Forest Elephants Research Articles

Devastating Decline of Forest Elephants in Central Africa

African forest elephants– taxonomically and functionally unique–are being poached at accelerating rates, but we lack range-wide information on the repercussions. Analysis of the largest survey dataset ever assembled for forest elephants (80 foot-surveys; covering 13,000 km; 91,600 person-days of fieldwork) revealed that population size declined by ca. 62% between 2002–2011, and the taxon lost 30% of its geographical range. The population is now less than 10% of its potential size, occupying less than 25% of its potential range. High human population density, hunting intensity, absence of law enforcement, poor governance, and proximity to expanding infrastructure are the strongest predictors of decline. To save the remaining African forest elephants, illegal poaching for ivory and encroachment into core elephant habitat must be stopped. In addition, the international demand for ivory, which fuels illegal trade, must be dramatically reduced.

Dispatches

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Doom of the elephant-dependent trees in a Congo tropical forest

In an evergreen lowland rain forest of the Cuvette Centrale, DR Congo, at the LuiKotale Max-Planck research site, forest elephants (Loxodonta cyclotis) are close to extinction. Between January 2009 and June 2011 we investigated the influence of elephant decline on sustainability of elephant-dispersed tree populations.For this, we explored how trees with the megafaunal syndrome reproduce without seed dispersal by elephants and how does this affect the demography and spatial distribution of these tree species. We studied alternative partners for functional replacement of the elephant.Overall, 18 tree species presenting the megafaunal syndrome were identified and studied. They represent 4.5% of the local tree diversity with a density of 28.2±2.7tree/ha. Seventy-eight percent (14/18) of these megafaunal-tree species are elephant-dependent and do not recruit enough young for self replacement, either under the parent or beneath other tree species. For 12 of these species populations, the first cohorts were absent in our plots. For species able to recruit, the spatial structures of the young generations are more clumped than adults while they are not different for control tree species.There is no alternative partner for seed dispersal for the majority of the megafaunal trees which are actually elephant dependent.We discuss the likely consequences of the loss of elephant dispersed tree species and propose alternatives for species survival to bridge the time until efficient conservation strategies take effect.

Sexual Dimorphism and Inter-Generic Variation in Proboscidean Tusks: Multivariate Assessment of American Mastodons (Mammut americanum) and Extant African Elephants

Characteristics of social structure, mating strategies, and parental investment can be inferred for mammalian species based on degree of sexual dimorphism, especially when males are substantially larger than females. American mastodons (Mammut americanum) and extant African elephants (Loxodonta africana, Loxodonta cyclotis) both exhibit marked dimorphism in tusk size. To evaluate the hypothesis that this dimorphism might be indicative of similar, and possibly conserved, behavioral patterns in each lineage, we undertook a detailed evaluation of the pattern of tusk growth in these two genera. Separate discriminant function analyses (DFA) of 21 adult mastodon tusks of inferred sex and 48 adult elephant tusks of known sex show that patterns of ontogenetic change in tusk circumference, regardless of genus, effectively discriminate between sexes. Canonical variates analysis (CVA) of tusks from male and female mastodons and male and female elephants shows that male tusks in both genera are larger than female tusks across all measurements, especially for maximum tusk circumference and pulp cavity depth. CVA’s emphasis of inter-group differences in tusk morphology also shows that mastodon tusks are more robust than elephant tusks. Overall, this study illustrates that there is a characteristic male and a characteristic female tusk form shared by elephants and mastodons. This shows that elephants and mastodons display a shared syndrome of traits beyond sex-linked differences in tusk size, supporting the hypothesis that mastodons exhibited behaviors similar to those we observe today in African elephants.

