Forest Elephants Loxodonta Cyclotis Research Articles

Call combination in African forest elephants Loxodonta cyclotis.

Syntax, the combination of meaning-devoid phonemes into meaningful words, which in turn are combined in structurally and semantically complex sentences, is fundamental to the unlimited expressiveness of human languages. Studying the functions of call combinations in non-human species provides insights into the evolution of such syntactic capabilities. Here, we investigated the combination of high amplitude broadband calls with low frequency rumble vocalizations in a highly social species, the African forest elephant Loxodonta cyclotis. Rumbles play an integral role in coordinating social interactions by transmitting socially relevant information, including individual identity. By contrast, broadband calls, such as roars, are thought to function as signals of distress and urgency as they are typically produced in situations of high emotional intensity. Functional changes associated with the combination of these calls remain little understood. We found that call combinations were produced by all age-sex classes but were most prevalent in immature individuals. We found that rumbles used singularly occurred in all five investigated social contexts, whereas single broadband calls were restricted to two resource-related contexts. Call combinations also occurred in all five contexts, suggesting an increase in the functional use of broadband calls when combined with rumbles, analogous to the generativity brought about through syntax in human speech. Moreover, combining calls appeared to lead to functional shifts towards high-stake contexts. Call combinations were more likely in competition contexts compared to single rumbles, and more likely in separation contexts compared to single broadband calls. We suggest that call combination in forest elephants may aide to reduce message ambiguity in high-stake situation by simultaneously communicating distress and individual identity, which may be critical to secure access to resources, reduce the risk of injury and to reunite with or recruit the support of the family group.

African Forest elephants persist in Guinea-Bissau but require an emergency conservation plan

AbstractThe status of the forest elephant Loxodonta cyclotis in Guinea-Bissau has been in doubt since the last assessment in 2006. In 2020–2022 we carried out field surveys to update the species' status. We found elephant signs within an area of c. 1,000 km2. Microsatellite genotyping of faeces identified four males. Females could not be individually identified but their presence was confirmed by molecular sex determination. Camera trapping (2,075 camera-trap days) recorded 824 photos in 24 independent sequences, involving three males and two presumed females. The continued presence of elephants in Guinea-Bissau raises hope for the species in the region, but urgent efforts are needed to refine population range and size estimates, increase protected area coverage, and reduce ongoing and impending habitat loss. An emergency conservation action plan is a priority.

The impacts of human activity on mammals in a community forest near the Dja Biosphere Reserve in Cameroon

AbstractHuman activity in African tropical rainforests continues to threaten wild mammals. Many rural communities are dependent on hunting, yet there is a widespread lack of baseline data on ecology and the sustainability of hunting. We investigated the impacts of human activity on mammal species composition and distributions within a community forest surrounding a village in the buffer zone of the Dja Biosphere Reserve in south-east Cameroon. We conducted a camera-trap survey in August–November 2017 and detected 24 mammal species, including Critically Endangered western lowland gorilla Gorilla gorilla gorilla, Endangered central African chimpanzee Pan troglodytes troglodytes and Endangered tree pangolin Phataginus tricuspis. We used occupancy analysis to explore relationships between indicators of human activity (distance to a road and the Reserve), habitat quality (distance to the river and tree cover) and the distributions of species. We found that the local distribution of threatened mammals was not apparently limited by human activity, and proximity to the road did not negatively influence occupancy for any species. However, most of the Reserve's large species were not detected, including the African forest elephant Loxodonta cyclotis and the largest ungulates, and the occupancy of two species commonly hunted for wild meat was positively correlated with distance from the village, indicating hunting may be unsustainable. Our results show that the community forest provides habitat for threatened species outside the Reserve and in close proximity to people. However, effective conservation management will require continued monitoring and research to determine whether current rates of hunting are sustainable.

