African forest elephant

African forest elephant[1]
Not evaluated (IUCN 3.1)[2]
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Proboscidea
Family: Elephantidae
Subfamily: Elephantinae
Genus: Loxodonta
Species: L. cyclotis
Binomial name
Loxodonta cyclotis
(Matschie, 1900)
African forest elephant range

The African forest elephant (Loxodonta cyclotis) is a forest-dwelling species of elephant found in the Congo Basin. It is the smallest of the three extant species of elephant, but still the third-largest living terrestrial animal. The African forest elephant and the African bush elephant, L. africana, were considered to be one species until genetic studies indicated that they separated an estimated 2-7 million years ago.[3] Due to a slower birth rate, the forest elephant takes longer to recover from poaching, which caused its population to fall by 65% from 2002 to 2013.[4]

In 2016, DNA sequence analysis showed that L. cyclotis is more closely related to the extinct European straight-tusked elephant, Palaeoloxodon antiquus, than it is to L. africana.[5]

Classification

The African forest elephant was once considered to be a subspecies, Loxodonta africana cyclotis, of the African elephant, together with the African bush elephant. DNA tests, however, indicated that the two populations were much more genetically diverse than previously believed.[6] In 2010, a genetic study confirmed they are separate species which diverged from each other an estimated two to seven million years ago.[3][7] Still, many governmental (e.g. USFWS) and non-governmental agencies (e.g. IUCN) consider the forest elephant to be a subspecies for regulatory and conservation purposes.

The disputed pygmy elephants of the Congo Basin, often assumed to be a separate species (Loxodonta pumilio) by cryptozoologists, are probably forest elephants whose diminutive size or early maturity is due to environmental conditions.[8]

Description

These forest-dwelling elephants are smaller and darker than their savanna relatives, the bush elephants, and have smaller and more rounded ears.[9] Compared to the bush elephant, the African forest elephant has a longer, narrower mandible. Its tusks are straighter and harder and have a more yellow or brownish color.[10] These strong tusks are used to push through the dense undergrowth of their habitat and bull elephants (mature males) are sometimes known to have exceptionally long tusks that reach almost to the ground.[9][11][12] The species normally has five toenails on the forefoot and four on the hindfoot, like the Asian elephant but unlike the African bush elephant which normally has four toenails on the forefoot and three on the hindfoot. They also protect themselves from the sun by using sand.

A male African forest elephant rarely exceeds 2.5 m (8.2 ft) in height, considerably smaller than the bush species which is usually over 3 m (9.8 ft) and sometimes almost 4 m (13.1 ft) tall. L. cyclotis reportedly weighs around 2.7 tonnes (5,950 lb), with the largest specimens attaining 6 tonnes (13,230 lb).[13] Pygmy elephants of the Congo Basin, presumed to be a subgroup of L. cyclotis, have reportedly weighed as little as 900 kg (1,980 lb) as adults.[14]

Behaviour

African forest elephants travel in smaller groups than other elephant species. A typical group size consists of 2 to 8 individuals. The average family unit is 3 to 5 individuals, usually made up of female relatives. Most family groups are a mother and several of her offspring, or several females and their offspring. Female offspring are philopatric, male offspring disperse at maturity. Unlike African savanna elephants (Loxodonta africana), African forest elephants (Loxodonta cyclotis) do not usually interact with other family groups. Male African forest elephants tend to be solitary and only associate with other elephants during the mating season. Males have a dominance hierarchy based on size.[12][15][16]

Reproduction

Females reach sexual maturity between the age of 8 and 12 years, depending on the population density and nutrition available. On average, they begin breeding at the age of 23 and give birth every five to six years.[4] As a result, the birth rate is lower than the bush species, which starts breeding at age 12 and has a calf every three to four years.[4]

