STUDIES ON THE FOOD HABITS OF LESSER KUDU IN TSAVO NATIONAL PARK, KENYA

As part of a broader ecological investigation, in the framework of the Tsavo Research Project, food habits of lesser kudu have been studied during 2 y in Tsavo National Park (East). Free-ranging lesser kudu were observed, from a Land Rover, while feeding in different habitats and at different times of the year. Each time one animal fed on one individual plant was noted as one “food record”; some 2000 records are analysed in this paper. Leaves of trees and shrubs constitute the main bulk of the diet of lesser kudu. Creepers and vines, herbs, grasses, fruits and tubers of some root succulents contribute variable but relatively small proportions of the food. Pronounced local and seasonal variations in the composition of the diet were found. Local variations are mainly a result of differences in the vegetation of the different habitats. Seasonal variations are caused by changes in the vegetation's condition, depending on rainfall. Deciduous trees and bushes, herbs, climbers and grasses account for much smaller proportions of the diet during the dry season, when evergreen species are crucial for survival. Lesser kudu feed on a wide variety of plants, utilizing all layers of the vegetation that they can reach, at least to some extent. A total of 105 plant species have so far been recorded as being eaten by lesser kudu. With regard to food only, the vegetation changes in Tsavo National Park do not appear to have had any adverse effects on the population of lesser kudu. However, the amount of suitably structured habitat has been substantially reduced in recent years. If present trends continue, it may decrease further, to the point of jeopardizing the future of lesser kudu in large parts of Tsavo National Park.     

FOOD PREFERENCES OF BLACK RHINOCEROS IN THE TSAVO NATIONAL PARK

Food preferences of the black rhinoceros population in Tsavo National Park, Kenya were studied from 1967 to 1969. Feeding rhinoceros were watched for a period of 1 h, and the plants which they selected and rejected were identified, either as they were feeding or when they had moved on. A technique was used which provided an indication of the relative importance of certain plants in the diet during the wet and dry seasons. A total of 70 h was spent actually watching feeding rhinoceros in six habitat types representative of the changing ecosystem; 3,600 feeding stations were examined. Black rhinoceros were observed eating 102 species from 32 botanical families. In all habitat types the rhinoceros is very selective for herbs and shrubs, and shows a marked preference for legumes. Available grasses are very rarely eaten. Results of food preference studies in other areas of East Africa are compared with the present study. It is suggested that the abundance and distribution of certain kinds of leguminose flora may be the key to an optimum black rhinoceros habitat.     

OBSERVATIONS ON THE CHANGING VEGETATION OF TSAVO NATIONAL PARK (EAST)

An analysis of woody vegetation in Tsavo National Park (East) by extensive variable-plot sampling indicates that the vegetation had been differentially destroyed up to 1966, but that by 1967 considerable local shrub regeneration had taken place. This may indicate that Commiphora woodland will become re-established over much of the park.     

OBSERVATIONS ON LIONS IN THE LAKE MANYARA NATIONAL PARK,TANZANIA

The lions of Lake Manyara National Park were observed for 1 1/4 years. About 0.4 lions/km² inhabited the park, a density nearly double that found in Nairobi National Park and Ngorongoro Crater. One group of lions occupied the southern half of the park; in the northern half, the range of two males included two distinct groups of lionesses each of which confined itself to its own area. The composition and changes in composition of each group are discussed. Buffalo were observed to kill a lion cub on three occasions, and elephant were seen to do so once. The lions' most important prey was buffalo, which comprised 62% of the kills, followed by zebra (18%) and impala (12%). Eighty-one per cent. of the buffalo killed were males. Lions were seen in trees on 2/3 of the occasions on which they were encountered. Possible reasons for tree-climbing are given.     

