Inter-population similarities and differences in predation efficiency of a mosquito natural enemy
- Cuthbert, Ross N, Dalu, Tatenda, Wasserman, Ryan J, Weyl, Olaf L F, Froneman, P William, Callaghan, Amanda, Dick, Jaimie T A
- Authors: Cuthbert, Ross N , Dalu, Tatenda , Wasserman, Ryan J , Weyl, Olaf L F , Froneman, P William , Callaghan, Amanda , Dick, Jaimie T A
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/466928 , vital:76799 , https://doi.org/10.1093/jme/tjaa093
- Description: Predation is a critical factor that mediates population stability, community structure, and ecosystem function. Predatory natural enemies can contribute to the regulation of disease vector groups such as mosquitoes, particularly where they naturally co-occur across landscapes. However, we must understand inter-population variation in predatory efficiency if we are to enhance vector control. The present study thus employs a functional response (FR; resource use under different densities) approach to quantify and compare predatory interaction strengths among six populations of a predatory temporary pond specialist copepod, Lovenula raynerae, from the Eastern Cape of South Africa preying on second instar Culex pipiens complex mosquito larvae.
- Full Text:
- Authors: Cuthbert, Ross N , Dalu, Tatenda , Wasserman, Ryan J , Weyl, Olaf L F , Froneman, P William , Callaghan, Amanda , Dick, Jaimie T A
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/466928 , vital:76799 , https://doi.org/10.1093/jme/tjaa093
- Description: Predation is a critical factor that mediates population stability, community structure, and ecosystem function. Predatory natural enemies can contribute to the regulation of disease vector groups such as mosquitoes, particularly where they naturally co-occur across landscapes. However, we must understand inter-population variation in predatory efficiency if we are to enhance vector control. The present study thus employs a functional response (FR; resource use under different densities) approach to quantify and compare predatory interaction strengths among six populations of a predatory temporary pond specialist copepod, Lovenula raynerae, from the Eastern Cape of South Africa preying on second instar Culex pipiens complex mosquito larvae.
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Lack of prey switching and strong preference for mosquito prey by a temporary pond specialist predator
- Cuthbert, Ross N, Dalu, Tatenda, Wasserman, Ryan J, Weyl, Olaf L F, Froneman, P William, Callaghan, Amanda, Dick, Jaimie T A
- Authors: Cuthbert, Ross N , Dalu, Tatenda , Wasserman, Ryan J , Weyl, Olaf L F , Froneman, P William , Callaghan, Amanda , Dick, Jaimie T A
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/466946 , vital:76801 , https://doi.org/10.1111/een.12801
- Description: The strengths of trophic interactions within ecosystems can be mediated by complex mechanisms that require elucidation if researchers are to understand and predict population‐ and community‐level stabilities. Where multiple prey types co‐occur, prey switching (i.e. frequency‐dependent predation) by predators may facilitate low‐density prey refuge effects which promote coexistence. On the other hand, lack of switching and strong preferences by predators can strongly suppress prey populations, which is especially important considering vector species such as mosquitoes.
- Full Text:
- Authors: Cuthbert, Ross N , Dalu, Tatenda , Wasserman, Ryan J , Weyl, Olaf L F , Froneman, P William , Callaghan, Amanda , Dick, Jaimie T A
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/466946 , vital:76801 , https://doi.org/10.1111/een.12801
- Description: The strengths of trophic interactions within ecosystems can be mediated by complex mechanisms that require elucidation if researchers are to understand and predict population‐ and community‐level stabilities. Where multiple prey types co‐occur, prey switching (i.e. frequency‐dependent predation) by predators may facilitate low‐density prey refuge effects which promote coexistence. On the other hand, lack of switching and strong preferences by predators can strongly suppress prey populations, which is especially important considering vector species such as mosquitoes.
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Life history parameters and diet of Risso's dolphins, Grampus griseus, from southeastern South Africa
- Plön, Stephanie, Heynes-Veale, Elodie R, Smale, Malcolm J, Froneman, P William
- Authors: Plön, Stephanie , Heynes-Veale, Elodie R , Smale, Malcolm J , Froneman, P William
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467266 , vital:76846 , https://doi.org/10.1111/mms.12675
- Description: The life history of Risso's dolphins (Grampus griseus) remains poorly known and data from strandings can help provide important information. Data from 126 Risso's dolphins stranded or bycaught along the southeastern coastline of South Africa between 1958 and 2017 were analyzed in relation to their sex, age structure, and diet. Mean estimated length at birth was 146.9 cm, while maximum length was 325 cm for males and 313 cm for females; small sample sizes precluded detailed examination of sexual dimorphism. Age estimates for 33 individuals (14 males, 17 females, 2 unknown sex) indicated a maximum age of 13 years (males) and 17 years (females), respectively; the oldest animal was 19 years (unknown sex). Mean length and age at attainment of sexual maturity were estimated at 280 cm and 7.1 years in males and at 282 cm and 7.7 years in females. Stomach contents from 27 individuals showed that diets of immature and mature males and females overlapped and consisted predominantly of cephalopods. Reported strandings decreased between 2000 and 2017, possibly due to a lack of reporting associated with a ban on driving on beaches or related to the collapse of the local “chokka” squid (Loligo reynaudii) fishery in 2014–2015.
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- Authors: Plön, Stephanie , Heynes-Veale, Elodie R , Smale, Malcolm J , Froneman, P William
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467266 , vital:76846 , https://doi.org/10.1111/mms.12675
- Description: The life history of Risso's dolphins (Grampus griseus) remains poorly known and data from strandings can help provide important information. Data from 126 Risso's dolphins stranded or bycaught along the southeastern coastline of South Africa between 1958 and 2017 were analyzed in relation to their sex, age structure, and diet. Mean estimated length at birth was 146.9 cm, while maximum length was 325 cm for males and 313 cm for females; small sample sizes precluded detailed examination of sexual dimorphism. Age estimates for 33 individuals (14 males, 17 females, 2 unknown sex) indicated a maximum age of 13 years (males) and 17 years (females), respectively; the oldest animal was 19 years (unknown sex). Mean length and age at attainment of sexual maturity were estimated at 280 cm and 7.1 years in males and at 282 cm and 7.7 years in females. Stomach contents from 27 individuals showed that diets of immature and mature males and females overlapped and consisted predominantly of cephalopods. Reported strandings decreased between 2000 and 2017, possibly due to a lack of reporting associated with a ban on driving on beaches or related to the collapse of the local “chokka” squid (Loligo reynaudii) fishery in 2014–2015.