Males generally pass puberty within the next year or two of females. The females are polyestrous, which means that they are capable of conceiving multiple times a year, which is a reason as to why they do not appear to have a breeding season. However, there does appear to be a peak in conceptions during the two rainy seasons of the year. Generally, the female conceives after two or three matings. Although the female has plenty of room in her uterus to gestate twins, it is rare for twins to be conceived. The female African forest elephant has a pregnancy that lasts 22 months. Based on the maturity, fertility and gestation rates, the African forest elephants have the capabilities of increasing the species' population size by 5% annually in ideal conditions.[17][18]

Diet and ecological role

The African forest elephant is an herbivore, and commonly eats leaves, fruit, and bark, with occasional visits to mineral licks. It eats a high proportion of fruit, and is sometimes the only disperser of some tree species, such as Balanites wilsoniana and Omphalocarpum spp. Elephants have been referred to as "forest gardeners" due to their significant role in seed dispersal and maintaining plant diversity.[19][20] In Afrotropical forests, many of these plant species are disseminated by forest elephants, sometimes at very long dispersal distances, a mutualism that matters to the population dynamics of plants and to the structure of forest tree communities. Moreover, the rate of seed germination of many forest plant species increases significantly after passage through an elephant’s gut.[21]

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.[22] The African forest elephant was observed opportunistically over a period of seven years between 1984 and 1991 in lowland rain forest in the Lopé Reserve, Gabon. Diet of elephants at Lopé was diverse, including a minimum of 307 items. The bulk of the diet, in terms of number of species and quantities eaten, came from leaves and bark (70% of all items recorded). Trees represented 73% of the species fed upon. In contrast to savanna-living populations, fruit was an important part of the diet. Fruit of at least 72 species is eaten and the remains of at least one species of fruit was found in 82% of 311 fresh dung piles searched over a one-year period.[23]

Threats and conservation

Tridom is a hotspot for poaching of forest elephants

Humans have proved to be one of the greatest threats to African forest elephants. While there was a ban on the international trade in elephant products including ivory that was implemented in 1990, when the African elephant was added to Appendix I of the Convention on International Trade in Endangered Species,[24] the ivory trade continues to be the reason for countless elephant deaths. Another threat to this species is the prolific logging industry in the Central Africa.[11] While selective logging, the more popular practice of extracting wood in Central Africa, may actually benefit forest elephants by creating more of their preferred habitat (secondary forest), the construction of roads used by the logging industry may have a detrimental effect by making these elephants more accessible to poachers as well as the bushmeat and ivory trade.[11] Other threats include habitat loss through the conversion of land to agriculture and increasing competition for resources with growing human populations.[12]

Late in the 20th century, conservation workers established a DNA identification system to trace the origin of poached ivory. Due to poaching to meet high demand for ivory, the African forest elephant population approached critical levels in the 1990s and early 2000s.[25][26] Over several decades, numbers are estimated to have fallen from approximately 700,000 to less than 100,000, with about half of the remaining population in Gabon.[27] In May 2013, Sudanese poachers invaded the Central African Republic's Dzanga Bai World Heritage Site and killed 26 elephants.[28][29] Communications equipment, video cameras, and additional training of park guards were provided following the massacre to improve protection of the site.[30] In September 2013, it was estimated that the forest elephant could become extinct within ten years.[31] From mid-April to mid-June 2014, poachers killed 68 elephants in Garamba National Park, including young ones without tusks.[32] According to DNA tests, most forest elephants are poached in Tridom, a border region of Gabon, the Republic of the Congo, and Cameroon.[33][34] At the request of President Ali Bongo Ondimba, twelve British soldiers traveled to Gabon in 2015 to assist in training park rangers following the poaching of many elephants in Minkebe National Park.[35]

Civil unrest, human encroachment, and habit fragmentation leaves some elephants confined to small patches of forest without sufficient food. In January 2014, IFAW undertook a relocation project at the request of the Côte d'Ivoire government, moving four elephants from Daloa to Azagny National Park.[36]

