Understanding resource use of an invasive species: Diet of the common warthog in Eastern Cape succulent thicket
- Mgqatsa, Nokubonga, Jama, Kanyisa, Landman, Marietjie, Kerley, Graham I H
- Authors: Mgqatsa, Nokubonga , Jama, Kanyisa , Landman, Marietjie , Kerley, Graham I H
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/462746 , vital:76331 , xlink:href="https://doi.org/10.1016/j.jaridenv.2024.105155"
- Description: Understanding resource use of invasive species provides insights for predicting and mitigating their impacts on biodiversity. We explored the predictability of diet of the invasive common warthog by describing and comparing the diet of warthog populations from two semi-arid, invaded sites, Addo Elephant National Park (AMC), and Great Fish River Nature Reserve (GFRNR), Eastern Cape, South Africa. These sites are both dominated by the Subtropical Thicket biome, but differ in vegetation type. We used forage availability to estimate diet preferences at AMC. We predicted that warthog would consume grass in invaded landscapes. Additionally, we predicted that the diet at one invaded site would predict this at another invaded site. As predicted, warthog mainly consumed grass at both sites (AMC – 87.4%, GFRNR – 88.5%), eating few woody plants, succulents, and forbs. Cynodon dactylon was the most consumed species in AMC, in GFRNR this was Eragrostis curvula and Cymbopogon pospichilii. Our ability to predict the diet between sites was constrained by variation in the plant species consumed. We found strong relationships between the consumption of preferred plant species at AMC and their consumption at GFRNR. We show that warthogs are specialised grazers outside their native range and thus can be expected to impact grass communities in invaded areas, especially preferred grass species. Thus, conservation managers need to monitor grasses in areas invaded by warthog to better detect and manage their impacts.
- Full Text:
- Date Issued: 2024
- Authors: Mgqatsa, Nokubonga , Jama, Kanyisa , Landman, Marietjie , Kerley, Graham I H
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/462746 , vital:76331 , xlink:href="https://doi.org/10.1016/j.jaridenv.2024.105155"
- Description: Understanding resource use of invasive species provides insights for predicting and mitigating their impacts on biodiversity. We explored the predictability of diet of the invasive common warthog by describing and comparing the diet of warthog populations from two semi-arid, invaded sites, Addo Elephant National Park (AMC), and Great Fish River Nature Reserve (GFRNR), Eastern Cape, South Africa. These sites are both dominated by the Subtropical Thicket biome, but differ in vegetation type. We used forage availability to estimate diet preferences at AMC. We predicted that warthog would consume grass in invaded landscapes. Additionally, we predicted that the diet at one invaded site would predict this at another invaded site. As predicted, warthog mainly consumed grass at both sites (AMC – 87.4%, GFRNR – 88.5%), eating few woody plants, succulents, and forbs. Cynodon dactylon was the most consumed species in AMC, in GFRNR this was Eragrostis curvula and Cymbopogon pospichilii. Our ability to predict the diet between sites was constrained by variation in the plant species consumed. We found strong relationships between the consumption of preferred plant species at AMC and their consumption at GFRNR. We show that warthogs are specialised grazers outside their native range and thus can be expected to impact grass communities in invaded areas, especially preferred grass species. Thus, conservation managers need to monitor grasses in areas invaded by warthog to better detect and manage their impacts.
- Full Text:
- Date Issued: 2024
Using photo by-catch data to reliably estimate spotted hyaena densities over time
- Mgqatsa, Nokubonga, Jama, Kanyisa, Landman, Marietjie, Kerley, Graham I H
- Authors: Mgqatsa, Nokubonga , Jama, Kanyisa , Landman, Marietjie , Kerley, Graham I H
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/462757 , vital:76332 , xlink:href="https://doi.org/10.1016/j.jaridenv.2024.105155"
- Description: Protected areas are becoming increasingly isolated refugia for large carnivores but remain critical for their survival. Spotted hyaenas (Crocuta crocuta) are important members of the African large carnivore guild but, like other members of the guild, routinely come into conflict with people because of their large home ranges that are not always confined to protected areas. To effectively conserve spotted hyaena populations, it is paramount to monitor their abundance through reliable and cost-effective techniques. We estimated the density of spotted hyaenas in Hluhluwe–iMfolozi Park (HiP), South Africa using camera trap images and a spatially explicit capture-recapture (SECR) framework between 2013 and 2018. We estimated an average of 18.29 ± 3.27 spotted hyaenas per 100 km2 between 2013 and 2018, with an annual estimated high of 20.83/100 km2 in 2014 and a low of 11.98/100 km2 in 2015. Our results demonstrate that camera trap by-catch data can be used for estimating spotted hyaena densities over time. We believe that given the widespread use and deployment of camera traps across Africa, collaborative efforts to use existing data to improve regional and continental estimates and population trends for spotted hyaenas should be a priority.