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Occurrence of Indo-Pacific bottlenose dolphins (Tursiops aduncus) off the Wild Coast of South Africa using photographic identification:
- Caputo, Michelle, Bouveroux, Thibaut N, Froneman, P William, Shaanika, Titus, Plön, Stephanie
- Authors: Caputo, Michelle , Bouveroux, Thibaut N , Froneman, P William , Shaanika, Titus , Plön, Stephanie
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160367 , vital:40439 , https://0-doi.org.wam.seals.ac.za/10.1111/mms.12740
- Description: The present study represents the first reported boat‐based photographic identification study of Indo‐Pacific bottlenose dolphins (Tursiops aduncus) off the Wild Coast of southeast South Africa. This area is known for the annual sardine run, which attracts apex predators to the region during the austral winter. Dedicated photo‐identification surveys were conducted along this coast at three different study sites in February, June, and November of each year from 2014 to 2016.
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- Authors: Caputo, Michelle , Bouveroux, Thibaut N , Froneman, P William , Shaanika, Titus , Plön, Stephanie
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160367 , vital:40439 , https://0-doi.org.wam.seals.ac.za/10.1111/mms.12740
- Description: The present study represents the first reported boat‐based photographic identification study of Indo‐Pacific bottlenose dolphins (Tursiops aduncus) off the Wild Coast of southeast South Africa. This area is known for the annual sardine run, which attracts apex predators to the region during the austral winter. Dedicated photo‐identification surveys were conducted along this coast at three different study sites in February, June, and November of each year from 2014 to 2016.
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Ratio-independent prey preferences by an estuarine mysid
- Froneman, P William, Cuthbert, Ross N
- Authors: Froneman, P William , Cuthbert, Ross N
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479341 , vital:78291 , https://doi.org/10.1093/plankt/fbaa024
- Description: The present study quantified prey preferences by adult males and females of the mysid Mesopodopsis wooldridgei fed the calanoid copepods Pseudodiaptomus hessei and Paracartia longipatella at varying proportions. Both sexes of M. wooldridgei showed a lack of prey switching and a strong preference for the smaller, less active P. longipatella irrespective of density. Given a lack of low-density prey refuge, this finding may have important implications for the distribution of P. longipatella in estuaries along the eastern seaboard of South Africa. Results of the present study contribute to a growing body of literature that suggests that selective predation may play an important role in structuring plankton prey populations in shallow water ecosystems.
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- Authors: Froneman, P William , Cuthbert, Ross N
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479341 , vital:78291 , https://doi.org/10.1093/plankt/fbaa024
- Description: The present study quantified prey preferences by adult males and females of the mysid Mesopodopsis wooldridgei fed the calanoid copepods Pseudodiaptomus hessei and Paracartia longipatella at varying proportions. Both sexes of M. wooldridgei showed a lack of prey switching and a strong preference for the smaller, less active P. longipatella irrespective of density. Given a lack of low-density prey refuge, this finding may have important implications for the distribution of P. longipatella in estuaries along the eastern seaboard of South Africa. Results of the present study contribute to a growing body of literature that suggests that selective predation may play an important role in structuring plankton prey populations in shallow water ecosystems.
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Sex demographics alter the effect of habitat structure on predation by a temporary pond specialist
- Cuthbert, Ross N, Sithagu, Rotondwa, Weyl, Olaf L F, Froneman, P William, Wasserman, Ryan J, Dick, Jaimie T A, Callaghan, Amanda, Foord, Stefan, Dalu, Tatenda
- Authors: Cuthbert, Ross N , Sithagu, Rotondwa , Weyl, Olaf L F , Froneman, P William , Wasserman, Ryan J , Dick, Jaimie T A , Callaghan, Amanda , Foord, Stefan , Dalu, Tatenda
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/466968 , vital:76803 , https://doi.org/10.1016/j.limno.2020.125747
- Description: Habitat structure can profoundly influence interaction strengths between predators and prey. Spatio-temporal habitat structure in temporary wetland ecosystems is particularly variable because of fluctuations in water levels and vegetation colonisation dynamics. Demographic characteristics within animal populations may also alter the influence of habitat structure on biotic interactions, but have remained untested. Here, we investigate the influence of vegetation habitat structure on the consumption of larval mosquito prey by the calanoid copepod Lovenula raynerae, a temporary pond specialist. Increased habitat complexity reduced predation, and gravid female copepods were generally more voracious than male copepods in simplified habitats. However, sexes were more similar as habitat complexity increased. Type II functional responses were exhibited by the copepods irrespective of habitat complexity and sex, owing to consistent high prey acquisition at low prey densities. Attack rates by copepods were relatively unaffected by the complexity gradient, whilst handling times lengthened under more complex environments in gravid female copepods. We demonstrate emergent effects of habitat complexity across species demographics, with predation by males more robust to differences in habitat complexity than females. For ecosystems such as temporary ponds where sex-skewed predator ratios develop, our laboratory findings suggest habitat complexity and sex demographics mediate prey risk.
