African leopard

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The African leopard (Panthera pardus pardus) is the nominate subspecies of the leopard, native to many countries in Africa. It is widely distributed in most of sub-Saharan Africa, but the historical range has been fragmented in the course of habitat conversion. Leopards have also been recorded in North Africa as well.

African leopard
Leopard (Panthera pardus pardus) Kruger.jpg
Kruger National Park
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Suborder: Feliformia
Family: Felidae
Subfamily: Pantherinae
Genus: Panthera
Species:
Subspecies:
P. p. pardus[1]
Trinomial name
Panthera pardus pardus[1]
Synonyms
List
    • P. p. panthera (Schreber, 1777)
    • P. p. leopardus (Schreber, 1777)
    • P. p. melanotica (Günther, 1885)
    • P. p. suahelicus (Neumann, 1900)
    • P. p. nanopardus (Thomas, 1904)
    • P. p. ruwenzorii (Camerano, 1906)
    • P. p. chui (Heller, 1913)
    • P. p. reichenowi (Cabrera, 1918)
    • P. p. antinorii (de Beaux, 1923)
    • P. p. ituriensis (Allen, 1924)
    • P. p. adusta Pocock, 1927
    • P. p. shortridgei (Pocock, 1932)
    • P. p. brockmani (Pocock, 1932)
    • P. p. puella (Pocock, 1932)
    • P. p. adersi Pocock, 1932[2]

Taxonomy

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Felis pardus was the scientific name used by Carl Linnaeus in the 10th edition of Systema Naturae in 1758. His description was based on descriptions by earlier naturalists such as Conrad Gessner. He assumed that the leopard occurred in India.[3] In the 18th and 19th centuries, several naturalists described various leopard skins and skulls from Africa, including:[4]

Results of genetic analyses indicate that all African leopard populations are generally closely related and represent only one subspecies, namely P. p. pardus.[9][10][11] However, results of an analysis of molecular variance and the pairwise fixation index of African leopard museum specimens shows differences in the ND-5 locus spanning five major haplogroups, namely in Central–Southern Africa, Southern Africa, West Africa, coastal West–Central Africa, and Central–East Africa. In some cases, fixation indices showed higher diversity than for the Arabian leopard and Panthera pardus tulliana in Asia.[12]

Characteristics

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A dark-coloured leopard skin from Central Africa
 
A leopard in the Serengeti

The African leopard exhibits great variation in coat color, depending on location and habitat. Coat colour varies from pale yellow to deep gold or tawny, and sometimes black, and is patterned with black rosettes while the head, lower limbs and belly are spotted with solid black. Male leopards are larger, averaging 58 kg (128 lb) with 90 kg (200 lb) being the maximum weight attained by a male. Females weigh about 37.5 kg (83 lb) on average.[13]

The African leopard is sexually dimorphic; males are larger and heavier than females.[14] Between 1996 and 2000, 11 adult leopards were radio-collared on Namibian farmlands. Males weighed 37.5 to 52.3 kg (83 to 115 lb) only, and females 24 to 33.5 kg (53 to 74 lb).[15] The heaviest known leopard weighed about 96 kg (212 lb), and was recorded in South West Africa.[16]

According to Alfred Edward Pease, black leopards in North Africa were similar in size to lions. An Algerian leopard killed in 1913 was reported to have measured approximately 8 ft 10 in (2.69 m), before being skinned.[17]

Leopards inhabiting the mountains of the Cape Provinces appear smaller and less heavy than leopards further north.[18] Leopards in Somalia and Ethiopia are also said to be smaller.[19]

The skull of a West African leopard specimen measured 11.25 in (286 mm) in basal length, and 7.125 in (181.0 mm) in breadth, and weighed 1 lb 12 oz (0.79 kg). To compare, that of an Indian leopard measured 11.2 in (280 mm) in basal length, and 7.9 in (20 cm) in breadth, and weighed 2 lb 4 oz (1.0 kg).[20]

Distribution and habitat

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Young female in Kruger National Park