Mammal distribution and trends in the threatened Ebo 'intact forest landscape', Cameroon

Intact forest landscapes (IFLs) are globally important for maintaining functional ecosystems. Ebo forest (~1400 km2) in Cameroon is one of the largest remaining IFLs in the Cross-Sanaga-Bioko coastal forest ecoregion and harbours several IUCN Red-Listed threatened mammal species. We evaluated the status, trends, and distribution of mammals ≥ 0.5 kg in the Ebo forest over 12 years using guided recce and camera trap monitoring surveys, as well as local knowledge to inform future land use and conservation planning. Recce monitoring of six taxa (blue duiker Philantomba monticola, chimpanzee Pan troglodytes, forest elephant Loxodonta cyclotis, putty-nosed monkey Cercopithecus nictitans, medium sized duikers Cephalophus spp., and red river hog Potamochoerus porcus) showed that some are stable or increasing. Indeed, our recent camera trap data confirmed breeding Gorilla gorilla (western gorilla) and elephant. Distribution models for chimpanzees and elephants showed that their populations are concentrated in the centre of the forest, away from human pressure. Some other species, however, including red colobus Piliocolobus preussi, leopard Panthera pardus, African golden cat Caracal aurata, and forest buffalo Syncerus caffer nanus are either close to extirpation or have been extirpated within living memory. We conclude that the Ebo intact forest landscape retains an important mammal community, despite no formal legal protection. Ebo’s future is uncertain, with two commercial logging concessions announced by Cameroon in 2020 and later suspended in response to national and international pressure. It is crucial to maintain Ebo’s integrity to protect the biodiversity and function of this important part of the Cross-Sanaga-Bioko coastal forest ecoregion.

Assessing the feasibility of density estimation methodologies for African forest elephant at large spatial scales

Effective wildlife management requires information on population status and distribution. Survey methods that provide estimates of these population parameters can vary greatly in effort required, area covered, precision of estimates, and cost. Trade-offs are required, because increasing precision and area coverage generally requires increasing field effort and incurs a higher cost. We compare DNA- and camera trap based-spatial capture-recapture approaches (DNA-SCR and CT-SCR) to the widely-used, dung-based line transect distance sampling (LTDS) method to assess their performance when applied to three relatively large populations of forest elephant Loxodonta cyclotis (>500 individuals), in order to evaluate their feasibility for future use at national and regional scales. Six of the nine surveys had a coefficient of variation below 20%; area coverage via DNA-SCR and LTDS was comparable and greatly exceeded that of the CT-SCR as applied; overall cost was highest for the LTDS surveys compared to the other two methods. We designed a new metric with which to compare survey methods: an integrated feasibility index (IFI). This combines three typical survey components: total area covered, level of precision achieved, and cost. The IFI suggests that DNA-SCR and LTDS are equally acceptable in terms of the combination of the three survey components, and that either survey method is suitable for large (national or regional) spatial scales for forest elephant density estimation. CT-SCR provides more precise estimates, but has double the IFI, due to the high cost per km2. DNA-SCR in particular, given the improvements highlighted in this study, is now being used at a national scale in Gabon. In conclusion, we recommend that the use of these spatial capture-recapture (SCR) methods, and their development, continue. Future findings and improvements should be compiled across studies to ensure their robust evolution as an option for monitoring the African forest elephant across its range and inform strategies and action for its conservation.

Entry and aggregation at a Central African bai reveal social patterns in the elusive forest elephant Loxodonta cyclotis

