Forest Elephants Research Articles

Species Composition and Structure of Habitats Exploited by Elephants (Loxodonta Africana Cyclotis) in the Campo Maan Forest, South Region, Cameroon

Purpose: The main objective of this study was to determine the species composition and structure of habitats exploited by elephants in the Campo Maan Forest.
 Methodology: Using the transect methods, purposively, 1km transects were laid along identified feeding tracts in various habitats. 15 transects with each having 4 quadrates of 30x30m were established at interval of 220m summing up to a total of 5.4 hectares of land covered for the study within which data was collected. In the quadrates, all vascular plants with dbh >10cm (diameter at breast height about 1.3m above the ground) were measured and identified. In each quadrate, four subplots of 15mx15m were placed at the corners to sample understory and herbs.
 Findings: Results reveal a total of 1113 individual trees with DBH of ≥ 10 cm identified and measured belong to 49 species from 24 families. Fabaceae was the most dominant family of plants with 425 individual trees counted with Caesalpinioideae being the dominant specie type (116); followed by Calpocalyx heitzii (92). Lowland evergreen forest (Casalpinioideae) recorded the highest number of tree species counted (462, 41.5%) of the total tree species. Trees DBH varies between 10 and 64 cm with mean values of 29.45±11.48 cm, 23.3±7.759 cm, 27.69±9.189 cm and 25.75±14.056 cm for Lowland evergreen forest (Casalpinioideae), Lowland evergreen forest (mixed), Coastal forest (Sacoglotis gabonensis) and Coastal forest (mixed) respectively. A large number of trees recorded heights of above 30m though it was higher for Lowland evergreen forest (mixed), Coastal forest (Sacoglotis gabonensis) and the Coastal forest (mixed). For the understory, the dominant specie types are Scaphopetalum blackii, Palisota ambigua, Asystasia macrophylla, Podococcus barteri, Microdesmis puberula, Heistera pavifora, Haumania danckelmaniana, Alchornea floribunda all counting 9 and 10 individual Trees). Results revealed highly positive and significant correlations between trees DBH and height (r=0.84, p=0.000). The Shannon’s diversity index indicates that the tree diversity for all habitats are fairly even with Coastal forest (Sacoglotis gabonensis) having a value of 4.73. The Coastal forest (mixed) shows the highest rate of basal area (76.39); followed by Coastal forest (Sacoglotis gabonensis) (41.50) and Lowland evergreen forest (Casalpinioideae) (32.26), all indicating high basal areas.
 Recommendation: Further studies on habitat fragmentation are needed to assess its effects on elephant movement within the area.

Recent decline in suitable large mammal habitats within the Dzanga Sangha Protected Areas, Central African Republic

The forests of the Congo Basin are an important home to some of the world’s most critically endangered species, including the central chimpanzee (Pan troglodytes troglodytes), the western lowland gorilla (Gorilla gorilla gorilla) and the forest elephant (Loxodanta cyclotis). To contribute to the long-term sustainability of these species and their habitats within the Dzanga Sangha Protected Areas (DSPA) in the Central African Republic, the World Wide Fund for Nature (WWF) developed an ecological monitoring program to assess the spatial drivers of species' habitat changes. Here, we assess and quantify chimpanzee, gorilla and elephant habitat suitability within the DSPA using data from two survey years (2015 and 2020), to identify priority habitat areas and recommend conservation measures to mitigate ongoing habitat changes. We found that priority chimpanzee habitats covered about 1383 km2 (30 %) of the entire DSPA in the year 2015, while priority gorilla and elephant habitats covered approximately 2569 km2 (56 %) and 3075 km2 (67 %) respectively. Priority habitat area for the three species declined by 4, 4.5 % and 9.8 % points respectively between 2015 and 2020, mostly due to increased human pressures. We further provide evidence that the Dzanga National Park represents a region of higher priority habitat for all three species owing to the reduced human pressure that has resulted from higher eco-guard patrol efforts. Based on our analysis, we recommend maintaining a nonviolent patrol presence to mitigate human pressures within remaining priority habitat areas, recognizing also the importance of collaboration with local communities to support long-term conservation goals.

