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ImODUonONGnyheron(Ardeacinerea)isabodofgnatbirdoftenseeninthenortheastmarshareaofP.KChinaIthasaPParenquanhtahveadVan-tageofgreatwatthewlsinZhalongNahonalN~ReserVe(l2359'-l2440'E,464O-4720N).Annually,thegreyheronAngratesfromsouthinMarch,andnestSfromMarch2OtoAPril20,reP~sfromAPriltoMay20,andfliestothesouthinthendddieofAUgUSt.Dur-ingreP~hon,thegreyheronoftennestSinthesameplaeewithpUrpleheron(ArdeaPUmprea),whites~bill(Phaasalleucorode)etC...Atsomeextet,thereareafeWhundredsofnest… 相似文献
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2000-2012年间在设置人工巢箱条件下,对内蒙古甘河林业局的黄眉柳莺繁殖生态进行了研究,收集了窝卵数、占巢率及对落叶松鞘蛾的防治效果等。统计分析表明：黄眉柳莺每年5月初返迁占巢,5月下旬产卵,窝卵数5-8枚,卵淡白色,具赤青色斑纹,且钝端密集。卵长径（14.75±0.56）mm,短径（11.78±0.59）mm。育雏期15-18 d,锥鸟存活率93.98%,建立了占巢率与落叶松鞘蛾虫口密度间、占巢率与窝卵数之间的一元关系式,黄眉柳莺人工巢箱防治区平均防治效果达到48.95%。 相似文献
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Evangelia Kornaraki Antonios D. Mazaris Yiannis G. Matsinos 《Biological conservation》2006,130(3):324-330
In this paper, we evaluate the effectiveness of different well-tested conservation techniques in an effort to successfully protect sea turtle nests. From an eight-year study on the island of Zakynthos, West Greece, we have experimentally investigated the effectiveness of two different conservation techniques applied to loggerhead sea turtle nests and provided statistical measures to evaluate their conservation value. The categories of nests evaluated include: (i) nests incubated in situ, (ii) translocated into a beach hatchery, or (iii) protected by metal cages. Results of the analysis showed significant interannual variations in hatching success as obtained for each one of the three groups of nests. Significant differences were also observed when comparing hatching success data among the three groups of nests during the eight-year period. Overall, our results indicate that relocation of nests laid at highly threatened locations and the placement of protective cages on nests in situ provide adequate conservation measures that could allow an increase in hatchling production; although their choice and application should be based on the specific conditions and threats of each nest. 相似文献
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Tim S. Jessop Joanna Sumner Deni Purwandana John A. Phillips 《Biological conservation》2004,117(5):463-470
We report the abundance, patterns of distribution and physical characteristics of Komodo dragon (Varanus komodoensis) nests on Komodo Island in Indonesia. A total of 46 Komodo dragon nesting sites were identified, of these 26 nests were considered active for the 2002/2003 season. The distribution of nests coincided with large coastal valleys in northern Komodo Island. There was a significant preference by breeding females to utilize the mound nests (61%) over both open hillside (19.5%) and ground nests (19.5%). Further, within these mound nests, females discriminated for nests based on habitat characteristics, especially sunlight exposure. The main implications for management and conservation drawn from this study is that there is a small number of females nesting annually on the largest island within Komodo National Park. Further, continuation of nesting surveys could provide a cost effective accurate way to gather important long term demographic information on this species. 相似文献
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Until the 1980s, at least 31 pairs of long-legged buzzards (Buteo rufinus) nested along the streams of the Judean Mountains in Israel, mostly on rocky cliffs, which – according to existing literature – is the common nesting style of this bird. During the past 40 years, however, nesting in these areas has substantially decreased, with many pairs of buzzards now nesting on trees in the Judean Foothills.We suggest that the geographical shift in nesting area, and with it the dramatic change from nesting on cliffs to nesting on trees, is probably due to the increase in land cover (as a result of afforestation, expansion of human settlements and recovery of the Mediterranean chaparral) that has taken place in the Judean Mountains during the last four decades. Buzzards forage in open habitats and the change in land cover has hindered their ability to locate prey. Since there are no cliffs appropriate for nesting in the Judean Foothills, the buzzards were thus forced to adapt to a new style of nesting. This hypothesis is further supported by our observations that within their new nesting grounds in the Judean Foothills, breeding success was significantly related to the area of the open habitat within the territory.These findings have important scientific and ecological implications. We recommend that foresters should take into consideration the effect of afforestation on open-landscape raptors, and while planning new forests will consider also their needs, particularly leaving large open swaths of land as foraging grounds for such raptors. 相似文献
