Poaching has devastated forest elephant populations (Loxodonta cyclotis), and their habitat is dramatically changing. The long-term effects of poaching and other anthropogenic threats have been well ...studied in savannah elephants (Loxodonta africana), but the impacts of these changes for Central Africa's forest elephants have not been discussed. We examined potential repercussions of these threats and the related consequences for forest elephants in Central Africa by summarizing the lessons learned from savannab elephants and small forest elephant populations in West Africa. Forest elephant social organization is less known than the social organization of savannab elephants, but the close evolutionary history of these species suggests that they will respond to anthropogenic threats in broadly similar ways. The loss of older, experienced individuals in an elephant population disrupts ecological, social, and population parameters. Severe reduction of elephant abundance within Central Africa's forests can alter plant communities and ecosystem functions. Poaching, habitat alterations, and human population increase are probably compressing forest elephants into protected areas and increasing human-elephant conflict, which negatively affects their conservation. We encourage conservationists to look beyond documenting forest elephant population decline and address the causes of these declines when developing conversation strategies. We suggest assessing the effectiveness of the existing protected-area networks for landscape connectivity in light of current industrial and infrastructure development. Longitudinal assessments of the effects of landscape changes on forest elephant sociality and behavior are also needed. Finally, lessons learned from West African elephant population loss and habitat fragmentation should be used to inform strategies for land-use planning and managing human-elephant interactions. La caza furtiva ha devastado a las poblaciones de los elefantes del bosque (Loxodonta cyclotis) y su hábitat está cambiando dramáticamente. Los efectos a largo plazo de la caza furtiva y de otras amenazas antropogénicas han sido estudiadas profundamente en los elefantes de la sabana (Loxodonta africana), pero el impacto de estos cambios sobre los elefantes del bosque del centro de África no ha sido discutido. Examinamos las repercusiones potenciales de estas amenazas y las consecuencias relacionadas para los elefantes del bosque del centro de África al resumir las lecciones aprendidas de los elefantes de la sabana y las pequeñas pablaciones de elefantes del bosque en el oeste de África. La organización social de los elefantes del bosque es menos conocida que la organización social de los elefantes de la sabana, pero la cercanía de la historia evolutiva de estas dos especies sugiere que responderán a las amenazas antropogénicas de maneras generalmente similares. La pérdida de individuos más viejos y con mayor experiencia en una población de elefantes causa disrupciones en los parámetros ecológicos, sociales y poblacionales. La reducción severa de la abundancia de elefantes dentro de los bosques del centro de África puede alterar a las comunidades vegetales y a las funciones del ecosistema. La caza furtiva, las alteraciones del hábitat y el incremento de la población humana probablemente estén orillando a las poblaciones de los elefantes del bosque hacia las áreas protegidas, e incrementado el conflicto humano-elefante, el cual afecta negativamente a su conservación. Alentamos a los conservacionistas a ver más allá de la documentación de la declinación de la población de elefantes del bosque y a enfocarse en las causas de esta declinación cuando se desarrollen estrategias de conservación. Sugerimos que se evalúe la efectividad de las redes existentes de áreas protegidas para la conectividad de paisajes de frente al desarrollo actual de industrias e infraestructuras. También es necesario realizar evaluaciones longitudinales de los efectos del cambio de paisaje sobre la organización social y el comportamiento de los elefantes del bosque. Finalmente, las lecciones aprendidas de la pérdida de poblaciones de elefantes del oeste de África y de la fragmentación del bábitat deberían usarse para informar a las estrategias de planeación del uso de suelo y de manejo de interacciones humano-elefante.
The Global Biodiversity Framework (GBF), signed in 2022 by Parties to the Convention on Biological Diversity, recognized the importance of area-based conservation, and its goals and targets specify ...the characteristics of protected and conserved areas (PCAs) that disproportionately contribute to biodiversity conservation. To achieve the GBF's target of conserving a global area of 30% by 2030, this Essay argues for recognizing these characteristics and scaling them up through the conservation of areas that are: extensive (typically larger than 5,000 km2); have interconnected PCAs (either physically or as part of a jurisdictional network, and frequently embedded in larger conservation landscapes); have high ecological integrity; and are effectively managed and equitably governed. These areas are presented as "Nature's Strongholds," illustrated by examples from the Congo and Amazon basins. Conserving Nature's Strongholds offers an approach to scale up initiatives to address global threats to biodiversity.