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- Authors: Cuthbert, Ross N , Sithagu, Rotondwa , Weyl, Olaf L F , Froneman, P William , Wasserman, Ryan J , Dick, Jaimie T A , Callaghan, Amanda , Foord, Stefan , Dalu, Tatenda
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/466968 , vital:76803 , https://doi.org/10.1016/j.limno.2020.125747
- Description: Habitat structure can profoundly influence interaction strengths between predators and prey. Spatio-temporal habitat structure in temporary wetland ecosystems is particularly variable because of fluctuations in water levels and vegetation colonisation dynamics. Demographic characteristics within animal populations may also alter the influence of habitat structure on biotic interactions, but have remained untested. Here, we investigate the influence of vegetation habitat structure on the consumption of larval mosquito prey by the calanoid copepod Lovenula raynerae, a temporary pond specialist. Increased habitat complexity reduced predation, and gravid female copepods were generally more voracious than male copepods in simplified habitats. However, sexes were more similar as habitat complexity increased. Type II functional responses were exhibited by the copepods irrespective of habitat complexity and sex, owing to consistent high prey acquisition at low prey densities. Attack rates by copepods were relatively unaffected by the complexity gradient, whilst handling times lengthened under more complex environments in gravid female copepods. We demonstrate emergent effects of habitat complexity across species demographics, with predation by males more robust to differences in habitat complexity than females. For ecosystems such as temporary ponds where sex-skewed predator ratios develop, our laboratory findings suggest habitat complexity and sex demographics mediate prey risk.
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Water volume differentially modifies copepod predatory strengths on two prey types
- Cuthbert, Ross N, Sithagu, Rotondwa, Weyl, Olaf L F, Froneman, P William, Wasserman, Ryan J, Dick, Jaimie T A, Callaghan, Amanda, Foord, Stefan, Dalu, Tatenda
- Authors: Cuthbert, Ross N , Sithagu, Rotondwa , Weyl, Olaf L F , Froneman, P William , Wasserman, Ryan J , Dick, Jaimie T A , Callaghan, Amanda , Foord, Stefan , Dalu, Tatenda
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/466979 , vital:76804 , https://doi.org/10.1016/j.limno.2020.125747
- Description: Predatory interaction strengths are highly context-dependent, and in temporary aquatic ecosystems, may be affected by water volume changes. We examine the influence of water volume on Lovenula raynerae (Copepoda) functional responses towards two temporary pond prey types. Daphnia prey risk was not affected by increasing water volume, whereas for Culex prey risk was reduced. Accordingly, water volume changes through the hydroperiod may have species-specific effects on prey, with implications for population persistence under environmental change.
- Full Text:
- Authors: Cuthbert, Ross N , Sithagu, Rotondwa , Weyl, Olaf L F , Froneman, P William , Wasserman, Ryan J , Dick, Jaimie T A , Callaghan, Amanda , Foord, Stefan , Dalu, Tatenda
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/466979 , vital:76804 , https://doi.org/10.1016/j.limno.2020.125747
- Description: Predatory interaction strengths are highly context-dependent, and in temporary aquatic ecosystems, may be affected by water volume changes. We examine the influence of water volume on Lovenula raynerae (Copepoda) functional responses towards two temporary pond prey types. Daphnia prey risk was not affected by increasing water volume, whereas for Culex prey risk was reduced. Accordingly, water volume changes through the hydroperiod may have species-specific effects on prey, with implications for population persistence under environmental change.
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Additive multiple predator effects of two specialist paradiaptomid copepods towards larval mosquitoes
- Cuthbert, Ross N, Dalu, Tatenda, Wasserman, Ryan J, Weyl, Olaf L F, Froneman, P William, Callaghan, Amanda, Dick, Jaimie T A
- Authors: Cuthbert, Ross N , Dalu, Tatenda , Wasserman, Ryan J , Weyl, Olaf L F , Froneman, P William , Callaghan, Amanda , Dick, Jaimie T A
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467137 , vital:76828 , https://doi.org/10.1016/j.limno.2019.125727
- Description: Interactions between multiple predators can profoundly affect prey risk, with implications for prey population stability and ecosystem functioning. In austral temporary wetlands, arid-area adapted specialist copepods are key predators for much of the hydroperiod. Limited autoecological information relating to species interactions negates understandings of trophic dynamics in these systems. In the present study, we examined multiple predator effects of two key predatory paradiaptomid copepods which often coexist in austral temporary wetlands, Lovenula raynerae Suárez-Morales, Wasserman and Dalu 2015 and Paradiaptomus lamellatus Sars, 1985. Predation rates towards larval mosquito prey across different water depths were quantified.
- Full Text:
- Authors: Cuthbert, Ross N , Dalu, Tatenda , Wasserman, Ryan J , Weyl, Olaf L F , Froneman, P William , Callaghan, Amanda , Dick, Jaimie T A
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467137 , vital:76828 , https://doi.org/10.1016/j.limno.2019.125727
- Description: Interactions between multiple predators can profoundly affect prey risk, with implications for prey population stability and ecosystem functioning. In austral temporary wetlands, arid-area adapted specialist copepods are key predators for much of the hydroperiod. Limited autoecological information relating to species interactions negates understandings of trophic dynamics in these systems. In the present study, we examined multiple predator effects of two key predatory paradiaptomid copepods which often coexist in austral temporary wetlands, Lovenula raynerae Suárez-Morales, Wasserman and Dalu 2015 and Paradiaptomus lamellatus Sars, 1985. Predation rates towards larval mosquito prey across different water depths were quantified.
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Biological monitoring in southern Africa: a review of the current status, challenges and future prospects
- Mangadze, Tinotenda, Dalu, Tatenda, Froneman, P William
- Authors: Mangadze, Tinotenda , Dalu, Tatenda , Froneman, P William
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467193 , vital:76838 , https://doi.org/10.1016/j.scitotenv.2018.08.252
- Description: Biological monitoring programmes have gained popularity around the world particularly in southern Africa as they are fast, integrative and cost-effective approaches for assessing the effects of environmental stressors on aquatic ecosystems. This article reviews current efforts that have been made to use bioindicators (i.e. macroinvertebrates, diatoms and fish) in monitoring water resources and to summarise the challenges in employing these biological monitoring tools in southern Africa. In South Africa, macroinvertebrate (South African Scoring System (SASS)) and diatom based indices (e.g. South African diatom index (SADI)) have demonstrated their utility in identifying sources of impairment and determining the extent of impacts thus giving natural resource managers a scientifically defensible rationale for developing guidelines for conservation and management. Despite this advancement in South Africa, however, developing regionally appropriate quantitative tools for diagnosing ecosystem health is a pressing need for several other southern African countries. Together with sound scientific research, it is imperative for southern African countries to develop specific legislation and have mandated agencies, with proper training and funding to implement biomonitoring and bioassessments. We recommend for the advancement and adoption of biological criteria as an integrated approach to assessing the impact of human activities in riverine ecosystems of the southern African region.
