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1.
R. A. Earle 《Ostrich》2013,84(3):118-121
Earle, R. A. 1987. Distribution, migration and timing of moult in the South African Cliff Swallow. Ostrich 58:118-121. The South African Cliff Swallow Hirundo spilodera breeds in South Africa mainly between 25 and 31S and 24 and 31E. In some years with exceptionally high rainfall the breeding range is more extensive. Man has probably had a pronounced influence on the present-day distribution of this species. Seven winter recovery/collecting localities are known from the lower Congo basin in Zaire. Possible migrating birds were observed in Zambia and Malawi in the east, and on the Namibian coast in the west. The few sight records suggest a direct migrational route over Botswana. Moult takes place between March and September primarily in the winter quarters, but about 2% of the birds handled during March and April started moult before migrating. 相似文献
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R. K. Schmidt 《Ostrich》2013,84(4):155-158
Earlé R. A. &; Herholdt, J. J. 1988. Breeding and moult of the Anteating Chat Myrmecocichla formicivora. Ostrich 59: 155–161. The general breeding biology and moult of the Anteating Chat Myrmecocichla formicivora was studied in open grassveld over a two-year period. During the winter (July), groups were significantly smaller than during summer (December) (1,81 ± 0,50 versus 2,85 ± 1,35 birds per group). There was a large turnover of individuals in the study area but the total population stayed the same. The breeding season in the study area lasted from September to February but analysis of nest record cards from a larger area gave a breeding season of August-April. Two types of nests were used: 90,6% were burrows in sand banks or other excavations, but 9,4%were in the mud pellet nests of Greater Striped Swallows Hirundo cucullata (n = 53). Consecutive breeding attempts were never made in the same burrow. Clutches consisted of three, four or five eggs ([Xbar] = 3,73 ± 0,67). Incubation lasted 14–14,5-15 days. The nestling period lasted 15–18 days. Fledgling/egg breeding success was 41,8% with 48,2% of all eggs not reaching the hatching stage. Juveniles showed an unequal sex ratio of 0,57 ♂ ♂: 1,0 ♀ ♀ but adults had a nearly equal ratio (0,9 ♂ ♂: 1,0 ♀ ♀). There was a significant positive correlation between the primary moult score and the week of the seven months in which moult was recorded. Juveniles underwent a complete body moult and partial primary moult 3–4 months after fledging. 相似文献
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ANDERS PAPE MØLLER 《Ibis》1982,124(3):339-343
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E. O. Höhn 《Ibis》1954,96(1):151-153
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有关棕头鸥和遗鸥两近似种的分类与分布问题研究 总被引:7,自引:0,他引:7
本文根据近几年的野外观察结果并分析有关文献资料,系统地比较研究了棕头鸥和遗鸥两近似种的分类和分布现状,直接依据野外活体形态并对照系列标本对两种鸥的成、幼鸟和雏鸟的形态及野外临别特征给出了较精确的描述,澄清了这两种鸥以往在分类上的混淆有分布认识上的错位,同时从生态-动物、地理和行为学的角度对两种鸥的现有分布和今后分布态势的演进做了分析论证。 相似文献
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Thalassiosira oestrupii (Ostenfeld) Hasle was studied from the southern Indian Ocean, Wed-dell Sea, and northern Atlantic Ocean. It has the longer extension of the strutted process inwards, with three small columnar supports. A single strutted process near the central areola is 2-3 areolae away from the single labiate process; both are usually visible in the light microscope. Two bands are septate: the valvocopula (intercalary band next to the mantle) is ribbed with a complex pattern of pores, while the other intercalary band (copula) present has but a single ring of large pores. T. oestrupii var. venrickae is described from warmer water with similar bands but with differences in areolae array and spacing of marginal strutted processes. It was found in the Gulf of Mexico, eastern and western Atlantic Ocean, Indian Ocean, and western Indian Ocean. The two varieties appear to differ in their ecology and distribution, with T. oestrupii var. oestrupii apparently a cosmopolitan oceanic taxon and T. oestrupii var. venrickae a tropical and subtropical continental shelf taxon. 相似文献
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Anders Pape Mller 《Evolution; international journal of organic evolution》1993,47(2):417-431
