Forest Elephants Research Articles

Eavesdropping on elephants

The Elephant Listening Project is creating an acoustic monitoring program for African forest elephants, an endangered species that lives in dense forests where visual censusing is impossible. In 2002, a 21/2-month continuous recording was made on an array of autonomous recording units (ARUs) surrounding a forest clearing in the Central African Republic. Each day between 10 and 160 forest elephants (Loxodonta cyclotis), the subjects of Andrea Turkalo’s 13-year demographic study, were present on the clearing. Thousands of vocalizations were recorded, most of which contained infrasonic energy. The calls were located in space using software developed in the Bioacoustics Research Program. During daylight hours simultaneous video recordings were made. GPS time-synchronization of video cameras and the ARUs made it possible to identify the elephants responsible for many calls and to examine associated circumstances and behaviors. Recordings were also made on a second acoustic array, permitting a preliminary estimate of propagation and an indication of source level for selected elephant calls. Automatic detection of elephant calls is increasing the feasibility of analyzing long acoustic recordings, and paving the way for finer-tuned analyses, with an ultimate goal of describing forest elephants’ acoustic repertoire.

Fruit, Minerals, and Forest Elephant Trails: Do All Roads Lead to Rome?1

Tropical forests are among the most heterogeneous environments on earth, and food resources for many animals are patchy both in time and space. In Africa's equatorial forest, permanent trails created and maintained by forest elephants are conspicuous features. Trails may be several meters wide and continue for tens of kilometers. Speculation on which resources determine the distribution of trails has identified fruit, browse, and mineral deposits as candidates. In this study, the relationships between these habitat variables and elephant trails were investigated. The size of individual trails and the density of the trail system increased dramatically with proximity to mineral deposits. Fruit tree basal area decreased with perpendicular distance from trails, while that of non-fruit trees did not. Fruit tree abundance and basal area were significantly higher on trail intersections than random sites and increased with intersection size. No relationship was found between monocotyledon browse abundance and elephant trail system characteristics. Clumped resources, which are at least partially reliable, provide a high nutritional payback, and are not rapidly depleted and can thus be visited repeatedly, appear to influence permanent trail formation by forest elephants. Permanent trails may allow naive individuals or those with imperfect knowledge to locate and acquire important resources.

Status of the so-called African pygmy elephant ( Loxodonta pumilio ( Noack 1906)): phylogeny of cytochrome b and mitochondrial control region sequences

Among the African elephants, it has been unanimously acknowledged that the forest elephants ( cyclotis form) are peculiar, so that they have been elevated to the specific rank. The development of molecular analyses of extant Loxodonta has only focused on two forms yet: the savannah form ( africana) and the forest form ( cyclotis), disregarding the so-called pygmy elephants ( pumilio or fransseni) the systematic status of which has been debated since their discovery. Therefore, we have sampled nine dwarfed-labelled specimens in collection and eight specimens of typical forest elephants that we compared to three savannah elephants and two Asian elephants. Because of the degraded nature of the nuclear DNA content in bone samples of old specimens, we assayed mitochondrial markers; 1961 bp of the mitochondrial genome were sequenced (over a continuous range spanning the cytochrome b gene, tRNA Thr, tRNA Pro, hypervariable region 1 and central conserved region of the control region). Pumilio and cyclotis are not sister-taxa: the phylogenetic analyses rather account for the inclusion of the so-called pygmy elephants within a monophyletic group of forest elephants sensu lato. The internal structure of this clade reveals to depend on isolation and remoteness between populations, characteristics that may have been extensively influenced by climatic variations during the Quaternary period. We conclude that the specific taxon Loxodonta pumilio (or Loxodonta fransseni) should be abandoned. To cite this article: R. Debruyne et al., C. R. Biologies 326 (2003).

