Applied Behavioural Ecology and Ecosystem Research Unit

Florida, South Africa

Applied Behavioural Ecology and Ecosystem Research Unit

Florida, South Africa

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Spear D.,Stellenbosch University | Foxcroft L.C.,Center for Invasion Biology and Conservation Services | Bezuidenhout H.,Scientific Services | Bezuidenhout H.,Applied Behavioural Ecology and Ecosystem Research Unit | And 2 more authors.
Biological Conservation | Year: 2013

Understanding the drivers of biological invasions, across taxa and regions, is important for designing appropriate management interventions. However there has been no work that has examined potential drivers of both plant and animal invasions, for both species considered to be aliens and those that are invasive. We use South Africa's national park system (19 national parks, throughout South Africa and covering ∼39,000km2) as a model to test the generality of predictors of alien species richness in protected areas. We also compare the predictors of alien versus invasive species richness, and alien plant versus alien animal species richness. Species were classified as alien, invasive (having known negative impact on biodiversity) or extralimital, using standard definitions. Potential predictors (numbers of years since the park was proclaimed and since new land was acquired, park area, data availability, human population density in the vicinity of the park, number of roads, number of rivers, indigenous plant species richness and normalised difference vegetation index) of the number of alien and invasive species in national parks were examined for plants and animals using generalised linear models. Human population density surrounding parks was a significant and strong predictor of numbers of alien and invasive species across plants and animals. The role of other predictors, such as NDVI and park age, was inconsistent across models. Human population density has emerged here as an important predictor of alien species richness in protected areas across taxa, providing a basis for guidelines on where to focus surveillance and eradication efforts. © 2012 Elsevier Ltd.


Van der Merwe H.,South African Environmental Observation Network | Van der Merwe H.,University of Cape Town | Bezuidenhout H.,South African National Parks | Bezuidenhout H.,Applied Behavioural Ecology and Ecosystem Research Unit | Bradshaw P.L.,Nelson Mandela Metropolitan University
South African Journal of Botany | Year: 2015

Effective management of conservation areas is critical to ensure the adequate protection of the natural resources. The landscape unit concept can be used as a tool in conservation management as a spatial planning unit. Landscape units are areas with a specific set of biotic and abiotic characteristics that can be classified, mapped and described. These units then form the basis on which a conservation area can be planned and managed.A vegetation map was compiled for Tankwa Karoo National Park (TKNP), when it was originally proclaimed at 27,064. ha. The park has subsequently expanded to more than 145,000. ha and is still growing. A need has been identified by park management as well as scientists working in the park for an effective framework for managing the park, and for conducting scientific research. The latest vegetation map of South Africa is at too coarse a scale for park planning. The purpose of the current study was to classify, map and describe the current extent of the TKNP to fulfill this need.Two primary zones were identified for the park: the Tanqua Plains Zone and the Roggeveld Mountain Zone. These two zones were further subdivided into landscape units using land type units and a combination of field work and satellite imagery. Futhermore, the landscape units were related to habitats and/or vegetation types as identified during previous studies in the area. Environmental parameters for each landscape unit were summarised in order to provide additional information for consideration in management and research decisions. Thirteen landscape units were identified in the current TKNP and are mapped and described.Delineation of the TKNP into landscape units will aid in the effective conservation management of this large national park as well as facilitate scientifc research and monitoring. © 2015 South African Association of Botanists.


Steyn H.M.,South African National Botanical Institute | Bester S.P.,South African National Botanical Institute | Bester S.P.,North West University South Africa | Bezuidenhout H.,Scientific Services | Bezuidenhout H.,Applied behavioural ecology and ecosystem research unit
South African Journal of Botany | Year: 2013

An updated checklist is provided for the flora of Tankwa Karoo National Park, which occupies an area of 143,600. ha. A total of 730 species and 780 plant taxa (species, subspecies and varieties), representing 267 genera in 73 families, are recorded for the park. This comprises 30 bryophytes, 7 pteridophytes, 189 monocotyledons and 554 dicotyledons. Sixteen species are endemic or near-endemic to the Hantam-Tanqua-Roggeveld subregion. Twenty-eight species are of conservation concern and six species have been declared as alien invasives. © 2013 South African Association of Botanists.