Social relationships are shaped by ecological conditions, giving rise to diverse societies even among related species. Among elephants, females exhibit close, often familial bonds with some degree of philopatry and fission–fusion dynamics. Forest elephant sociality is the least studied among elephant species, and their ecology differs from that of savannah and Asian elephants. We use over 15 years of data from an individually identified population using the Dzanga Bai forest clearing in Central African Republic to characterize social patterns of adult female elephants in two contexts, when entering the forest clearing and within the clearing. Social properties were nonrandom and highly stable over the study period in both contexts. Composition of aggregations within the clearing indicated considerable mixing among females, while association in groups entering the bai together were limited in composition, likely representing core social units. The co-entry data set exhibited distinct communities that were not apparent in the co-occurrence data set. In contrast to savannah elephants, network centrality and age were negatively correlated, suggesting a muted or absent matriarch social hub role in forest elephants at a broader level than family units. Temporal and community analyses indicated that bai co-entry and co-occurrence contexts may represent distinct processes, with the former social and the latter driven by shared resource use. Our results point to social patterns potentially driven by the need for families to fission into small units because of resource competition and highlight the importance of aggregation context in interpreting association indices. • We examined social patterns of female forest elephants using a bai forest clearing. • Composition of aggregations within the clearing indicated considerable mixing. • Groups that entered the bai together likely represented core social units. • Older females may not function as social hubs, unlike in other elephant species. • Forest resource constraints may shape social patterns of this elusive species.

Drawn out of the shadows: Surveying secretive forest species with camera trap distance sampling

Abstract With animal species disappearing at unprecedented rates, we need an efficient monitoring method providing reliable estimates of population density and abundance, critical for the assessment of population status and trend. We deployed 160 camera traps (CTs) systematically over 743 locations covering 17,127 km2 of evergreen lowland rainforest of Salonga National Park, block South, Democratic Republic of the Congo. We evaluated the applicability of CT distance sampling (CTDS) to species different in size and behaviour. To improve precision of estimates, we evaluated two methods estimating species' availability (‘A’) for detection by CTs. We recorded 16,700 video clips, revealing 43 different animal taxa. We estimated densities of 14 species differing in physical, behavioural and ecological traits, and extracted species‐specific availability from available video footage using two methods (a) ‘ACa’ (Cappelle et al. [2019] Am. J. Primatol., 81, e22962) and (b) ‘ARo’ (Rowcliffe et al. [2014] Methods Ecol. Evol. 5, 1170). With sample sizes being large enough, we found minor differences between ACa and ARo in estimated densities. In contrast, low detectability and reactivity to the camera were main sources of bias. CTDS proved efficient for estimating density of homogenously rather than patchily distributed species. Synthesis and applications. Our application of camera trap distance sampling (CTDS) to a diverse vertebrate community demonstrates the enormous potential of this methodology for surveys of terrestrial wildlife, allowing rapid assessments of species' status and trends that can translate into effective conservation strategies. By providing the first estimates of understudied species such as the Congo peafowl, the giant ground pangolin and the cusimanses, CTDS may be used as a tool to revise these species' conservation status in the IUCN Red List of Threatened Species. Based on the constraints we encountered, we identify improvements to the current application, enhancing the general applicability of this method.

Palynological analysis of faecal matter in African Forest Elephants Loxodonta cyclotis (Mammalia: Proboscidea: Elephantidae) at Omo Forest Reserve, Nigeria

The factors affecting African Forest Elephants include food availability, demand for ivory and changes in land-use. In order to survive, they tend to traverse considerable distances in search of food; on such occasions they are trapped and killed for their ivory. This present study is aimed at assessing the faecal matter of elephants, and at providing information on the season of ingestion and foraging preferences of these elephants. Faecal matter was collected at nine different locations for one year before being processed and subjected to standard palynological laboratory procedures. The analyses showed that the samples had moderately abundant and diversified palynomorphs. A total of 27 palynomorphs belonging to 22 families with a total count of 2,895 accounting for 94.34% were found to be eaten, while other plant fragments (epidermal cells, xylem vessel elements, and seeds) accounted for 5.66%. The wet and dry seasons accounted for 73.26% and 26.74% respectively. Epidermal cells and xylem vessel elements recorded (70.76%) and (29.2%) during the dry and wet seasons, respectively. In the palynological analysis, pollen of Balanites wilsoniana, Desplatsia subericarpa, Chrysophyllum albidum, among others were recovered in the faecal matter. Pollen analysis of faecal matters provided no information about the quantitative composition of the natural vegetation of elephants, but rather valuable information about their diet. It is recommended that these preferentially foraged parent plants should be cultivated on a large scale. This would potentially reduce competition for food and movement of these animals to other greener areas, consequently leading to poaching.

