971 resultados para Pachycondyla striata nest


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Mode of access: Internet.

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Mode of access: Internet.

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Purchased from Gilman, Crompond, N. Y.

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Mode of access: Internet.

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The leatherback turtle Dermochelys coriacea is considered to be at serious risk of global extinction, despite ongoing conservation efforts. Intensive long-term monitoring of a leatherback nesting population on Sandy Point (St. Croix, US Virgin Islands) offers a unique opportunity to quantify basic population parameters and evaluate effectiveness of nesting beach conservation practices. We report a significant increase in the number of females nesting annually from ca. 18-30 in the 1980s to 186 in 2001, with a corresponding increase in annual hatchling production from ca. 2000 to over 49,000. We then analyzed resighting data from 1991 to 2001 with an open robust-design capture-mark-recapture model to estimate annual nester survival and adult abundance for this population. The expected annual survival probability was estimated at ca. 0.893 (95% CL 0.87-0.92) and the population was estimated to be increasing ca. 13% pa since the early 1990s. Taken together with DNA fingerprinting that identify mother-daughter relations, our findings suggest that the increase in the size of the nesting population since 1991 was probably due to an aggressive program of beach protection and egg relocation initiated more than 20 years ago. Beach protection and egg relocation provide a simple and effective conservation strategy for this Northern Caribbean nesting population as long as adult survival at sea remains relatively high. (c) 2005 Elsevier Ltd. All rights reserved.

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One of the decisions made by hatchery managers around the world is what degree of shading and nest depth are required to maximise the production of high-quality hatchlings at optimal sex ratios. The primary objectives of this study were to determine the effects of (1) hatchery shading and nest depth on nest temperatures and emergence lag, and (2) nest temperatures and nest depth on hatchling sex ratio and quality. In 2001, 26 Chelonia mydas clutches from Ma'Daerah beach, Terengganu, Malaysia, were relocated alternatively at depths of 50 cm and 75 cm into a 70%-shaded and a 100%-shaded hatchery. Data loggers were placed into the centre of each relocated clutch to record the temperature every hour over the course of incubation. When the hatchlings emerged, a sample of the clutch was run, measured and weighed and a separate sample was examined histologically for sex characteristics. Nest temperatures ranged between 28 degrees C and 30 degrees C and generally showed increases over the second half of incubation due to metabolic heating of the clutch. There was no significant correlation found between nest temperature and any of the hatchling parameters measured. Hatchlings from 75-cm-deep nests had a longer emergence lag (46.4 (+/- 10.2) h) than hatchlings from 50-cm-deep nests. Hatch and emergence success were similar to those of natural populations and hatchling sex ratios were male dominant, with an average of 72% males. There was a poor correlation between mean middle-third incubation temperatures and sex ratio. Hatchlings from 75-cm-deep nests had similar running speeds but lower condition index than their conspecifics from 50-cm-deep nests.

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Sand and nest temperatures were monitored during the 2002-2003 nesting season of the green turtle, Chelonia mydas, at Heron Island, Great Barrier Reef, Australia. Sand temperatures increased from similar to 24 degrees C early in the season to 27-29 degrees C in the middle, before decreasing again. Beach orientation affected sand temperature at nest depth throughout the season; the north facing beach remained 0.7 degrees C warmer than the east, which was 0.9 degrees C warmer than the south, but monitored nest temperatures were similar across all beaches. Sand temperature at 100 cm depth was cooler than at 40 cm early in the season, but this reversed at the end. Nest temperatures increased 2-4 degrees C above sand temperatures during the later half of incubation due to metabolic heating. Hatchling sex ratio inferred from nest temperature profiles indicated a strong female bias.

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This report presents findings from a research project which investigates NEST schemes, how they operate and the experiences of the native English speaker teachers (NESTs) and local English teachers (LETs) taking part. The paper provides useful recommendations for how NESTs and LETs can be best supported to make the most out of their collaborations.