- Full Text:
- Authors: Mangadze, Tinotenda , Dalu, Tatenda , Froneman, P William
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467193 , vital:76838 , https://doi.org/10.1016/j.scitotenv.2018.08.252
- Description: Biological monitoring programmes have gained popularity around the world particularly in southern Africa as they are fast, integrative and cost-effective approaches for assessing the effects of environmental stressors on aquatic ecosystems. This article reviews current efforts that have been made to use bioindicators (i.e. macroinvertebrates, diatoms and fish) in monitoring water resources and to summarise the challenges in employing these biological monitoring tools in southern Africa. In South Africa, macroinvertebrate (South African Scoring System (SASS)) and diatom based indices (e.g. South African diatom index (SADI)) have demonstrated their utility in identifying sources of impairment and determining the extent of impacts thus giving natural resource managers a scientifically defensible rationale for developing guidelines for conservation and management. Despite this advancement in South Africa, however, developing regionally appropriate quantitative tools for diagnosing ecosystem health is a pressing need for several other southern African countries. Together with sound scientific research, it is imperative for southern African countries to develop specific legislation and have mandated agencies, with proper training and funding to implement biomonitoring and bioassessments. We recommend for the advancement and adoption of biological criteria as an integrated approach to assessing the impact of human activities in riverine ecosystems of the southern African region.
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Combined impacts of warming and salinisation on trophic interactions and mortality of a specialist ephemeral wetland predator
- Cuthbert, Ross N, Weyl, Olaf L F, Wasserman, Ryan J, Dick, Jaimie T A, Froneman, P William, Callaghan, Amanda, Dalu, Tatenda
- Authors: Cuthbert, Ross N , Weyl, Olaf L F , Wasserman, Ryan J , Dick, Jaimie T A , Froneman, P William , Callaghan, Amanda , Dalu, Tatenda
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467160 , vital:76832 , https://doi.org/10.1111/fwb.13353
- Description: Wetlands are of enormous importance for biodiversity globally but are under increasing risk from multiple stressors driven by ongoing anthro-pogenic environmental change. As the trophic structure and dynamics of ephemeral wetlands are poorly understood, it is difficult to predict how these biodiverse ecosystems will be impacted by global change. In particular, warming and salinisation are projected to have profound im-pacts on these wetlands in future. The present study examined the combined effects of warming and salinisation on species interaction strengths and mortality rates for two ephemeral wetland species. Using an ephemeral pond specialist copepod, Lovenula raynerae Suárez‐Morales, Wasserman, and Dalu, (2015) as a model predator species, we applied a functional response approach to derive warming and salinisa-tion effects on trophic interactions with a prey species. Furthermore, the effects of a salinisation gradient on mortality rates of adult copepods were quantified.
- Full Text:
- Authors: Cuthbert, Ross N , Weyl, Olaf L F , Wasserman, Ryan J , Dick, Jaimie T A , Froneman, P William , Callaghan, Amanda , Dalu, Tatenda
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467160 , vital:76832 , https://doi.org/10.1111/fwb.13353
- Description: Wetlands are of enormous importance for biodiversity globally but are under increasing risk from multiple stressors driven by ongoing anthro-pogenic environmental change. As the trophic structure and dynamics of ephemeral wetlands are poorly understood, it is difficult to predict how these biodiverse ecosystems will be impacted by global change. In particular, warming and salinisation are projected to have profound im-pacts on these wetlands in future. The present study examined the combined effects of warming and salinisation on species interaction strengths and mortality rates for two ephemeral wetland species. Using an ephemeral pond specialist copepod, Lovenula raynerae Suárez‐Morales, Wasserman, and Dalu, (2015) as a model predator species, we applied a functional response approach to derive warming and salinisa-tion effects on trophic interactions with a prey species. Furthermore, the effects of a salinisation gradient on mortality rates of adult copepods were quantified.
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Macroinvertebrate functional feeding group alterations in response to habitat degradation of headwater Austral streams
- Mangadze, Tinotenda, Wasserman, Ryan J, Froneman, P William, Dalu, Tatenda
- Authors: Mangadze, Tinotenda , Wasserman, Ryan J , Froneman, P William , Dalu, Tatenda
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467211 , vital:76840 , https://doi.org/10.1016/j.scitotenv.2019.133910
- Description: Protecting the structural and functional integrity of lotic ecosystems is becoming increasingly important as many ecological systems face escalating pressures from human population growth and environmental impacts. Knowledge on the functional composition of macroinvertebrates in austral temperate streams is generally lacking hindering the design and implementation of water management and restoration goals. Therefore, this study examined the effects of urban land–use activities on the benthic macroinvertebrate functional feeding guild structure among different stream orders in an austral river system (Bloukrans River) in the Eastern Cape Province of South Africa. Water quality and macroinvertebrate community data were collected across two seasons from 18 sites in two different stream order categories (i.e. 1, 2 + 3), following standard methods. We separated macroinvertebrates into functional feeding groups (FFGs), which we then used to assess the effects of riparian condition on FFG organization. Linear mixed effects model (LMM) results demonstrated that total dissolved solids (TDS), canopy cover, phosphate and channel width were the key variables that described the major sources of variation in macroinvertebrate FFGs.
