Figure 2 - uploaded by John Measey
Content may be subject to copyright.
Time-line and turnover of sector participants in the CAPE Invasive Alien Animals Working Group. Since 2008 there have been 24 meetings, with between one and four meetings a year except for a hiatus in 2016. The number of participants has fluctuated between 8 and 30 people per meeting, and includes 102 unique individuals over time. The relative representation from six main sectors is shown here.
Source publication
Background: The effectiveness of invasive alien species management in South Africa, and elsewhere, can be improved by ensuring there are strong links and feedbacks between science and management. The CAPE Invasive Alien Animals Working Group (CAPE IAAWG) was established in 2008 to enhance cooperation among stakeholders such as implementing agencies...
Contexts in source publication
Context 1
... CAPE IAAWG was established by the CAPE Invasive Alien Species Task Team leader early in 2008. The group meets two to four times a year on average ( Figure 2) for approximately four hours. In parallel, the CAPE Invasive Alien Plants Working Group was established (also in 2008), but that forum was dissolved after a few years due to overlap with other fora such as the Department of Environmental Affairs Working for Water Programme implementation fora. ...
Context 2
... CAPE IAAWG is composed of representatives of (i) national, provincial and local government agencies that have mandates related to invasive alien species control and management; (ii) private sector consultancies that take on contracts for invasive alien species control and management; (iii) tertiary education institutions and science councils that conduct research on alien and invasive animals; and (iv) NGOs with a regulatory or advocacy interest in alien and invasive animals ( Figure 2; Appendix 3). The individual members have a diversity of roles in their home organisations, including local authority and provincial officials, national parks staff and environmental ministry officials, nature conservation scientists, university academic staff, post-doctoral researchers, post-graduate students, NGO staff, animal welfare officers and private consultants. ...
Context 3
... individual members have a diversity of roles in their home organisations, including local authority and provincial officials, national parks staff and environmental ministry officials, nature conservation scientists, university academic staff, post-doctoral researchers, post-graduate students, NGO staff, animal welfare officers and private consultants. The working group has a core of organisational representatives (Fig- ure 2; Appendix 3) and other members are co-opted as and when required to represent specific interests or provide input on a particular subject or taxon. Therefore, the structure at a particular time reflects the workflow of specific projects and any issues being addressed by the working group. ...
Context 4
... this structure also ensures a high level of continuity, with the group developing a common understanding and shared experience. The co-option of additional participants means that the core of member organisations and individuals has grown substantially over the years due to strong interest in the work of the group and the increase in number and complexity of the projects addressed by the group (Figures 2, 3). Permanent members sign the TOR on behalf of their organisations, which commit to implementing the recommendations of the CAPE IAAWG (Appendix 2). ...
Citations
... One way to engage with people and affected communities is through "working groups" or "multi-stakeholder platforms". These have been created and used to manage a range of pest and natural resource management problems, including environmental management problems in Australia (Hajkowicz, 2008), water reforms in Bolivia and South Africa (Faysse, 2006), pest species in South Africa (Davies et al., 2020), and for conservation of pangolins in Singapore (Nash et al., 2020). Common across many of these groups is the desire to link research with policy and management implementation, but there is also a strong need to ensure that stakeholders are engaged and work for co-production of knowledge that is meaningful and accessible to a broad range of stakeholders (Davies et al., 2020). ...
... These have been created and used to manage a range of pest and natural resource management problems, including environmental management problems in Australia (Hajkowicz, 2008), water reforms in Bolivia and South Africa (Faysse, 2006), pest species in South Africa (Davies et al., 2020), and for conservation of pangolins in Singapore (Nash et al., 2020). Common across many of these groups is the desire to link research with policy and management implementation, but there is also a strong need to ensure that stakeholders are engaged and work for co-production of knowledge that is meaningful and accessible to a broad range of stakeholders (Davies et al., 2020). In many cases, the coordination of applied research seems to occur with little input from stakeholders in terms of detailed research questions and rarely includes stakeholder feedback in the process of research. ...
