The importance of winter-flowering Aloe ferox for specialist and generalist nectar-feeding birds
- Kuiper, Timothy R, Smith, Diane L, Wolmarans, Milena H L, Jones, Sara S, Forbes, Ross W, Hulley, Patrick E, Craig, Adrian J F K
- Authors: Kuiper, Timothy R , Smith, Diane L , Wolmarans, Milena H L , Jones, Sara S , Forbes, Ross W , Hulley, Patrick E , Craig, Adrian J F K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: article
- Identifier: http://hdl.handle.net/10962/465538 , vital:76618 , https://doi.org/10.1071/MU14054
- Description: The abundance of consumers and the availability of resources are often linked, and birds are known to track food resources at a variety of spatial and temporal scales. This study describes the seasonal influx of nectar-feeding birds during flowering in a 51-ha stand of Aloe ferox in the Eastern Cape, South Africa, over 5 years (2008–09 and 2011–13). Bimonthly point counts of birds were conducted before (April—May), during (June—July) and after (August) flowering, which occurs during the austral winter. The abundance of nectar-feeding birds increased significantly during flowering each year, whereas monthly abundances of non-nectarivores were unrelated to flowering. Models fitted to bird count-data revealed a significant interaction between feeding guild (nectarivorous versus non-nectarivorous species) and the percentage of flowering A. ferox over the 5 years of the study, confirming that these guilds responded differently to flowering events. Malachite Sunbirds (Nectarina famosa), which are specialist nectarivores, responded consistently to flowering of A. ferox each year, despite the low sugar concentrations of A. ferox nectar. The arrival of nectar-feeding birds en masse during flowering, and the number of bird species (16) observed feeding on A. ferox nectar, suggest that this plant is an important source of nutrition for birds at a time when other food resources are likely to be scarce.
- Full Text:
- Date Issued: 2015
- Authors: Kuiper, Timothy R , Smith, Diane L , Wolmarans, Milena H L , Jones, Sara S , Forbes, Ross W , Hulley, Patrick E , Craig, Adrian J F K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: article
- Identifier: http://hdl.handle.net/10962/465538 , vital:76618 , https://doi.org/10.1071/MU14054
- Description: The abundance of consumers and the availability of resources are often linked, and birds are known to track food resources at a variety of spatial and temporal scales. This study describes the seasonal influx of nectar-feeding birds during flowering in a 51-ha stand of Aloe ferox in the Eastern Cape, South Africa, over 5 years (2008–09 and 2011–13). Bimonthly point counts of birds were conducted before (April—May), during (June—July) and after (August) flowering, which occurs during the austral winter. The abundance of nectar-feeding birds increased significantly during flowering each year, whereas monthly abundances of non-nectarivores were unrelated to flowering. Models fitted to bird count-data revealed a significant interaction between feeding guild (nectarivorous versus non-nectarivorous species) and the percentage of flowering A. ferox over the 5 years of the study, confirming that these guilds responded differently to flowering events. Malachite Sunbirds (Nectarina famosa), which are specialist nectarivores, responded consistently to flowering of A. ferox each year, despite the low sugar concentrations of A. ferox nectar. The arrival of nectar-feeding birds en masse during flowering, and the number of bird species (16) observed feeding on A. ferox nectar, suggest that this plant is an important source of nutrition for birds at a time when other food resources are likely to be scarce.
- Full Text:
- Date Issued: 2015
Elephants in Africa: Big, grey biodiversity thieves?
- Kuiper, Timothy R, Parker, Daniel M
- Authors: Kuiper, Timothy R , Parker, Daniel M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124385 , vital:35601 , https://doi.org/10.2989/16085914.2011.589120
- Description: The conservation of biological diversity is one of the greatest challenges facing humanity today.1,2 Addressing this challenge must inevitably involve the maintenance of the composition, structure and functioning of multi-species ecosystems.2-4 While preventing the loss of particular species is an obvious strategy, a second goal might be to manage for local species diversity and the heterogeneity of habitats.5 A further objective may be the restoration of damaged ecosystems.6 Large herbivore assemblages form an important component of many diverse ecosystems and are of distinct ecological, and hence conservation, value.7-9 On the other hand, herbivores managed at unnaturally high densities may drive detrimental changes in the structural heterogeneity of habitats.10-12 Thus, decision-makers are faced with the challenge of balancing the needs of populations of large herbivores with the preservation of vegetation and ecosystem diversity.9 In light of these considerations, conclusions as to whether large herbivores are ‘good’ or ‘bad’ for biological diversity are both contentious and elusive. Nonetheless, we seek to explore this question with particular reference to African savannah elephants (Loxodonta africana). We discuss whether or not the elephant should be considered a biodiversity thief – a species that upsets the natural diversity of life in the habitat in which it lives.
- Full Text:
- Date Issued: 2014
- Authors: Kuiper, Timothy R , Parker, Daniel M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124385 , vital:35601 , https://doi.org/10.2989/16085914.2011.589120
- Description: The conservation of biological diversity is one of the greatest challenges facing humanity today.1,2 Addressing this challenge must inevitably involve the maintenance of the composition, structure and functioning of multi-species ecosystems.2-4 While preventing the loss of particular species is an obvious strategy, a second goal might be to manage for local species diversity and the heterogeneity of habitats.5 A further objective may be the restoration of damaged ecosystems.6 Large herbivore assemblages form an important component of many diverse ecosystems and are of distinct ecological, and hence conservation, value.7-9 On the other hand, herbivores managed at unnaturally high densities may drive detrimental changes in the structural heterogeneity of habitats.10-12 Thus, decision-makers are faced with the challenge of balancing the needs of populations of large herbivores with the preservation of vegetation and ecosystem diversity.9 In light of these considerations, conclusions as to whether large herbivores are ‘good’ or ‘bad’ for biological diversity are both contentious and elusive. Nonetheless, we seek to explore this question with particular reference to African savannah elephants (Loxodonta africana). We discuss whether or not the elephant should be considered a biodiversity thief – a species that upsets the natural diversity of life in the habitat in which it lives.
- Full Text:
- Date Issued: 2014
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