Modeling endangered mammal species distributions and forest connectivity across the humid Upper Guinea lowland rainforest of West Africa

Species distribution data provide critical baseline information for conservation planning and decision making. However, in many of the Earth’s most biodiverse regions, such data are lacking for many species. Here, we used ecological niche modeling and connectivity analyses to model distributions of endangered species and protected area connectivity across the Upper Guinea Forest (UGF) Global Conservation Hotspot of West Africa. We estimated the current distributions of African forest elephant Loxodonta cyclotis (Vulnerable), western chimpanzee Pan troglodytes verus (Critically Endangered), and pygmy hippopotamus Choeropsis liberiensis (Endangered) across the region and optimized connectivity in two main forest complexes in the region. We used occurrence data for the period 2010–2016 for the three species from two well-sampled national parks in Liberia (Sapo National Park and Gola National Park), and remotely sensed MODIS enhanced vegetation index data for the period 2010–2015. Our models predicted a total of 75,157 km2 of suitable habitat for chimpanzees in the region, 79,400 km2 for elephants, and 290,696 km2 for hippos. Of these areas, for chimpanzees, 30% of the area predicted falls within the boundaries of proposed or designated protected areas, and likewise 30% for elephants, and 19% for hippos. Liberia had the largest blocks of contiguous forest suitable for these species compared to other countries in the region but this forest was largely unprotected. This study identifies priority areas for biodiversity conservation and forest connectivity in the region, and reemphasizes the practicality of these tools to optimize conservation planning and implementation.

Not so far: attenuation of low-frequency vocalizations in a rainforest environment suggests limited acoustic mediation of social interaction in African forest elephants

Forest elephants Loxodonta cyclotis aggregate in large numbers in forest clearings. Whether they maintain contact as they move through the forest and are able to coordinate these aggregations, similar to the fission-fusion sociality of the well-studied savanna elephants Loxodonta africana, is currently unknown. Since sound attenuates faster in closed as compared to open habitats, the low-frequency rumble vocalizations of forest elephants may exhibit smaller detection ranges than measured for those of savanna elephants, which may restrict the ability of forest elephants to coordinate interactions between separated family units. Here, we modeled the attenuation of forest elephant rumbles using amplitude measurements of rumbles recorded in a rainforest in Gabon and estimated the distances at which elephants might be able to detect them under observed ambient sound conditions. Our results suggest an attenuation rate less than predictions of spherical spreading loss, suggesting that reflection of the sound waves within the forest results in constructive interference. Nevertheless, we found that forest elephant rumbles of average dominant frequency (31.07 Hz) under average ambient sound levels would not be detectable farther than 0.8 km. Moreover, for 50% of analyzed rumbles, the harmonic structure was completely attenuated at only 100 m. However, we estimated detection distances of up to 3.2 km for rumbles of average dominant frequency when ambient sound was at its lowest. Our findings suggest that long-distance communication to coordinate interactions among separated family units may be limited in forest elephants, with potentially important consequences for their social organization. The challenges associated with the extent of, and variation in, detection distances of long-distance vocalizations used by animals to mediate interactions between separated group members has rarely been investigated. While it has been suggested that forest elephants exhibit a fission-fusion sociality similar to savanna elephants, our results indicate shorter detection distances for forest elephant rumbles, suggesting a limited ability to mediate interactions between separated family units. However, under optimal ambient sound conditions, detection distances increased considerably. The long detection distances estimated for savanna elephants may reflect the optimal conditions under which the playback experiments were conducted. On average, savanna elephants may be much more limited in communication distance. Further studies on the constraints and opportunities that the different environments impose on these species’ communication capability may be critical to understanding potential differences in the social complexity they express.

