DIURNAL ACTIVITY OF ADELIE PENGUINS PYGOSCELIS ADELIAE AT CAPE BIRD

Activity cycles of non-breeding Adelie Penguins were investigated at Cape Bird, Antarctica. There was continuous light during the observation period, but none the less regular fluctuations of light intensity and temperature were maintained. The penguins had no single period of rest, but were active throughout the 24 hours. However, there were statistically significant diurnal variations in the levels of certain activities among non-breeders, with an overall reduction in activity-levels in the middle of the day, especially on warm midsummer afternoons. It is suggested that this cyclic activity minimum may be associated with the low heat tolerance of Adelie Penguins.     

长白山次生林繁殖鸟的群落结构

研究了长白山次生林繁殖鸟的群落结构及其与森林植被的关系。在３块林龄相同而样地面积不等的次生林中,繁殖鸟种类有随样地面积增加的趋势,繁殖鸟数量随面积的增加而增加更为明显。相似性指数测定表明,３样地鸟类群落组成基本相似,多样性指数也无显著差异。鸟类物种多样性与植被剖面层次多样性相关。边缘种随林缘长度的增加,种－数系数不断增加。由林缘至林内５０ｍ宽的地带为鸟类高密度带。由边缘至林内３００ｍ后,鸟类密度有     

遗鸥繁殖生境选择及其繁殖地湿地鸟类群落研究

本文就遗鸥(Larus relictus)在内蒙古鄂尔多斯高原对其繁殖生境的选择和该生境下所出现的湿地鸟类种类、数量、居留习性等作了记述,并对该地湿地鸟类的区系成份、生境类型与种的生态分布及数量配比关系、伴生种问题及东方白鹳(Ciconia boyciana)在鄂尔多斯的发现等作了分析和探讨。     

COMPARISON OF THE DIET OF BREEDING AND NONBREEDING CAPE GANNETS MORUS CAPENSIS

Berruti, A. 1991. Comparison of the diet of breeding and nonbreeding Cape Gannets Morus capensis. Ostrich 62:8-12.

The effects of breeding status on the diet composition of Cape Gannets Morus capensis were tested at two colonies in the western Cape, South Africa. At both colonies, there were no significant differences in the species composition of the diet, but the mean energy content of regurgitations of breeders was significantly greater. Although the regurgitations of breeders were heavier and contained more fish at both colonies, only the number of fish per regurgitation from breeders at one colony was significantly greater. Birds feeding chicks at Malgas Island took significantly shorter fish than nonbreeders. The small effect of breeding status on prey species composition shows that temporal and geographical variation in prey availability is more important than breeding status in affecting diet cornposition of the Cape Gannet.     

草兔繁殖生物学的初步研究

本文分析了１９９１年１－１０月获自山西省东南部丘陵山区以及１９９０－１９９３年１０月至翌年１月获自该省各地草兔的有关繁殖特征。草兔的繁殖季节为１－９月,雄性进入性活动的时间早于雌性。生殖腺测度有明显的季节变化,其峰值在４月和５月。当年兔３－４月龄时性可成熟,但达到性成熟月龄的当年兔只有５１．７％在７、８月参加繁殖。怀孕个体见于２－９月,３月怀孕率最高,此后逐渐下降。胎仔数１－７只,５月最多,年均值３．６只,每只雌兔年产幼兔１２．９只。     

BREEDING OF THE INDIAN WHITEBACKED VULTURE AT JODHPUR

Vulture populations have declined globally as well as regionally within Africa. Little is known about the status of the African White-backed Vulture Gyps africanus in Kenya, but ongoing studies indicate that its population has declined over the last two decades. A total of 32 African White-backed Vulture nests were monitored in the Masai Mara National Reserve over a five-year period between 2003 and 2007. Mean nesting success was 59%, which is comparable to that of populations from southern Africa. Nearest neighbour distances were significantly closer in wooded habitats (‘trees and shrubs savanna’) than in more open grassland habitats (‘open low shrubs’). Based on nearest neighbour distances, the estimated total breeding population within the Masai Mara National Reserve is 1 106 pairs, a figure that may be an overestimate and requires ground-truthing. Collecting baseline data on numbers of breeding pairs and regular nest monitoring are essential in order to assess the impact of various threats to vultures in Kenya, which include growing threats (elephant-mediated habitat disturbance and fire) as well as emerging threats (such as poisoning with the carbamate-based pesticide Furadan?).     

