INTERACTIONS BETWEEN CETACEANS AND THE TUNA FISHERY IN THE AZORES

We studied the operational and ecological interactions between cetaceans and the tuna-fishery in the Azores, based on reports of observers placed on board tuna fishing vessels from 1998 to 2000. Data were collected during 617 fishing trips (representing 43% of total fishing trips) and 6,554 fishing events. Cetaceans were present during <10% of the observed fishing events, with common dolphins ( Delphinus delphis ) accounting for 78% of the occurrences. The presence of cetaceans during fishing varied both spatially and temporally, depending on the distribution of fishing effort and on the pattern of occurrence of each cetacean species in the region. Overall, cetaceans interfered in 5% of the fishing events. This interference resulted in a higher proportion of events with no catches. In the three years, 49 dolphins were caught in the fishing lines but were released alive, although it is impossible to determine if they survived the interaction. Annual estimates of incidental capture of cetaceans by all the tuna fleet were calculated based on total tuna landings. An estimated 55 dolphins were captured in 1999, 38 in 1998, and 16 in 2000. Overall, our results suggest a low level of interaction between cetaceans and this fishery.     

THE EPIDEMIOLOGY AND CONTROL OF NOSEMA DISEASE OF THE HONEY-BEE

The proportion of honey-bees infected with Nosema apis (Zander) declines in summer as the old infected bees die, for they cease to transmit their infection to the newly emerged individuals during the flying season. N. apis spores survive the summer on combs contaminated with infected faeces during the preceding winter. Although bees clean the combs during the summer, all infected material is not removed, and even well-used brood comb, which has been repeatedly cleaned by bees, can carry infection. Only a few bees may contract infection in the autumn from these faeces, but they join the winter cluster and initiate the next outbreak of the disease. Transferring a colony on to clean comb early in the spring or summer removes the source of the disease, and it then disappears when all the old infected bees die.
Old broodless comb can be sterilized quite simply by fumigation for a few days with the vapours of formalin or glacial acetic acid. Acetic acid is preferable, because it does not poison any honey or pollen in the combs. Formaldehyde can safely be used only with empty combs.
The autumn is the best time for treating colonies chemotherapeutically, because the combs are then cleanest and the few bees which are infected can be cured during the winter. The drug can be incorporated in the syrup normally fed to colonies in autumn, and there is no risk of seriously contaminating subsequent honey crops. However, such treatment cannot eliminate the disease because sufficient spores remain on the combs for the disease to start again when the drug supplied in the winter stores is exhausted.     

淀粉类保水剂合成过程中皂化介质对吸水性的影响

合成适用于工业生产的淀粉接枝共聚物保水剂。系统地考察了淀粉接枝共聚物在皂化过程中,分散介质对产物吸水性能的影响。     

ASPECTS OF THE BREEDING BIOLOGY OF THE FIERYNECKED NIGHTJAR

Jackson H. D. 1985. Aspects of the breeding biology of the Fierynecked Nightjar. Ostrich 56: 263–276.

A marked population of nightjars in Zimbabwe was studied intensively for four breeding seasons. This paper covers certain aspects of the breeding biology of the Fierynecked Nightjar Caprimulgus pectoralis. The male shows strong site fidelity during the breeding season (September to December), singing, feeding and breeding within an area of about 5,8 ha. There is some evidence of site defence by the male. The female shows strong mate fidelity, resulting in a pair bond for life. Egg laying starts with full moon in September and is further stimulated by the next two full moon periods. The eggs are laid directly on dense leaf litter at a site overhung by foliage. The normal clutch is two eggs (12S % are one egg) laid on successive days during the afternoon. Incubation starts with the first egg and is by the male at night and the female by day. The incubation period is 18 days. The birds respond to undue disturbance by deserting the eggs and laying a replacement clutch. The chicks usually hatch on successive afternoons; they are mobile on the first day and will move to a parent if called. Both parents feed and brood the young during twilight and moonlight; the male broods them on dark nights and the female does so by day. The species is double-brooded when time permits, the female laying again once the first brood has reached independence; she may even lay a third clutch if the second one comes to grief. There is no evidence of adults transporting eggs or young.     