Observation

African forest elephants are estimated to constitute up to one-third of the continent's elephant population, but they have been poorly studied because of the difficulty in observing them through the dense vegetation that makes up their habitat.[37] Thermal imaging has facilitated observation of the species, leading to more information on their ecology, numbers, and behavior, including their interactions with elephants and other species. Scientists have learned more about how the elephants, who have poor night vision, negotiate their environment using only their hearing and olfactory senses. They also appeared to be much more active sexually during night compared to the day, which was unexpected.[17][18]

References

  1. ↑ Shoshani, J. (2005). "Order Proboscidea". In Wilson, D.E.; Reeder, D.M. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 91. ISBN 978-0-8018-8221-0. OCLC 62265494.
  2. ↑ "Threat to African forest elephants". Nature. 537 (7618): 7. 2016-09-01. doi:10.1038/537007b.
  3. 1 2 Steenhuysen, Julie (December 22, 2010). "Africa has two species of elephants, not one". Reuters.
  4. 1 2 3 Morelle, Rebecca (31 August 2016). "Slow birth rate found in African forest elephants". BBC News.
  5. ↑ Callaway, E. (2016-09-16). "Elephant history rewritten by ancient genomes". Nature. doi:10.1038/nature.2016.20622.
  6. ↑ Roca, Alfred L.; Georgiadis, Nicholas; Pecon-Slattery, Jill; O'Brien, Stephen J. (24 August 2001). "Genetic Evidence for Two Species of Elephant in Africa". Science. 293 (5534): 1473–1477. doi:10.1126/science.1059936. PMID 11520983.
  7. ↑ Rohland, Nadin; Reich, David; Mallick, Swapan; Meyer, Matthias; Green, Richard E.; Georgiadis, Nicholas J.; Roca, Alfred L.; Hofreiter, Michael (2010). Penny, David, ed. "Genomic DNA Sequences from Mastodon and Woolly Mammoth Reveal Deep Speciation of Forest and Savanna Elephants". PLoS Biology. 8 (12) (published December 2010). p. e1000564. doi:10.1371/journal.pbio.1000564.
  8. ↑ Debruyne R; van Holt A; Barriel V; Tassy P (2003). "Status of the so-called African pygmy elephant (Loxodonta pumilio (NOACK 1906)): phylogeny of cytochrome b and mitochondrial control region sequences". Comptes Rendus de Biologie. 326 (7): 687–69. doi:10.1016/S1631-0691(03)00158-6. PMID 14556388.
  9. 1 2 Spinage, C (1994). Elephants. London: T. & A. D. Poyser Ltd.
  10. ↑ Burnie, D. (2001). Animal. London: Dorling Kindersley.
  11. 1 2 3 Groning, K.; Saller, M. (1999). Elephants: a Cultural and Natural History. Cologne: Koneman.
  12. 1 2 3 "Forest elephant (Loxodonta cyclotis)". Arkive.org/. Retrieved October 23, 2014.
  13. ↑ "Forest elephant videos, photos and facts - Loxodonta cyclotis". ARKive. Retrieved 2012-07-23.
  14. ↑ "African Forest Elephant". The Animal Files. Retrieved 2012-07-23.
  15. ↑ Sukumar, R (2003). The Living Elephants: Evolutionary Ecology, Behavior, and Conservation. New York: Oxford University Press.
  16. ↑ Morgan, B; Lee, P (2003). "Forest elephant (Loxodonta africana cyclotis) stature in the Reserve de Faune du Petit Loango, Gabon". Journal of Zoology. 259: 337–344. doi:10.1017/s0952836902003291.
  17. 1 2 Allen, W (29 May 2006). "Ovulation, Pregnancy, Placentation and Husbandry in the African Elephant (Loxodonta africana)" (PDF). Philosophical Transactions: Biological Sciences. 361 (1469): 821–834. doi:10.1098/rstb.2006.1831. PMC 1609400Freely accessible. PMID 16627297.