Megaherbivores modify forest structure and increase carbon stocks through multiple pathways

Megaherbivores have pervasive ecological effects. In African rainforests, elephants can increase aboveground carbon, though the mechanisms are unclear. Here, we combine a large unpublished dataset of forest elephant feeding with published browsing preferences totaling nearly 200,000 records covering >800 plant species and with nutritional data for 145 species. Elephants increase carbon stocks by: 1) promoting high wood density trees via preferential browsing on leaves from low wood density species, which are more palatable and digestible; and 2) dispersing seeds of trees that are relatively large and have the highest average wood density among tree guilds based on dispersal mode. Loss of forest elephants could cause an increase in abundance of fast-growing low wood density trees and a 6% to 9% decline in aboveground carbon stocks due to regeneration failure of elephant-dispersed trees. These results demonstrate the importance of megaherbivores for maintaining diverse, high-carbon tropical forests. Successful elephant conservation will contribute to climate mitigation at a globally-relevant scale.

Human impacts on mammal communities in Rio Campo Nature Reserve, Equatorial Guinea

AbstractEquatorial Guinea in central Africa hosts rich biodiversity and a network of protected areas (PAs). However, infrastructure development has facilitated access to previously remote forests. This has likely increased poaching in PAs, thereby complicating efforts of agencies tasked with protecting threatened mammals. Reserva Natural de Río Campo (RNRC) in Equatorial Guinea was previously identified as a priority area for large mammals due to the presence of elephants and great apes and includes habitat for a diverse mammal community of commonly hunted species. To assess mammalian diversity in RNRC, we conducted a camera trap survey in 2017 and 2019. We used a two‐step modelling approach to quantify environmental and anthropogenic factors influencing mammal groups. We detected 32 terrestrial mammal species, including endangered forest elephant, western gorilla, chimpanzee, giant pangolin and white‐bellied pangolin. We found bushbuck and sitatunga closer to human‐dominated areas, while other common species were, in general, further from development. Monkey and pangolin abundance increased inward from the RNRC boundary. Endangered species appear restricted to northeast RNRC which connects to Campo Ma'an National Park in Cameroon. We recommend using our inventory and distributions of threatened mammals as starting points to determine effectiveness of future anti‐poaching and management strategies on mammal populations.

Drivers and facilitators of the illegal killing of elephants across 64 African sites.

Ivory poaching continues to threaten African elephants. We (1) used criminology theory and literature evidence to generate hypotheses about factors that may drive, facilitate or motivate poaching, (2) identified datasets representing these factors, and (3) tested those factors with strong hypotheses and sufficient data quality for empirical associations with poaching. We advance on previous analyses of correlates of elephant poaching by using additional poaching data and leveraging new datasets for previously untested explanatory variables. Using data on 10 286 illegally killed elephants detected at 64 sites in 30 African countries (2002-2020), we found strong evidence to support the hypotheses that the illegal killing of elephants is associated with poor national governance, low law enforcement capacity, low household wealth and health, and global elephant ivory prices. Forest elephant populations suffered higher rates of illegal killing than savannah elephants. We found only weak evidence that armed conflicts may increase the illegal killing of elephants, and no evidence for effects of site accessibility, vegetation density, elephant population density, precipitation or site area. Results suggest that addressing wider systemic challenges of human development, corruption and consumer demand would help reduce poaching, corroborating broader work highlighting these more ultimate drivers of the global illegal wildlife trade.