Exploitation of Wild Animals in Obafemi Owode Local Government Area, Ogun State, South West, Nigeria

The study investigated the reasons for exploiting, utilization and destruction of wild animals in Obaemi Owode Local Government Area of Ogun State, south west Nigeria. Well-structured questionnaires were used to obtain information from various categories of respondents, farmers; hunters, male, female, young and old etc. Wild animals were exploited and utilised for food (34.5%), sale (31.3%), medicine (15.6%), tradition (12.0%), farmland protection (5.0%) and trophy (0.9%). The animals mostly affected were Tryonomys swinderianus , Protoxerus stangeri , Cephalophus spp., Squamata spp., Cricetomys gambianus and Lepus spp.. These are still seen due to their size, short gestation period and their large litter size. While animals such as Loxodonta cyclotis , Syncerus caffer , Pan troglodities and Phacochoerus aethiopicus are no longer seen in the area. Other factors responsible for the high rate of wild animal exploitation are: unemployment, which drove must youth to hunting as the only means of survival, poverty among the population and low level of awareness of wildlife conservation education. Creation of employment, effective wildlife legislation, wildlife resources protection and public enlightenment through conservation education would go a long way in reducing the problem.

Demand for forest elephant ivory in Japan

Japan is the only country where a strong demand for ‘hard’ or forest elephant ivory still exists. This demand differs from that of China, which consumes more ivory but where no preference for soft or hard ivory exists. While there is no hard evidence that ivory originating from forest elephants in Central Africa is smuggled into Japan, the question remains whether only old stock of hard ivory can be meeting the stable demand. Through investigations in ivory markets in Japan, it was found that ivory dealers there have limited knowledge of the domestic ivory-trade control system and have not applied it. Also, this control system is not sufficient to manage the legal ivory trade. These factors may facilitate the illegal importation of hard ivory into the Japanese market. We recommend that the Japanese ivory-management system be re-evaluated and improved, focusing on hard ivory stock management. In addition, Japan should develop an information-sharing system for forest elephant conservation by producing and distributing practical education materials in Japanese. These are priorities because hard ivory originates in the Central African region, where poaching pressure on forest elephants is increasing, resulting in a drastic decline in their populations. Le Japon est le seul pays où il existe toujours une forte demande pour l’ivoire «dur» ou l’ivoire des éléphants de forêt. Cette tendance diffère de celle de la Chine qui a une plus grande consommation d’ivoire, mais où il n’existe aucune préférence pour l’ivoire souple ou dur. Bien qu’il n’y ait pas de preuves tangibles que l’ivoire provenant des éléphants de forêt en Afrique centrale passe en contrebande au Japon, il reste la question de savoir si seulement le vieux stock d’ivoire dur pourrait répondre à la demande stable. Grâce à des enquêtes sur les marchés d’ivoire au Japon, on a constaté que les négociants d’ivoire au Japon ont une connaissance limitée du système de contrôle interne du commerce de l’ivoire et ne l’appliquent pas. En outre, ce système de contrôle ne suffit pas à gérer le commerce légal de l’ivoire. Ces facteurs peuvent faciliter l’importation illégale d’ivoire dur sur le marché japonais. En conclusion, le système de gestion de l’ivoire japonais doit être réévalué et amélioré, et l’accent mis sur la ​​ gestion des stocks d’ivoire dur. En outre, le Japon devrait mettre au point un système d’échange d’informations sur la conservation de l’éléphant de forêt, en produisant et en distribuant du matériel didactique pratique aux Japonais. Tout cela est prioritaire parce que l’ivoire dur provient d’Afrique centrale, où la pression du braconnage sur les éléphants de forêt s’accroît ce qui donne lieu à une baisse drastique de leurs populations.

Identifying source populations and genetic structure for savannah elephants in human-dominated landscapes and protected areas in the Kenya-Tanzania borderlands.