- Full Text:
- Date Issued: 2024
- Authors: Mgqatsa, Nokubonga , Jama, Kanyisa , Landman, Marietjie , Kerley, Graham I H
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/462757 , vital:76332 , xlink:href="https://doi.org/10.1016/j.jaridenv.2024.105155"
- Description: Protected areas are becoming increasingly isolated refugia for large carnivores but remain critical for their survival. Spotted hyaenas (Crocuta crocuta) are important members of the African large carnivore guild but, like other members of the guild, routinely come into conflict with people because of their large home ranges that are not always confined to protected areas. To effectively conserve spotted hyaena populations, it is paramount to monitor their abundance through reliable and cost-effective techniques. We estimated the density of spotted hyaenas in Hluhluwe–iMfolozi Park (HiP), South Africa using camera trap images and a spatially explicit capture-recapture (SECR) framework between 2013 and 2018. We estimated an average of 18.29 ± 3.27 spotted hyaenas per 100 km2 between 2013 and 2018, with an annual estimated high of 20.83/100 km2 in 2014 and a low of 11.98/100 km2 in 2015. Our results demonstrate that camera trap by-catch data can be used for estimating spotted hyaena densities over time. We believe that given the widespread use and deployment of camera traps across Africa, collaborative efforts to use existing data to improve regional and continental estimates and population trends for spotted hyaenas should be a priority.
- Full Text:
- Date Issued: 2024
Elephant effects on treefall and logfall highlight the absence of megaherbivores in coarse woody debris conceptual frameworks
- Landman, Marietjie, Mgqatsa, Nokubonga, Cromsigt, Joris P, Kerley, Graham I H
- Authors: Landman, Marietjie , Mgqatsa, Nokubonga , Cromsigt, Joris P , Kerley, Graham I H
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/462614 , vital:76319 , xlink:href="https://doi.org/10.1016/j.foreco.2019.02.015"
- Description: Despite the importance of coarse woody debris (CWD) in woody ecosystems, conceptual frameworks of its dynamics currently exclude the role of the megaherbivores, focusing instead on the role of insects, disease, fire, wind and droughts. However, recognizing the ecological roles of the megaherbivores is one of the most urgent contemporary issues, particularly as their decline will likely have unanticipated outcomes at the ecosystem-level. Here we used sites with and without elephants in a semi-arid woodland ecosystem in South Africa to test whether elephants changed the quantitative and qualitative features of the CWD profile in relation to other wood producers. We show that elephants increased the abundance of CWD, influenced its quality by toppling mostly maturing trees, and changed the distribution of large woody items along gentle hillslopes. Surprisingly, and despite the recognized importance of both CWD and elephants for biodiversity, there is almost no published data on the role of elephants in shaping wood-living communities by changing fallen woody debris dynamics. Our study contributes towards developing a broader conceptual framework of CWD dynamics that includes the role of megaherbivores and provides a novel view of the ecological consequences of the loss of the Pleistocene megaherbivores. Our findings have important implications for CWD restoration efforts in transformed systems that previously supported megaherbivores.
- Full Text:
- Date Issued: 2019
- Authors: Landman, Marietjie , Mgqatsa, Nokubonga , Cromsigt, Joris P , Kerley, Graham I H
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/462614 , vital:76319 , xlink:href="https://doi.org/10.1016/j.foreco.2019.02.015"
- Description: Despite the importance of coarse woody debris (CWD) in woody ecosystems, conceptual frameworks of its dynamics currently exclude the role of the megaherbivores, focusing instead on the role of insects, disease, fire, wind and droughts. However, recognizing the ecological roles of the megaherbivores is one of the most urgent contemporary issues, particularly as their decline will likely have unanticipated outcomes at the ecosystem-level. Here we used sites with and without elephants in a semi-arid woodland ecosystem in South Africa to test whether elephants changed the quantitative and qualitative features of the CWD profile in relation to other wood producers. We show that elephants increased the abundance of CWD, influenced its quality by toppling mostly maturing trees, and changed the distribution of large woody items along gentle hillslopes. Surprisingly, and despite the recognized importance of both CWD and elephants for biodiversity, there is almost no published data on the role of elephants in shaping wood-living communities by changing fallen woody debris dynamics. Our study contributes towards developing a broader conceptual framework of CWD dynamics that includes the role of megaherbivores and provides a novel view of the ecological consequences of the loss of the Pleistocene megaherbivores. Our findings have important implications for CWD restoration efforts in transformed systems that previously supported megaherbivores.
- Full Text:
- Date Issued: 2019
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