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Fiatal felnőttek nagyarányú jelenléte a szülői háztartásokban nemcsak Magyarországon és Európában jellemző, de a fejlett ipari országokban általánosan megfigyelhető jelenség. Az Európai Unióban élő 18–34 év közötti fiatalok 46%-a él együtt legalább egyik szülőjével, a magyar fiatalok esetében hasonló az arány. A fiatalok kitolódó felnőtté válása azt is jelenti, hogy a szülők egyre későbbi időponttól kezdve rendelkeznek szabadabban idejükkel és anyagi forrásaikkal, a fiatal felnőttek döntései pedig részben szüleik részvételével történik. Jelen cikk arra keresi a választ, hogy a szülői fészekben élő vagy a szüleiktől részben függő fiatalok milyen döntési mintákkal rendelkeznek, illetve vásárlási döntéseikben mennyire önállóak. A kérdés vizsgálatát a szülői háztól függő egyetemista fiatalok körében végzett kérdőíves megkérdezés segítségével a szerzők elemezték, és arra is lehetőségük volt, hogy a családtagok által írt rövid esszék segítségével a kérdést több oldalról vizsgálják meg. Eredményeik szerint a szülői háztól függő fiatal felnőttek önálló döntésre képes, sok esetben szakértő fogyasztók, döntéseik önállóságát azonban a termékkategória, a családdal való kapcsolattartás gyakorisága, a családforma és a nemi szerepek is befolyásolják. ____ High ratio of adult children is still living in their parents’ home. This is a significant phenomenon that can be observed in Hungary and throughout Europe, while influences living trends globally. In the EU, 46% of youth between 18-34 years live with at least one of their parents and this same statistic holds true in the case of Hungary. This postponement of adulthood allows parents to enjoy more free time and have higher disposable income from later in life. The young adults, however, in the household make their consumer decisions under parental control. The purpose of this study is to explore the decisionmaking styles of young adults and their independence from their parents in shopping-related decision-making through a literature review and primary study. The survey focused on university students who are dependent on their parental home and short essays were also collected from family members of the target group in order to gain a more complex view on this phenomenon. According to the results the following conclusion can be made: young adults living in their parents’ home are competent consumers with individual decisions, in addition, they are consumer experts within the family in many cases. However, their independent shopping-related decision-making is influenced by product category, frequency of connection to the family home, family form and also sex role orientations.

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Funding. This work was supported by the Centre National de la Recherche Scientifique (PICS France-Switzerland to BD), the Ministe`re de l’Enseignement Supe´rieur et de la Recherche (PhD fellowship to CR), the University of Aberdeen (stipend to CR), the Uppsala Universitet (stipend to GD), the Universite´ de Lausanne (grant to JT), the Re´gion Rhoˆne-Alpes (Programme Cible PhD fellowship to GD and Explora’doc mobility grants to CR and GD), the L’Ore´al Foundation-UNESCO ‘For Women in Science’ programme (fellowship to CR), the Rectors’ Conference of the Swiss Universities and the Fondation pour l’Universite´ de Lausanne (grants to CR).

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Grasslands are often grazed by cattle and many grassland birds nest on the ground, potentially exposing nests to trampling. We tested for trampling risk introduced by cattle to nests of endangered Florida Grasshopper Sparrows (Ammodramus savannarum floridanus) using experimentally paired grids of artificial nests (i.e., clay targets) similar in size to nests of Florida Grasshopper Sparrows and counted the number of clay targets that were broken in paired grazed and ungrazed enclosures. Clay targets in grazed grids were trampled 3.9% more often than their respective ungrazed grids, and measurements of cattle presence or density were correlated with the number of broken clay targets, suggesting that excluding cattle during breeding is an important management recommendation for the Florida Grasshopper Sparrow. Trampling rates within grazed enclosures were spatially homogeneous with respect to cattle infrastructure such as supplemental feeding troughs and fences, and forests and stocking density were poor predictors of trampling rates when excluding ungrazed grids. We used population viability analysis to compare quasi-extinction rates, intrinsic growth rates, and median abundance in grazed and ungrazed Florida Grasshopper Sparrow aggregations to further understand the biological significance of management aimed at reducing trampling rates during the breeding season. Simulations indicated that trampling from grazing increased quasi-extinction rates by 41% while reducing intrinsic growth rates by 0.048, and reducing median abundance by an average of 214 singing males after 50 years. Management should avoid grazing enclosures occupied by Florida Grasshopper Sparrows during the nesting season to minimize trampling rates. Our methods that combine trampling experiments with population viability analysis provide a framework for testing effects from trampling on other grassland ground-nesting birds, and can directly inform conservation and management of the Florida Grasshopper Sparrow.