SOME OBSERVATIONS ON THE SITATUNGA IN KENYA

A 16-month study was made of sitatunga in a swamp in western Kenya, with particular reference to distribution within the habitat, daily activity, and food preferences. Absolute figures for density could not be obtained because of observational difficulties, but there was a minimum of 7.3 animals/linear km of swamp, or c. 55/km². The sitatunga preferred areas of swamp adjacent to patches of gallery forest, and areas where there was deep water and a dense growth of tall reeds. They were most active during the first five and last two hours of daylight, and at night. Much of this time was spent feeding. Feeding behaviour and food preferences were studied. The sitatunga usually moved along well-marked tracks through the swamp vegetation; some of these led to beds of flattened plants, raised above water level, which were probably used for resting and for breeding. The latter took place in most months of the year, with a possible peak in November. Calves remained hidden for some weeks after birth. Group size and structure were examined; most sightings were of single animals or groups of two. A majority of these two groupings were composed of adult females. The proportion of immature animals seen indicated a healthy population. Courtship behaviour was observed 18 times and mating once.     

旅游活动对张家界国家森林公园植物的影响

 旅游活动对旅游地环境的影响几乎是不可避免的,尤以对植物的影响最为显著。随着游客的大量增多及旅游宾馆酒楼释放的废气污染物的急剧增加,张家界国家森林公园境内的植物遭受了较为严重的污染和伤害。为了探明旅游活动对张家界国家森林公园植物生长发育、体内化学物质成分及林木树干伤害等方面的影响,该研究采用对比分析法,调查分析了公园内受大气污染较为严重的接待区的几种林木叶内氟化物和SO2含量及杉木(Cunninghamia lanceolata)生长速度的变化,同时还对游道两边树木受游客刻伤的程度进行了调查分析。结果表明,公园接待区杉木、柳杉(Cryptomeria fortunei)、枫杨(Pterocarya hupehensis)叶片中氟化物及SO2含量较对照区增大了1.6～16倍;杉木的直径生长量较对照区降低了32.3%～57.1%;游客的乱刻乱划给金鞭溪、黄石寨等景区游道两边的林木留下了许多伤痕,这些伤痕主要分布在离地面1.2～1.6 m的部位,受伤程度与树种、树皮光滑程度、树干与游道边缘距离及方位有关。为了保护公园内的植物,必须改善公园内的燃料结构,减少接待设施的数量,并加强对游客的环保教育。     