The abundance of large vertebrates is rapidly declining, particularly in the tropics where over-hunting has left many forests structurally intact but devoid of large animals. An urgent question then, ...is whether these 'empty' forests can sustain their biodiversity without large vertebrates. Here we examine the role of forest elephant (Loxodonta africana cyclotis) seed dispersal in maintaining the community structure of trees in the Ndoki Forest, northern Congo. Analysis of 855 elephant dung piles suggested that forest elephants disperse more intact seeds than any other species or genus of large vertebrate in African forests, while GPS telemetry data showed that forest elephants regularly disperse seeds over unprecedented distances compared to other dispersers. Our analysis of the spatial distribution of trees from a sample of 5667 individuals showed that dispersal mechanism was tightly correlated with the scale of spatial aggregation. Increasing amounts of elephant seed dispersal was associated with decreasing aggregation. At distances of<200 m, trees whose seeds are dispersed only by elephants were less aggregated than the random expectation, suggesting Janzen-Connell effects on seed/seedling mortality. At the landscape scale, seed dispersal mode predicted the rate at which local tree community similarity decayed in space. Our results suggest that the loss of forest elephants (and other large-bodied dispersers) may lead to a wave of recruitment failure among animal-dispersed tree species, and favor regeneration of the species-poor abiotically dispersed guild of trees.
A dramatic expansion of road building is underway in the Congo Basin fuelled by private enterprise, international aid, and government aspirations. Among the great wilderness areas on earth, the Congo ...Basin is outstanding for its high biodiversity, particularly mobile megafauna including forest elephants (Loxodonta africana cyclotis). The abundance of many mammal species in the Basin increases with distance from roads due to hunting pressure, but the impacts of road proliferation on the movements of individuals are unknown. We investigated the ranging behaviour of forest elephants in relation to roads and roadless wilderness by fitting GPS telemetry collars onto a sample of 28 forest elephants living in six priority conservation areas. We show that the size of roadless wilderness is a strong determinant of home range size in this species. Though our study sites included the largest wilderness areas in central African forests, none of 4 home range metrics we calculated, including core area, tended toward an asymptote with increasing wilderness size, suggesting that uninhibited ranging in forest elephants no longer exists. Furthermore we show that roads outside protected areas which are not protected from hunting are a formidable barrier to movement while roads inside protected areas are not. Only 1 elephant from our sample crossed an unprotected road. During crossings her mean speed increased 14-fold compared to normal movements. Forest elephants are increasingly confined and constrained by roads across the Congo Basin which is reducing effective habitat availability and isolating populations, significantly threatening long term conservation efforts. If the current road development trajectory continues, forest wildernesses and the forest elephants they contain will collapse.
Wildlife monitoring is essential for conservation science and data‐driven decision‐making. Tropical forests pose a particularly challenging environment for monitoring wildlife due to the dense ...vegetation, and diverse and cryptic species with relatively low abundances. The most commonly used monitoring methods in tropical forests are observations made by humans (visual or acoustic), camera traps, or passive acoustic sensors. These methods come with trade‐offs in terms of species coverage, accuracy and precision of population metrics, available technical expertise, and costs. Yet, there are no reviews that compare the characteristics of these methods in detail. Here, we comprehensively review the advantages and limitations of the three mentioned methods, by asking four key questions that are always important in relation to wildlife monitoring: (1) What are the target species?; (2) Which population metrics are desirable and attainable?; (3) What expertise, tools, and effort are required for species identification?; and (4) Which financial and human resources are required for data collection and processing? Given the diversity of monitoring objectives and circumstances, we do not aim to conclusively prescribe particular methods for all situations. Neither do we claim that any one method is superior to others. Rather, our review aims to support scientists and conservation practitioners in understanding the options and criteria that must be considered in choosing the appropriate method, given the objectives of their wildlife monitoring efforts and resources available. We focus on tropical forests because of their high conservation priority, although the information put forward is also relevant for other biomes.