The Dynamics of Crop-Raiding Activity of African Elephant (Loxodonta cyclotis) at the Periphery of Mount Cameroon National Park, Southwest Region, Cameroon

Human-elephant conflict is common on cropland due to human encroachment into wildlife habitat, a serious conservation challenge in many countries in sub Saharan Africa. Though, a variety of conflict management strategies have been taken for mitigation, the impact is not much, crop-raiding is still increasingly alarming especially in mount Cameroon national park periphery due to increase in human settlement. The main objective of this study was to assess the crop-raiding activity of elephants in the national park. Data collection method was focused on sampling the affected village communities by monitoring the feeding and foraging activities of elephants on cropland. The research data collection was done for a period of four months, during this period, elephants were monitored and their feeding and foraging activities were recorded from 8:00 am – 6:00 pm on different cropland. However, the study revealed crop-raiding behavior of the elephants significant, X2 = 18.55 df=8 P=0.017, X2 = 17.64 df=8 P=0.024, X2 = 10.04 df=8 P<0.05, X2 = 9.10 df=8 P<0.05 on photo-period, landscape, elephant trails, and affected villages respectively. Maize (Zea mays) 30%, cassava (Manihot escaulenta) 24%, and banana (Musa acuminata) 21% were the most raided crops by the elephants, while oil palm (Elaeis guineensis) 15% and plantains (Musa sapientum) 10% were the least. More so, cropland destruction distance from human residence recorded a significance, X2 = 29.75 df=20 P<0.05, and X2 =46.34 df=10 P=0.000 on farm-size estimate, and the day-period respectively. The destruction of cropland by the elephants was done during the morning, afternoon, and evening periods respectively and the most frequent distance of destruction from human homes, above 100 meters recorded 28%, and 81-100 meters recorded 15% respectively. Though, the scale of destruction was rated low 51%, and high 34% respectively, it was still very high (15%) in some farms. Humanelephant conflict at the periphery of mount Cameroon national park can be mitigated with elephant translocation to other national parks within the country.

Mitigating crop raiding by forest elephants and baboons at Kibale National Park

AbstractIn Africa, most protected forests are in densely human‐dominated landscapes where human–wildlife conflict is intense. We documented farmer perceptions and responses to crop‐raiding wildlife from Kibale National Park, Uganda. Crop raiding was mostly (95%) by baboons (Papio anubis) and elephants (Loxodonta africana). While the financial loss caused by baboons and elephants did not differ, elephants were perceived as more damaging. Guarding and trenches were perceived as the most effective deterrent strategies for baboons and elephants, respectively. Distance from the park boundary and household income were significantly associated with a greater likelihood of crop raiding. Distance from the park, household head age and the species that raided crops, influenced whether a household applied one or more deterrent strategies. Households headed by women or older adults were most vulnerable, experiencing greater losses to raiding. Patterns of human–wildlife conflict around Kibale forest are complex, but the extent of crop damage was mostly determined by distance from the park and farm socio‐economic status and thus their ability to mitigate or deter raiding. Managing crop raiding requires collaboration between the park and affected farmers to ensure that mutually managed deterrent methods, such as trenching (elephants) and guarding (baboons), are effectively shared, applied and maintained.

Habitat conversion intensifies human elephant conflicts in the Eastern Wildlife Corridor, Ghana

