The demography, spatial ecology and reproductive success of the black rhinoceros, Diceros bicornis, in Hluhluwe-iMfolozi Park, Kwazulu-Natal, South Africa
- Authors: Nhleko, Zoliswa Nombulelo
- Date: 2014
- Subjects: Hluhluwe-iMfolozi Park (South Africa) , Black rhinoceros -- South Africa -- Hluhluwe , Animal populations -- South Africa -- Hluhluwe , Spatial ecology -- South Africa -- Hluhluwe , Black rhinoceros -- Reproduction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5849 , http://hdl.handle.net/10962/d1011825 , Hluhluwe-iMfolozi Park (South Africa) , Black rhinoceros -- South Africa -- Hluhluwe , Animal populations -- South Africa -- Hluhluwe , Spatial ecology -- South Africa -- Hluhluwe , Black rhinoceros -- Reproduction
- Description: Black rhinoceroses (Diceros bicornis) are endangered; there are only ~5000 individuals remaining worldwide. Consequently, black rhinos are managed as a metapopulation in southern Africa. This means that even though several sub-populations of black rhinos are geographically separated, they are managed as a single population. This is achieved by interchanging genetic material between the sub-populations. The main aim of the metapopulation management approach is to increase black rhino numbers in the sub-region. The Rhino Management Group (RMG), formed in 1989, was tasked with setting scientifically defensible demographic targets for the remaining black rhino sub-populations in southern Africa. In the same year, the RMG set fecundity rate at 25% and stated that each black rhino sub-population should achieve a minimum growth rate of 5% per year. The black rhino population in the Hluhluwe-iMfolozi Park (HiP), KwaZulu-Natal, South Africa, is of international importance as it has historically been a significant donor population for the translocation of black rhinos to establish new subpopulations elsewhere in the sub-region. However, the black rhino population at HiP is performing poorly in terms of reproductive success. My study was initiated to assess the reproductive life-histories of the black rhino population at HiP and to determine whether the population was meeting the demographic targets set by the RMG. I also wished to assess the use of space by black rhinos in HiP as a potential explanation for the observed reproductive output. Detailed life-history information for known black rhinos (n = 120) was used to investigate reproductive success between 1998 and 2012. The mean age at sexual maturity (ASM) was determined as 12 years, which is higher than the ASM found in black rhino populations that are considered to be performing poorly (ASM = ~ 7 years). The intercalving interval (ICI) was three years, nine months; this was also longer than the ICI of most black rhino populations. Further, the 2012 black rhino population at HiP had a growth rate of 6.4%, and the population comprised 60% adults, 23% sub-adults and 13% juveniles. Such demographics are usually observed in stable populations and it is possible that poor habitat quality could be resulting in the delayed ASM and longer ICI’s at HiP. In addition, 5% of the population is removed annually as part of the Black Rhino Range Expansion Program (BRREP) to establish new sub-populations. This could also be negatively influencing the reproductive performance of the HiP population. To determine the home range and habitat use of black rhinos at HiP, field data from 13 individual adult black rhinos (n = 9 females and 4 males) over a two-year period (2011-2012) were analyzed. Black rhino female home ranges were slightly smaller (15.4 ± 12.9 km²) than the home ranges of males (23.3 ±14.0 km²) and both sexes utilized similar habitats in the centre of the park. In addition, both the male and female black rhinos were found closer to rivers and drainage lines than expected. However, the assessment of black rhino space use in HiP was limited by a small sample size, making inferences of the impact of space use on reproductive success difficult. Nevertheless, my study suggests that food availability likely influences the location and sizes of black rhino home ranges at HiP. I believe that my study forms the first step in understanding the factors that influence the reproductive success and habitat use patterns of the current black rhino population at HiP. The information produced by my study should enable park management to identify future research to be conducted at HiP, which will yield more robust data for making informed black rhino management decisions at HiP and elsewhere.