... Faysse (2006) suggests the objective of multi-stakeholder platforms is "To enable the empowered and active participation of stakeholders in the search for solutions to a common problem. " Multi-stakeholder working groups can deal with specific or cross-cutting issues (Davies et al., 2020), however there is often a "knowing-doing gap", thus the need for ongoing engagement with researchers including social scientists to understand how to bridge this gap. ...
... Risk analyses are routinely reviewed by national and international experts as well as working groups at the science-policy-management interface of biological invasions. 75,76 • Legitimate: the development of the regulations is mandated in South African legislation, i.e. NEM:BA. ...
... • Acceptable: measures have been put in place to try to preserve the benefits of alien species while reducing the harmful impacts of invasions. Any regulation of biodiversity is inimical to some ethical perspectives 77 , but a clear distinction should be made between the rationale for regulation and evaluating the ethics of particular management interventions 75 . ...
A key global change challenge is to significantly reduce the risks of alien taxa causing harmful impacts without compromising the rights of citizens. As part of efforts to address this challenge, South Africa promulgated comprehensive regulations and lists of alien taxa in 2014. In this paper, we review how the lists developed, changed over time, and how they have been implemented. As of March 2021, 560 taxa were listed under four broad regulatory categories, and between 2014 and 2020, almost 3000 permits were issued to regulate the continued use of listed taxa. The full lists of regulated taxa, permits issued, and corresponding regulations are available in the Supplementary material. A proposed standardised, transparent, and science-informed process to revise the regulatory lists is also presented – as of 30 April 2024, risk analyses have been developed for 140 taxa using the Risk Analysis for Alien Taxa (RAAT) framework and reviewed by an independent scientific body [the Alien Species Risk Analysis Review Panel (ASRARP)] with input from taxon-specific experts. These recommendations are being considered by an interdepartmental governmental decision-making body established in March 2023 [the Risk Analysis Review Committee (RARC)]. Finally, key issues with the listing of alien taxa in South Africa that remain to be resolved are presented. As South Africa’s regulatory framework continues to develop, the process of listing and regulating alien taxa will, we believe, become more transparent, consistent, and acceptable to stakeholders, and ultimately facilitate efforts to reduce the harmful impacts of alien taxa.
... 128 ponds, see also Vimercati et al. 2017a). As this strategy was implemented in Cape Town without preferentially removing any specific stage (Davies et al. 2020a), we assume, for simplicity, that the proportion of individuals removed across different stages emerges from the interplay between implementers' removal capacity and spatial and temporal occurrence of each stage class in and around the pond. For instance, the proportion of tadpoles that can be removed is expected to be low (0.25), because tadpoles are difficult to detect and capture (e.g. by netting) and they stay in the pond for only 4-5 weeks before metamorphosing. ...
Management strategies for invasive populations should be designed to maximise efficacy and efficiency, i.e. to accomplish their goals while operating with the least resource consumption. This optimisation is often difficult to achieve in stage-structured populations, because costs, benefits and feasibility of removing individuals may vary with stage. We use a spatially-explicit stage-structured model to assess efficacy of past, present and alternative control strategies for invasive guttural toads, Sclerophrys gutturalis , in Cape Town. The strategies involve removal of variable proportions of individuals at different life-history stages and spatial scales. We also quantify the time necessary to implement each strategy as a proxy of financial resources and we correct strategy outcomes by implementation of time to estimate efficiency. We found that the strategy initially pursued in Cape Town, which did not target any specific stage, was less efficient than the present strategy, which prioritises adult removal. The initial strategy was particularly inefficient because it did not reduce the population size despite allocating consistent resources to remove eggs and tadpoles. We also found that such removal might be detrimental when applied at high levels. This counter-intuitive outcome is due to the ‘hydra effect’: an undesired increase in population size caused by removing individuals before overcompensatory density dependence. Strategies that exclusively remove adults ensure much greater management efficiency than those that also remove eggs and tadpoles. Available management resources should rather be allocated to increase the proportion of adult guttural toads that are removed or the spatial extent at which this removal is pursued.
