Measey J
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- ItemAfter the fire: assessing the microhabitat of Capensibufo rosei (Hewitt, 1926)(2021) Measey, J.; Becker, F.; Tolley, K.A.Rose’s dwarf mountain toadlet, Capensibufo rosei (Hewitt, 1926), is endemic to fire-dependent, montane fynbos vegetation on South Africa’s Cape Peninsula. The area undergoes natural fire cycles that are disrupted due to increasing urban pressure from the City of Cape Town. In this natural history observation, we report on C. rosei microhabitats used and their distribution immediately after a wildfire that swept through the area in March 2015. We found that a substantial number of adult toadlets had survived the fire, and that they were located within 160 m of a known breeding site. Animals were consistently found inside burrows, presumed to have been excavated by small rodents. Our observations have important consequences on the conservation of this IUCN Critically Endangered species, especially with relation to compaction of areas in the immediate vicinity of breeding sites. We emphasise the importance of making natural history observations following extreme events, such as fire, to provide important insights into conservation of cryptic threatened species.
- ItemAnnual variation of ovarian structures of Boulengerula taitana (Loveridge 1935), a Kenyan caecilian(Herpetological Association of Africa, 2015) Raquet, M.A.; Measey, G.J.; Exbrayat, J.M.The Kenyan caecilian, Boulengerula taitanus inhabits a climate characterised by two distinct dry and wet seasons, and a single thermal minimum in June. It is oviparous with direct development and a remarkable dermatophagous maternal care, but the female reproductive cycle until now remains unknown. The purpose of this work was to complete the knowledge about the reproductive modes of this species, using anatomical and histological studies of the ovaries. Quantitative variations of follicle categories showed a continuous folliculogenesis. Yet, young corpora lutea were only detected between November and February during the short rain season and the short dry season, indicating ovulation occurred during these four months during the thermal maximum. Oestrogen and progesterone detection allowed determination of three reproductive periods during the year: preparation in September and October, ovulation from November until February and quiescence from March until August. So, the female reproductive cycle of B. taitanus appears to be annual and synchronised with testicular evolution. Because the ovulation was observed following the second peak of follicle production (beginning of June), temperature is supposed to be the main regulating factor of reproductive pattern in this caecilian.
- ItemAssessing the effects of climate change on distributions of Cape Floristic Region amphibians(Academy of Science of South Africa, 2015) Mokhatla, M.M.; Rodder, D.; Measey, G.J.Climatic changes have had profound impacts on species distributions throughout time. In response, species have shifted ranges, adapted genetically and behaviourally or become extinct. Using species distribution models, we examined how changes in suitable climatic space could affect the distributions of 37 endemic frog species in the Cape Floristic Region (CFR) – an area proposed to have evolved its megadiversity under a stable climate, which is expected to change substantially in future. Species distributions were projected onto mean climate for a current period (1950 to 2000), hindcasted to palaeoclimate (Last Glacial Maximum; LGM ≈ 21 kya and Holocene Glacial Minimum; HGM ≈ 6 kya) and forecasted for two emissions scenarios (A2a and B2a) for the year 2080. We then determined the changes in area sizes, direction (longitude and latitude), fragmentation index and biotic velocity, and assessed if these were affected by life-history traits and altitude. We found that the biotic velocity at which the CFR amphibian community is expected to shift north (A2a ≈ 540.5 km/kya) and east (B2a ≈ 198 km/kya) far exceeds historical background rates (≈1.05 km/kya, north and west ≈ 2.36 km/kya since the LGM). Our models further suggest that the CFR amphibian community has already lost about 56% of suitable climate space since the LGM and this loss is expected to accelerate under future emission scenarios (A2a ≈ 70%; B2a ≈ 60%). Lastly, we found that highland species were more fragmented than lowland species between the LGM and current period, but that the fragmentation of lowland species between current and future climates is expected to increase.