Ghana was ranged by fairly large herds of elephants up until the 1970s (Douglas-Hamilton 1979). At one time elephants were found throughout the country but, as elsewhere on the continent, elephant habitat contracted during the 20th century. Today both the African savannah elephant (Loxodonta africana) and the African forest elephant (L. cyclotis) are still found, respectively, in the savannah and forest zones of Ghana. However, the populations are now confined to a few Protected Areas (PAs) and isolated remnant habitats, mainly due to human population pressure and related land use and land cover changes (AfESG 2000). Elephants are also killed illegally by poachers for the ivory trade, which dates back to ancient times (Parker 1973). By 2000, there were only eleven elephant population ranges in the country, with an estimated population of 1,000–2,000 individuals (WD 2000). These trends call for drastic and far-reaching elephant conservation efforts, including effective anti-poaching measures with more supportive legislation, and community-based land-use planning to foster harmonious human–elephant coexistence (HECx) in the country. Ghana has exhibited zeal for the conservation of the African elephant, both domestically and on the international front. Ghana was the first country to propose listing of African elephants in Appendix 1 of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). The country is also signatory to other international conventions, including the Convention on Biological Diversity (CBD), Ramsar Convention on Wetlands of International Importance, Convention on the Conservation of Migratory Species of Wild Animals (Bonn Convention) and the United Nations Framework Convention on Climate Change (UNFCCC), among others. In July 2008, Ghana entered into a bilateral cooperation agreement in the form of a memorandum of understanding (MOU) with the Republic of Burkina Faso for the purpose of conserving natural resources shared by the two countries, including savannah elephants. In 2000, the Wildlife Division of the Forestry Commission of Ghana, in collaboration with the World Wide Fund for Nature (WWF) and IUCN’s African Elephant Specialist Group (AfESG), developed an Elephant Conservation Strategy as a guide to ensure the conservation and survival of viable elephant populations and their habitats throughout the country. This strategy informed studies conducted of elephant migratory corridors by the Northern Savannah Biodiversity Conservation Project (NSBCP), under the auspices of the Global Environment Facility (GEF) and the World Bank, between 2002 and 2009. These studies identified two main elephant migratory routes between Burkina Faso and northern Ghana, which were designated the Eastern and Western Wildlife Corridors (EWWC). The forests and wildlife in the corridors are jointly managed by the Forest Services Division (FSD) and Wildlife Division (WD) of the Forestry Commission. This article provides a summary description of the EWWC, presents data on human–elephant conflict in the Eastern Wildlife Corridor, and discusses approaches to mitigate conflicts and ensure the survival of the elephant population in the corridor.

Dietary Habits and Tusk Usage of Shovel-Tusked Gomphotheres from Florida: Evidence from Stereoscopic Wear of Molars and Upper and Lower Tusks.

The paleodiet of the shovel-tusked gomphotheres from Florida (Amebelodon floridanus, Konobelodon britti, and Serbelodon barbourensis) was assessed via microwear analysis of molar dental enamel and compared to a large database of both extant proboscideans and ungulates. Scratch and pit results show a consistent browsing signal in A. floridanus, K. britti and S. barbourensis. Fossil results are more similar to those of the extant Loxodonta cyclotis than to Loxodonta africana or Elephas maximus, the latter two taxa exhibiting a mixed feeding result. Scratch width scores are high in all three shovel tuskers as well as in the extant proboscideans indicating the ingestion of some coarse vegetation, most likely bark, and twigs. Gouging is relatively low in A. floridanus and S. barbourensis. Only K. britti has levels of gouging approximating that seen in extant elephants. Large pitting is relatively low in both fossil and extant forms although L. cyclotis has higher levels of large pitting including more puncture-like pits seen with fruit and/or seed consumption. A variety of scratch patterns indicating variation in tusk usage behavior was found. Some Serbelodon and Konobelodon mandibular tusks exhibited digging behavior, although Konobelodon digging behavior was much more common and obvious, whereas Amebelodon mandibular tusks did not exhibit digging behavior and were more likely used for stripping and scraping. Unusual distal tusk wear was found in Amebelodon and Serbelodon most likely due to stripping off tree bark. Upper tusk usage varied with all three fossil species exhibiting scraping and/or cutting behavior. Results indicate that shovel-tusked gomphotheres from Florida occupied a narrow dietary niche but employed a variety of strategies to obtain the vegetation that they consumed.