Norval G.,Applied Behavioural Ecology and Ecosystem Research Unit | Mao J.-J.,National Ilan University | Goldberg S.R.,Whittier College
Herpetological Conservation and Biology | Year: 2012

The Kühne's Grass Lizard (Takydromus kuehnei) is a poorly studied indigenous species in Taiwan. In this report we incorporate additional information concerning reproduction with our previous observations to provide a more comprehensive description of reproduction in T. kuehnei from southwestern Taiwan. We collected 48 T. kuehnei (18 male, 19 female) from a secondary forest in Santzepu, Sheishan District, Chiayi County, as part of a herpetofauna survey in the area. We also obtained five clutches of eggs from these lizards. The smallest reproductively active female was 49 mm snout-vent length (SVL). Oviposition took place from April to July. Clutch sizes ranged from one to two eggs with an average of 1.8. A histological examination of five museum specimens confirmed that females may produce multiple clutches in the same year. We obtained 11 eggs that had an average length, width, and mass of 10.6 mm, 6.1 mm, and 1.8 g, respectively. The average relative clutch mass was 16.7%. Five eggs successfully hatched after an average incubation period of 32.6 days. The hatchlings had an average SVL of 23.8 mm, total length of 51.4 mm, and mass of 0.3 g. © 2012. Gerrut Norval. All Rights Reserved.


van de Waal E.,University of Neuchatel | van de Waal E.,Applied Behavioural Ecology and Ecosystem Research Unit | van de Waal E.,University of St. Andrews | Spinelli M.,University of Neuchatel | And 6 more authors.
International Journal of Primatology | Year: 2013

Mutual grooming plays a central role in the establishment and maintenance of social relationships in primates. Allogrooming has two main functions: hygiene and bonding with partners. The duration of grooming bouts is commonly used in studies of the functional aspects of grooming, but few reflect on the proximate mechanisms that determine grooming bout lengths. As it is highly unlikely that groomer and groomee prefer exactly the same bout length, we are likely to observe the result of some form of negotiation. We currently lack information about the signals that primates employ to inform others about their intentions and desires concerning grooming interactions. From October 2006 until April 2007 we studied three behaviors shown in grooming interactions that could potentially have a signaling function in the negotiation process over the initiation and length of grooming bouts among adult females of two vervet groups freely ranging in the Loskop Dam Nature Reserve, South Africa: approaching another individual as far as that resulted in a grooming session, changing of the body position by the groomed individual, and lip smacking. We found that "approach" did not reliably predict which individual would receive grooming first, although approaching individuals groomed significantly more than those approached. Thus, in the context of grooming interactions, moving toward a group member may signal the willingness to invest. Body part presentations appeared to be the main signal used to demand a prolongation of the grooming by the partner. Finally, lip smacking was used under potentially stressful circumstances, notably shortly before using the mouth to groom the partner or an attempt to touch a mother's infant. Our exploratory study hopefully inspires colleagues to start looking at the role of communication during cooperative interactions for a better appreciation of how animals manage cooperation and negotiate exchange rates. © 2013 Springer Science+Business Media New York.


Price T.,German Primate Center | Price T.,University of Gottingen | Price T.,Applied Behavioural Ecology and Ecosystem Research Unit | Ndiaye O.,Direction de Parc National de Niokolo Koba | And 3 more authors.
Behavioral Ecology and Sociobiology | Year: 2014

The global diversity of human languages is a remarkable feature of our species, which requires a capacity for rapid vocal learning. Given that primate alarm calling systems have played an important role in the language origin debate, identifying geographic variation in primate alarm calls and understanding the underlying causal mechanisms are important steps to help uncover evolutionary precursors to language. This study investigates geographic variation in the alarm bark of the widely distributed African green monkey (Chlorocebus). To quantify geographic variation in spectral and temporal call structure, acoustic analysis was used to compare the adult male barks of green monkeys (Chlorocebus sabaeus) and two subspecies of vervet (Chlorocebus pygerythrus pygerythrus and Chlorocebus pygerythrus hilgerti). Playback experiments were also carried out to test whether adult male vervets would distinguish between the barks of own-group males, unknown conspecific males and green monkey males. Acoustic analysis showed that, whilst similar in overall structure, the barks of green monkeys could be distinguished from vervet barks with a high degree of accuracy; the barks of vervet subspecies could also be discriminated, although to a lesser degree. Males responded most strongly to unknown conspecific males' barks, and exhibited responses typical of leopard-avoidance and territorial defence. Taken together, these findings indicate that variation in alarm calls can be best explained by phylogenetic distance, and that intra- and inter-species differences are relevant during social interactions. Moreover, barks may function as an alarm and display call, which could explain the observed sexual dimorphism in barks in this genus. © 2014 The Author(s).