The African leopards inhabited a wide range of habitats within Africa, from mountainous forests to grasslands and savannahs, excluding only extremely sandy desert. It is most at risk in areas of semi-desert, where scarce resources often result in conflict with nomadic farmers and their livestock.[21][22] It used to occur in most of sub-Saharan Africa, occupying both rainforest and arid desert habitats. It lived in all habitats with annual rainfall above 50 mm (2.0 in), and can penetrate areas with less than this amount of rainfall along river courses. It ranges up to 5,700 m (18,700 ft), has been sighted on high slopes of the Ruwenzori and Virunga volcanoes, and observed when drinking thermal water 37 °C (99 °F) in the Virunga National Park.[22]

The African leopard appears to be successful at adapting to altered natural habitat and settled environments in the absence of intense persecution. It has often been recorded close to major cities. But already in the 1980s, it has become rare throughout much of West Africa.[23] Now, it remains patchily distributed within historical limits.[24] During surveys in 2013, it was recorded in Gbarpolu County and Bong County in the Upper Guinean forests of Liberia.[25]

Leopards are rare in North Africa. A relict population persists in the Atlas Mountains of Morocco, in forest and mountain steppe in elevations of 300 to 2,500 m (980 to 8,200 ft), where the climate is temperate to cold.[26][27]

In 2014, a leopard was killed in the Elba Protected Area in southeastern Egypt. This was the first sighting of a leopard in the country since the 1950s.[28]

In 2016, a leopard was recorded for the first time in a semi-arid area of Yechilay in northern Ethiopia.[29]

Behavior and ecology

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In Kruger National Park, male leopards and female leopards with cubs were more active at night than solitary females. The highest rates of daytime activity were recorded for leopards using thorn thickets during the wet season, when impala also used them.[30] Leopards are generally most active between sunset and sunrise, and kill more prey at this time.[31]

Diet and hunting

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A young male leopard with a Cape porcupine kill in Kruger National Park

The leopard has an exceptional ability to adapt to changes in prey availability, and has a very broad diet. It takes small prey where large ungulates are less common. The known prey of leopards ranges from dung beetles to adult elands, which can reach 900 kg (2,000 lb).[22] In sub-Saharan Africa, at least 92 prey species have been documented in leopard scat, including rodents, birds, small and large antelopes, hyraxes, hares, and arthropods. Leopards generally focus their hunting activity on locally abundant medium-sized ungulates in the 20 to 80 kg (44 to 176 lb) range, while opportunistically taking other prey. Average intervals between ungulate kills range from seven[30] to 12–13 days.[31] Leopards often hide large kills in trees, a behavior for which great strength is required. There have been several observations of leopards hoisting carcasses of young giraffes, estimated to weigh up to 125 kg (276 lb), i.e. 2–3 times the weight of the leopard, up to 5.7 m (19 ft) into trees.[31]

In Serengeti National Park, leopards were radio-collared for the first time in the early 1970s. Their hunting at night was difficult to watch; the best time for observing them was after dawn. Of their 64 daytime hunts, only three were successful. In this woodland area, they preyed mostly on impalas, both adult and young, and caught some Thomson's gazelles in the dry season. Occasionally, they successfully hunted warthogs, dik-diks, reedbucks, duikers, steenboks, blue wildebeest and topi calves, jackals, Cape hares, guineafowl and starlings. They were less successful in hunting plains zebras, Coke's hartebeests, giraffes, mongooses, genets, hyraxes and small birds. Scavenging from the carcasses of large animals made up a small proportion of their food.[32] In the tropical rainforests of Central Africa, their diet consists of duikers and primates. Some individual leopards have shown a strong preference for pangolins and porcupines.[33]

In North Africa, the leopard preys on Barbary macaque (Macaca sylvanus).[34][35] Analysis of leopard scat in Taï National Park revealed that primates are primary leopard prey during the day.[36] In Gabon's Lope National Park, the most important prey species was found to be the red river hog (Potamochoerus porcus), African buffaloes (Syncerus caffer) and greater cane rats (Thryonomys swinderianus), comprised 13% each of the consumed biomass.[37]

In the Central African Republic's Dzanga-Sangha Complex of Protected Areas, a leopard reportedly attacked and pursued a large western lowland gorilla, but did not catch it. Gorilla parts found in leopard scat indicates that the leopard either scavenged on gorilla remains or killed it.[38] African leopards were observed preying on adult eastern gorillas in the Kisoro area near Uganda's borders with Rwanda and the Democratic Republic of the Congo.[39]

