Ecology and Conservation of the African Golden Cat Caracal Aurata
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Ecology and Conservation of the African Golden Cat Caracal aurata By Laila Bahaa-el-din Submitted in fulfilment of the academic requirements for the degree of Doctor of Philosophy In the School of Life Sciences University of KwaZulu-Natal Durban, South Africa December 2015 As the candidate‘s supervisor, I have approved this thesis for submission. Signed:……….………. Name: Prof. Rob Slotow Date: 10/12/15 Signed:……………… Name: Prof. David Macdonald Date: 09/12/15 Signed:……………….. Name: Dr. Luke Hunter Date: 10/12/15 Abstract II Abstract The African golden cat Caracal aurata, hitherto almost unstudied, is Africa’s only forest- dependent felid. As such, it has the potential to act as both an indicator and flagship species for Africa’s rainforests, which face threats from rapid development, exploitation, deforestation, human population increase, and bushmeat hunting. I collected camera trap and scat data over four years (2010 – 2013) in the central African country of Gabon to assess the impact of these threats on golden cat populations, as well as gain insight into the behavioural ecology of the species. I used spatially-explicit capture-recapture models to estimate population density of golden cats across five sites differing in human-land use, including two protected areas, two logging concessions, and a site with subsistence bushmeat hunting. Density was highest at the undisturbed protected site (16.23 individuals per 100 km2) and lowest at the hunting site (3.8 individuals per 100 km2), with evidence of the latter being a result of wire snare use. The logging concessions supported important populations of golden cats (10.18 - 12.84 individuals per 100 km2), suggesting that areas under concessions can be included within the conservation estate, provided they are operated under a sound management plan. Golden cats occur in sympatry with leopards Panthera pardus in most of their range and there is evidence that leopards compete with, and prey on, golden cats, potentially limiting golden cat populations. In areas of sympatry, golden cat activity was cathemeral, but differed significantly in areas where leopards have been extirpated by people, displaying mostly nocturno-crepuscular activity. This provides evidence of behavioural plasticity in response to differing guild structure, supporting the mesopredator release hypothesis that mid-ranking predators respond to the removal of apex predators. Such behavioural shifts likely facilitate resource acquisition and avoidance of other threats, such as humans. Where the two species co-occur, their shared use of trails leads to high spatial overlap. However, at the finer spatio-temporal scale, golden cats generally avoided camera trap stations until at least one day after a leopard had gone past. Food niche overlap between the two species was low (0.18, where 0 is no overlap and 1 is complete overlap), with golden cats and leopards mostly consuming rodents and ungulates, respectively. I conclude that mechanisms of co- existence between the two felids include fine-scale reactive avoidance by golden cats, and food niche segregation. This research reveals that co-existence between competing species can happen at a fine-scale, and that broad-scale displacement of mesopredators need not occur. Mesopredators may adapt to human-induced changes in dominant species’ ecology and behaviour in order to persist in the face of disturbance. Preface III Preface The fieldwork described in this thesis was carried out by the author in central Gabon from June 2010 until November 2013, through the School of Life Sciences, University of KwaZulu-Natal, Westville campus. Supervision was provided by Prof. Rob Slotow, Prof. David Macdonald and Dr. Luke Hunter. Additional data was provided from studies in Uganda for use in comparative analyses. These studies represent original work by the author and have not otherwise been submitted in any form for any degree or diploma to any tertiary institution with the exception of chapter 4. The chapter 4 concept was originally developed as a diploma project of B. Mugerwa (Postgraduate Diploma in International Wildlife Conservation Practice at the University of Oxford), that was supervised by myself and with a large part of data used being from the data I collected. Following the submission of the diploma project, I then re-analysed the original data after adding in additional data, additional analyses, and revised the concept and redrafted the text for submission as part of this thesis. Candidate: Signed:…………………… Name: Laila Bahaa-el-din Date: 10/12/15 Supervisors: Signed:…… ….