Charisma failure: Understanding differences in support for conservation of Asian elephants compared to tigers and African elephants

The disproportionately high support for conservation of charismatic species is well-documented. However, available data demonstrate substantial discrepancies in funding for conservation even among charismatic species, and these differences are poorly understood. We use two survey experiments to explore explanations for differences in demand for conservation between charismatic species by comparing Asian elephants (Elephas maximus) with tigers (Panthera tigris) in India and with African elephants (Loxodonta africana and Loxodonta cyclotis) globally. Through social media, we collect data from conservation enthusiasts to measure (a) relative demand for conservation, (b) awareness about conservation status, (c) relative favourability, and (d) perception of which species faces greater conservation challenges (“risk perception”). Overall, respondents allocated significantly more funds to the species/taxon they perceive to be more at risk and 41–54 % more to the species/taxon they say they like more (though about 70 % of respondents claimed to like both species/taxa presented equally). On average, respondents in India allocated 5.6 % more for tigers than Asian elephants, a far smaller discrepancy than found in public data from key real-life funders. Internationally, respondents allocated 14 % more funds for African than Asian elephants (despite there being fewer Asian elephants) and generally overestimated how endangered African elephants are compared to Asian elephants. Our study suggests (i) conservation enthusiasts wish to donate more to more endangered charismatic species but are sometimes misinformed about the level of endangerment of even very well-known species, and (ii) discrepancies in actual funding levels across charismatic species appear to be greater than conservation enthusiasts believe they should be.

Determining baselines and trends of Eastern chimpanzees and forest elephants in a Central African protected area after civil strife

Protected areas are crucial to safeguard Sub-Saharan Africa’s extraordinary and abundant megafauna. In many of these areas, instability has derailed conservation efforts and impeded adequate wildlife monitoring. Discovered in 2004, Eastern chimpanzees are found in the Central Uele Basin in northern Democratic Republic of Congo (DRC) within the Bili-Uéré Protected Areas Complex (BUPAC), the largest contiguous protected area in the country. BUPAC is threatened by habitat destruction, mining, wild meat trade, and insecurity. BUPAC chimpanzees are part of the largest remaining continuous population of the species in Africa; they are also being behaviourally unique. Forest elephants were frequent in the 1960′s in the BUPAC but have declined significantly up to 2004–2007. We used line transects to estimate Eastern chimpanzee and forest elephant density in the BUPAC core area in 2016 and 2019 and compared these with the 2004–2007 surveys. A total of 37 and 137 two km long line transects were systematically placed in 5,841 km2 and 6,176 km2 survey areas in 2016 and 2019, respectively. We found that chimpanzee density did not change during the two survey periods but indicators for forest elephant density decreased eight-fold. Human activities were detected mainly along the core area periphery in both survey years, where they overlapped with centres of animal activity. The stable high density of chimpanzees is a positive outcome for the core BUPAC. However, despite being a conservation priority area that has received relatively intensified protection, declining forest elephant numbers are likely to reflect the high number of human conflict hotspots in vicinity as well as the increasing human population density around the core area. We propose by elevating the core area to National Park whilst strengthening on the ground enforcement and management structures as well as legal measures against poaching might ensure the long-term survival of such an important area in Africa.

Passive acoustic monitoring reveals behavioural response of African forest elephants to gunfire events

AbstractAfrican forest elephants (Loxodonta cyclotis) are a critically endangered and visually cryptic species that inhabits Central African rainforests. Using a 1250 sq‐km grid of 50 acoustic sensors in Republic of Congo, we investigated the landscape‐scale behavioural response of forest elephants to poaching events. We detected eight automatic weapon fire events over 1.5 years of recording (2017–2019). We examined detections of elephant vocalisations across grid sites within 10 km of the gunfire events in the 48 h surrounding the gunfire, and in paired 48‐h control periods free of gunfire. Fewer vocalisations were detected before gunfire events than during control periods, suggesting elephants show behavioural responses to poacher presence before any shots are fired. Immediately following the gunfire events, a significant increase in elephant calls was detected, which may indicate increased communication to facilitate group cohesion and movement. Elevated call levels dropped to lower‐than‐baseline rates after several hours, suggestive of a sustained response. These patterns indicate forest elephants respond to both poacher presence and to gunfire events themselves. As these patterns may reflect behaviours that mediate population processes, conservation strategies should account for the potential of poaching to impact populations via indirect effects on nontarget elephants in the area.