Male secondary sexual characters are often expressed in females, and the maintenance of the character in females can be due to either direct selection on females favoring the maintenance of the trait, or a correlated response to selection in males. Here I report on determinants of and phenotypic selection on tail length of female barn swallows Hirundo rustica. The homologous trait in males is under strong directional sexual selection. Female tail length was positively associated with several reproductive parameters including total seasonal reproductive success, even when controlling for year and age effects. A change in female tail length from one year to another was often associated with a change in the reproductive parameters correlated with absolute tail length. There was little evidence for an association between female tail length and the duration of the incubation period (only females incubate) and absolute and relative female provisioning rates of offspring, and subsequent size of offspring. Tail length of female barn swallows was positively correlated with that of their mates. Female tail length was a heritable trait as determined from regression of the tail trait of offspring on that of their mother and their father, and there was a positive genetic correlation between the tail trait in males and females. In conclusion, female tail length reliably reflects female reproductive potential, and the trait appears to be under directional selection, which may result in an evolutionary response to selection because of the heritability of the tail trait. 相似文献
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檬果樟属的分类与分布兼论这一分布区类型的特征 总被引:50,自引:4,他引:50
作者在本文中讨论了檬果樟属(Caryodaphnopsis Airy Shaw)的分类和分布。该属约14种,其中7种见于热带亚洲,7种见于热带美洲,其分布属于热带亚洲和热带美洲分布区式样。这一分布区式样的属在我国共有33个,隶属于27科。作者对这一分布区式样的属进行分析,论述这一分布区式样的特征,推测它们大多可能在中生代起源于古南大陆并且主要是第三纪古热带区系成分。 相似文献
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Anders Pape Mller 《Evolution; international journal of organic evolution》1991,45(8):1823-1836
The proportion of phenotypic variance in the length of the sexually selected tail of the monogamous barn swallow Hirundo rustica that is attributable to genetic variance was studied in the field in Denmark during a seven-year period. Tail length was on average 20% greater in males than in females. Tail length correlated with wing length, but not with other morphological traits. Tail length increased with the first molt, but remained constant during subsequent years. Changes in tail length between years, owing to molt were significantly affected by sex and by degree of infection with an haematophagous mite (Ornithonyssus bursa). There were significant differences in sexual size dimorphism between years, apparently as a result of environmental conditions in the African winter quarters during molt. Tail length was a highly repeatable morphological trait, and standardization of tail length for age effects only marginally increased repeatability. Heritability of tail length as estimated from regression of values for sons on those of their fathers was 0.59. This suggests that secondary sexual traits affected by strong directional selection still may show a statistically significant heritability. 相似文献
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To help clarify relationships within the Limnanthaceae, all 19 taxa were compared on the basis of flavonoids occurring in all tissues, and 14 of these taxa were additionally compared on the basis of flavonoids occurring only in the petals. Of the 46 flavonol glycosides encountered, 35 were identified as derivatives of six flavonol aglycone types: syringetin, isorhamnetin, kaempferol, laricytrin (myricetin 3'-methyl ether), quercetin and myricetin, all glycosylated with combinations of glucose and rhamnose. Varimax Factor Analysis with rotation of the flavonoid data indicated that the family probably contains 3 phyletic lines, an observation inconsistent with the conventional 2-generic interpretation of the family. Mason's sectional treatment of Limnanthes is supported by petal flavonoid results, but not by whole-plant flavonoid results, indicating that petal flavonoids more clearly reflect natural relationships in Limnanthes. Evolution of whole-plant flavonoids of Limnanthes appears to be partly linked to changes in breeding system. 相似文献
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Schmitt. M. B. & Whitehouse, P. J. 1976. Moult and mensural data of Ruff on the Witwatersrand. Ostrich 47: 179–190 During a five-and-a-half year study 1 600 Ruffs Philomachus pugnux were captured on the southern and eastern Witwatersrand, South Africa. Mensural data for these birds are given and the moult cycle discussed. Birds in the study area appear to moult much later than elsewhere, but the moulting sequence appears similar. Recaptures and leg colour are discussed. 相似文献
