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 Here we combine a large unpublished dataset of forest elephant feeding with published browsing preferences totaling > 120,000 records covering 700 plant species, including nutritional data for 102 species. Elephants increase carbon stocks by: 1) promoting high wood density tree species via preferential browsing on leaves from low wood density species, which are more digestible; 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 a 5-12% decline in carbon stocks due to regeneration failure of elephant-dispersed trees and an increase in abundance of low wood density trees. These results show the major importance of megaherbivores in maintaining diverse, high-carbon tropical forests. Successful elephant conservation will contribute to climate mitigation at a scale of global relevance.

Long Distance Seed Dispersal by Forest Elephants

By dispersing seeds long distances, large, fruit-eating animals influence plant population spread and community dynamics. After fruit consumption, animal gut passage time and movement determine seed dispersal patterns and distances. These, in turn, are influenced by extrinsic, environmental variables and intrinsic, individual-level variables. We simulated seed dispersal by forest elephants (Loxodonta cyclotis) by integrating gut passage data from wild elephants with movement data from 96 individuals. On average, elephants dispersed seeds 5.3 km, with 89% of seeds dispersed farther than 1 km. The longest simulated seed dispersal distance was 101 km, with an average maximum dispersal distance of 40.1 km. Seed dispersal distances varied among national parks, perhaps due to unmeasured environmental differences such as habitat heterogeneity and configuration, but not with human disturbance or habitat openness. On average, male elephants dispersed seeds farther than females. Elephant behavioral traits strongly influenced dispersal distances, with bold, exploratory elephants dispersing seeds 1.1 km farther than shy, idler elephants. Protection of forest elephants, particularly males and highly mobile, exploratory individuals, is critical to maintaining long distance seed dispersal services that shape plant communities and tropical forest habitat.

Valuation of carbon services produced by wild animals finances conservation

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 $35.9 billion (24.3-41.2) and store 377 MtC (318-388) across tropical Africa. Our methodology can also place lower bounds on the social cost of nature degradation. Poaching would result in $10-14 billion of lost carbon services. Our methodology enables the integration of animal services into global financial markets with major implications for conservation, local socio-economies, and conservation.

Biodiversity of Forest Elephants (Loxodonta Cyclotis) Diet in the Ogooué Leketi National Park, Congo Brazzaville

The Ogooué Leketi National Park (OLNP) is located within the Batéké-Léconi-Léfini Landscape in the central basin of the Congo River. The Ogooué Leketi Elephant Project (OLEP) area is important for biodiversity conservation from its significant populations of forest species (forest elephant, gorillas, chimpanzees, duikers, monkeys, etc.) combined with savanna species (Grimm’s duiker, side-striped jackal, etc). Elephant sign is highest 0.9/km in the northwest of the Landscape in the border area of the Batéké Plateau National Park in Gabon where a number of mineral-rich clearings, or bais, attract forest elephants and others wildlife. Elephants travel a long distance and consume diverse plants and occasionally animals’ species from one clearing to others throughout the forest. This paper intends to provide an overall preliminary list of plants consumed by forest elephants across their feeding trials. The results of the study points to the fact that, elephants were found to be feeding on 258 different vegetal species and three animal species recorded from twenty-six elephants feeding trials from March 2013 to December 2014 through different methods. Among these plant species, 156 were identified by us and checked by botanists in both the CERVE at Brazzaville and herbarium of Kinshasa University. Elephants were not only eating plants but they were also consuming occasionally some invertebrate such as bees, termites and ants. An analysis of 53 dung piles revealed that 43 dung piles had traces of 26 species of fruit consumed by elephants while 10 dung piles had no traces of fruits. The OLNP is among the least described protected areas in the Republic of Congo, despite its speculated high potential biodiversity. This lack of ground-truth knowledge is attributed to the status of the protected area that Congolese government classified as park in 2018 after 14 years of existence.

African forest elephant movements depend on time scale and individual behavior

The critically endangered African forest elephant (Loxodonta cyclotis) plays a vital role in maintaining the structure and composition of Afrotropical forests, but basic information is lacking regarding the drivers of elephant movement and behavior at landscape scales. We use GPS location data from 96 individuals throughout Gabon to determine how five movement behaviors vary at different scales, how they are influenced by anthropogenic and environmental covariates, and to assess evidence for behavioral syndromes—elephants which share suites of similar movement traits. Elephants show some evidence of behavioral syndromes along an ‘idler’ to ‘explorer’ axis—individuals that move more have larger home ranges and engage in more ‘exploratory’ movements. However, within these groups, forest elephants express remarkable inter-individual variation in movement behaviours. This variation highlights that no two elephants are the same and creates challenges for practitioners aiming to design conservation initiatives.

Elephants, Mobility and Captivity: What Can These Mighty and Majestic Animals Teach Us About Joint Health and Osteoarthritis?

The African bush and forest elephants, Loxodonta Africana and Loxodonta cyclotis, and the Asian elephant, Elephas maximus, are the largest land-dwelling animals. Elephants need to be highly mobile and active in order to find fresh food and water, and in the case of males, to locate females in estrus for breeding. Asian elephants walk up to 21 km each day and African elephants can walk up to 28 km per day. This high level of mobility in the wild is also important for maintaining an optimum musculoskeletal health. However, most zoo elephants live in restricted spaces and cold climates that require extended periods of indoor confinement are therefore unable to be as physically active. Zoo enclosures for elephants are relatively small with hard surfaces (i.e. concrete, tarmac and hard packed dirt), so they cannot exercise and are forced to stand on unnaturally hard surfaces continually. Physical inactivity in captivity makes them more prone to gaining weight and developing bone and joint diseases such as osteomyelitis, joint ankylosis and osteoarthritis (OA). Many health and welfare problems in captive elephants are likely to be caused by the lack of mobility. This perspective article focuses on the possible link between captivity, mobility, physical inactivity and the development of OA in captive elephants.

Elephants, Mobility and Captivity: What Can These Mighty and Majestic Animals Teach Us About Joint Health and Osteoarthritis?

The African bush and forest elephants, Loxodonta Africana and Loxodonta cyclotis, and the Asian elephant, Elephas maximus, are the largest land-dwelling animals. Elephants need to be highly mobile and active in order to find fresh food and water, and in the case of males, to locate females in estrus for breeding. Asian elephants walk up to 13 miles each day and African elephants can walk up to 28 km per day. This high level of mobility in the wild is also important for maintaining an optimum musculoskeletal health. However, their captive counterparts live in restricted spaces and cold climates that require extended periods of indoor confinement are therefore unable to be as physically active. Zoo enclosures for elephants are relatively small with hard surfaces (i.e. concrete, tarmac and hard packed dirt), so they cannot exercise and are forced to stand on unnaturally hard surfaces continually. Physical inactivity in captivity makes them more prone to gaining weight and developing bone and joint diseases such as osteomyelitis, joint ankylosis and osteoarthritis (OA). Up to 50% of deaths in captive elephants are caused by the lack of mobility. This perspective article focuses on the link between captivity, mobility, physical inactivity and the development of OA in captive elephants.