Distribution and habitat choice of Cape clawless otters, in South Africa

Nel, J.A.J.; Somers, Michael J.

doi:10.3957/0379-4369-37.1.61

Cited by 13 publications

(17 citation statements)

References 20 publications

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“…Its distribution range covers most of sub-Saharan Africa, only being absent in the Congo basin where it is replaced by the Congo clawless otter (A. congicus) (Rowe-Rowe & Nel & Somers, 2007). Cape clawless otters occur in a large range of habitats including both coastal and inland habitats, with occurrences along the coast being closely associated with freshwater availability (van Niekerk, Somers & Nel, 1998).…”

Section: Introductionmentioning

confidence: 99%

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An Assessment of Spatial and Temporal Variation in the Diet of Cape Clawless Otters (Aonyx capensis) in Marine Environments

Jordaan

McIntyre

Somers

et al. 2015

African Journal of Wildlife Research

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We studied the diet of Cape clawless otters (Aonyx capensis) at three sites along the eastern and southern coast of South Africa to assess possible spatial variation along a community species richness and biomass gradient associated with rocky shores. A total of 309 spraints representing two seasons (summer 2013/2014 and winter 2014) were collected and subsequently analysed. The percentage occurrence and percentage dry mass of numerous prey categories were compared between sites and seasons. Variation in the importance of prey items was found between sites, whilst no variation was found between seasons within the same site. Crab was the most important prey item in the southernmost study area (Tsitsikamma National Park) and at the northernmost study site (KwaZulu-Natal Coast), whilst lobster was the most important prey item in the central area (Mkambati Nature Reserve). Fish was the second most important prey item at all three sites. Our results suggest that otters are opportunistic feeders that are likely able to adapt to potential prey species and abundance changes associated with current and future anthropogenically driven changes. Furthermore, long-term, site-specific stability in diet suggests that monitoring the diet of otters could provide some useful information on the status of shoreline communities.

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Section: Introductionmentioning

confidence: 99%

“…The Cape clawless otter (Aonyx capensis) is the most widely distributed of the three endemic otter species in Africa (Nel & Somers, 2007). Its distribution range covers most of sub-Saharan Africa, only being absent in the Congo basin where it is replaced by the Congo clawless otter (A. congicus) (Rowe-Rowe & Nel & Somers, 2007).…”

Section: Introductionmentioning

confidence: 99%

An Assessment of Spatial and Temporal Variation in the Diet of Cape Clawless Otters (Aonyx capensis) in Marine Environments

Jordaan

McIntyre

Somers

et al. 2015

African Journal of Wildlife Research

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“…These are the Congo clawless otter (Aonyx congicus) limited to the Congo basin; the African clawless otter (A. capensis) occurring in most parts of western, eastern and southern Africa and the Spotted-necked otter (Lutra maculicollis) occurring in most parts of western, central and south-eastern Africa (Nel and Somers, 2007). The latter two species are found in Ethiopia (Yalden et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

“…There are 13 extant species of otters of which three are limited to Sub-Saharan Africa (Nel and Somers, 2007). These are the Congo clawless otter (Aonyx congicus) limited to the Congo basin; the African clawless otter (A. capensis) occurring in most parts of western, eastern and southern Africa and the Spotted-necked otter (Lutra maculicollis) occurring in most parts of western, central and south-eastern Africa (Nel and Somers, 2007).…”

Section: Introductionmentioning

confidence: 99%

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Diet analysis of the African clawless otter (Aonyx capensis) in and around Lake Tana

Andarge¹,

Wube²,

Balakrishnan³

2017

J. Ecol. Nat. Environ.

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The diet composition of the African clawless otter (Aonyx capensis) was studied by analyzing of 440 spraint samples collected during January, 2014 and December, 2015 in both dry and wet seasons from eight sites in and around Lake Tana, North West Ethiopia. Percentage frequency of occurrence and relative percentage frequency of diet items in the spraint samples were calculated.The statistical analysis was conducted using chi-square and one-way ANOVA tests.The number of diet categories per spraint ranged from 1 to 4 with a mean of 1.42 ± 0.591. Fish was the dominant prey item in all sites with an overall frequency of occurrence of 84.77% and a relative percentage frequency of 59.68%. Labeobarbus spp. was the most frequent fish prey (35.45%). Crabs were the second most frequent prey items with percentage frequency of 33.41% and a relative percentage frequency of 23.52%, while small mammals and birds were the least frequent dietary items with percentage frequency of 0.45 and 0.23%, respectively. Other identified diet items and the respective percentage frequency were plant matter (6.17%), insects (5.68%), amphibians (5%), mollusks (2.5%) and unidentified items (3.86%). Variation on fish and crab prey items were observed between seasons and sites, while no variation was observed for other prey items. The results suggested a dietary flexibility and shift in the African clawless otter from crabs to fish that can be explained by availability and accessibility.

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Otter occupancy in the Cape Peninsula: Estimating the probability of river habitat use by Cape clawless otters, Aonyx capensis, across a gradient of human influence

Okes

O’Riain

2017

Aquatic Conservation

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1. The distribution of Cape clawless otters, Aonyx capensis, in South Africa and their habitat requirements in freshwater and marine systems has been well established. There is, however, a lack of information on how otters are adapting to urban development and the transformation of critical freshwater habitat.2. Within the Western Cape, the Cape Peninsula exhibits substantial variation in levels of human impact over a small geographic range, offering an excellent opportunity to explore the hypothesis that otters are adversely affected by habitat transformation.3. A single season occupancy model was used based on otter sign to determine the probability of otter occupancy across a gradient of habitat transformation at both landscape and local scales.4. The probability of otters occupying river habitat in the Cape Peninsula was low (P = 0.29) but increased with proximity to marine protected areas (MPAs) that included estuaries and wetland habitat. Otter presence was not influenced by proximity to urban areas at the landscape scale, but declined in canalized sections of river that were heavily degraded by human activity. 5. Despite being heavily transformed, lowland aquatic ecosystems may still provide critical resources in the form of fresh water and breeding sites, and together with food within the marine habitat may be sustaining the peninsula's otter population.6. In order for otters to persist on the peninsula, conservation authorities must maintain wetland, estuarine and river habitat in close proximity to MPAs. Further research is needed to determine the long-term impacts on otters persisting in degraded ecosystems. 7. Annual single season occupancy surveys provide a rapid, cost-effective method for monitoring changes in otter occupancy which should be incorporated into current monitoring efforts to provide much needed long-term monitoring of a top predator in freshwater ecosystems.

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Distribution and habitat choice of Cape clawless otters, in South Africa

Cited by 13 publications

References 20 publications

An Assessment of Spatial and Temporal Variation in the Diet of Cape Clawless Otters (Aonyx capensis) in Marine Environments

An Assessment of Spatial and Temporal Variation in the Diet of Cape Clawless Otters (Aonyx capensis) in Marine Environments

Diet analysis of the African clawless otter (Aonyx capensis) in and around Lake Tana

Otter occupancy in the Cape Peninsula: Estimating the probability of river habitat use by Cape clawless otters, Aonyx capensis, across a gradient of human influence

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