OBSERVATIONS ON SOME KENYA EAGLES

This paper describes the continuation of work on eagles in Embu district, Kenya, especially at Eagle Hill, which has now been under observation continuously since 1949. Observations in other parts of Kenya have been included. The ecological changes possibly affecting eagles on Eagle Hill are discussed. The population fell from a pair each of Circaetus cinereus, Aquila verreauxi, Hieraetus fasciatus spilogaster, H. dubius, Polemaetus bellicosus and Stephanoaetus coronatus in 1952 to a pair each of H. dubius, P. bellicosus and S. coronatus in 1965. Possible causes of the decline are discussed. The species of eagles are not normally aggressive to one another, in contrast to other resident species such as Falco peregrinus and Buteo rufofuscus. Although the eagles appear to be ecologically separated by food preferences and habitat this is apparently not the whole explanation for the unusual concentration of eagles on this hill. Additional breeding data are given for H.f. spilogaster, H. dubius, P. bellicosus and S. coronatus. These species rear respectively 0.56, 0.65, 0.42 and 0.44 young per pair per annum. S. coronatus breeds in alternate years and cannot breed every year because of a protracted post-fledging period in which the young is fed for up to 350 days. P. bellicosus, with about the same annual reproductive rate, does not have the same breeding rhythm. Data on reproductive rates combined with other data suggest possible life spans in the wild state of adults of H.f. spilogaster 10–11 years, H. dubius nine years, P. bellicosus 14 years, and S. coronatus 16 years. At nests of H. dubius and S. coronatus changes of mates have been recorded for 16 and 17 years respectively. In S. coronatus a change occurs about every six years and in H. dubius about every four years, indicating that S. coronatus may live about 1.5 times as long as H. dubius in the wild state. One female S. coronatus was known to live for 8.5 years as an adult. Other incomplete life spans are eight and eight years for two male S. coronatus, and eight for one female of this species. Two male H. dubius have each lived for at least eight years but no female of this species has lived for more than five years. Two proven cases of re-laying after a natural disaster are recorded, one each in H. dubius and S. coronatus. Other instances are suspected in H. dubius. The habit may be commoner than is supposed in large eagles. The history of four pairs of S. coronatus, each observed for four years or more, totalling 34 pair/ years is given. S. coronatus breeds regularly every second year unless some unusual occurrence, such as a change of mates or a failure during incubation, upsets the rhythm. S. coronatus females lay 1–2 eggs at dates varying from June–October in Kenya; breeding is not confined to the dry season. Laying dates of individual females may vary by two months between one year and another. Incubation takes 48–49 days, fledging 105–116 days. The elder of two young hatched invariably kills the younger so that no more than one young is reared. Female adults are dangerously aggressive, especially during days 30–60 of the fledging period. In 86% of cases where eggs are laid a young bird is reared. Since clutches of two in practice do not result in more than one young this represents a breeding success of 86% of the potential, a very high percentage. The sex ratio of young leaving the nest is about equal, seven males to five females, in known cases. The post-fledging period in S. coronatus is 330–350 days, and the total breeding cycle about 560 days, making it impossible for the eagles to breed every year, if they rear a young bird to independence. In the post-fledging period the young S. coronatus remains within half a mile of the nest, where it is fed by the parents, the female bringing most of the prey. The adults call to attract the young bird, which flies into the nest receiving the prey there, or rarely on a tree nearby. If the adult obtains no response from the young it may carry the prey away. Although regularly fed by its parents the young eagle kills some of its own food from at least day 61 of the period onwards, but most often in the last third of the period, being then apparently stimulated by unusual periods of privation. Almost 100% of young eagles that leave the nest are reared to independence at about 15 months old. The possible biological advantages of this protracted adolescence in survival and economy of prey are discussed. The main prey of S. coronatus is antelopes, followed by hyrax. Monkeys are rarely taken. Killing methods, times, and relations with prey are discussed. The eagles usually kill in early morning or evening, but also at other times. They may cache portions of large kills. Most prey is brought to the nest between hours 4–6 of daylight. The male S. coronatus feeds his incubating mate about once every 3–3 days. Once the young has hatched his killing rate rises to about one kill per 1.7 days. The killing rate falls slowly to one kill per two days later in the fledging period. At normal times the killing rate of adults is apparently controlled by their own appetites, and the increased killing rate of the male after hatching is an exception to this rule. During the post-fledging period the feeding rate varies from 1: 2.0 days to 1: 6.2 days, averaging 1: 3 days in 130 cases. Periods of privation may last from 5–13 days. Alternatively several kills may be brought in a day, possibly from cached portions of large kills in some cases. Long foodless periods may stimulate the young eagle to kill for itself, especially in the last third of the post-fledging period. Final independence of the young is not brought about by aggressive parental behaviour, but is probably due to increasing indifference of the young to food-bringing adults. This indifference may act as a release to the adults, breaking the rhythm of bringing food to the young, and so stimulate the onset of a new breeding cycle.     

保定市蛉种及其季节分布的初步观察

一.前言 黑热病是河北省常见的流行病之一。其预防措施主要在于扑灭其传染媒介——白蛉。故如欲作出切合实际的防治计划,必需对白蛉的生态习性有所了解;以便掌握其生活规律,而用最经济而有效的办法扑灭之。据吴征鉴氏(1950)综合性报告,白蛉在我国分布极广,已发现者17种,其中以中华白蛉为黑热病主要传染媒介。在长江以北各流行省份皆曾发现。据 1949年中央卫生部召开的黑热病防治会议报告所载,在河北省北京、通县、天津、定县、北戴河等地均曾发现中华白蛉;在北京、天津、通县等地曾发现有     