THE SEA-BIRDS OF THE SOUTHEAST COAST OF ARABIA

The present study of an upwelling area off the southeast coast of Arabia, between 52° and 60° E. is based primarily on observations on board the R.R.S, `Discovery’ during the International Indian Ocean Expedition. During oceanographic surveys off the Arabian coast from June to August 1963 and in early March and late May 1964 I made 234 counts of birds of about an hour each, the results of which have been used as an index of bird density. In this area, the only offshore islands known to be important to sea-birds are the Kuria Muria Islands, which were apparently at the centre of an upwelling area. The upwelling of cold water along the Arabian coast during the southwest monsoon from May to September greatly increases organic production in the sea, and large populations of organisms at every level of the food chain develop there. Previous work in Arabia and the Arabian Sea is reviewed. Little is recorded about the ecology of sea-birds there, but the composition of the fauna is quite well-known. The distribution of every sea-bird species recorded from 52° E. to 60° E., and within 200 miles offshore, is described, with particular reference to my own observations. Details are given of the distribution of common species during the southwest monsoon of mid-June-mid-August 1963 and in March and May 1964. Specimens collected on the `Discovery’ are recorded together with their measurements. Of 12 sea-bird species seen commonly off Arabia during the southwest monsoon in 1963, 11 were seen in late May 1964, but only five in March. There is certain evidence that two species have bred on the Kuria Muria Islands and suggestive evidence for a further three. Information on breeding seasons in the Arabian Sea is based on short visits to breeding colonies, mostly outside the breeding season, and on the plumage condition of specimens. Nevertheless, the sum of the evidence suggests that breeding is regular at the same time every year, and in most species seems to be in the northern summer. The food of sea-birds in the Arabian Sea, determined from stomach contents and visual observation, only serves to stress the lack of knowledge on this subject. A brief summary of feeding methods recorded by me suggests that they may be important in avoiding interspecific competition, for there seems to be little overlap. The density of sea-birds during the southwest monsoon 1963, expressed as the number of each species seen per hour, was analysed in relation to: (i) the sea surface temperature, which was inversely correlated with the zooplankton density from 0–200 m. (ii) the distance from the Kuria Muria Islands, the only likely breeding station; (iii) the distance from the nearest land which may have been important to land-tied sea-birds. All the abundant species were commonest close to land in the cool-water area and, with the exception of migrants from the southern hemisphere, most were concentrated around the Kuria Muria Islands in the centre of upwelling. A multiple analysis suggested that the islands were of real importance to some species. A separate analysis also demonstrated the existence of a correlation between sea-bird numbers and the abundance of zooplankton from 0–200 m. depth, but not the abundance of zooplankton at the sea surface. During the southwest monsoon the southeast Arabian coast is inhabited by a distinctive cool-water fauna within the tropical zone of the Indian Ocean. The high degree of endemism, the high proportion of migrants, including some from the southern hemisphere, and the absence of most pantropical species, suggest that the marked changes in the environment off southeast Arabia demand considerable adaptation. A brief discussion of the possible origins of the Arabian coast sea-bird fauna shows that it is not typical of either a subtropical or a tropical community in other regions. The likelihood that sea-birds breed in the summer, the concentration of most species in the upwelling area at that time and their absence during the winter, clearly demonstrates the importance of the upwelling. However, the results of the analysis suggest that some species were concentrated around the Kuria Muria Islands in the centre of the upwelling because the islands had a real importance to them, possibly as a breeding station. The correlation between sea-bird density and zooplankton abundance in the top 200 m., but not at the surface, may be explained if sea-birds concentrate in areas of high productivity rather than in areas of abundant surface plankton, which is largely irrelevant as food.     

THE NEW MILITARY MEDICAL ETHICS: LEGACIES OF THE GULF WARS AND THE WAR ON TERROR

United States military medical ethics evolved during its involvement in two recent wars, Gulf War I (1990–1991) and the War on Terror (2001–). Norms of conduct for military clinicians with regard to the treatment of prisoners of war and the administration of non‐therapeutic bioactive agents to soldiers were set aside because of the sense of being in a ‘new kind of war’. Concurrently, the use of radioactive metal in weaponry and the ability to measure the health consequences of trade embargos on vulnerable civilians occasioned new concerns about the health effects of war on soldiers, their offspring, and civilians living on battlefields. Civilian medical societies and medical ethicists fitfully engaged the evolving nature of the medical ethics issues and policy changes during these wars. Medical codes of professionalism have not been substantively updated and procedures for accountability for new kinds of abuses of medical ethics are not established. Looking to the future, medicine and medical ethics have not articulated a vision for an ongoing military‐civilian dialogue to ensure that standards of medical ethics do not evolve simply in accord with military exigency.     

