Population surveys of fork-marked dwarf lemurs and needle-clawed galagos
Fork-marked dwarf lemurs (Phaner spp.) of Madagascar and the needle-clawed galagos (Euoticus spp.) of Central-West Africa are two genera within the primate suborder Strepsirrhini. Despite their distant relationship, these genera share remarkably convergent anatomical, behavioural and ecological characteristics. However, like most nocturnal primates in sub-Saharan Africa they are poorly studied and little is known about the population estimates of both genera. I conducted surveys of wild populations of Phaner pallescens, P. parienti and P. furcifer in Madagascar as well as Euoticus elegantulus and E. pallidus in Cameroon. Six transects were established in Madagascar covering a total distance of 20 km, within which I encountered 52 fork-marked dwarf lemurs. In Cameroon three transects were established covering a total distance of 8.5 km, and 56 encounters of needle-clawed galagos were made. Population encounter rates of P. pallescens, P. parienti, P. furcifer, E. elegantulus and E. pallidus were 3.3, 2.4, 2.3, 9.9 and 8.3 individuals per kilometre, respectively. Compared to previous estimates of population encounter rates in other study sites, these values are lower. Low population encounter rates of fork-marked dwarf lemurs and needle-clawed galagos may be due to environmental and anthropogenic pressures at the study sites. Further ecological, behavioural and conservation studies are required for these genera.
KeywordsFork-marked dwarf lemurs Needle-clawed galagos Population encounter rate
This project was funded in major part by the African Earth Observatory Network (AEON) under the scientific direction of Prof. Maarten de Wit. I thank my supervisors, Prof. Judith Masters and Dr. Fabien Génin, for their guidance and support during the study period, and for the funding they provided for field studies. Primate Conservation Incorporated supported purchase of a field camera, for which I thank Noel Rowe. The project was authorized by the Direction de la Conservation de la Biodiversité et du Système des Aires Protegées in Madagascar and authorities of Dja Biosphere Reserve, Mefou Sanctuary and Mount Kupé in Cameroon. This research complied with the ethical standards in the treatment of animals and guidelines laid down by the Primate Society of Japan and the national laws of Madagascar and Cameroon.
- Ambrose L (1999) Species diversity in West and Central African Galagos (Primates, Galagonidae): the use of acoustic analysis. PhD dissertation, Oxford Brookes UniversityGoogle Scholar
- Ausilio E, Raveloarinoro G (1993) Statut et densités des especes de lemuriens de la region d’Antsalova (ouest de Madagascar) (Forêts de l’Antsingy, de Tsimembo et de la region de Tsiandro). Unpublished report to UNESCO—Project 507/INT/40. Antananarivo, MadagascarGoogle Scholar
- Buckland JF, Anderson DR, Burnham KP, Laake TL, Borchers DL, Thomas L (2001) Introduction to distance sampling: estimating abundance of biological populations. Oxford University Press, OxfordGoogle Scholar
- Charles-Dominique P (1977) Ecology and behaviour of nocturnal primates: prosimians of equatorial West Africa. Duckworth, LondonGoogle Scholar
- Charles-Dominique P, Petter JJ (1980) Ecology and social life of Phaner furcifer. In: Charles-Dominique P, Cooper HM, Hladik A, Hladik CM, Pages E, Pariente G, Petter-Rousseaux A, Petter JJ, Schilling A (eds) Nocturnal malagasy primates: ecology, physiology, and behavior. Academic, New York, pp 75–95Google Scholar
- IUCN (2012) 2012 IUCN red list of threatened species. The International Union for Conservation of Nature (IUCN), Species Survival Commission (SSC), GlandGoogle Scholar
- Nekaris KAI (1997) A preliminary survey of the slender loris (Loris tardigradus) in South India. Am J Phys Anthropol 24:176–177Google Scholar
- Petter JJ, Schilling A, Pariente G (1971) Observations éco-éthologiques sur deux lémuriens malgaches nocturnes: Phaner furcifer et Microcebus coquereli. Terre Vie 25:287–327Google Scholar
- Ray IS, Wren BT, Bowers E (2017) Species density of Galago moholi at Loskop Dam Nature Reserve, South Africa. Afr Primates 12:1–8Google Scholar
- Sutherland WJ (2002) Mammals. In: Sutherland WJ (ed) Ecological censusing techniques. Cambridge University Press, Cambridge, pp 260–278Google Scholar
- Svensson M, Ingram DJ, Nekaris KAI, Nijman V (2015) Trade and ethnozoological use of African lorisiforms in the last 20 years. Hystrix It Mammal 26:153–161Google Scholar