  18. 1 2 Turkalo, A.K.; Fay, J.M. (2001). "African Rain Forest Ecology & Conservation". In Weber, W.; White, L.J.T.; Vedder, A.; Naughton-Treves, L. Forest Elephant Behavior and Ecology. Yale University Press. pp. 207–213. ISBN 9780300084337.
  19. ↑ Campos-Arceiz, Ahimsa; Blake, Steve (November–December 2011). "Megagardeners of the forest – the role of elephants in seed dispersal". Acta Oecologica. Science Direct. 37: 542–553. doi:10.1016/j.actao.2011.01.014.
  20. ↑ "Seed-dispersal by Elephants in a Tropical Rain Forest in Kahuzi-Biega National Park, Zaire". Biotropica. JSTOR. December 1995. pp. 526–530.
  21. ↑ Beaune, David; Fruth, Barbara; Bollache, Loïc; Hohmann, Gottfried; Bretagnolle, François (29 December 2012). "Doom of the elephant-dependent trees in a Congo tropical forest". Forest Ecology and Management. 295: 109–117. doi:10.1016/j.foreco.2012.12.041.
  22. ↑ Blake, Stephen; Deem, Sharon Lynn; Mossimbo, Eric; Maisels, Fiona; Walsh, Peter (25 March 2009). "Forest Elephants: Tree Planters of the Congo". Biotropica: The Journal of Tropical Biology and Conservation. 41 (4): 459–468. doi:10.1111/j.1744-7429.2009.00512.x.
  23. ↑ White, Lee J.T.; Tutin, Caroline E.G.; Fernandez, Michel (29 April 2008). "Group composition and diet of forest elephants, Loxodonta africana cyclotis Matschie 1900, in the Lopé Reserve, Gabon". African Journal of Ecology. 31 (3): 181–199. doi:10.1111/j.1365-2028.1993.tb00532.x.
  24. ↑ CITES. "Appendix I of the Convention on International Trade in Endangered Species". Cites.org.
  25. ↑ Barnes RF, Beardsley K, Michelmore F, Barnes KL, Alers MP, Blom A (1997). "Estimating Forest Elephant Numbers with Dung Counts and a Geographic Information System". The Journal of Wildlife Management. Allen Press. 61 (4): 1384–1393. doi:10.2307/3802142. JSTOR 3802142.
  26. ↑ Barnes RF, Alers MP, Blom A (1995). "A review of the status of forest elephants Loxodonta africana in central Africa". Biological Conservation. 71 (2): 125–132. doi:10.1016/0006-3207(94)00014-H.
  27. ↑ Gettleman, Jeffrey (26 December 2012). "In Gabon, Lure of Ivory Is Hard for Many to Resist". The New York Times.
  28. ↑ "At least 26 elephants massacred in World Heritage site". WWF Global. 10 May 2013.
  29. ↑ Neme, Laurel (13 May 2013). "Chaos and Confusion Following Elephant Poaching in a Central African World Heritage Site". National Geographic.
  30. ↑ Joyce, Christopher; McQuay, Bill (9 May 2014). "Former Commando Turns Conservationist To Save Elephants Of Dzanga Bai". NPR.
  31. ↑ Schiffman, Richard (5 January 2014). "African forest elephants are being massacred into extinction". Salon.com.
  32. ↑ Schemm, Paul (13 June 2014). "Poachers massacre elephants in Congo park". CTV News. The Associated Press.
  33. ↑ Jarvis, Brooke (18 June 2015). "DNA From Elephant Dung, Tusks Reveals Poaching Hot Spots". National Geographic.
  34. ↑ "Tridom". WWF Congo Basin. Retrieved May 1, 2016.
  35. ↑ "British troops head to West Africa to help stem elephant slaughter". Belfast Telegraph. 20 August 2015.
  36. ↑ Russo, Christina (29 January 2014). "Success and Tragedy: IFAW's Project to Relocate Elephants in Côte d'Ivoire". National Geographic.
  37. ↑ Clabby, Catherine. "Forest Elephant Chronicles". American Scientist. 100 (5): 416–17. doi:10.1511/2012.98.416.

Further reading

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