Threats

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An African leopard killed by Carl Akeley (right) barehanded

Throughout Africa, the major threats to leopards are habitat conversion and intense persecution,[40] especially in retribution for real and perceived livestock loss.[41] The Upper Guinean forests in Liberia are considered a biodiversity hotspot, but have already been fragmented into two blocks. Large tracts are affected by commercial logging and mining activities, and are converted for agricultural use including large-scale oil palm plantations in concessions obtained by a foreign company.[25]

The impact of trophy hunting on populations is unclear, but may have impacts at the demographic and population level, especially when females are shot. In Tanzania, only males are allowed to be hunted, but females comprised 28.6% of 77 trophies shot between 1995 and 1998.[42] Removing an excessively high number of males may produce a cascade of deleterious effects on the population. Although male leopards provide no parental care to cubs, the presence of the sire allows females to raise cubs with a reduced risk of infanticide by other males. There are few reliable observations of infanticide in leopards, but new males entering the population are likely to kill existing cubs.[43]

Analysis of leopard scats and camera trapping surveys in contiguous forest landscapes in the Congo Basin revealed a high dietary niche overlap and an exploitative competition between leopards and bushmeat hunters. With increasing proximity to settlements and concomitant human hunting pressure, leopards exploit smaller prey and occur at considerably reduced population densities. In the presence of intensive bushmeat hunting surrounding human settlements, leopards appear entirely absent.[44] Transhumant pastoralists from the border area between Sudan and the Central African Republic take their livestock to the Chinko area. They are accompanied by armed merchants who engage in poaching large herbivores, sale of bushmeat and trading leopard skins in Am Dafok. Surveys in the area revealed that the leopard population decreased from 97 individuals in 2012 to 50 individuals in 2017. Rangers confiscated large amounts of poison in the camps of livestock herders, who admitted that they use it for poisoning predators.[45]

Conservation

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The leopard is listed in CITES Appendix I. Hunting is banned in Zambia and Botswana, and was suspended in South Africa for 2016.[24]

Leopard populations are present in several protected areas, including:

  • Taï National Park[46]
  • Etosha National Park[47]
  • Virunga National Park[48]
  • Kruger National Park[49]