We investigated the genetic metapopulation structure of elephants across the trans Rift Valley region of Kenya and Tanzania, one of the remaining strongholds for savannah elephants (Loxodonata africana) in East Africa, using microsatellite and mitochondrial DNA (mtDNA) markers. We then examined this population structure to determine the source population for a recent colonization event of savannah elephants on community-owned land within the trans rift valley region. Four of the five sampled populations showed significant genetic differentiation (p<0.05) as measured with both mtDNA haplotypes and microsatellites. Only the samples from the adjacent Maasai Mara and Serengeti ecosystems showed no significant differentiation. A phylogenetic neighbour-joining tree constructed from mtDNA haplotypes detected four clades. Clade four corresponds to the F clade of previous mtDNA studies that reported to have originated in forest elephants (Loxodonta cyclotis) but to also be present in some savannah elephant populations. The split between clade four and the other three clades corresponded strongly to the geographic distribution of mtDNA haplotypes across the rift valley in the study area. Clade four was the dominant clade detected on the west side of the rift valley with rare occurrences on the east side. Finally, the strong patterns of population differentiation clearly indicated that the recent colonists to the community-owned land in Kenya came from the west side of the rift valley. Our results indicate strong female philopatry within the isolated populations of the trans rift valley region, with gene flow primarily mediated via male movements. The recent colonization event from Maasai Mara or Serengeti suggests there is hope for maintaining connectivity and population viability outside formal protected areas in the region.

Forest elephants: fission–fusion and social arenas

Fission–fusion systems provide models for studying grouping decisions and social complexity in a range of taxa, as individuals act to manage risks and enhance reproductive success. African savannah elephants, Loxodonta africana africana , live in a fluid society where individual relationships persist over decades and affect reproductive success. Social structures have yet to be fully characterized for forest elephants, Loxodonta africana cyclotis . Aggregations at natural forest clearings, which are frequent in this subspecies, may offer social benefits in addition to nutritional resources. We examined the social functions of aggregations in Odzala–Kokoua National Park, Republic of Congo. We tested whether clearings function as ‘social arenas’ by examining how social opportunities affected the timing and duration of visits, and how short-term grouping decisions were affected by age, sex, group size and number of elephants present. Aggregations reflected a fission–fusion society similar to that observed in savannah elephants. Grouping patterns were largely unaffected by the number of elephants present, from which we infer that elephants were not acting to minimize competition. Social opportunities affected visit patterns such that visits were longer when others were present. Social opportunities were maximized by joining large groups, often including older elephants, or, for males, parties with females. Large and dynamically changing social groups in clearings offer potential for information exchange and the maintenance of social relationships. Demonstrating that fission–fusion operates in forest elephant society allows future research to focus on cost–benefit modelling, to understand the fitness consequences of these groupings.

Seed dispersal strategies and the threat of defaunation in a Congo forest

Seed dispersal mode of plants and primary interactions with animals are studied in the evergreen Afrotropical forest of LuiKotale, at the south-western part of Salonga National Park (DR Congo). We first analysed seed dispersal strategies for (a) the plant species inventoried over a decade at the study site and (b) the tree community in 12 × 1 ha census plots. Our analyses of dispersal syndromes for 735 identified plant species show that 85 % produce fleshy fruits and rely on animals for primary seed dispersal. Trees depending on animals for primary dispersal dominate the tree community (95 %), while wind-dispersed and autochorous trees are rare in mixed tropical forests. A list of frugivorous vertebrate species of the ecosystem was established. Among the fruit-eating vertebrate species identified in the ecosystem, forest elephants and bonobos are threatened with extinction (IUCN, The IUCN red list of threatened species, 2012). Although most of the species listed previously are internationally and regionally protected, all the species we observed dispersing seeds are hunted, fished or trapped by humans in the area. With the exception of bush pigs, seed predators, mainly small-sized animals, are generally not targeted by hunters. As a consequence, we expect human pressure on key animal species to impact the plant community. We suggest defaunation to be considered as major conservation problem. Thus, not only for the sake of animal species but also for that of plant species conservation, anti-poaching measures should have priority in both “protected” and unprotected areas. Defaunation could bring a new impoverished era for plants in tropical forests.

Triangulating the provenance of African elephants using mitochondrial DNA.