成都平原4 000aBP以来的孢粉记录与环境变化

成都平原晚全新世以来沉积的泥质层发现丰富的孢粉。根据孢粉成分组合特征和生态类型可划分出5个孢粉组合带,结合剖面上6个14^C测年数据,提出在过去的4000a研究区植被类型及气候环境经历了5个阶段的变化：3800-3600aBP为亚热带常绿阔叶林,气候暖偏湿;3600-3400aBP为含常绿树种的落叶阔叶林,气候温暖湿润;3400-2600aBP为草／湿地,气温下降,环境更潮湿;2600-900aBP为落叶阔叶林,温度又开始逐渐回升,气候温和偏湿;900-300aBP再次变为草／湿地,偏干冷的气候环境。     

THE EARLY SOLAR SYSTEM

Life arose on an early Earth which was the product of the conditions present, and processes operating, during formation of the solar system. The formation and early state of the solar system are reviewed in order to better understand the nature of the early Earth, and to constrain the conditions present during the origin and early evolution of life on this planet.     

THE DARK ADAPTATION OF THE HUMAN EYE

During the dark adaptation of the human eye, its visual threshold decreases to a small fraction of its original value in the light. An analysis of the quantitative data describing this adaptation shows that it follows the course of a bimolecular chemical reaction. On the basis of these findings it is suggested that visual reception in dim light is conditioned by a reversible photochemical reaction involving a photosensitive substance and its two products of decomposition. Accordingly, dark adaptation depends on the course of the "dark" reaction during which the two products of decomposition reunite to synthesize the original photosensitive substance.     

朱顶红花粉管中营养核的纤丝状内含体

用透射是镜研究了朱顶红生殖细胞发育过程中花粉管的营养核中的纤丝状内含体的结构形态。此内含体在花粉管生长早期即可观察到,并在生殖细胞分裂过程中频繁发现。它们具各种方向,未见与其它细胞结构发生联系。通过比较此内含体与花粉管中肌动蛋白纤丝的形态及两者对细胞松弛素Ｄ（ＣＤ）处理的反应,我们倾向认为营养核的纤丝状内含体可能由肌动蛋白组成。讨论了此结构在建立营养核运动机制上的作用。     

大关杨树皮的形成与季节变化的关系

大关杨的输导韧皮部限于当年新生的次生韧皮部。４月中旬至５月中旬大量出现,７月底停止发育。其成熟筛分子中具一细胞核,以后才消失。前一个生长季产生的筛管变形,故二个生长季的韧皮部蛤限明显。韧皮纤维出现迟,呈切向束状分布。含晶细胞分布于纤维束两侧。木栓形成层５月中旬开始活动,７月进入发育高峰。     

运城盆地洪积扇全新世时期的野火与环境变化的初步探讨

通过对运城盆地典型黄土-古土壤剖面磁化率和炭屑含量的分析,研究了洪积扇全新世野火活动的规律及其与环境变化的关系。研究结果表明,在全新世早期(11500~8500 a B.P.), 气候向温湿过渡,但仍较干旱,炭屑含量较高,野火活动比较频繁,说明气候干旱是野火发生的重要原因。而全新世中期(8500~3100 a B.P.),除夏商文化时期外,炭屑含量在整个全新世时期居于最低,野火活动最为微弱,与此时期气候温暖湿润密切相关。但在夏商文化时期(3800~3500 a B.P.)炭屑浓度出现峰值,野火活动较为频繁,是人类生产和生活活动作用的结果。全新世晚期(3100~0 a B.P.)炭屑含量大幅度增加,野火活动最为频繁,一方面与气候向干旱化发展有关,另一方面与大范围的人类活动密切相关;在干旱的气候背景条件下, 人类活动加速了野火的发生频率和活动强度。     

A STUDY OF THE DEVELOPMENT OF THE ROOT SURFACE MICROFLORA DURING THE INITIAL STAGES OF PLANT GROWTH

SUMMARY: A study of the development of the microfloras on the seeds and roots of tomatoes and oats during germination and subsequent root development showed a rapid selective multiplication on the seed during the initial stages of germination and also on the root almost immediately after emergence. Evidence is presented that further development of the root surface population after the initial high rate of multiplication was dependent on the normal development of the plant.
Direct microscopic observations of the micro-organisms of the root surfaces showed interesting differences between the roots of tomatoes and oats. In the former, the root hairs of young plants were free from bacteria but in the oats even young root hairs supported large numbers of organisms. In both plants the root tips were invariably free from organisms.     