The challenging coexistence of forest elephants Loxodonta cyclotis and timber concessions in central Africa

Abstract With a drastic decrease in their populations over the last decades, forest elephants Loxodonta cyclotis are facing increasing human pressure. Their decline will have serious ecological consequences, as they are key actors in shaping ecosystems. Whilst timber concessions host many mammal species, the interactions between selective logging and forest elephants remain unclear. Through an extensive literature review, we discussed the following: 1) the ecological and human factors that drive the distribution of forest elephants on a large scale as well as in the specific context of logged forests; 2) the contribution of forest elephants to the regeneration of timber species; and 3) the damage caused by forest elephants to timber species. Although human activities have the greatest impact on forest elephant distribution, it is the availability of food, water, and minerals that locally determines their use of the habitat. Under specific conditions, timber concessions may host large populations of forest elephants. As effective seed dispersers, forest elephants contribute to the regeneration of at least 41 timber species, such as Bobgunnia fistuloides (pao rosa), one of the most expensive woods on the market. Damage caused by forest elephants is diverse and affects a wide range of species. From branch breaking to bark stripping, at least 61 timber species are used by forest elephants, and little is known about the consequences for the tree's vitality and wood quality. The interactions between forest elephants and logging are complex and involve many variables, requiring additional research. Nevertheless, this review suggests that timber concessions constitute key areas for forest elephant conservation, provided that low‐impact logging and wildlife management are implemented.

Examining attention given to threats to elephant conservation on social media

AbstractAlthough social media is growing rapidly as a news source, including for disseminating conservation information, studies comparing attention given to differing threats to species on social media are almost non‐existent. As the amount of attention given to differing threats can influence what people perceive to be important and impact the formation of environmental policies, it is vital that conservationists understand which issues are being discussed online. Using elephants (Loxodonta Africana,Loxodonta cyclotis, andElephas maximus) as test species, we conducted a content analysis of tweets about elephants posted to Twitter during 2019. According to the global conservation authority, the International Union for Conservation of Nature, the most pressing threats to the conservation of wild elephant populations are habitat loss, human‐elephant conflict, and poaching, with the magnitude of each threat differing between the three species of elephants. Our Twitter analysis revealed that these major threats were infrequently discussed, with habitat loss being the most infrequently discussed (<1% of all tweets). Instead, elephant welfare issues, such as tourist elephant rides, were the most frequently discussed topic (23%). Users from non‐elephant range countries were the dominant voice on Twitter (72% of tweets with an identifiable location), with these tweets likely to discuss elephant welfare concerns and trophy hunting, which is not a threat to elephant conservation. Conversely, tweets from users from African elephant range countries (14%) were more likely to discuss human‐elephant conflict, poaching, and promote elephant tourism. Similarly, users from Asian elephant range countries (13%) were likely to discuss human‐elephant conflict and elephant tourism but unlikely to tweet about poaching. Given the relatively low representation of local stakeholders and the limited coverage of key conservation threats, there is a need to ensure that social media discussions do not overly influence decision‐makers.

English

Forest elephants are nocturnal and elusive animals, making it difficult to perform direct observations on them. Data on elephants’ diet and feeding habit are lacking despite most forest elephants’ habitats being lost to anthropogenic activities; yet such knowledge may be important for their conservation, particularly in a human dominated landscape.  Local ecological knowledge and field investigations were combined to assess diet composition and feeding habit of forest elephants in Campo-Ma’an landscape. The study also aimed to evaluate the level of concordance between the two approaches. The study reports that forest elephants in Campo-Ma’an feed on 87 plants species, including crops. Twenty-two of these plant species were reported by both methods, most of them being potential drivers of human-elephant conflict as they are simultaneously used by humans and elephants. Also, field investigations revealed that, to satisfy their energy requirements, forest elephants relied mostly on leaves and fruits during the wet seasons and mostly on barks from trees during the dry seasons. Overall, the two methods appeared to be complementary, despite field investigations yielding fewer species, as we only covered the park partially. We suggest that combining both methods could be a cost-efficient way to address forest elephants ecological and management questions.   Key words: Indigenous knowledge, Loxodonta cyclotis, plants species consumed, traditional knowledge.

