Galago Moholi)
Total Page:16
File Type:pdf, Size:1020Kb
SPECIES DENSITY OF THE SOUTHERN LESSER BUSHBABY (GALAGO MOHOLI) AT LOSKOP DAM NATURE RESERVE, MPUMALANGA, SOUTH AFRICA, WITH NOTES ON HABITAT PREFERENCE A THESIS SUBMITTED TO THE GRADUATE SCHOOL IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE MASTER OF ARTS BY IAN S. RAY DR. EVELYN BOWERS, CHAIRPERSON BALL STATE UNIVERSITY MUNCIE, INDIANA MAY 2014 SPECIES DENSITY OF THE SOUTHERN LESSER BUSHBABY (GALAGO MOHOLI) AT LOSKOP DAM NATURE RESERVE, MPUMALANGA, SOUTH AFRICA, WITH NOTES ON HABITAT PREFERENCE A THESIS SUBMITTED TO THE GRADUATE SCHOOL IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE MASTER OF ARTS BY IAN S. RAY Committee Approval: ____________________________________ ________________________ Committee Chairperson Date ____________________________________ ________________________ Committee Member Date ____________________________________ ________________________ Committee Member Date Departmental Approval: ____________________________________ ________________________ Department Chairperson Date ____________________________________ ________________________ Dean of Graduate School Date BALL STATE UNIVERSITY MUNCIE, INDIANA MAY 2014 TABLE OF CONTENTS 1. ABSTRACT. iii 2. ACKNOWLEDGEMENTS. iv 3. LIST OF TABLES. .v 4. LIST OF FIGURES. vi 5. LIST OF APPENDICES. .vii 6. INTRODUCTION. .1 a. BACKGROUND AND THEORY. 1 b. LITERATURE REVIEW. 2 i. HABITAT. 4 ii. MORPHOLOGY. .5 iii. MOLECULAR BIOLOGY. 7 iv. REPRODUCTION. .8 v. SOCIALITY. 10 vi. DIET. 11 vii. LOCOMOTION. .12 c. OBJECTIVES. 13 7. MATERIALS AND METHODS. .15 a. STUDY SITE. .15 b. DATA COLLECTION. 16 c. DATA ANLYSES. .16 8. RESULTS. 20 a. SPECIES DENSITY. 20 i b. ASSOCIATED PLANT SPECIES. 21 9. DISCUSSION. 24 a. SPECIES DENSITY. 24 b. HABITAT PREFERENCE. 25 10. CONCLUSION. 28 11. REFERENCES CITED. 29 12. APPENDICES. 33 ii ABSTRACT THESIS: Species Density of the Southern Lesser Bush Baby (Galago moholi) at Loskop Dam Nature Reserve, Mpumalanga, South Africa with notes on habitat preference. STUDENT: Ian S. Ray DEGREE: Master of Arts COLLEGE: Sciences and Humanities DATE: May 2014 PAGES: 68 A population survey was conducted on Galago moholi along the road system at Loskop Dam Nature Reserve, Mpumalanga province, South Africa. The data were analyzed using the maximum perpendicular distance, mean perpendicular distance, and maximum reliable perpendicular distance methods. Vegetation sample plots were constructed at the location of each individual sighted in order to analyze the species’ habitat use. The results indicate that the species density of G. moholi is significantly lower at Loskop Dam Nature Reserve than previously reported at other sites within South Africa. G. moholi was found to prefer areas with high concentrations of Dichrostachys sp., Combretum sp., or Acacia sp. One individual was observed consuming vegetative matter, which may indicate that the population within the reserve is utilizing available resources in a different way than populations in other parts of southern Africa. iii ACKNOWLEDGEMENTS I will be eternally grateful to all who helped to make this project possible... My adviser and committee chairperson, Dr. Evelyn Bowers, deserves much gratitude for supplying me with a seemingly endless amount of advice and resources, both in the classroom and in the field. I thank my other committee members, Dr. S. Homes Hogue and Dr. Ronald Hicks, for their continued support throughout my academic career. Furthermore, I would like to extend my thanks to the full staff of Ball State University’s Department of Anthropology for their genuine compassion and dedication to the discipline. I would like to thank Dr. Brandi Wren for her help both in field training and throughout my field research, as well as Ruby Malzoni and Michele Mingini for their assistance in conducting the population survey. I am grateful to the aid provided by Jannie Coetzee and the staff of the Applied Behavioural Ecology and Ecosystem Research Unit (ABEERU) of the University of South Africa (UNISA), and for being allowed to work at Loskop Dam Nature Reserve. iv LIST OF TABLES TABLE 1: ESTIMATED SPECIES DENSITY OF G. MOHOLI ALONG VARIOUS TRANSECT SEGMENTS. .20 TABLE 2: ESTIMATED SPECIES DENSITY OF G. MOHOLI AT LOSKOP DAM NATURE RESERVE. .21 TALBE 3: PLANT SPECIES IDENTIFIED AND NUMBER OF EACH SPECIES. 22 TABLE 4: MAJOR PLANT GENUS AND PERCENT OF TOTAL WOODY SPECIES. 23 TABLE 5: PERCENTAGE OF TREES BY SIZE CLASS. .23 TABLE 6: PERCENTAGE OF CENTER TREE DBH BY SIZE CLASS. .23 TABLE 7: PERCENT CANOPY COVER BY CLASS. 23 v LIST OF FIGURES FIGURE 1: MAP DISPLAYING THE PROVINCES OF SOUTH AFRICA. 2 FIGURE 2: MAP DISPLAYING THE RANGE OF O. CRASSICAUDATUS AND G. MOHOLI. 3 FIGURE 3: LOCATION OF THE LOSKOP DAM NATURE RESERVE IN THE MPUMALANGA PROVINCE OF SOUTH AFRICA. .15 FIGURE 4: TRANSECTS LABELED BY COLOR. 