African elephant mitochondrial (mt) DNA follows a distinctive evolutionary trajectory. As females do not migrate between elephant herds, mtDNA exhibits low geographic dispersal. We therefore examined the effectiveness of mtDNA for assigning the provenance of African elephants (or their ivory). For 653 savanna and forest elephants from 22 localities in 13 countries, 4258 bp of mtDNA was sequenced. We detected eight mtDNA subclades, of which seven had regionally restricted distributions. Among 108 unique haplotypes identified, 72% were found at only one locality and 84% were country specific, while 44% of individuals carried a haplotype detected only at their sampling locality. We combined 316 bp of our control region sequences with those generated by previous trans-national surveys of African elephants. Among 101 unique control region haplotypes detected in African elephants across 81 locations in 22 countries, 62% were present in only a single country. Applying our mtDNA results to a previous microsatellite-based assignment study would improve estimates of the provenance of elephants in 115 of 122 mis-assigned cases. Nuclear partitioning followed species boundaries and not mtDNA subclade boundaries. For taxa such as elephants in which nuclear and mtDNA markers differ in phylogeography, combining the two markers can triangulate the origins of confiscated wildlife products.

The identification of elephant ivory evidences of illegal trade with mitochondrial cytochrome b gene and hypervariable D-loop region

DNA analysis of elephant ivory of illegal trade was handled in this work. The speciation and geographical origin of nine specimens of elephant ivory were requested by the police. Without national authorization, the suspect had purchased processed ivory seals from January to May, 2011 by Internet transactions from a site in a neighboring country. The DNA of decalcified ivory evidences was isolated with QIAGEN Micro Kit. The total 844–904 base pair sized sequences of mitochondrial cytochrome b and D-loop region could be acquired using direct sequencing analysis. They were compared with the sequences registered in GenBank. It was confirmed that most specimens were likely from African forest elephants (Loxodonta cyclotis), one from African savanna elephant (Loxodonta africana) and one from Asian elephant (Elephas maximus). Analysis of the mitochondrial hypervariable D-loop region sequence of elephants verified that one African savanna elephant might be from South Africa and one Asian elephant from Laos. Cytochrome b and D-loop region located in the mitochondrial DNA resulted in the successful determination of elephant DNA from nine processed ivory specimens.

Movement Patterns and Spatial Relationships Among African Forest Elephants

AbstractAfrican forest elephants (Loxodonta cyclotis) are of immediate conservation concern, yet are understudied due to inaccessible habitats. We analyzed the home range size and overlap of six adult females. Home ranges were among the smallest for all elephant species and individuals were positioned adjacent to one another with minimal overlap.

Exploring the relationship betweenNDVIand African elephant population density in protected areas

AbstractAssessing the extent to which populations are limited by bottom‐up processes driven by food limitation is crucial to our understanding of how ecosystems should be managed. Using satellite‐derived Normalised Difference Vegetation Index (NDVI) as an index of resource availability, we investigated the relationships between greenness levels and African elephant (Loxodonta africana) population densities. Our results unveiled a positive relationship betweenNDVIand elephant densities in nonforest populations, but failed to capture any significant effects of survey area and type, number of years after the continental poaching ban and theIUCNcategory of the protected area in which the survey was undertaken. The number of forest elephant populations for which density estimates were available was very low, and no significant relationship betweenNDVIand forest elephant density could be established. Altogether, our study suggests thatNDVIcan successfully be linked to megaherbivore abundance across Africa and further highlights that a continental approach to energy–abundance relationships can be conducted in a relatively low‐cost manner and short timescale, supporting managers' efforts to identify future suitable areas for elephant populations.

Using Threatening Sounds as a Conservation Tool: Evolutionary Bases for Managing Human–Elephant Conflict in India

Asian elephants (Elephas maximus) are one of three species of elephants in the world, the others being the African bush elephant (Loxodonta africana) and the African forest elephant (Loxodonta cycl...

Dispatches

Dispatches

Molecular phylogenetics of the elephant schistosome Bivitellobilharzia loxodontae (Trematoda: Schistosomatidae) from the Central African Republic