Karssing R.J.,Ezemvelo KZN Wildlife | Rivers-Moore N.A.,Consulting Freshwater Ecologist | Slater K.,Applied Behavioural Ecology and Ecosystem Research Unit
African Journal of Aquatic Science | Year: 2012

Current literature suggests that little, if any, research has been conducted in South Africa to determine the impact of alien trout on indigenous amphibian biodiversity. The aim of this study was to establish whether waterfalls in the uKhahlamba Drakensberg Park, South Africa, are seasonally important in conserving indigenous Natal cascade frog Hadromophryne natalensis tadpole populations from the threat of predation by alien rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta at Injesuthi and Monk's Cowl Nature Reserves, respectively. Relative abundances of trout and tadpoles of Natal cascade frogs were assessed after sampling using electrofishing. Habitat templates were compared for above- versus below-waterfall sites. Trout predation is the most likely causative agent for an observed abrupt decline in H. natalensis tadpole abundance occurring below waterfalls. Tadpole abundance in the study was reduced by a factor of 4.69 and 15.71 below the selected waterfalls at Injesuthi and Monk's Cowl in association with O. mykiss and S. trutta populations, respectively. © 2012 Copyright NISC (Pty) Ltd.


Van De Waal E.,University of Neuchatel | Van De Waal E.,Applied Behavioural Ecology and Ecosystem Research Unit | Renevey N.,University of Neuchatel | Renevey N.,Applied Behavioural Ecology and Ecosystem Research Unit | And 4 more authors.
Proceedings of the Royal Society B: Biological Sciences | Year: 2010

Human behaviour is often based on social learning, a mechanism that has been documented also in a variety of other vertebrates. However, social learning as a means of problem-solving may be optimal only under specific conditions, and both theoretical work and laboratory experiments highlight the importance of a potential model's identity. Here we present the results from a social learning experiment on six wild vervet monkey groups, where models were either a dominant female or a dominant male. We presented 'artificial fruit' boxes that had doors on opposite, differently coloured ends for access to food. One option was blocked during the demonstration phase, creating consistent demonstrations of one possible solution. Following demonstrations we found a significantly higher participation rate and same-door manipulation in groups with female models compared to groups with male models. These differences appeared to be owing to selective attention of bystanders to female model behaviour rather than owing to female tolerance. Our results demonstrate the favoured role of dominant females as a source for 'directed' social learning in a species with female philopatry. Our findings imply that migration does not necessarily lead to an exchange of socially acquired information within populations, potentially causing highly localized traditions. © 2010 The Royal Society.


Jordaan H.,Applied Behavioural Ecology and Ecosystem Research Unit | Brown L.R.,Applied Behavioural Ecology and Ecosystem Research Unit | Slater K.,Applied Behavioural Ecology and Ecosystem Research Unit
Pachyderm | Year: 2015

The grassland biome of the Free-State Province of South Africa meets all the suggested habitat requirements for the white rhino, but in contrast to wanner savannah areas experiences extremely cold winters. The aim of this study was to investigate the habitat utilization of white rhinos in the Free-State area. Five major plant community types were identified and data on movement and habitat utilization of white rhinos were collected over one year. Adult cows (n = 5) had a mean range size of 3.78 km2 (SE ± 0.37) during the wet and 4.08 km2 (SE ± 0.570) during the dry season, but no significant differences between the two seasons were found. The adult bull had a range size of 8.13 km2 during the wet and 6.37 km2 during the dry season. Based on availability, the expected utilization of each habitat type differed significantly from the observed usage during both the wet (i.e.χ2 = 2,236.6: 6 df; p = 0.05) and dry season (χ2 = 4.721.3; 6 df; p = 0.05). Wetland. Damkom, Savannah, and Grassveld habitats were used significantly less than expected, but the Thomveld and the Trees and Shrub habitats were used significantly more than expected, during both seasons. The River habitat was preferred during the wet but not the dry season. White rhinos were recorded to feed on 33 plant species in varying proportions. The results of this study suggest that in areas that experience hot or cold environments, some form of cover for white rhinos is important. © 2015 International Union for Conservation of Nature and Natural Resources. All rights reserved.

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