... Due to its recent introduction, this population consists of a core (site of introduction) and continuously expanding range edge (naturally dispersed sites) [17]. Concerns regarding the guttural toad invasions' impact on the endemic, Endangered Sclerophrys pantherina (western leopard toad), have led to considerable control efforts by the City of Cape Town since 2010 [22]. All guttural toad invasive populations have been genetically determined to be from the same population in Durban, South Africa [16]. ...
... Ethics Approval Ethical clearance for research was obtained from Stellenbosch University Animal Ethics Committee (Protocol Number ACU-2019-9533). Collections in Cape Town occurred as part of an ongoing eradication programme of Sclerophrys gutturalis to mitigate impacts on the threatened endemic, the western leopard toad Sclerophrys pantherina (Davies et al. 2020), and in Durban and Mauritius under the permission from KZN wildlife (OP 4353/2018) and the Mauritian National Parks and Conservation Services (NP 46/3 V3), respectively. ...
Studies of laboratory animals demonstrate extensive variation of host gut microbiomes and their functional capabilities across populations, but how does anthropogenic change impact the microbiomes of non-model species? The anthropogenic movement of species to novel environments can drastically alter animals' microbiomes; however, factors that shape invasive species gut microbiota during introduction remain relatively unexplored. Through 16S amplicon sequencing on guttural toad (Sclerophrys gutturalis) faecal samples, we determine that residence time does not impact microbiome variation between source and introduced populations. The youngest population (~ 20 years in Cape Town) has the most distinct microbiome and associated functional capabilities, whereas longer residence times (~ 100 years in Réunion and Mauritius) produce less divergent microbial compositional, phylogenetic, and predicted functional diversity and differential abundance from source populations (Durban). Additionally, we show extensive variation of microbial and functional diversity, as well as differential abundance patterns in an expanding introduced population (Cape Town) between core and periphery sites. Contrasting previous studies, we suggest that introduction pathways might be an important factor impacting host microbial divergence. These findings also imply that the microbiome can diverge in accordance with host population dynamics.
... et al., 2017; Davies et al., 2020). Even for the Asian tiger mosquito (Aedes albopictus), control has been occasionally hampered by access restriction. ...
... The lack of legislation that provides staff powers of access to private lands for IAS control has been proposed as a negative point in some projects (Dana et al., 2019;La Haye, 2019;Davies et al., 2020). Such legislation was adopted in Great Britain and South Africa, but it has not been applied yet in both countries (Crowley et al., 2017;Davies et al., 2020) and therefore its effectiveness is still unknown. ...
... The lack of legislation that provides staff powers of access to private lands for IAS control has been proposed as a negative point in some projects (Dana et al., 2019;La Haye, 2019;Davies et al., 2020). Such legislation was adopted in Great Britain and South Africa, but it has not been applied yet in both countries (Crowley et al., 2017;Davies et al., 2020) and therefore its effectiveness is still unknown. ...
Biological invasions are one of the major drivers of global environmental change and there is a need to develop integrated strategies to counteract this phenomenon. Eradication is an effective management option to mitigate the deleterious impacts of invasive alien species (IAS). Eradication can be achieved if all reproductive individuals are removed and population recovery is prevented. However, individuals may survive removal operations in private areas if interventions are not allowed. Here, we present 1) three case studies in which restricted private property access prevented the local eradication of invasive alien populations, and 2) a list of reasons for denying access to private properties and a list of actions implemented or suggested by managers to facilitate access and reported in 29 reviewed papers. The restricted access affected the local eradication of three Eastern grey squirrel (Sciurus carolinensis) populations in Italy. In Lombardy region, in one area a planned eradication did not start and in another area the implemented eradication failed due to the refusal from the owner of a large private property to grant access to managers. In Umbria region, the lack of collaboration from an Italian financial institution produced a delay of 15 months in the removal. In our case studies, therefore, a single person or institution denied access for a personal gain or presumed internal security. The reasons behind landowner opposition may be diverse and individual attitudes towards IAS management will depend on interactions with owners. According to our review, in many cases the denial of access takes place in a general perception of mistrust or opposition to the project as the results of a limited engagement of local people. Such opposition often jeopardizes control activities, with profound negative consequences on eradication, expecially at landscape scale. Bottom-up approaches aiming at involving stakeholders can increase the possibility to achieve IAS eradication, however appropriate legislation remains pivotal to enforce eradication in case of non-cooperative behaviour.