- Full Text:
- Authors: Mangadze, Tinotenda , Wasserman, Ryan J , Froneman, P William , Dalu, Tatenda
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467211 , vital:76840 , https://doi.org/10.1016/j.scitotenv.2019.133910
- Description: Protecting the structural and functional integrity of lotic ecosystems is becoming increasingly important as many ecological systems face escalating pressures from human population growth and environmental impacts. Knowledge on the functional composition of macroinvertebrates in austral temperate streams is generally lacking hindering the design and implementation of water management and restoration goals. Therefore, this study examined the effects of urban land–use activities on the benthic macroinvertebrate functional feeding guild structure among different stream orders in an austral river system (Bloukrans River) in the Eastern Cape Province of South Africa. Water quality and macroinvertebrate community data were collected across two seasons from 18 sites in two different stream order categories (i.e. 1, 2 + 3), following standard methods. We separated macroinvertebrates into functional feeding groups (FFGs), which we then used to assess the effects of riparian condition on FFG organization. Linear mixed effects model (LMM) results demonstrated that total dissolved solids (TDS), canopy cover, phosphate and channel width were the key variables that described the major sources of variation in macroinvertebrate FFGs.
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Quantifying reproductive state and predator effects on copepod motility in ephemeral ecosystems
- Cuthbert, Ross N, Dalu, Tatenda, Wasserman, Ryan J, Dick, Jaimie T A, Callaghan, Amanda, Froneman, P William, Weyl, Olaf L F
- Authors: Cuthbert, Ross N , Dalu, Tatenda , Wasserman, Ryan J , Dick, Jaimie T A , Callaghan, Amanda , Froneman, P William , Weyl, Olaf L F
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467171 , vital:76836 , https://doi.org/10.1016/j.jaridenv.2019.05.010
- Description: Ephemeral wetlands in arid environments are unique ecosystems with atypical trophic structuring, often dominated by invertebrate predation. Copepod behavioural traits and vulnerabilities to predation can vary substantially according to reproductive status. Gravid female copepods may be more vulnerable to predation due to reduced escape speeds or higher visibility to predators. Here, we quantify how reproductive status modulates horizontal motility rates of the predatory ephemeral pond specialist copepod Lovenula raynerae, and the responsiveness of the copepod to predator cues of the notonectid Anisops debilis. Males exhibited significantly higher motility rates than gravid female copepods, however chemical predator cues did not significantly influence activity rates in either sex. The lack of responsiveness to predator cues by specialist copepods in ephemeral wetlands may result from a lack of predation pressure in these systems, or due to time stress to reproduce during short hydroperiods. In turn, this could increase predation risk to copepods from externally-recruited top predators in ephemeral wetlands, and potentially contribute to the development of skewed sex ratios in favour of females.
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- Authors: Cuthbert, Ross N , Dalu, Tatenda , Wasserman, Ryan J , Dick, Jaimie T A , Callaghan, Amanda , Froneman, P William , Weyl, Olaf L F
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467171 , vital:76836 , https://doi.org/10.1016/j.jaridenv.2019.05.010
- Description: Ephemeral wetlands in arid environments are unique ecosystems with atypical trophic structuring, often dominated by invertebrate predation. Copepod behavioural traits and vulnerabilities to predation can vary substantially according to reproductive status. Gravid female copepods may be more vulnerable to predation due to reduced escape speeds or higher visibility to predators. Here, we quantify how reproductive status modulates horizontal motility rates of the predatory ephemeral pond specialist copepod Lovenula raynerae, and the responsiveness of the copepod to predator cues of the notonectid Anisops debilis. Males exhibited significantly higher motility rates than gravid female copepods, however chemical predator cues did not significantly influence activity rates in either sex. The lack of responsiveness to predator cues by specialist copepods in ephemeral wetlands may result from a lack of predation pressure in these systems, or due to time stress to reproduce during short hydroperiods. In turn, this could increase predation risk to copepods from externally-recruited top predators in ephemeral wetlands, and potentially contribute to the development of skewed sex ratios in favour of females.
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River nutrient water and sediment measurements inform on nutrient retention, with implications for eutrophication
- Dalu, Tatenda, Wasserman, Ryan J, Magoro, Mandla L, Froneman, P William, Weyl, Olaf, L F
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Magoro, Mandla L , Froneman, P William , Weyl, Olaf, L F
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467222 , vital:76841 , https://doi.org/10.1016/j.scitotenv.2019.05.167
- Description: The consideration of nutrients in pollution dynamics is important for environmental management and conservation. Developing countries are yet to appreciate the aquatic ecosystem pollution impacts on their economies and as such, information on water pollution dynamics is limited. This study assessed the spatio-temporal dynamics of nutrient loading and retention in stream water and sediments in the Bloukrans River system, Eastern Cape province, South Africa over the course of the wet and dry season. Sediment and water samples were analysed for total phosphorus (TP) and nitrogen (TN) concentrations, and were used in combination with river flow discharge, to determine nutrient loads. The study results highlight that river discharge plays a significant role in temporal differences in sediment and water column nutrient concentrations.
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- Authors: Dalu, Tatenda , Wasserman, Ryan J , Magoro, Mandla L , Froneman, P William , Weyl, Olaf, L F
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467222 , vital:76841 , https://doi.org/10.1016/j.scitotenv.2019.05.167
- Description: The consideration of nutrients in pollution dynamics is important for environmental management and conservation. Developing countries are yet to appreciate the aquatic ecosystem pollution impacts on their economies and as such, information on water pollution dynamics is limited. This study assessed the spatio-temporal dynamics of nutrient loading and retention in stream water and sediments in the Bloukrans River system, Eastern Cape province, South Africa over the course of the wet and dry season. Sediment and water samples were analysed for total phosphorus (TP) and nitrogen (TN) concentrations, and were used in combination with river flow discharge, to determine nutrient loads. The study results highlight that river discharge plays a significant role in temporal differences in sediment and water column nutrient concentrations.