Preliminary results on movements of a radio-collared elephant in Lobéké National Park, south-east Cameroon

Athough actual numbers and movements are unclear the south east region of Cameroon harbours a significant population of forest elephants. Preliminary results from data collected for 8 months from a 5 year old male forest elephant radio collared in March 2001 suggest that elephants spent more time in the forest in the logging concessions and professional hunting zones that they did in the Lobeke NP itself. Initial results from the telemetry programme, which was part of WWF's Jengi project, confirm the need to step up protection efforts including anti-poaching patrols to curb the poaching and illegal ivory trade opportunities that are common within the logging concessions. Further monitoring on radio collared elephant will assist in determining important corridors and migratory routes within the trans-boundary conservation programme region involving contiguous protected areas in this region including the Dzanga-Sangha in Central African Republic, and Nouabale Ndoki NP in the Congo (where at least 3 elephant have been radio collared).

Elephant poaching and ivory trafficking in African tropical forests with special reference to the Republic of Congo

"Elephant poaching is chronic and ivory is traded in and around Odzala NP in the Congo. Larger pieces of ivory and more high-calibre weapons that had been seen for some time appeared in 1999 about the time the southern African countries legally exported ivory in a one off sale to Japan. However there have been no large scale slaughters reported since the 1997 one at Mouadje where 300 animals were killed. Laws are not enforced and Congolese authorities themselves are often involved in illegal activity. Several factors encourage elephant poaching including: widespread availability of military weapons, local peoples' urge to profit from ivory sale; conflict between local people and conservation authorities over policies, and logging activities. 'The MIKE programme currently does not seem to function well in central Africa because of difficult logistics in the tropical forest and lack of experienced personnel.' The author suggests that the driving force behind elephant poaching is the international demand for ivory, and in particular the Japanese demand for hard forest elephant ivory for name seals. He notes 'Allowing ivory trade, as adopted in the CITES... will encourage illegal traffic in hard ivory and stimulate more poaching of forest elephants'."

Forest elephant (Loxodonta africana cyclotis) stature in the Réserve de Faune du Petit Loango, Gabon

AbstractThe stature of forest elephants Loxodonta africana cyclotis was determined at the Petit Loango Reserve over 14 months from January to December 1998 and May to June 1999 using three measures: shoulder height, hind footprint length and boli diameter. The shoulder height of 53 identified elephants was measured using photogrammetric methods. The minimum estimated shoulder height was 69 cm from a young calf, and the tallest animal was 216 cm. Hind footprint length and boli diameter data were collected from unidentified individuals. The minimum footprint size was 12.5 cm and the largest 35.3 cm. Boli diameter ranged from 4.0 to 16.0 cm. A comparison of the size categories with those of savanna elephants in Amboseli National Park, Kenya, suggested a similar distribution of size, age and population structure, despite a marked difference in overall stature. These are the first data for measures of African forest elephant size compared to African savanna elephant size. Such data may add morphological evidence supporting recent genetic work suggesting that African forest elephants be re‐classified as a distinct species from the African savanna elephant.

Wild forest elephants shake down fruit and leaves from trees

This short paper reviews aspects of observed feeding behaviour of forest elephants in the vicinity Bomassa near of the headquarters of Nouabale-Ndoki NP, near the Dzanga Clearing and in Gamba. These observations suggest that 'forest elepants frequently manipulate both objects and inedible parts of food plants to obtain food as part of their behavioural repertoire'. The assumption that forest elephant simply eat the fallen fruit is no longer valid, these observations note animals knocking fruit down by throwing sticks, using branches to swipe at fruit and foliage, shake trees, and push at trunks in order to bring down fruit. Night observations in the vicinity Bomassa and assessment of the appearance of the ground around favoured food trees in other areas notes fruits from trees such as Pseudospondias microcarpa, Myrianthus aboreus and Tetrapleura tetraptera, Omphalocarpum elatum and Chrysophyllum lacourteanum are taken by either repeatedly shaking the trunks of the smaller trees or repeatedly pushing against the larger ones. Near the Dzanga Clearing elephants have been heard and observed knocking fruit from additional tree species. Pygmies claim that elephants wait for fruit of certain trees to ripen and fall rather than attempt to gain quick access to the fruits by knocking them down. A film crew in Gamba noted elephant knocking Borassus aethiopum fruits down.