- ItemAssessing water conditions for Heleophryne rosei tadpoles and the conservation relevance(2020) Ebrahim, Z.; de Villiers, A.; Measey, J.The Table Mountain Ghost Frog (Heleophryne rosei) is endemic to the Table Mountain massif and is Critically Endangered. Other than clear, clean perennial stream flow, the optimal aquatic conditions required by their larvae are unknown. Dissolved oxygen, temperature, pH, electro-conductivity, aspect and permanence of flow are the independent variables measured seasonally at two sampling altitudes at 12 rivers of the massif. Using a logistic regression model we found that a permanence of water flow and lower water temperature were significant predictors of tadpole presence. Streams with mean summer temperature above 17.2 °C, at 300 m – 400 m above sea level, do not have tadpoles. Summer and autumn abstraction should be avoided, while a summer water temperature above an average of 17.2 °C is a threshold of potential concern for management authorities responsible for biodiversity conservation, threat mitigation efforts, and bulk-water supply and abstraction. Conservation implications: The Environmental Water Reserve has not been determined for streams of Table Mountain. The requirements of the Critically Endangered Table Mountain Ghost Frog (Heleophryne rosei) can be adopted as the minimum conditions to support this species and associated communities. Perennial flow, an average January water temperature of 17.2 °C or lower.
- ItemCannibalism or congeneric predation? The African clawed frog, Xenopus laevis(Daudin), preferentially predates on larvae of Cape platannas, Xenopus gilli Rose & Hewitt(John Wiley & Sons Ltd, 2019) Thorp, C.J.; Vonesh, J.R.; Measey, J.Predators are not limited to prey from other species as they can cannibalise vulnerable individuals within their own population. The African clawed frog, Xenopus laevis (Daudin), is a predator with a broad diet, known to consume multiple prey species, including congeners and conspecifics. African clawed frogs occur in sympatry with the Endangered Cape platanna, Xenopus gilli Rose & Hewitt, which are under threat through competition and predation from X. laevis. We investigated the threat of X. laevis predation on X. gilli using choice and no‐choice experiments to evaluate the relative vulnerability of X. laevis and X. gilli larvae. Results showed that large X. gilli larvae had a significantly higher vulnerability to X. laevis predation compared to small X. gilli larvae. However, the same discrimination was not discerned when offered large and small X. laevis larvae, or mixed larvae of the same size. We report ontogenic shifts in behaviour of X. gilli larvae that may be a factor in contributing to the vulnerability of large X. gilli larvae to adult X. leavis predation. Congeneric predation likely has negative implications for the population structure of the Endangered X. gilli. Our study underlines the call for the removal of X. laevis to conserve populations of X. gilli.
- ItemChallenges of a novel range: water balance, stress, and immunity in an invasive toad(2021) Barsotti, A.M.G.; Madelaire, C.B.; Wagener, C.; Titon Jr, B.; Measey, J.; Gomesa, F.R.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.
- ItemChallenges of dehydration result in a behavioral shift in invasive toads(2020) Madelaire, C.B.; Barsotti, A.M.G.; Wagener, C.; Sugano, Y.Y.V.; Baxter-Gilbert, J.; Gomes, F.R.; Measey, J.The adaptive nature of invasive species facilitates their survival in conditions that differ markedly from their native range. Behavioral changes in invasive populations are poorly explored but offer a wide potential when combined with physiological traits. For amphibians invading xeric habitats, finding water is important to function optimally and avoid dehydration. The water-finding hypothesis postulates that survival can be enhanced through the increased behavioral ability to find water. We tested the water-finding hypothesis in guttural toads (Sclerophrys gutturalis) from their native range and an invasive population. Additionally, we tested if artificially elevated corticosterone levels, which increase during dehydration, affect behavioral traits linked to water balance. In a labyrinth experiment, we observed the toads’ ability to find water in different hydration states (100%, 90%, and 80%). We found that individuals from the invasive population took longer to engage in water-searching behavior and spent more time close to the water source after finding it. Toads from the invasive population were also more active, and at 90% hydration, their attempts to find water increased. Moreover, artificially increasing corticosterone in fully hydrated invasive toads increased water-finding success. Our experiments demonstrated that invasive toads show water-conservation behaviors that can optimize water balance and might facilitate survival in an invaded xeric environment. Additionally, we suggest a link between elevated corticosterone levels and water-finding success. Our results lend support to the importance of behavior in successful invasions and the modulation of water-finding behavior by corticosterone.
- ItemControlling the African clawed frog Xenopus laevis to conserve the Cape platanna Xenopus gilli in South Africa(2016) de Villiers, F.A.; de Kock, M.; Measey, G.J.A five year control programme of the African clawed frog Xenopus laevis resulted in improved population demographics in the Cape platanna Xenopus gilli in comparison to a population without removal.