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Sex-specific grazing dynamics of the recently described copepod, Lovenula raynerae, in an ephemeral pond in the Eastern Cape province of South Africa
- Authors: Froneman, P William
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479352 , vital:78292 , https://doi.org/10.2989/16085914.2019.1615405
- Description: This study investigated the temporal changes in the sex specific ingestion rates of the recently described calanoid copepod, Lovenula raynerae, which numerically and by biomass dominates the plankton community in ephemeral ponds in the Eastern Cape province of South Africa. Ingestion rates of the copepod were investigated on two occasions, one week after emergence and two weeks thereafter, employing the gut fluorescent technique. Results of the study indicate the absence of any diel patterns in feeding for both sexes on both sampling occasions (p > 0.05 in both cases). Moreover, there was no significant differences in gut pigment contents between adult male and females during either of the surveys (p > 0.05). Daily rations of the adult copepods during the two studies were equivalent to 2% (range 0.8 to 1.8%) body carbon per day suggesting that they are consuming alternative carbon sources to meet their daily carbon requirements. The main findings of this study suggest that L. raynerae can be considered as a generalist omnivore.
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- Authors: Froneman, P William
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479352 , vital:78292 , https://doi.org/10.2989/16085914.2019.1615405
- Description: This study investigated the temporal changes in the sex specific ingestion rates of the recently described calanoid copepod, Lovenula raynerae, which numerically and by biomass dominates the plankton community in ephemeral ponds in the Eastern Cape province of South Africa. Ingestion rates of the copepod were investigated on two occasions, one week after emergence and two weeks thereafter, employing the gut fluorescent technique. Results of the study indicate the absence of any diel patterns in feeding for both sexes on both sampling occasions (p > 0.05 in both cases). Moreover, there was no significant differences in gut pigment contents between adult male and females during either of the surveys (p > 0.05). Daily rations of the adult copepods during the two studies were equivalent to 2% (range 0.8 to 1.8%) body carbon per day suggesting that they are consuming alternative carbon sources to meet their daily carbon requirements. The main findings of this study suggest that L. raynerae can be considered as a generalist omnivore.
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Distinct responses of bacterial communities to agricultural and urban impacts in temperate southern African estuaries
- Matcher, Gwynneth F, Froneman, P William, Meiklejohn, Ian, Dorrington, Rosemary A
- Authors: Matcher, Gwynneth F , Froneman, P William , Meiklejohn, Ian , Dorrington, Rosemary A
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479218 , vital:78271 , https://doi.org/10.1016/j.ecss.2017.11.015
- Description: Worldwide, estuaries are regarded as amongst the most ecologically threatened ecosystems and are increasingly being impacted by urban development, agricultural activities and reduced freshwater inflow. In this study, we examined the influence of different human activities on the diversity and structure of bacterial communities in the water column and sediment in three distinct, temperate permanently open estuarine systems within the same geographic region of southern Africa. The Kariega system is freshwater-deprived and is considered to be relatively pristine; the Kowie estuary is marine-dominated and impacted by urban development, while the Sundays system is fresh-water dominated and impacted by agricultural activity in its catchment. The bacterial communities in all three systems comprise predominantly heterotrophic species belonging to the Bacteroidetes and Proteobacteria phyla with little overlap between bacterioplankton and benthic bacterial communities at the species level. There was overlap between the operational taxonomic units (OTUs) of the Kowie and Kariega, both marine-influenced estuaries. However, lower species richness in the Kowie, likely reflects the impact of human settlements along the estuary. The dominant OTUs in the Sundays River system were distinct from those of the Kariega and Kowie estuaries with an overall decrease in species richness and evenness. This study provides an important snapshot into the microbial population structures of permanently open temperate estuarine systems and the influence of anthropogenic impacts on bacterial diversity and community structure.
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- Authors: Matcher, Gwynneth F , Froneman, P William , Meiklejohn, Ian , Dorrington, Rosemary A
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479218 , vital:78271 , https://doi.org/10.1016/j.ecss.2017.11.015
- Description: Worldwide, estuaries are regarded as amongst the most ecologically threatened ecosystems and are increasingly being impacted by urban development, agricultural activities and reduced freshwater inflow. In this study, we examined the influence of different human activities on the diversity and structure of bacterial communities in the water column and sediment in three distinct, temperate permanently open estuarine systems within the same geographic region of southern Africa. The Kariega system is freshwater-deprived and is considered to be relatively pristine; the Kowie estuary is marine-dominated and impacted by urban development, while the Sundays system is fresh-water dominated and impacted by agricultural activity in its catchment. The bacterial communities in all three systems comprise predominantly heterotrophic species belonging to the Bacteroidetes and Proteobacteria phyla with little overlap between bacterioplankton and benthic bacterial communities at the species level. There was overlap between the operational taxonomic units (OTUs) of the Kowie and Kariega, both marine-influenced estuaries. However, lower species richness in the Kowie, likely reflects the impact of human settlements along the estuary. The dominant OTUs in the Sundays River system were distinct from those of the Kariega and Kowie estuaries with an overall decrease in species richness and evenness. This study provides an important snapshot into the microbial population structures of permanently open temperate estuarine systems and the influence of anthropogenic impacts on bacterial diversity and community structure.
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Largest reported groups for the Indo-Pacific bottlenose dolphin (Tursiops aduncus) found in Algoa Bay, South Africa: trends and potential drivers
- Bouveroux, Thibaut N, Caputo, Michelle, Froneman, P William, Plön, Stephanie
- Authors: Bouveroux, Thibaut N , Caputo, Michelle , Froneman, P William , Plön, Stephanie
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67913 , vital:29168 , https://doi.org/10.1111/mms.12471
- Description: Publisher version , This study investigates how group size of Indo‐Pacific bottlenose dolphins (Tursiops aduncus) changes temporally, spatially, and/or with predominant behavior at two discreet sites along the Eastern Cape coastline of South Africa: Algoa Bay and the Wild Coast. The mean group size of bottlenose dolphins was large with an average of 52 animals. Significantly larger groups were observed in Algoa Bay ( = 60, range = 1–600) than off the Wild Coast ( = 32.9, range = 1–250). In Algoa Bay, the mean group size increased significantly over the study period, from an average 18 animals in 2008 to 76 animals in 2016. Additionally, the largest average and maximum group sizes ever reported both in South Africa and worldwide, were recorded in Algoa Bay (maximum group size = 600). Neither season nor behavior had a significant effect on mean group size at both sites. Similarly environmental variables such as the depth and substrate type also had no influence on group size. It remains unclear which ecological drivers, such as predation risk and food availability, are leading to the large groups observed in this area, and further research on abundance and distribution of both predators and prey is necessary.