18 FIGURE 5: LOCATION OF EACH INDIVIDUAL AT INITIAL SIGHTING. 19 FIGURE 6: G. MOHOLI CONSUMING THE FRUIT OF D. CINEREA. 27 vi LIST OF APPENDICES APPENDIX 1: TRANSECT DATA. .33 APPENDIX 2: VEGETATION SAMPLE PLOT DATA. 44 vii INTRODUCTION Background and Theory Speciation by means of natural selection was first proposed by Darwin (2009). The concept of natural selection has been modified, resulting in the Synthetic Theory of evolution (Huxley 1939). This synthetic theory combines natural selection, genetics, and random processes (Huxley 1939). It is necessary to understand a population’s environment in order to understand the selective pressures to which the population is exposed. Thus, ecological studies are an important step towards understanding the evolution of a species, both past and present. The study of ecology would be impossible without the concept of a niche (Colwell and Rangel 2009; Wake et al. 2009). A niche is commonly described as a multidimensional hypervolume of space having the required resources and environmental conditions allowing a species to live (Colwell and Rangel 2009). In the face of climate change, niches change and populations may shift to new territory, adapt, or go into decline (Colwell and Rangel 2009; Wake et al. 2009). These niche changes produce differing pressures upon which natural selection acts, providing the mechanism for evolution (Darwin 2009; Wake et al. 2009) Two generally recognized species of prosimians are found within South Africa, Galago moholi A. Smith 1836 and Otolemur crassicaudatus E. Geoffroy 1812 (Ravosa et al. 2010). These species are partially sympatric and may display similar ecological adaptations, thus their exact evolutionary relationship is not entirely clear. The goal of this research is to determine what ecological niche G. moholi occupies and whether this niche could overlap with that of a population of O. crassicaudatus should one be introduced to Loskop Dam Nature Reserve, through either natural processes or artificial releases. 1 Literature Review The family Galagidae, or the bush babies, is composed of small nocturnal primates that inhabit the forests, woodlands, and savannahs of the African continent (Stephenson et al. 2010). Galagidae, along with the sister family Lorisidae, form the order Lorisiformes (Seiffert et al. 2003). In turn, Lorisiformes is a sister group to the Lemuriformes of Madagascar (Seiffert et al. 2003). The clade of the Galagidae, the African Lorisiformes, is of interest not only because ancestral populations are a likely source of the Madagascar Lemuriformes, but also because of the role of the animals within their own ecosystem (Stankiewicz et al. 2006). Many species of galago have been described and considerable debate exists over which populations belong to each species (Stephenson et al. 2010). Many species depend heavily on tree exudates, with saps and gums forming up to 75 percent of the diet of some species (Stephenson et al. 2010). The establishment of species currently is based predominantly on behavioral and genetic distinctions rather than on physical similarities between populations (Lawes 2005). This is contrary to the morphological Figure 1: Map displaying the provinces of South Africa (Skinner and Chimimba 2005:XVII) observations that have previously been used to distinguish galago species. Within South Africa, two generally accepted species are found. Galago moholi (the South African galago) is found in Limpopo, Mpumalanga, Gauteng, and northeast KwaZulu-Natal 2 provinces (Lawes 2005). The South African galago was grouped with Galago senegalensis É. Geoffroy 1796 as Galago senegalensis moholi (Anderson 1998; Nash et al. 1989). Otolemur crassicaudatus (the thick-tailed galago) is found in Limpopo, eastern Mpumalanga, and only at lower elevations in KwaZulu- Natal provinces (Lawes 2005). Bearder (1974) suggested that the discontinuous distribution of both species indicates that the forests of South Africa have not been continuous since bushbabies first evolved. The two species occur sympatrically in some areas but at lower overall densities than in areas where they are separate (Bearder and Doyle 1974). These are the only members of the Lorisidae that are known to be sympatric outside of the tropics (Crompton 1980). This may be due to niche overlap or to sympatric environments being suboptimal habitat for Figure 2: Maps displaying the distribution of O. both species (Bearder and Doyle 1974). crassicaudatus (top) and G. moholi (bottom) (Lawes 2005:212, 214) 3 Habitat O. crassicaudatus has been said to prefer riverine savannah and woodlands (Nash et al. 1989). O. crassicaudatus is found from sea level to over 1,800 m (Lawes 2005). In Limpopo and Mpumalanga provinces, they often are found