Patterns of molecular genetic variation among African elephant populations.

The highly threatened African elephants have recently been subdivided into two species, Loxodonta africana (savannah or bush elephant) and L. cyclotis (forest elephant) based on morphological and molecular studies. A molecular genetic assessment of 16 microsatellite loci across 20 populations (189 individuals) affirms species level genetic differentiation and provides robust genotypic assessment of species affiliation. Savannah elephant populations show modest levels of phylogeographic subdivision based on composite microsatellite genotype, an indication of recent population isolation and restricted gene flow between locales. The savannah elephants show significantly lower genetic diversity than forest elephants, probably reflecting a founder effect in the recent history of the savannah species.

The evolution and phylogeography of the African elephant inferred from mitochondrial DNA sequence and nuclear microsatellite markers.

Recent genetic results support the recognition of two African elephant species: Loxodonta africana, the savannah elephant, and Loxodonta cyclotis, the forest elephant. The study, however, did not include the populations of West Africa, where the taxonomic affinities of elephants have been much debated. We examined mitochondrial cytochrome b control region sequences and four microsatellite loci to investigate the genetic differences between the forest and savannah elephants of West and Central Africa. We then combined our data with published control region sequences from across Africa to examine patterns at the continental level. Our analysis reveals several deeply divergent lineages that do not correspond with the currently recognized taxonomy: (i) the forest elephants of Central Africa; the forest and savannah elephants of West Africa; and (iii) the savannah elephants of eastern, southern and Central Africa. We propose that the complex phylogeographic patterns we detect in African elephants result from repeated continental-scale climatic changes over their five-to-six million year evolutionary history. Until there is consensus on the taxonomy, we suggest that the genetic and ecological distinctness of these lineages should be an important factor in conservation management planning.

More than just big ears

To the non-specialist, large ears in elephants used to mean African, small ears, Indian. But to taxonomists African elephants have long posed a more complex puzzle. During the nineteenth century, it was fashionable for wealthy trophy hunters to assign their own names to species they had shot destined for the museums of Europe. At least 18 elephant subspecies were claimed following this fashion.But more recently, taxonomists have been building a stronger case that the African elephant may comprise more than one species. As in many other studies, molecular data have now been gathered to examine population and species relationships on the back of differences in morphological characteristics: forest elephants in central Africa are significantly smaller, have longer, thinner and straighter tusks and smaller ears than their savannah counterparts. These differences have led to suggestions that they may be different species. But the relationship of the savannah and forest elephants of western Africa to the others has been more difficult to determine because of the difficulty of obtaining DNA samples from animals in dense, remote forest.View Large Image | View Hi-Res Image | Download PowerPoint SlideBut a new study by Lori Eggert, Caylor Rasner and David Woodruff at the University of California San Diego, (Proc. Roy. Soc B, published online) uses new techniques for extracting DNA samples from faeces to help study the western elephants. They have looked at sequences in the mitochondrial cytochrome b control regions, along with those from four microsatellite loci for comparison with material from other elephant populations.Their studies suggest that western forest and savannah elephants may be a distinct species from the two proposed central and eastern counterparts. They also believe that historical separations may have been the result of dramatic climatic changes on the continent forcing populations apart.The researchers therefore believe the African elephants may hold a trace of some of the climatic calamities that occurred on the continent over the 5–6 million years of their evolution. These clues may also offer important input to conservation management planning of remaining stocks in the face of both human and climatic changes that are reducing and fragmenting their ranges. Numbers are estimated to have declined across the continent by a half to two-thirds of their population of around 1.3 million in 1979. And if three species are confirmed, especially as the western forest elephants are particularly vulnerable to human exploitation, a major rethink in conservation strategy may be required.