- ItemThe cost and complexity of assessing impact(2020) Measey, J.; Wagener, C.; Mohanty, N.P.; Baxter-Gilbert, J.; Pienaar, E.F.The environmental and socio-economic impacts of invasive species have long been recognised to be unequal, with some species being benign while others are disastrous. Until recently there was no recognised standard impact scoring framework with which to compare impacts of species from very different taxa. The advent of the Environmental Impact Classification for Alien Taxa (EICAT) and Socio‐Economic Impact Classification of Alien Taxa (SEICAT) schemes allows for the possibility of assessing impact through a standard approach. However, both these schemes are still in their infancy and the associated costs of the research that informs them is unknown. We aimed to determine the study costs and complexity associated with assessing invasive species’ socio-economic and environmental impacts. We used amphibians as a model group to investigate papers from which EICAT and SEICAT scores could be drawn up to 2019. Our analysis shows that studies that resulted in higher impact scores were more costly. Furthermore, the costs of studies were best predicted by their complexity and the time taken to complete them. If impact scores from EICAT and SEICAT are allowed to inform policy, then we need to carefully consider whether species with low scores represent true impact, or require more research investment and time. Policy makers needing accurate assessments will need to finance larger, more complex, and rigorous studies. Assessing impacts in low and middle income countries may need investment using international research collaborations and capacity building with scientists from high income areas.
- ItemDietary observations of four southern African agamid lizards (Agamidae)(2020) Tan, Wei Cheng; Herrel, Anthony; Measey, JohnAnalysis of stomach contents can provide insights into foraging mode, habitat use, and dietary specialization of animals. In this paper, we make observations on the poorly known diet of four southern African agamid species, Agama aculeata distanti (Eastern Ground Agama), Agama armata (Peter’s Ground Agama), Agama atra (Southern Rock Agama), and Acanthocercus atricollis (Southern Tree Agama). We examined the diet of 67 individuals by identifying and weighing prey items after stomach flushing lizards in the field. We found that these agama species fed on a broad spectrum of arthropods (11 orders). A high relative importance of ants was present for all agama species examined here, which suggests that ants are a major food source in the arid ecosystem. We found that active prey such as ants, beetles, and highly mobile flying insects like wasps and flies to be major components of the diet, indicating that these lizards are ambush predators. We also found that 43% of the stomachs contained herbaceous material and 39% contained sand particles. Agama atra had the most diverse dietary niche, eating fewer ants and more beetles, hemipterans, and dipterans than other species, whereas A. armata had a narrower dietary niche consisting mainly of ants. Lastly, although low in sample size, we found that juveniles qualitatively had a diet of functionally similar prey items, albeit with a narrower niche breadth, when compared to adults. We discuss how diet corresponds with differences in foraging behavior and habitat specialization.
- ItemDoes restricted access limit management of invasive urban frogs?(Springer, 2017) Vimercati, G.; Davies, S.J.; Hui, C.; Measey, J.Management recommendations that target urban invaders should consider environmental and socio-economic aspects peculiar to the urban landscape. Urbanization often leads to the fragmentation of the invaded landscape into subunits inaccessible to managers (restricted access) or for which detailed information is lacking. Using models to explore impact of these limitations on management success provides a useful approach to propose effective counter measures. Here we deploy a spatially explicit age-structured model applied to a pond network to investigate how restricted access and lack of detailed information may affect management of three invasive anuran species across a peri-urban landscape. The target species, the guttural toad Sclerophrys gutturalis, the African clawed frog Xenopus laevis and the painted reed frog Hyperolius marmoratus, belong to different ecotypes (terrestrial, aquatic and arboreal, respectively) and have different life history traits. We show that restricted property access significantly constrains management success in two of the three species (the guttural toad and the painted reed frog), while lack of detailed information around the invaded landscape impedes successful management in only one species (the guttural toad). The species-dependent response we detected is due to contrasting demographic and spatial invasion dynamics linked to the different anuran ecotypes. Our work highlights the necessity to adopt a context-dependent approach when proposing management recommendations in urban environment.
