Inter-and intra-specific trophic interactions of coastal delphinids off the eastern coast of South Africa inferred from stable isotope analysis
- Caputo, Michelle, Bouveroux, Thibaut N, Van der Bank, Megan, Cliff, Geremy, Kiszka, Jeremy J, Froneman, P William, Plön, Stephanie
- Authors: Caputo, Michelle , Bouveroux, Thibaut N , Van der Bank, Megan , Cliff, Geremy , Kiszka, Jeremy J , Froneman, P William , Plön, Stephanie
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: article
- Identifier: http://hdl.handle.net/10962/466545 , vital:76745 , https://doi.org/10.1016/j.marenvres.2022.105784
- Description: Dietary tracers, such as bulk stable carbon (δ13C) and nitrogen (δ15N) isotopes, can be used to investigate the trophic interactions of marine predators, which is useful to assess their ecological roles within communities. These tracers have also been used to elucidate population structure and substructure, which is critical for the better identification of management units for these species affected by a range of threats, particularly bycatch in fishing gears. Off eastern South Africa, large populations of Indo-Pacific bottlenose (Tursiops aduncus) and common dolphins (Delphinus delphis) co-occur and are thought to follow the pulses of shoaling sardines (Sardinops sagax) heading north-east in the austral winter. Here we used δ13C and δ15N to investigate the trophic interactions and define ecological units of these two species along a ≈800 km stretch of the east coast of South Africa, from Algoa Bay to the coast of KwaZulu-Natal. Common and bottlenose dolphin dietary niche overlapped by 39.7% overall in our study area, with the highest overlap occurring off the Wild Coast (40.7% at Hluleka).
- Full Text:
- Date Issued: 2022
- Authors: Caputo, Michelle , Bouveroux, Thibaut N , Van der Bank, Megan , Cliff, Geremy , Kiszka, Jeremy J , Froneman, P William , Plön, Stephanie
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: article
- Identifier: http://hdl.handle.net/10962/466545 , vital:76745 , https://doi.org/10.1016/j.marenvres.2022.105784
- Description: Dietary tracers, such as bulk stable carbon (δ13C) and nitrogen (δ15N) isotopes, can be used to investigate the trophic interactions of marine predators, which is useful to assess their ecological roles within communities. These tracers have also been used to elucidate population structure and substructure, which is critical for the better identification of management units for these species affected by a range of threats, particularly bycatch in fishing gears. Off eastern South Africa, large populations of Indo-Pacific bottlenose (Tursiops aduncus) and common dolphins (Delphinus delphis) co-occur and are thought to follow the pulses of shoaling sardines (Sardinops sagax) heading north-east in the austral winter. Here we used δ13C and δ15N to investigate the trophic interactions and define ecological units of these two species along a ≈800 km stretch of the east coast of South Africa, from Algoa Bay to the coast of KwaZulu-Natal. Common and bottlenose dolphin dietary niche overlapped by 39.7% overall in our study area, with the highest overlap occurring off the Wild Coast (40.7% at Hluleka).
- Full Text:
- Date Issued: 2022
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.
- Full Text:
- Date Issued: 2020
- 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.
- Full Text:
- Date Issued: 2020
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
- Date Issued: 2018
- 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
- Date Issued: 2018
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.
- Full Text:
- Date Issued: 2018
- 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.
- Full Text:
- Date Issued: 2018
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