See also

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References

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  1. ^ Wozencraft, W. C. (2005). "Subspecies Panthera pardus pardus". In Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 547. ISBN 978-0-8018-8221-0. OCLC 62265494.
  2. ^ Wozencraft, W. C. (2005). "Species Panther pardus". In Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 547. ISBN 978-0-8018-8221-0. OCLC 62265494.
  3. ^ Linnaeus, C. (1758). "Felis pardus". Caroli Linnæi Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis (in Latin). Vol. Tomus I (decima, reformata ed.). Holmiae: Laurentius Salvius. p. 41−42.
  4. ^ Allen, G. M. (1939). A Checklist of African Mammals. Bulletin of the Museum of Comparative Zoology at Harvard College. Vol. 83. Cambridge, Mass.: The Museum. pp. 1–763.
  5. ^ Schreber, J. C. D. (1778). "Der Panther". Die Säugethiere in Abbildungen nach der Natur, mit Beschreibungen. Erlangen: Wolfgang Walther. pp. 384–386.
  6. ^ Camerano, L. (1906). "Spedizione al Ruwenzori di S.A.R. Luigi Amedeo di Savoia Duca degli Abruzzi". Bollettino dei Musei di Zoologia ed Anatomia Comparata della R. Università di Torino. 21 (545): 1–6.
  7. ^ Allen, J. A. (1924). "Carnivora collected by the American Museum Congo Expedition" (PDF). Bulletin of the American Museum of Natural History. 47 (3): 1–281.
  8. ^ a b Pocock, R. I. (1932). "The Leopards of Africa". Proceedings of the Zoological Society of London. 102 (2): 543–591. doi:10.1111/j.1096-3642.1932.tb01085.x.
  9. ^ Miththapala, S.; Seidensticker, J. & O'Brien, S. J. (1996). "Phylogeographic Subspecies Recognition in Leopards (Panthera pardus): Molecular Genetic Variation". Conservation Biology. 10 (4): 1115–1132. Bibcode:1996ConBi..10.1115M. doi:10.1046/j.1523-1739.1996.10041115.x. ISSN 0888-8892.
  10. ^ Uphyrkina, O.; Johnson, E. W.; Quigley, H.; Miquelle, D.; Marker, L.; Bush, M. & O'Brien, S. J. (2001). "Phylogenetics, genome diversity and origin of modern leopard, Panthera pardus" (PDF). Molecular Ecology. 10 (11): 2617–2633. Bibcode:2001MolEc..10.2617U. doi:10.1046/j.0962-1083.2001.01350.x. PMID 11883877. S2CID 304770. Archived from the original (PDF) on 2020-04-28. Retrieved 2012-05-10.
  11. ^ Kitchener, A. C.; Breitenmoser-Würsten, C.; Eizirik, E.; Gentry, A.; Werdelin, L.; Wilting, A.; Yamaguchi, N.; Abramov, A. V.; Christiansen, P.; Driscoll, C.; Duckworth, J. W.; Johnson, W.; Luo, S.-J.; Meijaard, E.; O’Donoghue, P.; Sanderson, J.; Seymour, K.; Bruford, M.; Groves, C.; Hoffmann, M.; Nowell, K.; Timmons, Z. & Tobe, S. (2017). "A revised taxonomy of the Felidae: The final report of the Cat Classification Task Force of the IUCN Cat Specialist Group" (PDF). Cat News. Special Issue 11: 73–75.
  12. ^ Anco, C.; Kolokotronis, S. O.; Henschel, P.; Cunningham, S. W.; Amato, G. & Hekkala, E. (2017). "Historical mitochondrial diversity in African leopards (Panthera pardus) revealed by archival museum specimens". Mitochondrial DNA Part A. 29 (3): 455–473. doi:10.1080/24701394.2017.1307973. PMID 28423965. S2CID 4348541.
  13. ^ "African leopard". SANBI. 24 May 2018. Retrieved 2022-11-12.
  14. ^ Hoath, R. (2009). "Leopard (Panthera pardus) Linnaeus, 1758". A Field Guide to the Mammals of Egypt. Cairo: American University in Cairo Press. pp. 106–107. ISBN 978-977-416-254-1.
  15. ^ Marker, L. L.; Dickman, A. J. (2005). "Factors affecting leopard (Panthera pardus) spatial ecology, with particular reference to Namibian farmlands" (PDF). South African Journal of Wildlife Research. 35 (2): 105–115. hdl:10520/EJC117223. ISSN 2410-7220. Archived from the original (PDF) on 2015-05-16. Retrieved 2015-06-07.
  16. ^ Brain, C. K. (1983). The Hunters Or the Hunted?: An Introduction to African Cave Taphonomy. University of Chicago Press. pp. 84–102. ISBN 978-0-226-07090-2.