THE WINTER FEEDING ECOLOGY OF THE REDSHANK TRINGA TOTANUS

The aim of the work was to find out how the Redshank which over-winter on the Ythan estuary, Aberdeenshire, adapt their feeding activities to the short daylength in winter. To achieve this, the feeding behaviour and daily routine in winter were compared with those in autumn and spring. Corophium volutator was the main prey on the estuary during the day. However, the temperature of the mud greatly affected the diet in the two areas where the feeding behaviour was studied in detail. At temperatures above 6°C, most of the biomass ingested consisted of Corophium. However, in one study area in one winter, Macoma balthica was taken more frequently at lower than at high temperatures. In the other area, Nereis diversicolor was taken more frequently at low than at high temperatures. These changes in diet appeared related to changes in the behaviour of the prey affecting their availability and not due to the birds changing their preference at low temperatures. The ingestion rate was not affected by the change in diet in the first area but decreased at low temperatures in the second. The sizes of Macoma and Nereis taken by the birds did not vary seasonally. The sizes of Corophium taken decreased in winter as a result of a reduction in the size of those present in the substrate. It was concluded that there was no evidence of Redshank increasing their ingestion rate in winter to compensate for the short daylength. The proportion of the time spent feeding on the estuary in daylight was greater in winter than in spring. Redshank continued feeding at high water in the surrounding fields and on the estuary at night during the winter but not in either autumn or spring. During the winter they obtained less than 50% of their daily food requirements from the estuary in daylight, mainly because of the short daylength. Consequently, they had to collect the balance at night and at high water. Seasonal changes in the numbers of Redshank were recorded. After an autumn decrease in numbers, no decrease in numbers could be detected during the winter. These findings are discussed in relation to the possible difficulties for Redshank in collecting their daily food requirements during the winter. The impact of the birds on their main estuarine prey Corophium is also discussed.     

A QUANTITATIVE STUDY OF THE DAILY ACTIVITY OF THE UGANDA DEFASSA WATERBUCK

Waterbuck activity was recorded at four-minute intervals for continuous periods of 12 hours on two or three consecutive days, and for single nocturnal periods. Feeding patterns of the male and female were similar and during the day there was no hour during which some feeding did not take place. Only male activity was recorded at night. This showed more intensive feeding but with periods of no feeding just after dark and just before dawn. The use of a four-minute recording interval was found to work well in practice.     