………. Name: Prof. Rob Slotow Date: 10/12/15 Signed:……………… Name: Prof. David Macdonald Date: 09/12/15 Signed:……………….. Name: Dr. Luke Hunter Date: 10/12/15 Declaration 1: Plagiarism IV Declaration 1 - Plagiarism I, Laila Bahaa-el-din, declare that 1) The research reported in this thesis, except where otherwise indicated, is my original research. 2) This thesis has not been submitted for any degree or examination at any other university. 3) This thesis does not contain other persons’ data, pictures, graphs or other information, unless specifically acknowledged as being sourced from other persons. 4) This thesis does not contain other persons' writing, unless specifically acknowledged as being sourced from other researchers. Where other written sources have been quoted, then: a. Their words have been re-written but the general information attributed to them has been referenced b. Where their exact words have been used, then their writing has been placed in italics and inside quotation marks, and referenced. 5) This thesis does not contain text, graphics or tables copied and pasted from the Internet, unless specifically acknowledged, and the source being detailed in the thesis and in the References sections. Signed Laila Bahaa-el-din Date: 10/12/15 Declaration 2: Publications V Declaration 2 - Publications Publication 1 (Chapter 2) Bahaa‐el‐din, L., Henschel, P., Butynski, T. M., Macdonald, D. W., Mills, D., Slotow, R., & Hunter, L. (2015). The African golden cat Caracal aurata: Africa's least‐known felid. Mammal Review, 45(1): 63-77. Author contributions: LB collected and processed the data, and designed and wrote the paper. DM collected data; PH, TMB, DWM, DM, RS & LH provided valuable comments on the manuscript. Publication 2 (Chapter 3) Bahaa-el-din, L., Sollmann, R., Hunter, L., Slotow, R., Macdonald, D.W. & Henschel, P. (in review). The effects of human-land use on Africa’s only forest dependent cat: the African golden cat. Submitted to Biological Conservation. Author contributions: LB collected data, processed and analysed the data, and designed and wrote the paper. R Sollmann provided data analysis support and comments on the manuscript. LH, DWM, R Slotow & PH provided valuable comments on the manuscript. Publication 3 (Chapter 4) Bahaa-el-din, L., Mugerwa, B. Mills, D. Henschel, P., Hunter, L., Slotow, R. Hockemba, M.B., Astares, C. & Macdonald, D. (in review). Behavioural plasticity in a forest-adapted felid; African golden cats adjust their activity to the presence of leopards and humans. Submitted to Behavioural Ecology. Author contributions: LB collected data, processed and analysed the data, and co-designed and wrote the paper. BM and DM collected data from additional sites. LB, BM & DM co-designed the paper as part of BM’s Diploma project. MBH collected data. PH, LH, RS, CA & DWM provided valuable comments on the manuscript. Publication 4 (Chapter 5) Bahaa-el-din, L., Henschel, P., Caragiulo, A. Sollmann, R., Hutterer, R., Slotow, R., Macdonald, D.W. & Hunter, L. (in prep.). Co-existence of the two African rainforest felids under increasing disturbance from land-use. To be submitted to Journal of Animal Ecology. Declaration 2: Publications VI Author contributions: LB collected data, processed and analysed the data, and designed and wrote the paper. AC carried out the genetic analysis of the faecal samples. RH assisted with identification of small mammal remains in faecal samples. R Sollmann provided data analysis support and comments on the manuscript. PH, R Slotow, DWM & LH provided valuable comments on the manuscript. Publication 5 (Appendix 1) Bahaa-el-din, L., Mills, D., Hunter, L., & Henschel, P. (2015). Caracal aurata. The IUCN Red List of Threatened Species 2015. (http://www.iucnredlist.org/details/18306/0). Author contributions: LB collected data, assimilated information and updated the assessment. DM carried out range mapping and, alongside LH & PH, provided ideas and valuable comments on the content. Publication 6 (Appendix 2) Bahaa-el-din, L., Henschel, P., Aba’a, R., Abernethy, K., Bohm, T., Bout, N., Coad, L.M., Head, J., Inoue, E., Lahm, S., Lee, M., Maisels, F., Rabanal, L., Starkey, M., Taylor, G., Vanthomme, H., Nakashima, Y., Hunter, L. (2013). Notes on the distribution and status of small carnivores in Gabon. Small Carnivore Conservation 48 (2013): 19-29. Author contributions: LB & PH collected data, processed and analysed data, and designed and wrote the paper. LC collected, processed and analysed the bushmeat data. RA, KA, TB, NB, JH, EI, SM, ML, FM, LR, MS, GT, HV & YN collected data. LH provided valuable comments on the manuscript. Signed Laila Bahaa-el-din Date: 10/12/15 Table of contents VII Table of Contents Abstract ................................................................................................................... II Preface .................................................................................................................... III Declaration