- ItemAn established population of African clawed frogs, Xenopus laevis (Daudin, 1802), in mainland China.(Creative Commons Attribution License (CC BY 4.0), 2019) Wang, S.; Hong, Y.; Measey, J.Reports of amphibian invasions are increasing, although it seems likely that there are more extant populations of alien species than we are currently aware of, and we are far from understanding their full environmental and economic impact. Here we provide data on another established population of African clawed frogs, Xenopus laevis (Daudin, 1802); from Yunnan Province in mainland China. The site is an aquaculture area immediately adjacent to the northern shores of Lake Kunming. This report is significant as it is the first known alien population of an albino form of this species, the form that is most prevalent in the pet trade. We call for urgent surveys using eDNA to determine the extent of the invasion of this cryptic amphibian invader around Lake Kunming, as well as studies to determine the environmental and economic impacts at this site, which is already known for an invasion of American bullfrogs, Lithobates catesbeianus (Shaw, 1802).
- ItemFunctional divergence between morphs of a dwarf chameleon: differentiaol locomotor kinematics in relation to habitat structure(The Linnean Society of London, 2015) Higham, T.E.; Measey, G.J.; Birn-Jeffery, A.V.; Herrel, A.; Tolley, K.A.Arboreal lizards are extremely effective at moving in structurally complex habitats, including surfaces of varying diameter and incline. Chameleons exemplify this by exhibiting a number of morphological specializations for moving in these habitats, including the use of prehensile feet and tail to grasp branches. Despite their unique morphology and behaviour, little is known about how locomotor movements vary between species. In addition, some species, such as the Cape Dwarf Chameleon, Bradypodion pumilum, consist of two morphs that differ in ecology, morphology, and behaviour. The two morphs can be found in either closed canopy woodland habitat or relatively open fynbos habitat. The morph that occupies the woodland habitat tends to be larger and utilizes larger diameter perches. Although their ecological and morphological divergence is established, whether this translates into differences in three-dimensional kinematics of locomotion is not known. Given the potentially strong selective pressures from structurally different habitats, kinematic differences might reveal the functional basis of incipient speciation. We determined that the two morphs diverge significantly in multidimensional kinematic space, and that this occurs for the forelimb and hindlimb independently. These differences outweigh the effects of substrate within each morph, although the differences between morphs were more pronounced on the vertical treatments.
- ItemFunctional responses can’t unify invasion ecology(Springer, 2017) Vonesh, J.; McCoy, M.; Altwegg, R.; Landi, P.; Measey, J.Dick et al. (Biol Invasions, 2017) propose that the comparative functional response framework provides a unifying approach for the study of invasive species. We agree that functional responses are an important and powerful quantitative description of consumer effects on resources, and co-opting classical ecological theory to better predict invasive species impacts is a laudable move for invasion biology. However, we fear that the early successes of select examples of the comparative functional response (CFR) approach has led Dick et al. to exaggerate the generality of its utility, and about its ability to unify the field. Further, they fail to provide a convincing argument why CFR is better than existing tools such as invasion history or impact indices, even when considering emerging or potential invaders. In this response we provide details of three conceptual issues stemming from classical ecological theoretical frameworks and two practical problems that Dick et al. and other CFR proponents need to address.
- ItemGenetic diversity and differentiation of the Western Leopard Toad (Sclerophrys pantherina) based on mitochondrial and microsatellite markers(Taylor & Francis, 2017) da Silva, J.M.; Feldheim, K.A.; Measey, G.J.; Doucette-Riise, S.; Daniels, R.J.; Chauke, L.F.; Tolley, K.A.Intraspecific genetic diversity provides the basis for evolutionary change and is therefore considered the most fundamental level of biodiversity. Mitochondrial DNA (mtDNA) and microsatellite loci are the markers most typically used in population-level studies; however, their patterns of genetic variation are not always congruent. This can result in different interpretations of the data, which can impact on management decisions, especially for threatened species. Consequently, in this study, we developed and analysed novel microsatellite markers for the Endangered Western Leopard Toad (WLT), Sclerophrys pantherina, and compared the results to previously published mtDNA data to compare the level of genetic diversity between the two molecular markers. The microsatellite evidence showed signs of a past bottleneck, yet relatively high levels of genetic diversity and low genetic differentiation between two sampling sites. In contrast, the mtDNA revealed moderate to low levels of diversity between sampling sites, and strong genetic differentiation. An explanation for the conflicting patterns may be that the current genetic signature, as depicted by the microsatellite data, is not yet reflected in the mitochondrial dataset; and, as such the data are depicting a timeline for genetic variation within the WLT. Both markers revealed important information about the two sampling sites, which can help inform conservation management of the species.