A proposal for a transnational forest network area for elephants in Côte d'Ivoire and Ghana

Forest elephants Loxodonta africana cyclotis in Ghana and eastern Côte d'Ivoire live in small isolated populations and number fewer than 1,000 individuals in total. To ensure the long-term survival of these elephants the present forest reserves need to be linked into a network by forest corridors. The potential of such corridors is demonstrated by the active use by elephants in Ghana of forest ‘shelterbelts’, created in the 1930s. Using information from recent surveys of elephants and vegetation status, and from published information, we propose three possible wildlife corridors in the border region between Côte d'Ivoire and Ghana, establishment of which would lead to a transnational forest network area in the Bia and Bossematié areas. Establishing a forest network for forest elephants would require political will, transnational cooperation among forest and wildlife managers, and participation of the local people.

Estimating forest elephant density in Sapo National Park (Liberia) with a rainfall model

AbstractThe number of elephant dung‐piles lying on the forest floor is a function of the number of elephants present and the rainfall in the 2 preceding months. We present the results of a stochastic model that describes this relationship and we show how it can be used to estimate elephant numbers. The data from a survey in Sapo NP (Liberia) in 1989 are used as an example. The dung‐pile density was estimated at 152 km−2 with confidence interval from 72 to 322, and the number of elephants was estimated to be 313 with confidence interval from 172 to 617.

Arkæologen Erik Westerby – Frontforsker på fritidsbasis

Arkæologen Erik Westerby – Frontforsker på fritidsbasis

Ikpan wetland rainforest : an area of high biodiversity importance in south-eastern Nigeria

A careful survey for mammals, reptiles, and amphibians, was conducted at the wetlands and rainforests of Ikpan Forest block, Cross River State (south-eastern Nigeria), during the period 1998-2001. The surveys proved that Ikpan Forest, although formally not protected at either regional or national levels, houses an extraordinarily rich biodiversity, including many vertebrates of ecological, biogeographic, and conservation importance. Among mammals, the most important taxa are primates (11 different species, including Mandrillus leucophaeus, Pan troglodytes, Procolobus badius preussi ), forest elephants, forest buffalos, and many ungulates. Manatees and leopards may also be present. Among reptiles, Osteolaemus tetraspis, Kinixys spp., Varanus niloticus omatus, Python sebae, and chameleons are especially important in conservation terms. Moreover, the study forest houses a conspicuous diversity of species of snakes (27) and amphibians (27), including many species which are good ecological indicators of forest quality, and some species which were rarely recorded in Nigeria before (e.g., the anurans Bufo superciliaris and Conraua crassipes). The study area has potentials for conservation and sustainable development (eco-tourism), but should certainly be monitored carefully in the next years to avoid the negative effects of timber extraction, local hunting, farming, and fishing with dynamites.

Status of northern white rhinos and elephants in Garamba National Park, Democratic Republic of Congo, during the wars

In recent years meat has been the premis behind poaching in Garamba NP. Patrol records suggest 70-80% of the poachers are Sudanese, often SPLA deserters, and the rest are Congolese. The significant increase in poaching in 1997 during the first DRC war was related to the fact that the guards were disarmed by occupying military forces and so had no control over poaching. There was no increase during the second DRC war, 1999-2000, although the Park headquarters was occupied by Ugandan-backed rebel forces, the personnel were not disarmed and there was little disruption to their anti-poaching efforts. Aerial survey counts in 1995 estimated 11,175 elephant. In May-June 1998, the estimated population was 5874, and in 2000 it was 6022. Observations suggest one half the elephants were lost during the first war, but there was no significant loss during the initial phase of the second war. Recent genetic results illustrate what observers have long suggested: Garamba elephants appear morphologially and behaviourly to be an intergrade between forest elephant (Loxodonta africana cyclotis) and savannah elephant (Loxodonta africana africana). International assistance focused on Garamba is noted.

Two species of African elephants

Genetic evidence supports the recognition and conservation management of African forest and savannah elephants as two distinct species.