... s. l.], respectively), from two urban sites in and near Durban (hereafter referred to as "Durban Urban": 29°50'55"S, 31°00'30"E and 29°49'08"S, 30°56'37"E with 24 m and 194 m elevation a. s. l., respectively). Toads from the extra-limital range in Constantia near Cape Town (hereafter referred to as "Cape Town": 34°01'29"S, 18°26'03"E with 50-100 m elevation a. s. l.) were collected as part of an invasive species control operation (Davies et al. 2020a(Davies et al. , 2020b. We chose the Durban Urban sites because they show similar habitat characteristics as the Cape Town sites, like high relative proportion of impervious surface area, well-established human populations, high numbers of buildings and roads, and the bodies of water within those urban sampling sites were either anthropogenically altered or created (e.g., fish ponds, fountains, or ditches) with heavily modified shorelines (Fig. 1D, E) and frequently contained ornamental fish species. ...
Cities are focal points of introduction for invasive species. Urban evolution might facilitate the success of invasive species in recipient urban habitats. Here we test this hypothesis by rearing tadpoles of a successful amphibian urban coloniser and invader in a common garden environment. We compared growth rate, morphological traits, swimming performance, and developmental rate of guttural toad tadpoles (Sclerophrys gutturalis) from native rural, native urban, and non-native urban habitats. By measuring these traits across ontogeny, we were also able to compare divergence across different origins as the tadpoles develop. The tadpoles of non-native urban origin showed significantly slower developmental rate (e.g., the proportion of tadpoles reaching Gosner stage 31 or higher was lower at age 40 days) than tadpoles of native urban origin. Yet, tadpoles did not differ in growth rate or any morphological or performance trait examined, and none of these traits showed divergent ontogenetic changes between tadpoles of different origin. These findings suggest that prior adaptation to urban habitats in larval traits likely does not play an important role in facilitating the invasion success of guttural toads into other urban habitats. Instead, we suggest that evolutionary changes in larval traits after colonization (e.g., developmental rate), together with decoupling of other traits and phenotypic plasticity might explain how this species succeeded in colonising extra-limital urban habitats.
... However, the interaction between response to stress and functions modulated by this response, such as immunocompetence, has not yet been explored in this invasive population of the guttural toad. Despite an eradication program, the species is still spreading across the invaded area, in a small peri-urban area of Cape Town Davies et al., 2020). Therefore, it is important to study the adjustments in the physiological characteristics and life history of invasive guttural toads, in order to predict its potential for propagation within Cape Town. ...