One of the most poorly known of all schistosomes infecting mammals is Bivitellobilharzia loxodontae. Nearly all of our available information about this species comes from the original description of worms that were obtained from an animal park-maintained elephant in Germany, probably a forest elephant Loxodonta cyclotis, originating from the present-day Democratic Republic of Congo. We obtained schistosome eggs from faecal samples from wild forest elephants from the Central African Republic. The eggs, which were similar in size and shape to those of described B. loxodontae, were sequenced for the 28S nuclear ribosomal gene and the mitochondrial cytochrome oxidase I (cox1) gene. In a phylogenetic analysis of 28S sequences, our specimens grouped closely with B. nairi, the schistosome from the Indian elephant Elephas maximus, to the exclusion of schistosomes from other genera. However, the eggs were genetically distinct (12% distance cox1) from those of B. nairi. We conclude the specimens we recovered were of B. loxodontae and confirm this is a distinct Bivitellobilharzia species. In addition to providing the first sequence data for B. loxodontae, this report also supports Bivitellobilharzia as a monophyletic group and gives the relative phylogenetic position of the genus within the Schistosomatidae. We also provide a review of the biology of this poorly known schistosome genus.

Forest elephant mitochondrial genomes reveal that elephantid diversification in Africa tracked climate transitions

Among elephants, the phylogeographic patterns of mitochondrial (mt) and nuclear markers are often incongruent. One hypothesis attributes this to sex differences in dispersal and in the variance of reproductive success. We tested this hypothesis by examining the coalescent dates of genetic markers within elephantid lineages, predicting that lower dispersal and lower variance in reproductive success among females would have increased mtDNA relative to nuclear coalescent dates. We sequenced the mitochondrial genomes of two forest elephants, aligning them to mitogenomes of African savanna and Asian elephants, and of woolly mammoths, including the most divergent mitogenomes within each lineage. Using fossil calibrations, the divergence between African elephant F and S clade mitochondrial genomes (originating in forest and savanna elephant lineages, respectively) was estimated as 5.5 Ma. We estimated that the (African) ancestor of the mammoth and Asian elephant lineages diverged 6.0 Ma, indicating that four elephantid lineages had differentiated in Africa by the Miocene-Pliocene transition, concurrent with drier climates. The coalescent date for forest elephant mtDNAs was c. 2.4 Ma, suggesting that the decrease in tropical forest cover during the Pleistocene isolated distinct African forest elephant lineages. For all elephantid lineages, the ratio of mtDNA to nuclear coalescent dates was much greater than 0.25. This is consistent with the expectation that sex differences in dispersal and in variance of reproductive success would have increased the effective population size of mtDNA relative to nuclear markers in elephantids, contributing to the persistence of incongruent mtDNA phylogeographic patterns.

Opening a larger window onto forest elephant ecology

AbstractAfrican forest elephants (Loxodonta cyclotis) can be observed reliably in forest clearings but are difficult to observe directly in their otherwise forested habitat. To obtain data on population demography and activity cycles, conservation programmes commit considerable human and financial resources to observations at clearings. However, individual elephants spend only a tiny proportion of their annual activity budget in a particular clearing, and there may be demographic differences between daytime and nighttime populations. Using acoustic monitoring tools to assess elephant numbers continuously for long time periods at multiple clearings, we show that daytime‐only observations are likely to be biased. In this study, (i) 79% of all elephant visitation occurred at night, (ii) sometimes large changes in nocturnal elephant numbers occurred without proportional changes in daytime elephant numbers, and (iii) there were indications that a different demographic of the population visits clearings at night compared with the day. These results suggest that acoustic monitoring should be incorporated into forest elephant monitoring programmes to augment direct observation and that more study is needed to explicitly identify any biases inherent in daytime‐only observation.