THE EFFECT OF COMPLETE REMOVAL OF HIPPOPOTAMUS ON GRASSLAND IN THE QUEEN ELIZABETH NATIONAL PARK, UGANDA

Coincident with the shooting out of hippopotamus in May 1958 20 permanent 30.46 m line intercept transects were established on the denuded grassland of the Mweya Peninsula, Queen Elizabeth National Park, western Uganda, to assess botanical changes in basal cover, species composition and frequency. Between May 1958 and May 1959, grass basal cover (GBC) decreased from 14.7% to 5.3% and bare ground increased from 78.3% to 83.6%. After four years total ground cover was 10.9% GBC, 27.2% litter, 1.3% dicotyledons and 60.6% bare ground. Changes occurred in grass species composition. The perennial carpet grass, Chrysochloa orientalis, declined from 37.7% GBC (transect frequency 100%) to 6.6% (87%) by May 1962. Bunch grasses showed marked recovery: Sporobolus pyramidalis increased from 8.0% GBC (60%) to 27.6% (100% frequency). Cynodon dactylon, initially prominent in two lakeside transects only, declined from 9.2% GBC to 2.1%, then became re-established in inland localities and recovered to 11.7% GBC. The variable rainfall (714 mm annual average) and its influence on plant growth is discussed and the advantage of mechanically increasing effective rainfall mentioned. Authorities for plant names are given in Table 3.     

OBSERVATIONS ON THE FOOD HABITS OF TAME WARTHOG AND ANTELOPE IN UGANDA

Monthly observations were made of the food habits of tame warthog, reedbuck and kob over a period of a year. Measurements were taken of the shoulder height and size of mouth of the animals at different stages of their growth. Whilst a few species of grass were regularly preferred, the majority showed fluctuations in their preference. Some consistent seasonal differences were apparent. Most herbs were avoided. Large differences in food habits occurred between warthog and antelope; however, there was some overlap during the rains when food was abundant and at the height of the dry season when it was scarce. Some differences were apparent between kob and reedbuck and between individual warthog and reedbuck. Intraspecific differences, however, were less noticeable than interspecific differences. The height of the animal and the size of its mouth were important in determining the portion of the sward available for food and the degree of selection possible within the available food supply.     

FOOD HABITS OF WILDEBEEST, ZEBRA, HARTEBEEST AND CATTLE IN KENYA MASAILAND

A study was conducted of grass selectivity shown by four herbivores on open range lands of Kenya Masailand. At four seasons over one year, wildebeest, zebra and kongoni (Coke's hartebeest) were taken. Stomach materials and faeces were sampled from each animal. Faecal samples were collected from cattle that had been grazing in the same area. Simultaneously, vegetation availability assessments were made. A comparison of techniques for determining the food selectivity indicates that faecal and stomach-content analyses provide similar results when the diets are almost entirely grass. The selectivity exhibited by the four herbivores was determined by faecal analyses. Three grass species were preponderant in all diets as well as in the available menu. In comparing the selectivity shown for the three dominant grasses there is a high degree of similarity even though statistical differences are demonstrated. All animals favoured Themeda triandra over Pennisetum mezianum and Digitaria macroblephara. Kongoni displayed the highest degree of selectivity and cattle and zebra had the greatest similarity in diets. Each animal species had a wide spectrum of grasses in their diets: these contained a greater number of species during the drier seasons than during the rainy seasons. Wild animals had a greater diet variation between seasons than did cattle, the diet of the latter remaining much more consistent than the combination of available grasses.     

THE GIRAFFE OF NAIROBI NATIONAL PARK: HOME RANGE, SEX RATIOS, THE HERD, AND FOOD

The giraffe of Nairobi National Park, Kenya have been studied for one year. Each animal seen has been photographed from the left side and the pattern on the neck used to recognize each individual. While the pattern may become darker with age, it does not significantly change in detail even over many years. At present 65 adult male, 72 adult female and 30 immature giraffe can be recognized. Movements of individuals are described as well as associations with other individuals. The 3ex ratio of the giraffe is discussed in relation to that found in the plains ungulates. The population of giraffe in the Park is considered to be particularly high and the relation of giraffe to the vegetation is discussed briefly.     