- ItemA global meta-analysis of the ecological impacts of alien species on native amphibians(The Royal Society Publishing, 2019) Nunes, A.L.; Fill, J.M.; Davies, S.J.; Louw, M.; Rebelo, A.D.; Thorp, C.J.; Vimercati, G.; Measey, J.The exponential increase in species introductions during the Anthropocene has brought about a major loss of biodiversity. Amphibians have suffered large declines, with more than 16% considered to be threatened by invasive species. We conducted a global meta-analysis of the impacts of alien species on native amphibians to determine which aspects of amphibian ecology are most affected by plant, invertebrate, fish, amphibian, reptile, or mammal introductions. Measures of fitness were most strongly affected; amphibian performance was consistently lower in the presence of alien species. While exposure to alien species caused a significant decrease in amphibian behavioural activity when compared with a no species control, this response was stronger towards a control of native impacting species. This indicates a high degree of prey naivete´ towards alien species and highlights the importance of using different types of controls in empirical studies. Alien invertebrates had the greatest overall impact on amphibians. This study sets a new agenda for research on biological invasions, highlighting the lack of studies investigating the impacts of alien species on amphibian terrestrial life-history stages. It also emphasizes the strong ecological impacts that alien species have on amphibian fitness and suggests that future introductions or global spread of alien invertebrates could strongly exacerbate current amphibian declines.
- ItemHabitat characteristics influence the breeding of Rose’s dwarf mountain toadlet Capensibufo rosei (Anura: Bufonidae)(British Herpetological Society, 2017) Edwards, S.; Tolley, K.A.; Measey, G.J.Direct anthropogenic factors (e.g., habitat loss, fragmentation, and degradation) threaten many amphibian populations, however some declines have occurred in supposedly pristine environments with no obvious causes. These enigmatic declines may be due to shifts in environmental factors influencing development and ultimately adult survival. Rose’s mountain toadlet Capensibufo rosei has undergone such an enigmatic decline, with several populations presumed to be locally extinct at historic breeding sites. The two remaining breeding sites (Silvermine (SILV) and Cape of Good Hope (CGH)) on the Cape Peninsula of South Africa were monitored for three years (2012-2014) for life history traits and ecological requirements. Males congregate at ephemeral pools during the middle of the austral winter, with females arriving to lay eggs and then immediately leaving. Breeding only occurs in a few of the available pools. We hypothesised that larval development in colder, deeper pools would result in smaller-bodied tadpoles, and ultimately in relatively smaller adults. Pools at SILV were significantly deeper and colder compared to CGH, with breeding occurring in pools that were 27.05±10.21 mm and 21.55±6.95 mm deep at SILV and CGH, respectively. Contrary to expectations, breeding adults and developing tadpoles at SILV were larger than CGH individuals. The percentage of non-developing eggs at CGH was high compared to SILV and other anuran species. Development within this threatened species may be influenced by pool characteristics, which could provide clues as to the factors that influenced local extinctions in historical populations.
- ItemHow repeatable is the Environmental Impact Classification of Alien Taxa (EICAT)? Comparing independent global impact assessments of amphibians(John Wiley & Sons Ltd., 2017) Kumschick, S.; Measey, G.J.; Vimercati, G.; de Villiers, F.A.; Mokhatla, M.M.; Davies, S.J.; Thorp, C.J.; Rebelo, A.D.; Blackburn, T.M.; Kraus, F.The magnitude of impacts some alien species cause to native environments makes them targets for regulation and management. However, which species to target is not always clear, and comparisons of a wide variety of impacts are necessary. Impact scoring systems can aid management prioritization of alien species. For such tools to be objective, they need to be robust to assessor bias. Here, we assess the newly proposed Environmental Impact Classification for Alien Taxa (EICAT) used for amphibians and test how outcomes differ between assessors. Two independent assessments were made by Kraus (Annual Review of Ecology Evolution and Systematics, 46, 2015, 75-97) and Kumschick et al. (Neobiota, 33, 2017, 53-66), including independent literature searches for impact records. Most of the differences between these two classifications can be attributed to different literature search strategies used with only one-third of the combined number of references shared between both studies. For the commonly assessed species, the classification of maximum impacts for most species is similar between assessors, but there are differences in the more detailed assessments. We clarify one specific issue resulting from different interpretations of EICAT, namely the practical interpretation and assigning of disease impacts in the absence of direct evidence of transmission from alien to native species. The differences between assessments outlined here cannot be attributed to features of the scheme. Reporting bias should be avoided by assessing all alien species rather than only the seemingly high-impacting ones, which also improves the utility of the data for management and prioritization for future research. Furthermore, assessments of the same taxon by various assessors and a structured review process for assessments, as proposed by Hawkins et al. (Diversity and Distributions, 21, 2015, 1360), can ensure that biases can be avoided and all important literature is included.