Assessment of the Large Mammals of Arakhuan Range, Okomu National Park, Nigeria

An assessment of the large mammals of Arakhuan Range, Okomu National Park, Edo State, Nigeria, was carried out using land transect methods. A total of 12 large mammalian species were observed (eight directly and four by their signs). These are made up of four primate species; Red-capped mangabey ( Cercocebus torquatus ), Mona monkey ( Cercopithecus mona ), White-throated monkey ( C. erythrogaster pocok i), and Putty-nosed monkey ( C. nictitans ludio ), three species of antelope: Maxwell duiker ( Cephalophus maxwelli ), Yellow-backed duiker ( Cephalophus silvicultor ), and Red-flanked duiker ( Cephalophus rufilatus ), and a species of mangoose ( Herpestes sp). Those observed through their activities were forest elephants ( Loxodonta africana cylotis ), forest buffalo ( Syncerus caffer nanus ), civet cat ( Viverra civetta ) and the red river hog ( Patamochoerus porcus ). Altogether, 145 sightings of animals were recorded during the study period. Mona monkeys were most commonly sighted (sighted 37 times, producing 0.22 sighting/km) -2 and population of 1970.93±412.93 individuals. The yellow-backed duiker was very rare in the range as it was sighted three times with an estimated population of 9 ± 2 individuals. There is very strong correlation between sightings in the morning and that of evening (r = 0.94, P < 0.05). However, there were significant differences in sighting on transects (χ2 cal. = 35.18, χ2 tab. = 32.7, df = 10, P < 0.05) indicating that sightings are transect-dependent. Over 50% of all sightings were achieved in the matured forest. Keywords: Mammals, line transect, sightings, estimated population.

The relic population of forest elephants near Lake Tumba, Democratic Republic of Congo: abundance, dung lifespan, food items and movements

A survey of forest elephant was conducted in the southern Lake Tumba region, using both transect and forest reconnaissance methods. Three focal areas of elephants were discovered in the region stretching from Ngombe down to the region of Malebo. Due to insufficient data, only relative abundances were calculated and varied among these three different locations: 0.03 dung-piles/km (Ngombe–Lake Tumba), 0.04 dungpiles/km (Mbanzi–Malebo) and 0.33 dung-piles/km (Lukolela). Elephant trails in the Malebo–Mbanzi area were traversed 0.52 passages/day, within the range [0.50–3.0], indicating a permanent presence of elephants in the zone. Dung-piles in the dry and rainy seasons yielded an overall mean dung lifespan of μ = 109 days within the range [42–182] and seasonal mean lifespan μ = 127.6 days within [70–182] and μ = 87.33 days within [42–126] respectively. Dung-pile heights decreased following the equations y = -4.8818lnx + 16.278 and y = 26.025e-0.3734+x respectively. Seed counts on elephant dung-piles indicated that Dysplasia dewevrei, Klainedoxa gabonensis, Treculia africana and Anonidium mannii constituted ca 70% of seeds found in elephant dung-piles. Elephant movements were suspected by the layout of trails but their confirmation would need a more detailed study. Key words: forest elephant, Lake Tumba, food items, elephant movements Une étude de l’éléphant de forêt a été menée dans la région sud du Lac Tumba, en utilisant les deux méthodes de transect et de reconnaissance de forêt. On a découvert trois domaines de concentration d’éléphants dans la région s’étendant de Ngombe vers la région de Malebo. En raison des données insuffisantes, on a calculé seulement les abondances relatives et elles variaient entre ces trois endroits différents: 0,03 tas de crottes/km (Ngombe-Lac Tumba), 0,04 tas de crottes/km (Mbanzi-Malebo) et 0,33 tas de crottes/km (Lukolela). Les pistes d’éléphants dans la zone de Malebo-Mbanzi ont été parcourues avec 0,52 passages/jour, dans l’intervalle [0,50 à 3,0], indiquant une présence permanente des éléphants dans la zone. Les tas de crottes pendant les saisons sèches et pluvieuses ont donné une durée de vie moyenne globale de crotte μ = 109 jours dans l’intervalle [42-182] et une durée de vie moyenne saisonnière μ = 127,6 jours dans l’intervalle [70-182] et μ = 87,33 jours dans l’intervalle [42 - 126] respectivement. Les hauteurs des tas de crottes ont diminué d’après les équations y =-4.8818lnx + 16.278 et y = 26.025e-0.3734+x respectivement. Le nombre de graines sur les tas de crottes d’éléphants indiquaient que le Dysplatsia dewevrei, le Klainodoxa gabonensis, le Treculia Africana et le Manii Annonaduim constituaient environ 70% de celles trouvées dans les tas de crottes d’éléphants. On a eu le sentiment que la disposition des pistes correspondait aux déplacements des éléphants, mais il faudra une étude plus détaillée pour la confirmation.