HUNTING BEHAVIOUR OF THE CHEETAH IN THE SERENGETI NATIONAL PARK, TANZANIA

Eighty-nine per cent, of 136 cheetah kills in the Serengeti National Park consisted of Thomson's gazelles, the most abundant and readily available species in the size category (60 kg or less) preferred by the cheetah. Fifty-four per cent, of the Thomson's gazelle kills were subadult; among the adults all age classes were represented. One female cheetah captured 24 Thomson's gazelles in 26 days, a killing rate of 10 kg/day. The actual food intake of this female was about 4 kg/day. The hunting success of cheetah pursuing large subadult and adult Thomson's gazelles was about 50 per cent. The hunting methods–including the various means of approaching prey–are described as are the typical ways of killing and feeding. Twelve per cent, of the cheetah kills were appropriated by lions and hyaenas.     

THE COLLECTION OF FOUND IVORY IN MURCHISON FALLS NATIONAL PARK, UGANDA

The paper concerns the circumstances surrounding the collection of ivory from dead elephants, with particular reference to Murchison Falls National Park. The characteristics of the interval between death and complete disintegration of an elephant are described. These, combined with observations of known age skeletons, comprised the criteria used in classifying skeletons found from the air into three relative age classes. Average annual mortality is estimated for the population north of the Nile (MFPN) at 147 animals yielding 1945 kg of ivory, and for that south of the Nile (MFPS) at 474 animals yielding 7497 kg ivory. Park-found ivory records are analyzed for the 11 y 1959–69. The expected age distribution of deaths is compared with the observed. For MFPN a bias in favour of large (male) tusks is present, explicable by the concentration of ranger search effort in areas of known high male density. For MFPS a bias towards small tusks is thought to be caused by elephants wounded outside the park dying inside it. The National Park recovers an average of 27.6 % of its available ivory per annum, with large annual fluctuations probably correlated with the incidence of wounding outside the park. High losses to poachers are evident. An aerial search for ivory showed a tendency for elephants to die near watercourses. A finding rate of one carcass every 4.3 km of watercourse was obtained. As only 5 % of carcasses still had tusks the aerial searching was prematurely terminated. The results indicated a finding efficiency of 26.4% of the available current year carcasses. Comparative costing suggests that ground searching would be a more efficient method of finding ivory than aerial searching. The high value of the available ivory in Murchison and other areas justifies intensive searching. The low collection rates prevailing in East Africa are largely attributable to the absence of appropriate search efforts.     

苏州地区金线蛙食性的初步研究

金线蛙各月份的食性分析表明,成蛙以捕食昆虫为主,首食种类是水生动物中的负子昃、螺、虾等,摄食种类变化主要与生境及生长发育相关。     

内蒙古东部地区狼的食性初步研究

本文采用粪便分析法和食痕分析法对内蒙古东部狼的食性进行初步研究。结果表明, 该地区狼的主要食物是大、中型有蹄类（出现频率53.8%, 相对生物量85.17%）, 粪便中家畜出现频率为40.3%, 相对生物量为75.67%。该地区狼的食性同黑龙江狼的食性相比, 存在地区差异。通过饲喂实验, 提出狼粪便中所含猎物的干重与鲜重间的线性回归方程为Y=2.76+0.02x（r=0.99）, 应用此方程可估计出狼消耗各种猎物的相对生物量和数量。在该地区狼对家畜危害比较严重, 要适当猎取同时也应保持其适当数量。     

THE FATE OF BLACK RHINOCEROSES RELEASED IN NAIROBI NATIONAL PARK

Information on the black rhinoceros population of Nairobi National Park has been obtained from two-month surveys in 1967 and 1968 backed by data collected at random over the past few years. It proved impossible to identify some of the rhinoceroses whose presence was indicated by spoor and unidentified sightings, and an estimate of the total number present at the end of 1968 must vary between 27 and 33 animals. Twenty-two rhinoceroses have been brought into the Park by the Game Department Capture Unit since November 1966. The fate of these animals has been: two dead, two not seen and 18 identified in the Park 3–33 months after release. The newcomers have produced only one serious conflict with a resident rhinoceros and two collisions with motor vehicles. Despite the small size of the Park, the inadequacy of its boundaries and the legendary intolerance of the species, it would appear that the translocation operations have been a success.