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The heaviest clutches (2 eggs) laid by Woodpigeons Columba palumbus in a Cambridgeshire study area weighed 30% more than the lightest. Yet the variation in egg-weight within clutches was less than 1 %. Irrespective of initial weight, eggs lost weight at the same constant rate during incubation. Heavy eggs hatched more successfully than light eggs and none weighing less than 16 g hatched. There was no correlation between chicks' weight at hatching and their weight at day 6 during the July-September part of the breeding season. The ability to feed crop milk at this stage could compensate for low chick-weight, but this might not be true early in the season. Weight at day 6 was correlated with the weight at day 16 or 17. The growth pattern is discussed. Chicks in broods of one achieved a higher weight at day 17 than those in broods of two. The survival rate both in and after leaving the nest was the same in both brood-sizes. Chick-weight in artificially created broods of three was almost as high as in broods of two, but again data refer to the July-September period when abundant cereal food is available. Survival before and after fledging was lower in broods of three. Clutch- and egg-weight declined from April until September. It is suggested that this is adaptive, in that the adults produce heavier eggs when food supplies are most difficult to collect. The critical period probably occurs during the few days when the adult must produce crop milk and the young cannot be left unattended. Thus egg-weight depends on the female's capacity to acquire nutrients, and is related to the needs of embryonic development and the amount of compensation in nutrient supply which can be provided immediately after hatching. But clutch-size is more related to the bird's ability to feed and rear young to the point of fledging, thereby influencing the number of offspring which survive to leave progeny. Egg-weight and female body-weight were positively correlated in females weighing less than 480 g but not in heavier females. First-year birds did not acquire adult weight until midsummer and they would probably produce light eggs if they could breed before this month. However, their gonads do not recrudesce until July and this prevents them breeding in the spring. Seasonal changes in body-weight and fat content of adults and first-year birds are described and discussed; differences were noted between adult males and females which were considered to be adaptive. The moult is described. It begins in April and continues until November, approximately one pair of primaries being replaced per month. The moult ceases during the winter months, when it is known that food supplies become limiting. Woodpigeons lay light eggs relative to their body-weight but can achieve the extra parental care needed for the altricial chicks by producing crop milk. Because the moult is extended, the energy demands of moulting and breeding combined are relatively low and this enables the Woodpigeon to have a long breeding season and to moult coincidentally. 相似文献
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INTERRELATIONSHIPS AND TAXONOMY OF THE DIGENETIC TREMATODES 总被引:1,自引:0,他引:1
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G. R. Potts 《Ibis》1971,113(3):298-305
There are three main types of plumage in the Shag, the juvenal which is brown, the post-juvenal which is dark brown and the nuptial which is black-green. The replacement of these plumages and the ontogeny of the Staffelmauser was studied in a sample of 566 Shags mainly from northeast England. The replacement of the juvenal primaries starts at the age of eight months with the loss of the innermost primary and continues outwards at a rate of about one primary per 17 days. Another cycle starts when the first reaches the 8th primary but both cycles soon pause for the winter. Successive cycles are established annually in August or September in this way, so that cycles which take longer than one year to complete result eventually in a Staffelmauser in which each feather is replaced once annually. Most individual Shags in a breeding population will retain feathers from two or three cycles, but a large sample of breeding adults of the same age will retain the feathers of four cycles. The winter pause is considered an adaptation to the increased probability of adverse conditions at this time. The system described for the ontogeny of the Staffelmauser is applicable to those other sea-birds which have been studied in detail, and is probably advantageous since it combines slow moult during the difficult early years with a highly efficient moult during the breeding years, especially where moult and breeding occur together. 相似文献
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柏科分类和分布:亚科,族和属 总被引:4,自引:0,他引:4
柏科Cupressaceae和杉科Taxodiaceae有许多相似之处,近年来不少分类学家主张把两科合并成广义的柏科。原杉科中的金松属Sciadopitys与两科其他属的差异较大,被提升为单种科Sciadopity-aceae。本文根据球果可育种鳞的位置把柏科(狭义)分为2亚科,即上部种鳞不可育的柏木亚科Cupres-soideae和上部种鳞可育的澳洲柏亚科Callitroideae。综合其他形态学和解剖学证据,柏木亚科又分4族,即柏木族Cupresseae(包括:柏术属Cupressus、杂交柏属×Cupressocyparis、扁柏属Chamaecyparis和福建柏属Fokeinia)、侧柏族Thujopsideae(包括:崖柏属Thuja、罗汉柏属Thujopsis和侧柏属Platycladus)、圆柏族Junipereae(包括:圆柏属Juniperus和海参威柏属Microbiota)以及香漆柏族Tetraclineae(包括:翠柏属Calocedrus和香漆柏属Tetraclinis)。澳洲柏亚科又分3族,即澳洲柏族Actinostrobeae(包括:西澳柏属Actinostuobus、澳洲柏属Callitris、智利柏属Fitzroya和杉叶柏属Neocallitropsis)、南非柏族Widdring-toneae(包括:白智利柏属Pilgerodendron、塔斯曼柏属Diselma和南非柏属Widdringtonia)以及甜柏族Libocedreae(包括:甜柏属Libocedrus、巴布亚柏属Papuacedrus和南美柏属Austrocedrus)。柏科21个属的地理分布可划分为5种类型,即:( 相似文献