- Full Text:
- Authors: Nhleko, Zoliswa Nombulelo
- Date: 2014
- Subjects: Hluhluwe-iMfolozi Park (South Africa) , Black rhinoceros -- South Africa -- Hluhluwe , Animal populations -- South Africa -- Hluhluwe , Spatial ecology -- South Africa -- Hluhluwe , Black rhinoceros -- Reproduction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5849 , http://hdl.handle.net/10962/d1011825 , Hluhluwe-iMfolozi Park (South Africa) , Black rhinoceros -- South Africa -- Hluhluwe , Animal populations -- South Africa -- Hluhluwe , Spatial ecology -- South Africa -- Hluhluwe , Black rhinoceros -- Reproduction
- Description: Black rhinoceroses (Diceros bicornis) are endangered; there are only ~5000 individuals remaining worldwide. Consequently, black rhinos are managed as a metapopulation in southern Africa. This means that even though several sub-populations of black rhinos are geographically separated, they are managed as a single population. This is achieved by interchanging genetic material between the sub-populations. The main aim of the metapopulation management approach is to increase black rhino numbers in the sub-region. The Rhino Management Group (RMG), formed in 1989, was tasked with setting scientifically defensible demographic targets for the remaining black rhino sub-populations in southern Africa. In the same year, the RMG set fecundity rate at 25% and stated that each black rhino sub-population should achieve a minimum growth rate of 5% per year. The black rhino population in the Hluhluwe-iMfolozi Park (HiP), KwaZulu-Natal, South Africa, is of international importance as it has historically been a significant donor population for the translocation of black rhinos to establish new subpopulations elsewhere in the sub-region. However, the black rhino population at HiP is performing poorly in terms of reproductive success. My study was initiated to assess the reproductive life-histories of the black rhino population at HiP and to determine whether the population was meeting the demographic targets set by the RMG. I also wished to assess the use of space by black rhinos in HiP as a potential explanation for the observed reproductive output. Detailed life-history information for known black rhinos (n = 120) was used to investigate reproductive success between 1998 and 2012. The mean age at sexual maturity (ASM) was determined as 12 years, which is higher than the ASM found in black rhino populations that are considered to be performing poorly (ASM = ~ 7 years). The intercalving interval (ICI) was three years, nine months; this was also longer than the ICI of most black rhino populations. Further, the 2012 black rhino population at HiP had a growth rate of 6.4%, and the population comprised 60% adults, 23% sub-adults and 13% juveniles. Such demographics are usually observed in stable populations and it is possible that poor habitat quality could be resulting in the delayed ASM and longer ICI’s at HiP. In addition, 5% of the population is removed annually as part of the Black Rhino Range Expansion Program (BRREP) to establish new sub-populations. This could also be negatively influencing the reproductive performance of the HiP population. To determine the home range and habitat use of black rhinos at HiP, field data from 13 individual adult black rhinos (n = 9 females and 4 males) over a two-year period (2011-2012) were analyzed. Black rhino female home ranges were slightly smaller (15.4 ± 12.9 km²) than the home ranges of males (23.3 ±14.0 km²) and both sexes utilized similar habitats in the centre of the park. In addition, both the male and female black rhinos were found closer to rivers and drainage lines than expected. However, the assessment of black rhino space use in HiP was limited by a small sample size, making inferences of the impact of space use on reproductive success difficult. Nevertheless, my study suggests that food availability likely influences the location and sizes of black rhino home ranges at HiP. I believe that my study forms the first step in understanding the factors that influence the reproductive success and habitat use patterns of the current black rhino population at HiP. The information produced by my study should enable park management to identify future research to be conducted at HiP, which will yield more robust data for making informed black rhino management decisions at HiP and elsewhere.
- Full Text:
The feasibility of reintroducing African wild dogs (Lycaon pictus) into the Great Fish River Nature Reserve, Eastern Cape, South Africa
- Authors: Page, Samantha Karin
- Date: 2014
- Subjects: Great Fish River Nature Reserve (South Africa) , African wild dog -- South Africa -- Eastern Cape , Population biology -- South Africa -- Eastern Cape , African wild dog -- Reintroduction -- South Africa -- Eastern Cape , African wild dog -- Population viability analysis -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5915 , http://hdl.handle.net/10962/d1016078
- Description: With a declining population of roughly 3000-5000 individuals in Africa, African wild dogs (Lycaon pictus) are one of the most endangered carnivores in the world. As the global human population expands, it is becoming increasingly unlikely that large portions of land will be set aside for conservation, especially in developing countries. Thus, recent wild dog conservation efforts in South Africa have concentrated on establishing a managed metapopulation. A metapopulation is a group of geographically isolated subpopulations of a species that are managed (using supplementation and harvesting) to mimic natural gene flow. The Great Fish River Nature Reserve (GFRNR) in the Eastern Cape Province of South Africa has been identified as a potential reserve to become part of the national wild dog metapopulation. My research aimed to conduct a feasibility assessment of the long-term (~ 25 years) success of a wild dog reintroduction into the GFRNR. This assessment included biological modelling of wild dogs and their expected prey, and determining the potential anthropogenic threats to wild dogs on the private and communal land surrounding the reserve. I used VORTEX population modelling and determined that the GFRNR is likely to have a wild dog carrying capacity of ~22 individuals. Using a 25-year modelling simulation, the most appropriate wild dog reintroduction scenario would be to reintroduce six females and four males initially and supplement the population with one female and two males in years 3, 10, 15 and 23. In addition, the harvesting/removal of one male and one female in years 10 and 20 would be required to ensure 100% population persistence and adequate genetic diversity. Kudu (Tragelaphus strepsiceros) and bushbuck (Tragelaphus scriptus) are expected to be the two most important prey species for reintroduced wild dogs in the GFRNR. Furthermore, wild dogs are likely to prefer the north-western and south-western sectors of the reserve because of the relatively high prey densities in these areas. However, regular monitoring of both the potential prey and the wild dog populations is essential to ensure persistence of the wild dogs and to prevent prey populations decreasing precipitously. Using structured questionnaire interviews (n = 128), I found that while neighbouring land owners and local communities were generally positive about the potential wild dog reintroduction (56 % of all respondents), several threats to wild dogs were identified along the reserve boundary and on the adjoining unprotected land. Some private landowners and members of rural communities around the reserve (34 %) stated that they would kill any wild dogs that dispersed onto their land. In addition, some respondents (8 %) admitted to believing in traditional uses for wild dog products (e.g. fur) which could result in the illegal killing of wild dogs outside of the GFRNR for traditional purposes. Poaching and the presence of unvaccinated domestic dogs on neighbouring land were also identified as being potential threats to a reintroduced wild dog population. However, such anthropogenic threats appear to be localised to the western and southern boundaries of the reserve. Therefore, by implementing preventative measures (such as anti-snare collars, anti-poaching patrols and vaccination against rabies and canine distemper) the likelihood of such threats occurring can be reduced. I conclude that the GFRNR can sustain a population of wild dogs and successfully contribute to South Africa‘s national metapopulation. An additional reserve will benefit the country‘s metapopulation by increasing the number of wild dogs available for translocation, thereby increasing genetic diversity and overall resilience (to environmental change, disease etc.) of South Africa‘s wild dog population. This will contribute towards the future conservation of this endangered species.