Diurnality in the defensive behaviour of African honeybees Apis mellifera adansonii and implications for their potential efficacy in beehive fences

AbstractAcross the range of African elephants Loxodonta spp., negative interactions with people are prevalent, and the impact of the resulting economic losses on farmers calls for solutions. The use of beehive fences, a mitigation method with ecological and socio-economic benefits, is gaining momentum in African savannah landscapes. We assessed the diurnal and nocturnal defensive behaviours of African honeybees Apis mellifera adansonii in response to visual and physical disturbances in the Campo–Ma'an conservation area, Cameroon. We examined six bee colonies, assessing their activity level, aggressive behaviour and ability to defend themselves when disturbed at different times of day. We found that activity levels varied between colonies and that colonies were more active during the day and inactive at night. The defensive perimeter around the hives also varied between the colonies and was generally greater during morning and evening periods. Bee colonies did not defend their hives around midday and at night. In response to a threat, bees were more likely to fly out from the hive during daytime than at night, with variation amongst colonies. Overall, as elephant intrusions occur mostly at night, beehive fences alone may not be an adequate mitigation method against crop damage caused by forest elephants Loxodonta cyclotis. We suggest combining beehive fences with other mitigation methods to improve crop protection.

Fruit Availability Influences Forest Elephant Habitat Use in a Human Dominated Landscape, Campo-Ma’an, Southern Cameroon

Background and Research Aim African forest elephants ( Loxodonta cyclotis) are critically endangered yet research on factors influencing their resource use is limited in Central Africa. We assessed the influence of fruit availability, land use types, and anthropogenic activity on forest elephant presence and relative abundance in the southwest part of the Campo-Ma’an Technical Operational Unit (CMTOU) to better understand elephant habitat use in human dominated systems and inform elephant management strategies. Methods We used 17 camera trap stations and surveyed 17 line transects to monitor forest elephant presence and relative abundance as a function of fruit availability, tree species richness, and land use types. Our study area spanned a gradient of human disturbance and included a National Park (NP), Forest Management Unit (FMU), and Community Land (CL). Results Forest elephants were more likely to occur in areas with increased fruit availability and tree species richness. Also, the likelihood of their presence was higher in CL than in FMU and NP. Elephant relative abundance was negatively affected by human activities such as hunting and logging. The relationship between elephant relative abundance and fruit availability was stronger in CL and NP as compared to the FMU. Elephant relative abundance was higher during the rainy season. Conclusion Forest elephant habitat use was positively affected by fruit availability across land use types, and negatively affected by human activities in the southwest part of the CMTOU. Implications for Conservation Continued monitoring of elephant responses to food availability in CMTOU is warranted to track changes in elephant habitat use. Knowledge of the distribution of fruiting trees consumed by forest elephants may allow managers to predict hotspots of habitat use, and to therefore develop effective management strategies.

Phenotypical characterization of African savannah and forest elephants, with special emphasis on hybrids: the case of Kibale National Park, Uganda