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扎龙保护区苍鹭营巢最适生境选择模型 总被引：4，自引：1，他引：3
本文建立了扎龙国家自然保护区苍鹭营巢的最适生境选择指数模型。通过对影响苍鹭营巢的主要生境因子水源、植被种类、植被密度和植被高度等进行调查分析，分别建立了相应的选择指数，为苍鹭营巢的生境质量评价提供了一种建模思想。 相似文献
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Although nesting beaches are critical resources for sea turtles, most beaches in the United States are disturbed by human influence, including human access, artificial lighting, and habitat alteration. In contrast, very few undisturbed beaches remain along the Atlantic coast, and these areas represent unique habitats that can help decipher the impacts of development on various species. We monitored nesting patterns and hatching success of three sea turtle species (Caretta caretta, Chelonia mydas, and Dermochelys coriacea) from 1985 to 2003 on Canaveral National Seashore, an uninhabited 38.3 km stretch of beach in Florida. We monitored the number of nests deposited annually, hatching success, predation rates, and spatial nesting patterns. Clutch sizes varied within, but not among years, most likely due to variation in size of nesting females rather than climate change or resource availability. The number of nests increased over the study period for all three species, indicating growing populations. Higher numbers of nests were deposited on the southern end of our beach than on the northern end. Hatching success did not vary by species, but was dependent on nest-protection effort, which increased during the study period. Protecting more nests with wire screens resulted in lower predation rates. We did not find any evidence suggesting that predators are using nest markers to locate eggs, even after using the same method of marking nests for 19 years. Our conservation efforts have lowered predation levels through increased screening effort, and over time the number of nests laid increased for each species. Collecting baseline data on nesting patterns in undisturbed locations will allow comparisons to be made on nesting trends and patterns at geographically close, but disturbed, localities. 相似文献
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Three-dimensional modeling was performed in Tongyeong, South Korea to identify a space suitable for Yesso scallop farming that may not be successful if seawater temperature remains above 22 °C. In the research area, an underwater basin was found at a depth of 70 m; the depth outside the basin was not deeper than 30 m. It was expected that the water temperature in the interior of the basin might be low enough for farming during summer. The present study was then designed to investigate the temperature distribution in this basin area to verify if a water layer with consistently low temperature existed below the surface layer, using a MOHID (MOdelo HIDrodinámico) three-dimensional numerical model. The model applied mixed vertical coordinates so that the difficulties in modeling near the basin, where water depth sharply changes, could be overcome. In addition, a multi-level nesting system was developed based on the 72 -h forecasting system of the sea status around South Korea, which increased the modeling accuracy using updated boundary conditions. The model was validated by the measured tide and temperature data. The results showed that a strong thermocline was formed at depth of 15 m and a sub-surface space existed at depths deeper than 30 m, where seawater temperature was lower than 22 °C even in summer, which indicates the possibility of successful farming in the research area. The measurements also supported this result because dissolved oxygen and chlorophyll-a were not scarce in the sub-surface space probably due to the strong tidal mixing that could bring the surface seawater properties down below the thermocline. It was also found that the model was effective in resolving the thin thermocline and the sub-surface space below it due to the mixed vertical coordinate system. 相似文献