BREEDING BIOLOGY OF THE BLACK-BROWED ALBATROSS DIOMEDEA MELANOPHRIS AND GREY-HEADED ALBATROSS D. CHRYSOSTOMA AT BIRD ISLAND, SOUTH GEORGIA

The two small albatrosses Diomedea melanophris and Diomedea chrysostoma were studied during five summers and one winter at Bird Island, South Georgia. Although superficially similar in habit small but consistent differences in breeding biology were demonstrated between the two species and may be related to differences in breeding frequency. The breeding season of D. chrysostoma was longer than that of D. melanophris and each species favoured slightly different colony sites. The development time (incubation+fledging) of D. chrysostoma (213 days) was substantially longer than that of D. melanophris (184 days). The eggs of D. chrysostoma were slightly larger than those of D. melanophris and there was marked difference in the behaviour of those breeding adults who lost eggs or chicks. D. chrysostoma departed to sea straight away whereas D. melanophris continued to visit the colony for some weeks before going. Daily weighings of nestlings suggested that chrysostoma bring in less food per a given time than melanophris, and this may account for the longer fledgling period.     

THE DIET AND IMPLICATIONS OF DIETARY CHANGE OF CAPE GANNETS ON BIRD ISLAND,ALGOA BAY

Batchelor, A. L. & Ross, G. J. B. 1984. The diet and implications of dietary change of Cape Gannets on Bird Island, Algoa Bay. Ostrich 55:45-63.

The diet of the Cape Gannet Sula capensis breeding on Bird Island, Algoa Bay, South Africa, was investigated. Approximately 2000 regurgitations representing 13300 prey items were examined. Twenty-three teleost and two cephalopod species were recorded in the diet. More than 90 % of the numerical composition consisted of the three species Pilchard Sardinops ocellata, Anchovy Engraulis capensis and Saury Scomberesox saurus. The proportions of these three species in the diet changed during the sampling periods. These changes were not related to the implied migration patterns of these species. Chick growth rates were investigated in conjunction with the dietary study. These results indicated that Cape Gannet chicks on a diet of Pilchard and/or Anchovy were more likely to fledge successfully than those on a diet of Stockfish Merluccius capensis or Saury. These observations were based on differences in growth rate, and peak and fledgling mass, The data suggest that Pilchard is a preferred prey species and its presence or absence in regurgitationsMayreflect a similar situation on the feeding grounds. The observed increase in the Bird Island gannet populationMaybe related to the availability of high-quality food and consequent reduced pre-breeding mortality. In the absence of historical dietary data, further detailed population dynamics studies are required to support this supposition.     

ASPECTS OF THE POPULATION DYNAMICS OF CAPE VULTURES IN THE CAPE PROVINCE

Robertson, A. S. 1984. Aspects of the population dynamics of Cape Vultures in the Cape Province. Ostrich 55: 196–206.

Information gathered in 1981 and 1982 and collated from previous records on the numbers, spatial distribution, proportion of age classes, age and frequency of breeding, breeding success and causes of breeding failure, and the survival of immature and adult Cape Vultures Gyps coprotheres in the southern and southwestern areas of the Cape Province, South Africa, is presented. This sub-population of about 75 birds is apparently isolated from conspecifics in the rest of southern Africa; the implications of this are discussed. At the Potberg colony in both years an average of 85% of birds 5 years and older were involved in breeding attempts. The age of first breeding was 4–6 years. Nest sites were active for about two in every three years. Between 1975 and 1982, 0,51-0,67 nestlings were reared per active nest site (n=165). Four (possible maximum six) of 21 immatures were resighted one year after they had flown. Of 123 birds that had been ringed at Potberg to 1980, 14 (11%) were sighted in 1981; only four of 48(8%) colour-ringed birds 5 years old and older were breeding in 1981.