Forest elephant distribution and habitat use in the Bossematie Forest Reserve, Ivory Coast

An August 1993-April 1994 study on the influence of human presence and habitat structure on the distribution and habitat use of forest elephant in the heavily exploited Bossematie FR in southeastern Ivory Coast. The distribution of elephants was estimated by dung counts on transects, and the habitat use was documented by trail mapping. Dung density incresed with the distance to the forest border and to the nearest village. Elephant appeared to use about 60% of the forest regularly, the rest they avoided because of foresty operations and human presence. The main influence on the spatial distribution of elephants in the study area was human presence, followed by ahbitat structure. Forest roads, regardless of usage, seemed to have no influence on elephant distribution. Elephant avoided coffee and cocoa plantations in all seasons. During the dry season they walked more often through forest parts with greater tree canopy cover than during the wet season, when they avoided valley bottoms.

GPS telemetry of forest elephants in Central Africa: results of a preliminary study

AbstractFew data exist on the ranging behaviour of forest elephants. A feasibility study on the use of GPS telemetry as a tool to study ranging, seasonal movements and distribution was implemented in the Dzanga‐Sangha and Nouabalé‐Ndoki National Parks Complex of Central African Republic and Congo. The study consisted of two parts – a thorough hand‐held testing of an elephant GPS telemetry collar under tropical forest conditions and the deployment of collars on two elephants. During the feasibility study the system performance was satisfactory; GPS fix acquisition success rate, VHF and UHF collar–researcher communications were adequate. Two elephants, a mature bull and an adult female, were immobilized and fitted with GPS collars in October 1998. After deployment, the female's GPS collar performed well initially, but in less than a month the GPS within the collar stopped acquiring fixes. She was subsequently located using VHF tracking. The male was never relocated strongly suggesting complete failure of the collar. Despite these setbacks, the small amount of data retrieved provide an important first insight into forest elephant ranging and daily activity patterns, with significant conservation implications. When technical difficulties of reliability are overcome, GPS telemetry will provide an exceptionally useful tool in forest elephant research and management.

Estimates of forest elephant abundance: projecting the relationship between precision and effort

Summary A key element of African elephant conservation is monitoring how different forms of human activity influence elephant distribution and abundance. Information on human–elephant interaction is critical for guiding conservation action at all levels, from very local management interventions, through national protected area planning, to international policy initiatives such as the ban on ivory trade. However, methods for monitoring elephant numbers often produce rather poor estimate precision. Therefore, a major challenge for elephant monitoring programmes at all levels is to allocate survey effort efficiently: the greatest possible statistical power to detect the effects of particular forms of human activity must be obtained from limited survey effort.This study examined an approach to survey design based on the assumption that the precision of an abundance estimate is directly proportional to sampling effort. Field data from three sites in Central Africa were used to evaluate the potential of this approach for projecting how much effort will be necessary to survey and monitor forest elephants.Variance in elephant dung pile encounter rate was proportional to sampling effort, but variance was also influenced by mean encounter rate. The relationship between variance and mean encounter rate followed a power law more closely than the linear model suggested by many previous authors. The linear model tended to substantially underestimate the effort level required for areas with high encounter rates. A bootstrapping exercise suggested that modelling the precision–effort relationship across strata should produce more accurate projections than estimating a distinct precision–effort relationship for each stratum.Our results suggest that the survey design framework examined could substantially improve the statistical power of forest elephant monitoring programmes, although the use of a power law (rather than linear) model seems preferable. A similar approach should be appropriate for designing savanna elephant monitoring programmes and for addressing other issues, including rates of hunting and human elephant conflict. Furthermore, the parameter estimates reported in this study should be useful in designing elephant survey and monitoring programmes at other forested sites in Central Africa.

Elephants et dissemination des graines de quelques espèces vegetales dans le Ranch de Gibier de Nazinga (sud du Burkina Faso)

Seed dispersal by forest elephants was assessed from dung samples collected monthly July 1996-June 1997. Seeds contained in the dung piles were counted and natural germination was simulated. Seed densities varied significantly between months, with a maximum in April, suggesting that fruits replace green forage as the food supply for elephants during the dry season. The seeds collected at the beginning of the dry season germinated at a higher rate that those collected towards the end of the season. Elephants dispersed about 20% of the woody species at various habitats of the study area. Results illustrate that elephant feed on fruits mainly during the dry season, and that they play an important role in disseminating seeds in the Nazinga area.