- Full Text: false
- Authors: Bouveroux, Thibaut N , Caputo, Michelle , Froneman, P William , Plön, Stephanie
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67913 , vital:29168 , https://doi.org/10.1111/mms.12471
- Description: Publisher version , This study investigates how group size of Indo‐Pacific bottlenose dolphins (Tursiops aduncus) changes temporally, spatially, and/or with predominant behavior at two discreet sites along the Eastern Cape coastline of South Africa: Algoa Bay and the Wild Coast. The mean group size of bottlenose dolphins was large with an average of 52 animals. Significantly larger groups were observed in Algoa Bay ( = 60, range = 1–600) than off the Wild Coast ( = 32.9, range = 1–250). In Algoa Bay, the mean group size increased significantly over the study period, from an average 18 animals in 2008 to 76 animals in 2016. Additionally, the largest average and maximum group sizes ever reported both in South Africa and worldwide, were recorded in Algoa Bay (maximum group size = 600). Neither season nor behavior had a significant effect on mean group size at both sites. Similarly environmental variables such as the depth and substrate type also had no influence on group size. It remains unclear which ecological drivers, such as predation risk and food availability, are leading to the large groups observed in this area, and further research on abundance and distribution of both predators and prey is necessary.
- Full Text: false
Overview and status of estuarine microphytobenthos ecological research in South Africa
- Dalu, Tatenda, Adams, Janine B, Taylor, Jonathan C, Bate, G C, Nunes, M, Froneman, P William, Wasserman, Ryan J
- Authors: Dalu, Tatenda , Adams, Janine B , Taylor, Jonathan C , Bate, G C , Nunes, M , Froneman, P William , Wasserman, Ryan J
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479308 , vital:78285 , https://doi.org/10.2989/1814232X.2018.1431309
- Description: This article presents a historical overview of estuarine microphytobenthos (MPB) research in South Africa published over the period 1950 to the present, highlighting major milestones, challenges and estuarine management problems, as well as future research needs within the South African context. The studies that were covered comprise peer-reviewed books and journal articles on relevant research conducted in any estuarine environment during the period reviewed. There was a general increase in MPB research outputs over the decades, from only two publications in the 1950s, to over 20 outputs between 2010 and the present. Whereas the MPB studies in South Africa cover a broad spectrum of themes, the research priorities in these works have changed from taxonomically biased studies to those of ecologically based research. Research in the 1950s and 1960s was exclusively taxonomic in nature, with the first ecological investigation incorporating MPB being produced in the 1970s. By the 1980s, ecological studies dominated the research outputs and this trend has persisted to the present. The 1990s and 2000s saw the rise of research into the role of fresh water as a driver of MPB dynamics, whereas the period 2010 to the present saw an increase in more diverse ecological themes, ranging from an autecological investigation to food-web studies and the assessment of multiple drivers of MPB dynamics. However, the majority of studies have focused on either diatoms or estimates of overall MPB biomass. Moreover, there is a regional underrepresentation that runs broadly along biogeographic lines, with the bulk of the work having been conducted in the warm-temperate and subtropical zones of South Africa. Challenges and future research needs for the region are outlined, as is the need to expand MPB research to include other aspects of the biology and ecology of this flora.
- Full Text:
- Authors: Dalu, Tatenda , Adams, Janine B , Taylor, Jonathan C , Bate, G C , Nunes, M , Froneman, P William , Wasserman, Ryan J
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479308 , vital:78285 , https://doi.org/10.2989/1814232X.2018.1431309
- Description: This article presents a historical overview of estuarine microphytobenthos (MPB) research in South Africa published over the period 1950 to the present, highlighting major milestones, challenges and estuarine management problems, as well as future research needs within the South African context. The studies that were covered comprise peer-reviewed books and journal articles on relevant research conducted in any estuarine environment during the period reviewed. There was a general increase in MPB research outputs over the decades, from only two publications in the 1950s, to over 20 outputs between 2010 and the present. Whereas the MPB studies in South Africa cover a broad spectrum of themes, the research priorities in these works have changed from taxonomically biased studies to those of ecologically based research. Research in the 1950s and 1960s was exclusively taxonomic in nature, with the first ecological investigation incorporating MPB being produced in the 1970s. By the 1980s, ecological studies dominated the research outputs and this trend has persisted to the present. The 1990s and 2000s saw the rise of research into the role of fresh water as a driver of MPB dynamics, whereas the period 2010 to the present saw an increase in more diverse ecological themes, ranging from an autecological investigation to food-web studies and the assessment of multiple drivers of MPB dynamics. However, the majority of studies have focused on either diatoms or estimates of overall MPB biomass. Moreover, there is a regional underrepresentation that runs broadly along biogeographic lines, with the bulk of the work having been conducted in the warm-temperate and subtropical zones of South Africa. Challenges and future research needs for the region are outlined, as is the need to expand MPB research to include other aspects of the biology and ecology of this flora.