Wildlife monitoring is essential for conservation science and data‐driven decision‐making. We compare three commonly used monitoring methods by following four questions that are always important in relation to wildlife monitoring.
Overexploitation is one of the main pressures driving wildlife closer to extinction, yet broad‐scale data to evaluate species’ declines are limited. Using African pangolins (Family: Pholidota) as a ...case study, we demonstrate that collating local‐scale data can provide crucial information on regional trends in exploitation of threatened species to inform conservation actions and policy. We estimate that 0.4‐2.7 million pangolins are hunted annually in Central African forests. The number of pangolins hunted has increased by ∼150% and the proportion of pangolins of all vertebrates hunted increased from 0.04% to 1.83% over the past four decades. However, there were no trends in pangolins observed at markets, suggesting use of alternative supply chains. The price of giant (Smutsia gigantea) and arboreal (Phataginus sp.) pangolins in urban markets has increased 5.8 and 2.3 times respectively, mirroring trends in Asian pangolins. Efforts and resources are needed to increase law enforcement and population monitoring, and investigate linkages between subsistence hunting and illegal wildlife trade.
Forest loss and overhunting are eroding African tropical biodiversity and threatening local human food security, livelihoods, and health. Emblematic of this ecological crisis is Africa's most ...endangered group of monkeys, the red colobus (genus Piliocolobus). All 17 species, found in forests from Senegal in the west to the Zanzibar archipelago in the east, are threatened with extinction. Red colobus are among the most vulnerable mammals to gun hunting, typically disappearing from heavily hunted forests before most other large‐bodied animals. Despite their conservation status, they are rarely a focus of conservation attention and continue to be understudied. However, red colobus can act as critical barometers of forest health and serve as flagships for catalyzing broader African tropical forest conservation efforts. We offer a plan for conservation of red colobus and their habitats and discuss conservation and policy implications.
Debate over repealing the ivory trade ban dominates conferences of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Resolving this controversy requires ...accurate estimates of elephant population trends and rates of illegal killing. Most African savannah elephant populations are well known; however, the status of forest elephants, perhaps a distinct species, in the vast Congo Basin is unclear. We assessed population status and incidence of poaching from line-transect and reconnaissance surveys conducted on foot in sites throughout the Congo Basin. Results indicate that the abundance and range of forest elephants are threatened from poaching that is most intense close to roads. The probability of elephant presence increased with distance to roads, whereas that of human signs declined. At all distances from roads, the probability of elephant occurrence was always higher inside, compared to outside, protected areas, whereas that of humans was always lower. Inside protected areas, forest elephant density was correlated with the size of remote forest core, but not with size of protected area. Forest elephants must be prioritised in elephant management planning at the continental scale.
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.
Indicators for wild animal offtake Ingram, Daniel J.; Coad, Lauren; Collen, Ben ...
Ecology and society,
01/2015, Letnik:
20, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Unsustainable exploitation of wild animals is one of the greatest threats to biodiversity and to millions of people depending on wild meat for food and income. The international conservation and ...development community has committed to implementing plans for sustainable use of natural resources and has requested development of monitoring systems of bushmeat offtake and trade. Although offtake monitoring systems and indicators for marine species are more developed, information on harvesting terrestrial species is limited. Building on approaches developed to monitor exploitation of fisheries and population trends, we have proposed two novel indicators for harvested terrestrial species: the mean body mass indicator (MBMI) assessing whether hunters are relying increasingly on smaller species over time, as a measure of defaunation, by tracking body mass composition of harvested species within samples across various sites and dates; and the offtake pressure indicator (OPI) as a measure of harvesting pressure on groups of wild animals within a region by combining multiple time series of the number of harvested individuals across species. We applied these two indicators to recently compiled data for West and Central African mammals and birds. Our exploratory analyses show that the MBMI of harvested mammals decreased but that of birds rose between 1966/1975 and 2010. For both mammals and birds the OPI increased substantially during the observed time period. Given our results, time-series data and information collated from multiple sources are useful to investigate trends in body mass of hunted species and offtake volumes. In the absence of comprehensive monitoring systems, we suggest that the two indicators developed in our study are adequate proxies of wildlife offtake, which together with additional data can inform conservation policies and actions at regional and global scales.
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