526 resultados para seaside sparrow


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Marine spatial planning (MSP) is advocated as a means of managing human uses of the sea in a manner that is consistent with the maintenance of the ecological goods and services of the marine environment. Support for the process is evident at international and national levels but the degree to which it is acceptable to local level stakeholders is not clear. An Daingean (formely Dingle) is a small sea-oriented town situated on the southwest coast of Ireland in which marine-based tourism and other relatively new uses of the sea are pursued along side traditional fishing activities. Stakeholders in An Daingean are found to be positively disposed to a local process of MSP that incorporates meaningful local involvement.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Indenture between Robert Sparrow Delatre of Stamford Township, Thomas Sheppard Smyth of Brussels, Belgium, formerly of Stamford Township and Thomas Hector of Quebec, trustees of the last will and testament of Philip Chesneau Delatre to the Bank of Upper Canada and Arthur Shaw of Niagara Township regarding Lot no. 3 in the 1st Concession and Lot no. 4 in the 1st Concession, part of Lot no. 3 in the 2nd Concession, 50 acres of Lot no. 4 in the 4th Concession, 200 acres in Lot no. 8 in the 11th Concession in Blandford in the County of Oxford and broken Lot no. 11 in the 18th Concession in the Township of Zorra - instrument no. 6083. This is listed in the Blandford folio 184 and 185 in folio 63 and 64. Joseph Woodruff has signed this as conveyancer, March 29, 1853.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Varias historietas de humor absurdo sobre situaciones en la playa. Una chica toma el sol tranquilamente a la orilla del mar en una silla y detrás de ella tiene un amenazador oso pardo. Unos niños hacen en la playa unos enormes castillos de arena utilizando una pala excavadora.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Salt marshes constitute habitat islands for many endemic animal species, particularly along the California coast, where urban sprawl has fragmented this habitat. Recreational activities in salt marshes have increased recently, posing an interesting problem: how do endemic species lacking alternative habitat modify their tolerance to humans? We assessed seasonal and site variations in three tolerance parameters (distances at which animals became alert, fled, and moved after fleeing) of California's endangered Belding’s Savannah Sparrow ((Passerculus sandwichensis beldingi). We approached individuals on trails in three salt marshes with different levels of vehicle and pedestrian traffic. Belding’s Savannah Sparrows became aware and fled at shorter distances in the salt marsh coincident with greater levels of recreational activity as a result of habituation or visual obstruction effects. Seasonal effects in tolerance varied between sites. Alert and flight initiation distances were higher in the pre-nesting than in the non-breeding season in the site with the highest levels of recreational use likely due to greater exposure of breeding individuals; however, the opposite seasonal trend was found in each of the two sites with relatively lower human use, probably because individuals were less spatially attached in the non-breeding season when they foraged in aggregations. Distance fled was greater in the non-breeding than in the breeding season. Our findings call for dynamic management of recreational activities in different salt marshes depending on the degree of exposure to humans and seasonal variations in tolerance. We recommend a minimum approaching distance of 63 m and buffer areas of 1.3 ha around Belding's Savannah Sparrows.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Bachman’s Sparrow (Peucaea aestivalis), an endemic North American passerine, requires frequent (≤ 3 yr) prescribed fires to maintain preferred habitat conditions. Prescribed fires that coincide with the sparrow’s nesting season are increasingly used to manage sparrow habitat, but concerns exist regarding the effects that nesting-season fires may pose to this understory-dwelling species. Previous studies suggested that threats posed by fires might be lessened by reducing the extent of prescribed fires, thereby providing unburned areas close to the areas where fires eliminate ground-cover vegetation. To assess this hypothesis, we monitored color-marked male Bachman’s Sparrows on 2 sites where the extent of nesting-season fires differed 5-fold (> 70 ha vs. < 15 ha). Monthly survival for males did not differ between the large- and small-extent treatments, and survival rates exceeded 90% for all months except one during the second year of our study when fires were applied later in the season. Male densities also did not differ between treatments, but treatment-by-year interactions pointed to effects relating to the specific time that fires were applied. The distances separating observations of marked males before and after burns were smaller on small-extent treatments in the first year of study but larger on the small-extent treatments in the second year of study. Burn extents also had no consistent effect on postburn reproductive status. The largest extent we examined could have been too small to affect sparrow populations, but responses may also reflect sustainable metapopulation dynamics in a setting where a large sparrow population is maintained at a regional scale (> 100,000 ha) using frequent prescribed fire (≤ 2-yr return intervals). Additional research is needed regarding the effects that nesting-season fires may have on small, isolated populations as well as sites where much larger burn extents (> 100 ha) or longer burn intervals (> 2 yr) are used.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Spermiogenesis of the domestic sparrow was investigated with the light and electron microscopes and a step by step classification is proposed. Three cell populations corresponding to early, mid and late spermatids were easily divided according to their positions in the seminiferous epithelium. In addition to this initial separation, six steps were recognized, based on nuclear morphology and the degree of chromatin condensation, in association to their acrosomal and flagellar development. Early spermiogenesis is the period previous to chromatin condensation. The first step can be recognized by the extending flagellum and the second by the pro-acrosome development in contact with the nucleus. During the third or intermediate step, chromatin condenses and the cell becomes polarized with the pro-acrosomic vesicle and the tail occupying opposite sides of the nucleus. Late spermiogenesis, including steps IV-VI, is marked by complete chromatin condensation. The final cellular modifications lead to the formation of a spiraled spermatozoon. This shape is due to the twisting of the acrosome and nucleus, as well as the helical arrangement of mitochondria around the axoneme along most of the flagellum, making an exceptionally long middle piece. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Seaside is the open source framework of choice for developing sophisticated and dynamic web applications. Seaside uses the power of objects to master the web. With Seaside web applications is as simple as building desktop applications. Seaside lets you build highly dynamic and interactive web applications. Seaside supports agile development through interactive debugging and unit testing. Seaside is based on Smalltalk, a proven and robust language implemented by different vendors. Seaside is now available for all the major Smalltalk including Pharo, Squeak, GNU Smalltalk, Cincom Smalltalk, GemStone Smalltalk, and VA Smalltalk.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Sperm competition exerts strong selection on males to produce spermatozoa with an optimal morphology that maximizes their fertilization success. Long sperm were first suggested to be favored because they should swim faster. However, studies that investigated the relationship between sperm length and sperm competitive ability or sperm swimming velocity yielded contradictory results. More recently, ratios of the different sections of a spermatozoon (the head, midpiece, and flagellum) were suggested to be more crucial in determining swimming velocity. Additionally, sperm ability to remain and survive in the female storage organs may also influence fertilization success, so that optimal sperm morphology may rather maximize sperm longevity than velocity. In this study, we investigated how sperm morphology is related to sperm velocity and sperm longevity in the house sparrow Passer domesticus. Sperm velocity was found to be correlated with head/flagellum ratio. Sperm with small heads relative to their flagellum showed higher swimming velocity. Additionally, shorter sperm were found to live longer. Finally, we found sperm morphological traits to vary substantially within males and the head/flagellum ratio to be unrelated to total sperm length. We discuss the hypothesis that the substantial within-male variation in sperm morphology reflects a male strategy to produce a diversity of sperm from long, fast-swimming to short, long-living sperm to maximize their fertilization success in a context of sperm competition.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

List also includes one book donated by a Dr. Amory.