African forest elephant social networks: fission-fusion dynamics, but fewer associations

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 25:165-173 (2014) - DOI: https://doi.org/10.3354/esr00618 African forest elephant social networks: fission-fusion dynamics, but fewer associations Stephanie G. Schuttler1,*, Alden Whittaker2, Kathryn J. Jeffery3,4,5, Lori S. Eggert1 1Division of Biological Sciences, 226 Tucker Hall, University of Missouri, Columbia, MO 65211, USA 2Zakouma National Park, African Parks Network, PO Box 510, N’Djaména, Republic of Chad 3Agence Nationale des Parcs Nationaux, BP20379, Libreville, Gabon 4School of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK 5Institut de Recherche en Ecologie Tropicale, BP13354, Libreville, Gabon *Corresponding author: stephanie.schuttler@gmail.com ABSTRACT: For animal species with dynamic interactions, understanding social patterns can be difficult. Social network analysis quantifies associations and their intensity between individuals within a population, revealing the overall patterns of the society. We used networks to test the hypothesis that the elusive African forest elephant Loxodonta cyclotis exhibits fission-fusion social dynamics, similar to other elephant species. We observed associations between individuals in savanna clearings in Lopé National Park, Gabon, in 2006, 2008, and 2010. When possible, dung was collected from individuals for genetic analyses using 10 microsatellite loci and the mitochondrial DNA control region. Using simple ratio association indices, networks were created for each year, wet and dry seasons, individuals detected at least twice, and for all females. We identified 118 unique adult females, for 40 of which we obtained genetic information. Networks had low densities, many disconnected components, short average path lengths, and high clustering coefficients. Within components, average relatedness was 0.093 ± 0.071 (SD) and females appeared to share mitochondrial haplotypes. We detected 1 large component consisting of 22 adult females, but there were few preferred associations (8 of 65, 12.3%). No seasonal or yearly differences were observed. Our results substantiate fission-fusion dynamics in forest elephants; however, the networks are more disconnected than those for other elephant species, possibly due to poaching and ecological constraints in the forest environment. KEY WORDS: Social networks · Social structure · Loxodonta cyclotis · Fission-fusion · Elephants Full text in pdf format Supplementary material PreviousNextCite this article as: Schuttler SG, Whittaker A, Jeffery KJ, Eggert LS (2014) African forest elephant social networks: fission-fusion dynamics, but fewer associations. Endang Species Res 25:165-173. https://doi.org/10.3354/esr00618 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 25, No. 2. Online publication date: September 19, 2014 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2014 Inter-Research.

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.

Patch-occupancy models indicate human activity as major determinant of forest elephant Loxodonta cyclotis seasonal distribution in an industrial corridor in Gabon

The importance of human activity and ecological features in influencing African forest elephant ranging behaviour was investigated in the Rabi–Ndogo corridor of the Gamba Complex of Protected Areas in southwest Gabon. Locations in a wide geographical area with a range of environmental variables were selected for patch-occupancy surveys using elephant dung to assess seasonal presence and absence of elephants. Patch-occupancy procedures allowed for covariate modelling evaluating hypotheses for both occupancy in relation to human activity and ecological features, and detection probability in relation to vegetation density. The best fitting models for old and fresh dung data sets indicate that (1) detection probability for elephant dung is negatively related to the relative density of the vegetation, and (2) human activity, such as presence and infrastructure, are more closely associated with elephant distribution patterns than are ecological features, such as the presence of wetlands and preferred fresh fruit. Our findings emphasize the sensitivity of elephants to human disturbance, in this case infrastructure development associated with gas and oil production. Patch-occupancy methodology offers a viable alternative to current transect protocols for monitoring programs with multiple covariates.