THE THERMAL SIGNIFICANCE OF THE NEST OF THE SOCIABLE WEAVER PHILETAIRUS SOCIUS: SUMMER OBSERVATIONS

Extending a previous study of the thermal significance of the nest of the Sociable Weaver carried out during the winter, we measured temperature and humidity in the matrix and chambers of a large nest of this species in the Kalahari Gemsbok National Park, South Africa, during the austral summer of December 1973. Air temperatures outside the nest ranged from 16 to 33.5°C but temperatures in occupied chambers varied over a range of only 7 or 8°C and remained well within the zone of thermal neutrality for a passerine bird of this size. Compared to outside air temperatures, those within the nest matrix were lower during the day and higher at night. Thus, the nest ameliorates the effects of external temperatures and allows maintenance inside the chambers of a range of temperature favourable to the birds. In winter we found up to five roosting adults per chamber, with some chambers left empty. In the same nest in summer we found no more than two adults per chamber but virtually all chambers were occupied. The principal mechanism for maintaining chambers within the zone of minimal energetic cost is changes in the number of birds in the nest chambers at night. Humidity inside the occupied and unoccupied chambers was somewhat higher in the former but always less than that of outside air in both cases. Air movement through the desiccated nest materials causes uptake by these materials of most of the water vapour introduced by the birds, and this moisture is dissipated to the outside during the day so that the nest remains dry. The highly social and colonial habits of the birds and their year-round occupancy and maintenance of the nest favour a system of opportunistic breeding that may be initiated by rainfall at any season. Larger nests provide the most favourable environment for energy conservation and successful reproduction. Even the largest nests, however, do not prevent predation during the warm season by snakes such as the Cape Cobra, which may consume all the eggs and young in all the chambers of a large nest. The effects of such heavy predation may be offset by the birds' capability for breeding during times too cold for reptile activity. It seems likely that in smaller nests such as those on telephone poles, lack of predation would favour summer breeding while thermal problems would limit breeding success in winter. In larger nests, breeding success may be lower in summer because of predation and higher in winter when reptile predation is lacking and thermal problems are minimized by the nest structure. The large nest not only makes possible the success of the Sociable Weaver in desert areas, but the nest could only exist in such areas and the species' range is thereby restricted. Higher humidity and heavier rainfall would cause fermentation within the nest mass, loss of its thermoregulatory advantages, and ultimately its decomposition and destruction. Therefore, the unique nesting system of the Sociable Weaver appears to be initially self-reinforcing and ultimately self-limiting.     

THE INUNDATION ZONE OF THE NIGER AS AN ENVIRONMENT FOR PALAEARCTIC MIGRANTS

Of at least 350 species so far recorded within the boundaries of the Niger Inundation Zone, no less than 108 (31%) are wholly or partially of Palaearctic origin. Five main habitats are recognized in the region: wetland, hygrophilous grassland, transition zone, non-flooded areas and aerial. The habitats, the Palaearctic migrants and their possible Ethiopian competitors are described and discussed. The annual Niger flood regime enables Palaearctic waterbirds to find suitable habitats somewhere within the region during all seasons, but most widely during the autumn and winter months of the flood recession. Non-aquatic species inhabiting flood plain grassland are scarce during the Palaearctic autumn, when the growth of vegetation reaches its maximum, becoming commoner and more diverse during the winter months. Wetland warblers of the genera Acrocephalus and Locustella have not been recorded on autumn passage. It is suggested that in some years at least, these and other trans-Saharan migrants from the West Palaearctic overfly the Sahelian latitudes of mid-West Africa. Species inhabiting the transition zone (which increases in area during years of below average rains and floods) are most in evidence at the end of the winter period and during the spring hot dry season, prior to northward trans-Saharan migration. Habitats and species encountered in the non-flooded areas are similar to those recorded in the Sahel zone elsewhere in West Africa. Aerial habitat is utilized by Common Swifts arriving en masse in early August, at the maximum development of the south-westerly monsoon airstream. Several aquatic species and the first few trans-Saharan migrants also occur during the summer rainy season. Some species (e. g. Whiskered Tern, Lesser Kestrel, Turtle Dove, Short-toed Lark and Sand Martin) are most numerous during the late winter and spring hot seasons, when conditions provided by the Inundation Zone may be more suitable for pre-migration feeding than in other parts of the Sahel zone. As yet there is virtually no information available to determine any effects that drought seasons or flood variation may have on the migrant populations.     

SOME NOTES ON THE BIRDS OF THE ISOKA DISTRICT OF THE NORTHERN PROVINCE OF NORTHERN RHODESIA

Dean, W. R. J. 1978. Moult seasons of some Anatidae in the western Transvaal. Ostrich 49:76-84.

Spurwinged Geese Plectropterus gambensis, Egyptian Geese Alopochen aegyptiacus, Yellow-billed Ducks Anas undulata, Redbilled Teal A. erythrorhyncha and Southern Pochard Netta erythrophthalma have a flightless moult mainly during the dry season, from April to August, in the western Transvaal. South African Shelduck Tadorna cana moult during October to February after breeding during July and August. The Cape Shoveller Anas smithii has two main flightless periods, April-May and October-January. Cape Teal A. capensis have been recorded in flightless moult in October, December and January.

The duration of the flightless period correlates with wing length; larger and longer winged Anatidae require proportionally more time for wing moult than do smaller and shorter winged Anatidae.

Geese and shelducks moult on large open lakes with an open shore. Ducks have been recorded flightless on lakes and dams, with or without emergent vegetation.