dry seasons of 1996 and 1997 deter-mined that species richness was higher in riverine habitat (71 species) than in the surrounding Nama Karoo (46 species) confirming the linear oasis effect. Surveys revealed five Namibian Red Data species. Peregrine Falcons, Falco peregrinus, and African Fish Eagles, Haliaeetus vocifer, were relatively common while the endangered Cape Eagle Owl, Bubo capensis, occurred sporadically. Among wetland Red Data bird species, Black Storks, Ciconia nigra, occurred in less disturbed areas, and White-backed Night Herons, Gorsachius leuconotus, were an unexpected species at this locality. The overall species richness of 103 birds and a density of riparian birds of 31 -3 4 birds/10 km, makes the lower Orange River avifauna similar to the Cunene River but tenfold less abundant than Namibia's other perennial rivers. Despite the low diversity, the arid habitats of the lower Orange River support greater diversity than more easterly regions when all current surveys of richness and abundance from Lesotho to the mouth on the Namib coast are combined. This east-west trend may be explained by the slower flow and warmer water of the lower Orange River but natural turbidity and regulation may explain the generally low diversity and abundance indices. Major rivers in southern Africa appear to have been over-looked as wetland habitats, and further avifaunal surveys of all of them are recommended.  相似文献   

12.
《Ibis》1939,81(4):643-654
A fter I had finished my work in the Department of Huancavelica, in January 1938, I made a lengthy stay on Lake Junin. This lake is the source of the Mantaro River, and lies about 50 miles north of Oroya, at an altitude of a little less than 14,000 feet. It is situated in a great plain, ringed by rather low rolling brown hills. It is, of course, in typical Puna zone.  相似文献   

13.
近代云南鸟类学简史   总被引:2,自引:0,他引:2  
魏天昊 《动物学研究》1989,10(2):163-168
云南省独特的地理位置、复杂的自然环境、丰富的生物资源,及其区系组成和物种分化的特异性,早就吸引着中外学者。鸦片战争以后,西方学者纷至沓来,而国内学者的研究则主要是新中国成立以后才发展起来的。六十年代以前,进行了大量的野外区系普查,七十年代起开始转为对标本、资料的整理,同时,生态等其他领域也有了新的开端。近代云南鸟类学的发展,从时间上可划分为三个阶段,从内容上又可分若干方面。  相似文献   

14.
Biocontrol of invasive tamarisk (Tamarix spp.) in the arid Southwest using the introduced tamarisk beetle (Diorhabda elongata) has been hypothesized to negatively affect some breeding bird species, but no studies to date have documented the effects of beetle-induced defoliation on riparian bird abundance. We assessed the effects of tamarisk defoliation by monitoring defoliation rates, changes in vegetation composition, and changes in density of six obligate riparian breeding bird species at two sites along the Dolores River in Colorado following the arrival of tamarisk beetles. We conducted bird point counts from 2010 to 2014 and modeled bird density as a function of native vegetation density and extent of defoliation using hierarchical distance sampling. Maximum annual defoliation decreased throughout the study period, peaking at 32–37% in 2009–2010 and dropping to 0.5–15% from 2011–2014. Stem density of both tamarisk and native plants declined throughout the study period until 2014. Density of all bird species declined throughout most of the study, with Song Sparrow disappearing from the study sites after 2011. Blue Grosbeak, Yellow-breasted Chat, and Yellow Warbler densities were negatively related to defoliation in the previous year, while Lazuli Bunting exhibited a positive relationship with defoliation. These findings corroborate earlier predictions of species expected to be sensitive to defoliation as a result of nest site selection. Tamarisk defoliation thus had short-term negative impacts on riparian bird species; active restoration may be needed to encourage the regrowth of native riparian vegetation, which in the longer-term may result in increased riparian bird density.  相似文献   

