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W. R. J. Dean 《Ostrich》2013,84(4):234-239
Dean, W. R. J. 1979. Population, diet and the annual cycle of the Laughing Dove at Barbers-pan, Part 3: The annual cycle. Ostrich 50:234-239. Laughing Doves Streptopelia senegalensis were collected each month from July 1976 to June 1977. In each sample some males and females were breeding. Breeding and primary moult overlapped, and some birds began to moult after starting to breed, and began to breed after starting moult. Adult Laughing Doves require about 120 days to complete primary moult, and juveniles require about 90 days. Weights of moulting birds were not significantly different from those of non-moulting birds, and there were no seasonal trends in the weights of either group. The mean weight of 79 males was 101,6 g and of 39 females was 100,2 g. 相似文献
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W. R. J. Dean 《Ostrich》2013,84(2):80-91
Dean, W. R. J. 1980. Population, diet and the annual cycle of the Laughing Dove at Barber-span, Part 4: Breeding data and population estimates. Ostrich 51:80-91. From 1974–1976, Laughing Doves Streptopelia senegalensis raised an observed total of 436 young in 619 nest attempts, giving a breeding success of 0,70 young per pair nest attempt, or an overall success of 0,35 young per egg. Breeding success, estimated by computing the probability of survival of an egg through the incubation period, and of a chick through the nestling period suggest that the breeding success is about 0,33 young per egg. Nests were found in every month of the year, though there was a tendency for breeding to be concentrated during the late rainy season and the dry season. The mean annual population size of the Laughing Dove in the study area was estimated at 221 adults and juveniles by one method and at 237 adults and juveniles by another method. The number of young produced each year is correlated with the estimated population size for each year. 相似文献
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Cooper, J. 1981. Biology of the Bank Cormorant, Part 1: Distribution, population size, movements and conservation. Ostrich 52: 208–215. The Bank Cormorant Phalacrocorax neglectus is a marine species, endemic to southern Africa. Its non-breeding range extends from Walvis Bay to Cape Agulhas. Breeding range extends from Hollamsbird Island to Quoin Rock. Its distribution is broadly similar to that of kelp beds Ecklonia maxima. A total of 44 breeding localities supports approximately 18 000 adult birds; 12 800 (71%) occur on two islands (Ichaboe and Mercury) north of large kelp beds. Adult Bank Cormorants are resident but juveniles may disperse several hundred kilometres. The species is not considered to be seriously at risk to disturbance at most breeding localities. However, modern expansion of fishing activities may affect the very large populations of Ichaboe and Mercury Islands. 相似文献
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Observations were made on the diet and distribution of eightspecies of nudibranchs found in Borge Bay, Signy Island, Antarctica.Specimens from seven sites were examined in situ on four separateoccasions during 1992 and 1993 using SCUBA. A small collectionfor identification was also made Six of the eight species presentwere identified, and the first ecological data for at leastone species (Charcotia granulosa) were recorded. Notaeolidiagigas was feeding principally on hydroids of the genus Tubulariaover the entire depth range surveyed (336 m), and wasmost abundant in shallow water, whereas Truomella belli wasonly found at deeper sites, mostly on an octocoral of the genusAscolepis. Charcoaa granulosa and Pseudotritoma gracilidensappeared to be specialist bryozoan feeders and, as has beenfound at other locations, Austrodoris kerguelenesis specialisedon the demosponge Dendnlla antarcnca. Two unidentified aeolidspecies occurred almost entirely on particular hydroids andthe prey of Tritonia antarctica was not apparent. The physicalsize of Antarctic nudibranchs may have important implicationsto the type of prey and feeding strategy used by different species. (Received 11 May 1995; accepted 3 December 1995) 相似文献
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Gillian M. Puttick 《Ostrich》2013,84(4):158-167
Puttick, G. M. 1978. The diet of the Curlew Sandpiper at Langebaan Lagoon, South Africa. Ostrich 49:158-167. Nereid worms (mainly Ceratonereis erythraensis) and the hydrobiid gastropod Assiminea globulus were the most important prey items throughout the year for Curlew Sandpipers Calidris ferruginea feeding at Langebaan Lagoon. Other important items were the amphipod Urothoe grimaldi, the crabs Hymenosoma orbiculare and Cleistostoma edwardsii and dipteran larvae (Stratiomyidae). Immature Curlew Sandpipers took smaller prey items than adult birds. The diet of male and female birds differed in the proportion, sue and range of prey items taken. 相似文献
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R. E. HUTCHISON 《Ibis》1979,121(1):68-74
The magnum region of oviducts of female Barbary Doves was examined at different phases of development before egg laying, and during incubation and brooding of the young. The tubular glands in the mucosal folds of the magnum region increased in size with increase in precursor albumen granule content during the pre-egg-laying phase, and decreased during incubation and brooding. Enlargement of tubular glands was correlated with an increase in plasma progesterone level. The temporal relationships between ovarian development, ovarian hormones, oviduct development and nesting behaviour are discussed. 相似文献
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La Cock, G. D., Hecht, T. & Klages, N. 1984. The winter diet of Gentoo Penguins at Marion Island. Ostrich 55: 188–191. The diet of Gentoo Penguins Pygoscelis papua at Marion Island was studied during September 1982. Samples were obtained from 64 birds using a stomach-pump. Fish accounted for 70% of the diet by wet weight, and crustaceans 30%. Fishes occurred in 72% of the samples, crustaceans in 75%, cephalopods in 13%, and molluscs in 8%. Cephalopods and molluscs did not form a significant proportion of any single sample. Harpagifer georgianus was the predominant fish in the diet (92,7% of otoliths recovered), and Nauticaris marionis was the only crustacean. 相似文献
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Zonotrichia capensis australis inhabits Argentina from the northernmost limits of the Patagonian steppe south through Tierra del Fuego, and extends westward to the Pacific slope in southern Chile. At least part of the population has a north-south migration along the Andean foothills of Argentina as far north as southwestern Bolivia. The breeding range of australis is bounded on the north and northwest by subspecies of Z. capensis (chilensis, choraules , and possibly hypoleuca ) having conspicuous black lateral crown-stripes. Topotypical australis (Tierra del Fuego) have plain grey crowns, but the frequency of black nuchal markings and faint lateral crown-lines increases northward in the coastal populations. In inland populations (Andean piedmont) the frequency of black crown markings is apparently reversed, increasing southward. The size (wing-length, tarsus, bill, and probably body-weight) of australis decreases northward in both coastal and inland samples.