AbstractThe IUCN now recognizes the savannah Loxodonta africana and forest Loxodonta cyclotis elephants to be separate species. Despite ecological, behavioural and morphological differences, and different habitat ranges, genetic studies confirm that the two species and hybrids coexist in forest–savannah ecotones. However, the hybrid phenotypes have not yet been described. In this survey we examined whether the phenotypes of the two species and of hybrids can be distinguished. In the first step, we used a machine learning algorithm (K-nearest neighbours) to compare 296 reference images of African elephants from five forest areas and six savannah areas where hybrids have not been recorded, confirming that six morphological criteria can be used to distinguish the species with more than 90% confidence. In the second step, we analysed 1,408 videos of elephants from 14 camera traps in Sebitoli, in Kibale National Park, Uganda, part of the main hybridization area. We used a multiple correspondence analysis and a species assignment key, highlighting the presence of three categories of phenotypes. Compared to the savannah and forest phenotypes (36.8 and 12.1%, respectively), the intermediate phenotypes, which could include hybrids, were more frequent (51.1%). Further studies combining morphology and genetics of the same individuals will be necessary to refine this species assignment key to characterize phenotypes confidently. This non-invasive, fast and inexpensive phenotypical-based method could be a valuable tool for conservation programmes.

Financing conservation by valuing carbon services produced by wild animals

Filling the global biodiversity financing gap will require significant investments from financial markets, which demand credible valuations of ecosystem services and natural capital. However, current valuation approaches discourage investment in conservation because their results cannot be verified using market-determined prices. Here, we bridge the gap between finance and conservation by valuing only wild animals’ carbon services for which market prices exist. By projecting the future path of carbon service production using a spatially explicit demographic model, we place a credible value on the carbon capture services produced by African forest elephants. If elephants were protected, their services would be worth $20.8 billion ($10.3 to $29.7 billion) and $25.9 billion ($12.8 to $37.6 billion) for the next 10 and 30 y, respectively, and could finance antipoaching and conservation programs. Elephant population growth would generate a carbon sink of 109 MtC (64 to 153) across tropical Africa in the next 30 y. Avoided elephant extinction would also prevent the loss of 93 MtC (46 to 130), which is the contribution of the remaining populations. Uncertainties in our projections are controlled mainly by forest regeneration rates and poaching intensity, which indicate that conservation can actively reduce uncertainty for increased financial and biodiversity benefits. Our methodology can also place lower bounds on the social cost of nature degradation. Poaching would result in $2 to $7 billion of lost carbon services within the next 10 to 30 y, suggesting that the benefits of protecting elephants far outweigh the costs. Our methodology enables the integration of animal services into global financial markets with major implications for conservation, local socioeconomies, and conservation.

Pre-trained models are not enough: active and lifelong learning is important for long-term visual monitoring of mammals in biodiversity research—Individual identification and attribute prediction with image features from deep neural networks and decoupled decision models applied to elephants and great apes

Animal re-identification based on image data, either recorded manually by photographers or automatically with camera traps, is an important task for ecological studies about biodiversity and conservation that can be highly automatized with algorithms from computer vision and machine learning. However, fixed identification models only trained with standard datasets before their application will quickly reach their limits, especially for long-term monitoring with changing environmental conditions, varying visual appearances of individuals over time that differ a lot from those in the training data, and new occurring individuals that have not been observed before. Hence, we believe that active learning with human-in-the-loop and continuous lifelong learning is important to tackle these challenges and to obtain high-performance recognition systems when dealing with huge amounts of additional data that become available during the application. Our general approach with image features from deep neural networks and decoupled decision models can be applied to many different mammalian species and is perfectly suited for continuous improvements of the recognition systems via lifelong learning. In our identification experiments, we consider four different taxa, namely two elephant species: African forest elephants and Asian elephants, as well as two species of great apes: gorillas and chimpanzees. Going beyond classical re-identification, our decoupled approach can also be used for predicting attributes of individuals such as gender or age using classification or regression methods. Although applicable for small datasets of individuals as well, we argue that even better recognition performance will be achieved by improving decision models gradually via lifelong learning to exploit huge datasets and continuous recordings from long-term applications. We highlight that algorithms for deploying lifelong learning in real observational studies exist and are ready for use. Hence, lifelong learning might become a valuable concept that supports practitioners when analyzing large-scale image data during long-term monitoring of mammals.