  17. ^ Pease, A. E. (1913). "Of dangerous game". The Book of the Lion. London: John Murray. pp. 46–68.
  18. ^ Martins, Q. & Martins, N. (2006). "Leopards of the Cape: conservation and conservation concerns". International Journal of Environmental Studies. 63 (5): 579–585. Bibcode:2006IJEnS..63..579M. doi:10.1080/00207230600963486. S2CID 95270721.
  19. ^ Brakefield, T. (1993). "The Somali Leopard". Big Cats. Voyageur Press. p. 82. ISBN 978-1-61060-354-6.
  20. ^ Prater, S. H. (1921). "Record Panther Skull (P. p. pardus)". The Journal of the Bombay Natural History Society. XXVII (1, part IV): 933–935.
  21. ^ Kirby, F. V. (1899). "The Leopard (Felis pardus)". In Bryden, H. A. (ed.). Great and small game of Africa. London: Rowland Ward Ltd. pp. 568–574.
  22. ^ a b c Nowell, K. & Jackson, P. (1996). "Leopard Panthera pardus" (PDF). Wild Cats: Status Survey and Conservation Action Plan. Gland, Switzerland: IUCN/SSC Cat Specialist Group. pp. 1–334. ISBN 2-8317-0045-0.
  23. ^ Martin, R. B. & De Meulenaer, T. (1988). Survey of the status of the leopard (Panthera pardus) in sub-Saharan Africa (Report). Lausanne: CITES Secretariat.
  24. ^ a b Stein, A.B.; Gerngross, P.; Al Hikmani, H.; Balme, G.; Bertola, L.; Drouilly, M.; Farhadinia, M.S.; Feng, L.; Ghoddousi, A.; Henschel, P.; Jhala, Y.; Khorozyan, I.; Kittle, A.; Laguardia, A.; Luo, S.-J.; Mann, G.; Miquelle, D.; Moheb, Z.; Raza, H.; Rostro-García, S.; Shivakumar, S.; Song, D. & Wibisono, H. (2024). "Panthera pardus". IUCN Red List of Threatened Species. 2024: e.T15954A254576956. Retrieved 30 June 2024.
  25. ^ a b Bene, J.C.K.; Bitty, E.A.; Bohoussou, K.H.; Abedilartey, M.; Gamys, J. & Soribah, P.A. (2013). "Current conservation status of large mammals in Sime Darby Oil Palm Concession in Liberia". Global Journal of Biology, Agriculture & Health Sciences. 2 (2): 93–102.
  26. ^ Cuzin, F. (2003). Les grands mammifères du Maroc méridional (Haut Atlas, Anti Atlas et Sahara): Distribution, Ecologie et Conservation (PDF) (Ph.D. Thesis). Université Montpellier II: Laboratoire de Biogéographie et Ecologie des Vertèbrés, Ecole Pratique des Hautes Etudes.
  27. ^ Busby, G. B. J.; Gottelli, D.; Durant, S.; Wacher, T.; Marker, L.; Belbachir, F.; de Smet, K.; Belbachir-Bazi, A.; Fellous, A. & Belghoul, M. (2006). "Part 5: Using Molecular Genetics to study the presence of Endangered carnivores". A Report from the Sahelo Saharan Interest Group. Algeria: Parc National de l'Ahaggar Survey.
  28. ^ Soultan, A.; Attum, O.; Hamada, A.; Hatab, E.-B.; Ahmed, S. E.; Eisa, A.; Sharif, I. A.; Nagy, A. & Shohdi, W. (2017). "Recent observation for leopard Panthera pardus in Egypt". Mammalia. 81 (1): 115–117. doi:10.1515/mammalia-2015-0089. S2CID 90676105.
  29. ^ Westerberg, M.; Craig, E. & Meheretu, Y. (2017). "First record of African leopard (Panthera pardus pardus L.) in semi-arid area of Yechilay, northern Ethiopia". African Journal of Ecology. 56 (2): 375–377. doi:10.1111/aje.12436.
  30. ^ a b Bailey, T. N. (2005) [1993]. The African Leopard: Ecology and Behavior of a Solitary Felid (Illustrated, reprint ed.). Blackburn Press. ISBN 978-1-932846-11-9.
  31. ^ a b c Hamilton, P. H. (1976). The Movements of Leopards in Tsavo National Park, Kenya as Determined by Radio-tracking (PhD). Nairobi: University of Nairobi.
  32. ^ Bertram, B. (1974). "Radio-Tracking Leopards in the Serengeti". African Wildlife Leadership Foundation News 1974 (9): 8–10.
  33. ^ Jenny, D. (1993). "Leopard research in Ivory Coast rain forest". Cat News (18): 12–13.
  34. ^ Fa, J. E. (1982). "A survey of population and habitat of the Barbary macaque Macaca sylvanus L. in north Morocco". Biological Conservation. 24 (1): 45–66. Bibcode:1982BCons..24...45F. doi:10.1016/0006-3207(82)90046-5.