The nesting season of australis begins in late November and early December and extends to mid January and early February. Postnuptial moult begins from mid December to early January. Moult proceeds while the testes are apparently still functional. Postnuptial moult terminates from late January through mid March. There is no evidence in the current data of geographical trends in the chronology of nesting and postnuptial moult. The calendars appear to be about the same throughout the range of australis .
Postjuvenal moult begins about 4–5 weeks later than the onset of postnuptial moult and terminates in the latest birds in about mid March. Northward migration begins at about this time. 相似文献
The nesting season of australis begins in late November and early December and extends to mid January and early February. Postnuptial moult begins from mid December to early January. Moult proceeds while the testes are apparently still functional. Postnuptial moult terminates from late January through mid March. There is no evidence in the current data of geographical trends in the chronology of nesting and postnuptial moult. The calendars appear to be about the same throughout the range of australis .
Postjuvenal moult begins about 4–5 weeks later than the onset of postnuptial moult and terminates in the latest birds in about mid March. Northward migration begins at about this time. 相似文献
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Lemna paucicostata Hegelm. 6746: LIFE CYCLE AND CHARACTERIZATION OF THE COLONY TYPES IN A POPULATION
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The sequence of frond emergence and the intervals required for daughter colony separation have been determined for Lemna paucicostata Hegelm. 6746 growing under standardized conditions. After separation of a new mother colony, the first daughter colony is produced from the left meristematic pocket and separates after approximately 60 hours, the second daughter, produced from the right pocket, separates after a further 30 hours, and the third daughter, again from the left, after a further 40 hours. The pattern of alternating longer and shorter intervals for separation of daughters continues throughout the life of the mother colony. 相似文献
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The sexual cycle of the cuttlefish, Sepia officinalis, fromthe northern part of the Bay of Biscay was followed over severalyears (1988 to 1990 and 1992 to 1993). Successive maturity stagesare reached at the same time regardless of site in the northernpart of the Bay. In this area, the majority of cuttlefish reproduceduring their second year of life (group II) whereas the remainderreproduce in their first year (group I). The first visible signsof sexual development concern the testis in males and the genitaltract in females. Males mature earlier than females: the firstspermatophores appear in July (group II) and October (groupI) while mature eggs appear from December (group II) and March(group I). The breeding season lasts from about mid-March tolate June (3.5 months). (Received 2 February 1996; accepted 30 May 1996) 相似文献
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蛋白聚糖和溶血磷脂酸对不同细胞周期心脏成纤维细胞生长的影响 总被引:5,自引:0,他引:5
本文研究了蛋白聚糖(pG和)和溶血磷酸(LGA)对培养的处于不同细胞周期的SD乳鼠心脏成纤维细胞生长的影响及PG对LPA生物学活性的调节食用。采用流式细胞术测定细胞所处的周期;3H-TdR参人法测定细胞的DNA合成。研究结果表明(1)培养至次融汇状态的乳鼠心脏成纤维细胞经低血清(0.4%FBS)饥饿培养48小时,G0/G1期细胞占88.5%;G0/G1期细胞经2%FBS刺激24小时,G2期细胞占91。7%。(2)PGs对G0/G1期和G2期的心脏成纤维细胞的DNA合成均有摄制作用。2.94-47.04μg/ml PGs对G0/G1期细胞DNA合成的摄制率为80%-93%对G2期的抑制率为13%-94%.(3)1-80μmol/L范围内,LPA以浓度依赖方式促进不同细胞周期的心脏成纤维细胞DNA合成增加,50μmol/L LPA诱导G0/G1期和G2期细胞DNA合成的增加分别为78%±和122%±21%。(4)10μmol/L LPA存在下,2.94%-47.04μg/ml PGs使G0/G1期细胞和G2期细胞的DNA合成分别下降为对照的36%±11%-15%±10%和91%±13%-3%±1%,说明PGs可以抑制LPA诱导的心脏成纤维细胞DNA合成.上述研究结果提示PGs和LPA对乳鼠心脏成纤维细胞G1期至S期的转换有重要的调节作用,并可能通过调节心脏成纤维细胞的生长影响心肌肥厚的形成和发展. 相似文献