15.
《Ibis》1897,39(4):564-574
A mongst the Waders, a class of birds I have had unusual opportunities of watching for many years along the shores of Kingsbridge Estuary, South Devon, the Bar-tailed Godwits have always been a great attraction. The striking change of plumage from winter to summer, their erratic appearance at the times of migration, and the desire to raise this group above the level of that hen-pecked one of Phalaropes, to which they have been likened in their habits of courtship and nidification, have induced me to follow the Godwit in his coming in and going out ever since I could tell one bird from another.  相似文献   

16.
Gösta Montell 《Ethnos》2013,78(1-4):5-6
There are major contextural differences between the two bird forms carved on the pillars of the Acosta reconstruction of the Quetzalpapalotl courtyard. The frontal bird on the west side and its distinctive border decorations suggest differences of meaning from the profile bird representation which occupies the remaining three sides. Séjourné's argument that the carvings represent two views of the same bird is refuted in the light of careful visual comparisons of the forms and ornithological examination. Other iconographic research on bird meaning in the context of Teotihuacán culture is discussed followed by an interpretation of the meaning of the two bird images.  相似文献   

17.
鄱阳湖流域非繁殖期鸟类多样性   总被引:7,自引:1,他引:7  
2010年11月-2011年3月,采用样线和样点法相结合,对鄱阳湖流域非繁殖期鸟类种类及数量进行了调查.共记录鸟类13目36科106种.其中,国家Ⅰ级重点保护鸟类1种,国家Ⅱ级重点保护鸟类10种.居留型方面,留鸟和冬候鸟最多,分别占鸟类物种总数的56.60%和35.85%.鸟类区系上,古北界种类最多,占41.51%;其次是东洋界鸟类,占32.08%.鸟类物种数1月份和3月份最多,多样性和均匀度指数均以12月份和3月份最高,以11月份和2月份最低.欧氏距离显示,修水段、龙虎山段和靖安段与其他河段的鸟类组成差异较大.宜黄段、耳口段和浮梁段的鸟类组成比较相近.研究结果表明,鸟类的相似度与各河段间隔的距离无关,而可能与当地的生境密切相关.鄱阳湖流域分布着一些濒危鸟类,然而人类活动如采砂、非法捕鱼等严重影响了这些鸟类的生存环境.因此建议降低人类活动强度,维持鄱阳湖流域鸟类多样性.  相似文献   

18.
1997-1999年对豫北黄河故道湿地鸟类自然保护区的鸟类进行了调查,共记录鸟类119种,隶属16目37科,其中留鸟32种,占总数的26.89%,冬候鸟24种,占总数的20.17%,夏候鸟30种,占总数的25.21%,旅鸟占33种,占总数的27.73%,国家一级重点保护鸟类2种,二级重点保护鸟类19种,河南省重点保护的鸟类6种。  相似文献   

19.
The route of the zoological subunit of the Yakut complex expedition of the USSR Academy of Sciences for the study of the productive resources of the Yakut ASSR in 1925 is described. The expedition, including researchers from the Zoological Institute of the USSR Academy of Sciences L.V. Bianchi (head) and A.I. Ivanov, collected insects in the Lena-Amga interfluve. First, they explored the right bank of the Lena River from Bestyakh Station to Kachikattsy Village, then crossed the Lena-Amga interfluve through the Menda and Tengyutte river basins, then rafted down the Amga River from the Tengyutte River mouth to Amga Village, and returned to Bestyakh Station by the Amga-Yakutsk road. Geographic coordinates of the collection localities and camping places along the entire expedition route are given for the first time; many of the visited localities are not marked in the modern maps.  相似文献   

20.
C. S. Barlow 《Ostrich》2013,84(1):5-9
Skead, D. M. 1974. Roadside counts of Blackshouldered Kites in the central Transvaal. Ostrich 45: 5–8.

From August 1967 to November 1970 roadside counts of Blackshouldered Kites Elanus caeruleus were made along the Great North Road from the Pienaar's River Irrigation Settlement, near Hammanskraal, to Warmbaths, Transvaal. The mean density for this period was 10 km per bird. Counts were also made along the same route, but for a shorter distance to the farm Vaalbosch. The mean density for this route was 17 km per bird. Relative density was higher than in the Cape Province.  相似文献   

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