  35. ^ Van Lavieren, E. (2012). "The Barbary Macaque (Macaca sylvanus); A unique endangered primate species struggling to survive" (PDF). Revista Eubacteria (3 0): 1–4.
  36. ^ Zuberbühler, K.; Jenny, D. (2002). "Leopard predation and primate evolution" (PDF). Journal of Human Evolution. 43 (6): 873–886. Bibcode:2002JHumE..43..873Z. doi:10.1006/jhev.2002.0605. PMID 12473487.
  37. ^ Henschel, P.; Abernethy, K. A. & White, L. J. T. (2005). "Leopard food habits in the Lope National Park, Gabon, Central Africa". African Journal of Ecology. 43 (1): 21–28. Bibcode:2005AfJEc..43...21H. doi:10.1111/j.1365-2028.2004.00518.x.
  38. ^ Fay, J. M.; Carroll, R.; Kerbis Peterhans, J. C.; Harris, D. (1995). "Leopard attack on and consumption of gorillas in the Central African Republic". Journal of Human Evolution. 29 (1): 93–99. Bibcode:1995JHumE..29...93F. doi:10.1006/jhev.1995.1048.
  39. ^ Schaller, G. B. (2010). "7: A Home in the Highlands". The Year of the Gorilla. Chicago: University of Chicago Press. p. 139. ISBN 978-0-2267-3647-1.
  40. ^ Williams, S.T.; Williams, K.S.; Lewis, B.P.; Hill, R.A. (2017). "Population dynamics and threats to an apex predator outside protected areas: implications for carnivore management". Royal Society Open Science. 4 (4): 161090. Bibcode:2017RSOS....461090W. doi:10.1098/rsos.161090. PMC 5414262. PMID 28484625.
  41. ^ Ray, J.C.; Hunter, L.; Zigouris, J. (2005). Setting Conservation and Research Priorities for Larger African Carnivores (PDF). New York: Wildlife Conservation Society.
  42. ^ Spong, G.; Johansson, M.; Björklund, M. (2000). "High genetic variation in leopards indicates large and long-term stable effective population size". Molecular Ecology. 9 (11): 1773–1782. Bibcode:2000MolEc...9.1773S. doi:10.1046/j.1365-294x.2000.01067.x. PMID 11091313. S2CID 14549268.
  43. ^ Cat Specialist Group (2005). Cat Project of the Month – November 2005: Conservation biology of leopards (Panthera pardus) in a fragmented landscape; spatial ecology, population biology and human threats. IUCN/SSC Cat Specialist Group
  44. ^ Henschel, P.; Hunter, L. T. B.; Coad, L.; Abernethy, K. A.; Mühlenberg, M. (2011). "Leopard prey choice in the Congo Basin rainforest suggests exploitative competition with human bushmeat hunters" (PDF). Journal of Zoology. 285: 11–20. doi:10.1111/j.1469-7998.2011.00826.x. Archived from the original (PDF) on 2012-03-15.
  45. ^ Äbischer, T.; Ibrahim, T.; Hickisch, R.; Furrer, R. D.; Leuenberger, C. & Wegmann, D. (2020). "Apex predators decline after an influx of pastoralists in former Central African Republic hunting zones" (PDF). Biological Conservation. 241: 108326. Bibcode:2020BCons.24108326A. doi:10.1016/j.biocon.2019.108326. S2CID 213766740.
  46. ^ Jenny, D. (1996). "Spatial organization of leopards Panthera pardus in Taï National Park, Ivory Coast: is rainforest habitat a 'tropical haven'?". Journal of Zoology. 240 (3): 427–440. doi:10.1111/j.1469-7998.1996.tb05296.x.
  47. ^ Linnell, J. D. C.; Aanes, R.; Swenson, J. E.; Odden, J.; Smith, M. E. (1997). "Translocation of Carnivores as a Method for Managing Problem Animals: A Review". Biodiversity and Conservation. 6 (1): 1245–1257. Bibcode:1997BiCon...6.1245L. doi:10.1023/B:BIOC.0000034011.05412.cd. S2CID 32511170.
  48. ^ Nixon, S. C. & Lusenge, T. (2008). Conservation status of okapi in Virunga National Park, Democratic Republic of Congo. ZSL Conservation Report No. 9 (PDF) (Report). London: The Zoological Society of London.
  49. ^ Maputla, N. W.; Chimimba, C. T.; Ferreira, S. M. (2013). "Calibrating a camera trap-based biased mark-recapture sampling design to survey the leopard population in the N'wanetsi concession, Kruger National Park, South Africa" (PDF). African Journal of Ecology. 51 (3): 422–430. Bibcode:2013AfJEc..51..422M. doi:10.1111/aje.12047. hdl:2263/31024.
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