Life history of the springhare (Pedetes capensis) from a strongly seasonal environment in the Eastern Cape Province of South Africa
- Peinke, Dean, Bernard, Ric T F
- Authors: Peinke, Dean , Bernard, Ric T F
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447089 , vital:74583 , doi.org/10.1080/15627020.2005.11407327
- Description: The life history of the springhare (Pedetes capensis, Forster, 1778) at 33°S, in the Eastern Cape Province of South Africa, was characterized by continuous, aseasonal and asynchronous reproduction. Females were monotocous and consecutive pregnancies were separated by a non pregnant period (30–50 days) similar in length to the period of lactation. Young were relatively large at birth (8% of adult body weight) but were altricial and only emerged from the burrow at weaning. Towards the end of lactation, many females mated again (20% of all females were both lactating and in early pregnancy) and annual fecundity was probably two but never more than three. For a rodent, albeit a large one, this is a very slow rate of reproduction and we propose that the ricochetal locomotion (jumping on the hind legs) and semi-fossorial life style of the springhare will have resulted in decreased juvenile and adult mortality, and increased longevity, and that these factors have shaped the evolution of the life history of the springhare.
- Full Text:
- Date Issued: 2005
- Authors: Peinke, Dean , Bernard, Ric T F
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447089 , vital:74583 , doi.org/10.1080/15627020.2005.11407327
- Description: The life history of the springhare (Pedetes capensis, Forster, 1778) at 33°S, in the Eastern Cape Province of South Africa, was characterized by continuous, aseasonal and asynchronous reproduction. Females were monotocous and consecutive pregnancies were separated by a non pregnant period (30–50 days) similar in length to the period of lactation. Young were relatively large at birth (8% of adult body weight) but were altricial and only emerged from the burrow at weaning. Towards the end of lactation, many females mated again (20% of all females were both lactating and in early pregnancy) and annual fecundity was probably two but never more than three. For a rodent, albeit a large one, this is a very slow rate of reproduction and we propose that the ricochetal locomotion (jumping on the hind legs) and semi-fossorial life style of the springhare will have resulted in decreased juvenile and adult mortality, and increased longevity, and that these factors have shaped the evolution of the life history of the springhare.
- Full Text:
- Date Issued: 2005
The diet and ecological role of giraffe (Giraffa camelopardalis) introduced to the Eastern Cape, South Africa
- Parker, Daniel M, Bernard, Ric T F
- Authors: Parker, Daniel M , Bernard, Ric T F
- Date: 2005
- Subjects: Giraffe Giraffa camelopardalis Herbivore
- Language: English
- Type: Article
- Identifier: vital:6942 , http://hdl.handle.net/10962/d1011967
- Description: With an increase in the popularity of wildlife ranching in southern Africa has come the introduction of non-native (extralimital) mammalian herbivores. Financial gain has arguably been at the forefront of these introductions, with little or no assessment of the ecological consequences. The diet of three populations of introduced giraffe Giraffa camelopardalis was assessed by direct observation in the Eastern Cape Province, South Africa between January 2002 and October 2003, as the first step towards understanding the ecological role played by giraffe in the region. Similar to the diet of giraffe within their native range, a deciduous species from the genus Acacia (Acacia karroo) was the most important species in the diet. Giraffe in the Eastern Cape Province, however, consumed more evergreen species than those within their native range. The relative lack of deciduous species in the Eastern Cape Province provides a probable explanation for such a result. Seasonal variation in the consumption of the most important species in the diet was evident with members of the genus Rhus being more important in the winter months. This was attributed to the deciduous nature of A. karroo. The potential for giraffe to have a detrimental effect on the indigenous vegetation is discussed. We conclude that the study provides a much-needed list of plant species threatened by giraffe browsing in a region where the vegetation is thought to have evolved in the absence of such a browser.
- Full Text:
- Date Issued: 2005
- Authors: Parker, Daniel M , Bernard, Ric T F
- Date: 2005
- Subjects: Giraffe Giraffa camelopardalis Herbivore
- Language: English
- Type: Article
- Identifier: vital:6942 , http://hdl.handle.net/10962/d1011967
- Description: With an increase in the popularity of wildlife ranching in southern Africa has come the introduction of non-native (extralimital) mammalian herbivores. Financial gain has arguably been at the forefront of these introductions, with little or no assessment of the ecological consequences. The diet of three populations of introduced giraffe Giraffa camelopardalis was assessed by direct observation in the Eastern Cape Province, South Africa between January 2002 and October 2003, as the first step towards understanding the ecological role played by giraffe in the region. Similar to the diet of giraffe within their native range, a deciduous species from the genus Acacia (Acacia karroo) was the most important species in the diet. Giraffe in the Eastern Cape Province, however, consumed more evergreen species than those within their native range. The relative lack of deciduous species in the Eastern Cape Province provides a probable explanation for such a result. Seasonal variation in the consumption of the most important species in the diet was evident with members of the genus Rhus being more important in the winter months. This was attributed to the deciduous nature of A. karroo. The potential for giraffe to have a detrimental effect on the indigenous vegetation is discussed. We conclude that the study provides a much-needed list of plant species threatened by giraffe browsing in a region where the vegetation is thought to have evolved in the absence of such a browser.