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Presence of microplastics in the tube structure of the reef-building polychaete Gunnarea gaimardi (Quatrefages 1848)
- Nel, Holly A, Froneman, P William
- Authors: Nel, Holly A , Froneman, P William
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479330 , vital:78287 , https://doi.org/10.2989/1814232X.2018.1443835
- Description: The prevalence of microplastics in the marine environment has resulted in a need to understand their association with various fauna. The aim of this study was to assess whether microplastic particles are present in the tube structure of the indigenous reef-building polychaete Gunnarea gaimardi, which occurs along the coast of South Africa. Sampling was conducted at nine stations along the west and southeast coastlines of South Africa, in July 2016 and April/May 2017. Microplastic particles were recorded in all tube structures of G. gaimardi, with the density ranging between 0.056 and 1.113 microplastic particles g–1 dry weight (dwt). There were no significant differences between sites (p > 0.05), resulting in an overall average of 0.275 (SD 0.215) microplastic particles g–1 (dwt). To the authors’ knowledge, this is the first study to show that synthetic polymers are found in the tubes of reef-building polychaetes along the coast of South Africa.
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- Authors: Nel, Holly A , Froneman, P William
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479330 , vital:78287 , https://doi.org/10.2989/1814232X.2018.1443835
- Description: The prevalence of microplastics in the marine environment has resulted in a need to understand their association with various fauna. The aim of this study was to assess whether microplastic particles are present in the tube structure of the indigenous reef-building polychaete Gunnarea gaimardi, which occurs along the coast of South Africa. Sampling was conducted at nine stations along the west and southeast coastlines of South Africa, in July 2016 and April/May 2017. Microplastic particles were recorded in all tube structures of G. gaimardi, with the density ranging between 0.056 and 1.113 microplastic particles g–1 dry weight (dwt). There were no significant differences between sites (p > 0.05), resulting in an overall average of 0.275 (SD 0.215) microplastic particles g–1 (dwt). To the authors’ knowledge, this is the first study to show that synthetic polymers are found in the tubes of reef-building polychaetes along the coast of South Africa.
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Sacrificial males the potential role of copulation and predation in contributing to copepod sex-skewed ratios
- Wasserman, Ryan J, Weston, Mark, Weyl, Olaf, L F, Froneman, P William, Welch, Rebecca J, Vink, Tim J F, Dalu, Tatenda
- Authors: Wasserman, Ryan J , Weston, Mark , Weyl, Olaf, L F , Froneman, P William , Welch, Rebecca J , Vink, Tim J F , Dalu, Tatenda
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467233 , vital:76843 , https://doi.org/10.1111/oik.04832
- Description: Predation is thought to play a selective role in the emergence of behavioural traits in prey. Differences in behaviour between prey demographics may, therefore, be driven by predation with select components of the population being less vulnerable to predators. While under controlled conditions prey demography has been shown to have consequences for predation success, investigations linking these implications to natural prey population demographics are scarce. Here we assess predator–prey dynamics between notonectid predators (backswimmers) and Lovenula raynerae (Copepoda), key faunal groups in temperate ephemeral pond ecosystems. Using a combination of field and experimental approaches we test for the development and mechanism of predation‐induced sex‐skewed ratios. A natural population of L. raynerae was tracked over time in relation to their predator (notonectid) and prey (Cladocera) numbers. In the laboratory, L. raynerae sex ratios were also assessed over time but in the absence of predation pressure.
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- Authors: Wasserman, Ryan J , Weston, Mark , Weyl, Olaf, L F , Froneman, P William , Welch, Rebecca J , Vink, Tim J F , Dalu, Tatenda
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467233 , vital:76843 , https://doi.org/10.1111/oik.04832
- Description: Predation is thought to play a selective role in the emergence of behavioural traits in prey. Differences in behaviour between prey demographics may, therefore, be driven by predation with select components of the population being less vulnerable to predators. While under controlled conditions prey demography has been shown to have consequences for predation success, investigations linking these implications to natural prey population demographics are scarce. Here we assess predator–prey dynamics between notonectid predators (backswimmers) and Lovenula raynerae (Copepoda), key faunal groups in temperate ephemeral pond ecosystems. Using a combination of field and experimental approaches we test for the development and mechanism of predation‐induced sex‐skewed ratios. A natural population of L. raynerae was tracked over time in relation to their predator (notonectid) and prey (Cladocera) numbers. In the laboratory, L. raynerae sex ratios were also assessed over time but in the absence of predation pressure.
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Striping patterns may not influence social interactions and mating in zebra: Observations from melanic zebra in South Africa
- Caputo, Michelle, Rubenstein, Daniel I, Froneman, P William, Bouveroux, Thibaut N
- Authors: Caputo, Michelle , Rubenstein, Daniel I , Froneman, P William , Bouveroux, Thibaut N
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479363 , vital:78294 , https://doi.org/10.1111/aje.12463
- Description: Colouration serves many functions in animals including crypsis, aposematism, mimicry, intraspecific communication, communication between species and thermoregulation (Caro, Caswell Stoddard, and Stuard-Fox, 2017). On occasions, abnormalities or discontinuous variations in colouration and/or patterning of an individual within a population can occur, leading to albinism (Osinga, ‘t Hart, and Vader, 2010), leucism (Reisinger, Mufanadzo, de Bruyn, and Bester, 2009) or melanism (Eizirik et al., 2003; Majerus, 1998). Melanism, a rare condition occurring when a group of pigments (pheomelanin or eumelanin) is overproduced, has been reported in a variety of mammal species.
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- Authors: Caputo, Michelle , Rubenstein, Daniel I , Froneman, P William , Bouveroux, Thibaut N
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479363 , vital:78294 , https://doi.org/10.1111/aje.12463
- Description: Colouration serves many functions in animals including crypsis, aposematism, mimicry, intraspecific communication, communication between species and thermoregulation (Caro, Caswell Stoddard, and Stuard-Fox, 2017). On occasions, abnormalities or discontinuous variations in colouration and/or patterning of an individual within a population can occur, leading to albinism (Osinga, ‘t Hart, and Vader, 2010), leucism (Reisinger, Mufanadzo, de Bruyn, and Bester, 2009) or melanism (Eizirik et al., 2003; Majerus, 1998). Melanism, a rare condition occurring when a group of pigments (pheomelanin or eumelanin) is overproduced, has been reported in a variety of mammal species.
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