Species introduced by human activities can alter the normal functioning of ecosystems promoting negative impacts on native biodiversity, as they can rapidly expand their population size, demonstrating phenotypic plasticity and possible adaptive capacity to novel environments. Twenty years ago, the guttural toad, Sclerophrys gutturalis, was introduced to a peri-urban area of Cape Town, with cooler and drier climatic characteristics than its native source population, Durban, South Africa. Our goal was to understand the phenotypic changes, in terms of physiology and immunity, of populations in native and novel environments. We evaluated body index (BI), field hydration level, plasma corticosterone levels (CORT), proportion of neutrophils: lymphocytes (N: L), plasma bacterial killing ability (BKA), and hematocrit (HTC) in the field, and after standardized stressors (dehydration and movement restriction) in males from the native and invasive populations. Toads from the invasive population presented lower BI and tended to show a lower field hydration state, which is consistent with living in the drier environmental conditions of Cape Town. Additionally, invasive toads also showed higher BKA and N:L ratio under field conditions. After exposure to stressors, invasive animals presented higher BKA than the natives. Individuals from both populations showed increased CORT after dehydration, an intense stressor for these animals. The highest BKA and N:L ratio in the field and after submission to stressors in the laboratory shows that the invasive population has a phenotype that might increase their fitness, leading to adaptive responses in the novel environment and, thus, favoring successful dispersion and population increase.
... However, this was not an option in the South African case due to budgetary and time constraints. Increasingly, risk analyses are discussed at appropriate national working groups before submission to ASRARP [e.g., national working groups on alien Cactaceae, alien grasses, and a working group on alien animals in the Cape Floristic Region (Kaplan et al. 2017;Visser et al. 2017;Davies et al. 2020)]. The intention is that the risk analyses, once approved, represent both the best available scientific evidence and are also a consensus of those working on the species. ...
Human livelihoods and well-being in almost all regions of the world depend on taxa which are alien. Such taxa also, however, threaten human health, sustainable development, and biodiversity. Since it is not feasible or desirable to control all alien taxa, decision-makers increasingly rely on risk analyses to formalise the best available evidence of the threats posed and whether and how they can be managed. There are a variety of schemes available that consider the risks of alien taxa, but we argue a new framework is needed: 1) given major recent developments in international frameworks dealing with biological invasions (including the scoring of impacts); 2) so that decisions can be made consistently across taxa, regions and realms; 3) to explicitly set out uncertainties; and 4) to provide decision-makers with information both on the risks posed and on what can be done to mitigate or prevent impacts. Any such scheme must also be flexible enough to deal with constraints in capacity and information. Here we present a framework to address these points – the Risk Analysis for Alien Taxa (RAAT). It outlines a series of questions related to an alien taxon’s likelihood of invasion, realised and potential impacts, and options for management. The framework provides a structure for collating relevant data from the published literature to support a robust, transparent process to list alien taxa under legislative and regulatory requirements, with the aim that it can be completed by a trained science graduate within a few days. The framework also provides a defensible process for developing recommendations for the management of assessed taxa. We trialled the framework in South Africa and outline the process followed and some of the taxa assessed to date.
Gut microbial communities regulate host physiology and health of humans and laboratory animals. The functional significance of these collective bacterial genomes (i.e. the microbiome) to the adaptive potential of wildlife hosts is still unknown. Studies demonstrating convincing examples of microbial flexibility to environmental change so far lack the experimental approaches to demonstrate the effect on host physiology. Invasive species provide natural experiments to tease apart these host-microbe relationships. However, no studies have investigated how microbial symbionts might mediate responses of invasive hosts’ physiology to environmental change. In this study, we examine whether invasive gut microbiomes have significantly diverged in their ability to respond to novel environmental change (i.e. a dietary challenge) compared to native gut microbiomes by performing reciprocal faecal microbial transplant (FMT) experiments in native and invasive guttural toad (Sclerophrys gutturalis) populations. Subsequently, we determine how the microbiome regulates host physiological changes in response to a dietary challenge. We show that invasive gut microbiomes exhibit higher microbial compositional and predicted functional flexibility to novel dietary change, compared to native gut microbiomes. This increased microbial flexibility is coupled with significant flexibility in energy harvesting. Furthermore, our results indicate that overall invasive gut microbiomes significantly upregulate energy harvesting and physiological performance of hosts, compared to native microbiomes. Our study is the first identifying gut microbiota as the sole factor contributing to the adaptive physiology of a vertebrate using a unique study design. These findings provide novel insights into the key role of gut microbial symbionts in increasing the invasive potential of its vertebrate host.
