African elephant

About: African elephant is a research topic. Over the lifetime, 950 publications have been published within this topic receiving 23767 citations. The topic is also known as: Loxodonta.

African elephant status report 2007 : an update from the African elephant database

Abstract: The African Elephant Database is a spatial database used to store, manage, analyze and disseminate information on the distribution and abundance of elephant populations on the African continent, in order to provide a current and accurate picture of the status African elephants. Elephants are the largest living land mammals, and their potential impact on their habitats raises important management issues both for protected areas and unprotected land. This Status Report is rich in data and information on numbers, distribution and current issues, and provides continent-wide information that is vital for conservation. It will help wildlife management authorities to harmonize their policy and management decisions across regions, as well as the continent, to reduce conflict and relax the pressure on habitats.

Herbivore population crashes and woodland structure in east-africa

Abstract: 1. Between 1985 and 1991, bush encroachment was serious in Lake Manyara National Park, northern Tanzania. Shrub cover increased by c. 20%. The increase was independent of initial (1985) shrub cover. 2. Since 1987 there has been a steep decline in the number of African elephant in the Park due to poaching. Elephant density decreased from about 6 km-2 to about 1 km-2. However, shrub establishment, as determined from counting tree-rings, preceded poaching. 3. Shrub establishment in two areas of the Park coincided with anthrax epidemics that drastically reduced the impala population. In the northern section of the Park this was in 1984, in the southern section in 1977. 4. The diameter increment of Acacia tortilis was 5-24 mm year-1, irrespective of the size of the trees. Size measurements indicated an even-aged stand of Acacia established in 1961, which coincided with another anthrax outbreak among impala. 5. Size measurements of old Acacia tortilis trees indicated another even-aged stand established at the end of the 1880s. The size of trees of this stand was not significantly different from a stand in Tarangire National Park, nor from a stand near Ndutu (on the boundary between Serengeti National Park and Ngorongoro Conservation Area), also northern Tanzania. All three stands are likely to have originated from bush establishment caused by the rinderpest pandemic at the end of the 1880s. 6. It is suggested that seedling establishment of Acacia is a rare event under the prevailing conditions of high browsing pressures by ungulates such as impala. Punctuated disturbances by epidemics among these ungulates create narrow windows for seedling establishment, which may explain the occurrence of even-aged stands.

The demography of an African elephant (Loxodonta africana) population in Amboseli, Kenya

Abstract: This paper presents basic demographic parameters of African elephants (Loxodonta africana) living in and around Amboseli National Park, Kenya. The study was conducted from 1972 to the present and results are based on the histories of 1778 individually known elephants. From 1972 to 1978, the Amboseli elephant population declined and then increased steadily from 1979 to the present. Births occurred throughout the year but over 80% occurred between November and May. Birth rate varied from year to year with a pattern of peaks and troughs at 4- to 5-year intervals. The birth sex ratio did not differ significantly from 1:1. Mean age at first birth was 14.1 years, determined from a sample of 546 known-age females. Mean birth interval (n = 732) was 4.5 years for 255 females. Fecundity and calf survival varied by age of the females. Mortality fluctuated from year to year. Sex-specific mortality rates were consistently higher for males than females at all ages.

Sequencing the nuclear genome of the extinct woolly mammoth

Abstract: In 1994, two independent groups extracted DNA from several Pleistocene epoch mammoths and noted differences among individual specimens. Subsequently, DNA sequences have been published for a number of extinct species. However, such ancient DNA is often fragmented and damaged, and studies to date have typically focused on short mitochondrial sequences, never yielding more than a fraction of a per cent of any nuclear genome. Here we describe 4.17 billion bases (Gb) of sequence from several mammoth specimens, 3.3 billion (80%) of which are from the woolly mammoth (Mammuthus primigenius) genome and thus comprise an extensive set of genome-wide sequence from an extinct species. Our data support earlier reports that elephantid genomes exceed 4 Gb. The estimated divergence rate between mammoth and African elephant is half of that between human and chimpanzee. The observed number of nucleotide differences between two particular mammoths was approximately one-eighth of that between one of them and the African elephant, corresponding to a separation between the mammoths of 1.5-2.0 Myr. The estimated probability that orthologous elephant and mammoth amino acids differ is 0.002, corresponding to about one residue per protein. Differences were discovered between mammoth and African elephant in amino-acid positions that are otherwise invariant over several billion years of combined mammalian evolution. This study shows that nuclear genome sequencing of extinct species can reveal population differences not evident from the fossil record, and perhaps even discover genetic factors that affect extinction.

Determinants of human–elephant conflict in a land‐use mosaic

Abstract: Summary 1. The resolution of direct conflict between humans and elephants in Africa has become a serious local political issue in recent years, and a continental conservation problem. ‘Problem elephants’ damage crops, food stores and water sources, and sometimes threaten human life. 2. Eighty per cent of the African elephant's range lies outside formally protected areas, and inadequate management of human–elephant conflict is frequently a precursor to further decline in the numbers and distribution of elephants. Conflict appears to be increasing in an assortment of African ecosystems as the agricultural interface with elephant range expands. 3. The present study recorded incidents by problem elephants in small subdivisions of a 15 000 km2 elephant range. The level of problem elephant activity over 3 years showed huge variation and could not be explained by elephant density, proximity of a protected area, area of human settlement, human density or local rainfall. 4. It is proposed that the irregular and unpredictable nature of human–elephant conflict incidents in the study area mainly depended upon the behavioural ecology of individual elephant bulls. 5. This study proposes a statistic to quantify problem elephant activity in Africa which can be used to compare the intensity of problem incidents between different ecosystems at different times: ‘elephant incidents per square kilometre of human settlement area per year’. Spatial analyses of appropriate data at the human–elephant interface may yield a more predictive understanding of the conflict process.