- Full Text:
- Authors: Page, Samantha Karin
- Date: 2014
- Subjects: Great Fish River Nature Reserve (South Africa) , African wild dog -- South Africa -- Eastern Cape , Population biology -- South Africa -- Eastern Cape , African wild dog -- Reintroduction -- South Africa -- Eastern Cape , African wild dog -- Population viability analysis -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5915 , http://hdl.handle.net/10962/d1016078
- Description: With a declining population of roughly 3000-5000 individuals in Africa, African wild dogs (Lycaon pictus) are one of the most endangered carnivores in the world. As the global human population expands, it is becoming increasingly unlikely that large portions of land will be set aside for conservation, especially in developing countries. Thus, recent wild dog conservation efforts in South Africa have concentrated on establishing a managed metapopulation. A metapopulation is a group of geographically isolated subpopulations of a species that are managed (using supplementation and harvesting) to mimic natural gene flow. The Great Fish River Nature Reserve (GFRNR) in the Eastern Cape Province of South Africa has been identified as a potential reserve to become part of the national wild dog metapopulation. My research aimed to conduct a feasibility assessment of the long-term (~ 25 years) success of a wild dog reintroduction into the GFRNR. This assessment included biological modelling of wild dogs and their expected prey, and determining the potential anthropogenic threats to wild dogs on the private and communal land surrounding the reserve. I used VORTEX population modelling and determined that the GFRNR is likely to have a wild dog carrying capacity of ~22 individuals. Using a 25-year modelling simulation, the most appropriate wild dog reintroduction scenario would be to reintroduce six females and four males initially and supplement the population with one female and two males in years 3, 10, 15 and 23. In addition, the harvesting/removal of one male and one female in years 10 and 20 would be required to ensure 100% population persistence and adequate genetic diversity. Kudu (Tragelaphus strepsiceros) and bushbuck (Tragelaphus scriptus) are expected to be the two most important prey species for reintroduced wild dogs in the GFRNR. Furthermore, wild dogs are likely to prefer the north-western and south-western sectors of the reserve because of the relatively high prey densities in these areas. However, regular monitoring of both the potential prey and the wild dog populations is essential to ensure persistence of the wild dogs and to prevent prey populations decreasing precipitously. Using structured questionnaire interviews (n = 128), I found that while neighbouring land owners and local communities were generally positive about the potential wild dog reintroduction (56 % of all respondents), several threats to wild dogs were identified along the reserve boundary and on the adjoining unprotected land. Some private landowners and members of rural communities around the reserve (34 %) stated that they would kill any wild dogs that dispersed onto their land. In addition, some respondents (8 %) admitted to believing in traditional uses for wild dog products (e.g. fur) which could result in the illegal killing of wild dogs outside of the GFRNR for traditional purposes. Poaching and the presence of unvaccinated domestic dogs on neighbouring land were also identified as being potential threats to a reintroduced wild dog population. However, such anthropogenic threats appear to be localised to the western and southern boundaries of the reserve. Therefore, by implementing preventative measures (such as anti-snare collars, anti-poaching patrols and vaccination against rabies and canine distemper) the likelihood of such threats occurring can be reduced. I conclude that the GFRNR can sustain a population of wild dogs and successfully contribute to South Africa‘s national metapopulation. An additional reserve will benefit the country‘s metapopulation by increasing the number of wild dogs available for translocation, thereby increasing genetic diversity and overall resilience (to environmental change, disease etc.) of South Africa‘s wild dog population. This will contribute towards the future conservation of this endangered species.
- Full Text:
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