- Full Text:
- Date Issued: 2005
The diet of Cape clawless otters at two sites along the Bloukrans River, Eastern Cape Province, South Africa
- Parker, Daniel M, Burchell, R K, Bernard, Ric T F
- Authors: Parker, Daniel M , Burchell, R K , Bernard, Ric T F
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6959 , http://hdl.handle.net/10962/d1012004
- Description: The diet of Cape clawless otters was assessed at two sites along the Bloukrans River using faecal analysis. Spraints (n = 78) were collected during 2000 and 2001 and analysed using the relative frequency of occurrence and the reconstituted wet weight methods. Both methods found crab (Potamonautes perlatus) to be the most important component (>50%) of the diet. Frog, Xenopus and Rana spp., (11–42%) was the second most important component while fish (Micropteris salmoides) was relatively unimportant (<14%). Although the diet of Cape clawless otters in the Eastern Cape Province was similar to that reported elsewhere, the fact that they were preying on an alien invasive fish and not the indigenous endemic Sandelia bainsii is significant. The validity of faecal analysis methods is also discussed.
- Full Text:
- Date Issued: 2005
- Authors: Parker, Daniel M , Burchell, R K , Bernard, Ric T F
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6959 , http://hdl.handle.net/10962/d1012004
- Description: The diet of Cape clawless otters was assessed at two sites along the Bloukrans River using faecal analysis. Spraints (n = 78) were collected during 2000 and 2001 and analysed using the relative frequency of occurrence and the reconstituted wet weight methods. Both methods found crab (Potamonautes perlatus) to be the most important component (>50%) of the diet. Frog, Xenopus and Rana spp., (11–42%) was the second most important component while fish (Micropteris salmoides) was relatively unimportant (<14%). Although the diet of Cape clawless otters in the Eastern Cape Province was similar to that reported elsewhere, the fact that they were preying on an alien invasive fish and not the indigenous endemic Sandelia bainsii is significant. The validity of faecal analysis methods is also discussed.
- Full Text:
- Date Issued: 2005
The effect of prolonged cold storage of eland (Taurotragus oryx) cauda epididymides on the spermatozoa: possible implications for the conservation of biodiversity
- Bissett, Charlene, Bernard, Ric T F
- Authors: Bissett, Charlene , Bernard, Ric T F
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6947 , http://hdl.handle.net/10962/d1011976
- Description: The objectives of this study were to investigate the effects of prolonged storage of cauda epididymides at 4 °C on spermatozoa, and to determine the practicality of utilising epididymal sperm, harvested from testes collected during routine culling of game animals, in assisted reproductive technologies. Testes from eland (Taurotragus oryx) were collected and epididymides removed and maintained at 4 °C. Sperm motility, viability, morphology and membrane integrity were examined at 12 h intervals for 108 h. Sperm motility and viability were significantly lower at the end of the experiment than at the start (P < 0.05) and there was individual variation in the rate at which motility and viability declined. The total number of normal sperm decreased significantly with prolonged storage at 4 °C. Midpiece defects were the most common and head and tail abnormalities were rare. A significant decrease in acrosomal and nuclear membrane integrity was observed with prolonged cold storage but there was no significant change in cell membrane integrity. However, about 30% of epididymal sperm survived for 3 days at 4 °C and more than 10% survived for 4 days, and it should be possible to use sperm from culled animals in some assisted reproductive technologies.
- Full Text:
- Date Issued: 2005
- Authors: Bissett, Charlene , Bernard, Ric T F
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6947 , http://hdl.handle.net/10962/d1011976
- Description: The objectives of this study were to investigate the effects of prolonged storage of cauda epididymides at 4 °C on spermatozoa, and to determine the practicality of utilising epididymal sperm, harvested from testes collected during routine culling of game animals, in assisted reproductive technologies. Testes from eland (Taurotragus oryx) were collected and epididymides removed and maintained at 4 °C. Sperm motility, viability, morphology and membrane integrity were examined at 12 h intervals for 108 h. Sperm motility and viability were significantly lower at the end of the experiment than at the start (P < 0.05) and there was individual variation in the rate at which motility and viability declined. The total number of normal sperm decreased significantly with prolonged storage at 4 °C. Midpiece defects were the most common and head and tail abnormalities were rare. A significant decrease in acrosomal and nuclear membrane integrity was observed with prolonged cold storage but there was no significant change in cell membrane integrity. However, about 30% of epididymal sperm survived for 3 days at 4 °C and more than 10% survived for 4 days, and it should be possible to use sperm from culled animals in some assisted reproductive technologies.
- Full Text:
- Date Issued: 2005
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