- ItemImplications of summer breeding frogs from Langebaanweg, South Africa: Regional climate evolution at 5.1 mya(Academy of Science of South Africa, 2016) Matthews, T.; Measey, G.J.; Roberts, D.L.No direct palaeoclimatic proxies have been available to indicate the seasonality or amount of rainfall on the west coast of southern Africa during the Early Pliocene. The Benguela Upwelling System (BUS) is today one of the factors responsible for the present-day aridity on the west coast of southern Africa. The initiation of the BUS is frequently linked to the entrenchment of aridity and the establishment of the current winter rainfall pattern on the west coast; however, marine proxies are inconclusive regarding the effects of past fluctuations in the BUS and sea surface temperatures on the rainfall regime. Neither the fossil evidence nor the fact that plants using the C3 photosynthetic pathway predominate at this time, provide direct evidence of winter rainfall at Langebaanweg. We challenge certain assumptions which are commonly made in the literature regarding the timing of inception of a winter rainfall regime on the west coast and the onset of aridity in the Langebaan region, and provide new evidence as to seasonality of rainfall at Langebaanweg in the Early Pliocene. Herein, the identification of frog species from the genus Ptychadena from Langebaanweg provides new and compelling evidence for a summer rainfall regime, or of at least significant summer rainfall, at 5.1 mya in the southwestern Cape of South Africa. Significance: • Advances understanding of the evolution of the winter rainfall zone on the west coast of South Africa • Assesses evidence for the inception of aridity and a winter rainfall regime on the west coast of South Africa • Fossil Ptychadenidae from the Early Pliocene site of Langebaanweg provide evidence for a summer rainfall regime at 5.1 mya on the west coast of the southwestern Cape.
- ItemIntegrating age structured and landscape resistance models to disentangle invasion dynamics of a pond-breeding anuran(Elsevier B.V., 2017) Vimercati, G.; Hui, C.; Davies, S.J.; Measey, G.J.Modelling population dynamics of invasive species may help to propose effective management countermeasures. Invasion dynamics generally show recursive patterns across species and regions, where initial lag is followed by spread and eventual dominance phases. However, timing and modes of these phases are highly variable, emerging from the interplay between traits of the invader and characteristics of the invaded landscape. Disentangling this interplay is particularly arduous in species with complex life-histories, where an individual passes through different life stages that alter physiology, behaviour and interactions with the environment. Here, we describe an age structured model that can be utilized to simulate population dynamics of invasive pond-breeding anurans. The model follows a spatially structured population approach, each pond representing a discrete habitat patch that exchanges individuals with other similar patches, and simulates change in survival and dispersal behaviour as a function of age.It also integrates dispersal with landscape complexity through landscape resistance modelling to depict functional connectivity across the pond network. Then we apply the model to a case study, the invasion of the guttural toad Sclerophrys gutturalis in Cape Town, first detected in 2000. Age-structured demographic and spatial dynamics of the focal population are reconstructed in a network of 415 ponds embedded in a heterogeneous landscape. Parameterization is conducted through field and laboratory surveys, a liter-ature review and data collected during an ongoing extirpation from 2010. We use the model to explore:i) occurrence and duration of lag phase; ii) whether the spatial spread fits an accelerating or a lineartrend; iii) how simulated dynamics match field observations. Additionally we test model sensitivity to demographic and behavioural traits. We found a lag phase in both demographic and spatial dynamics;however the lag duration of these dynamics does not coincide, where invaders start to spread across thepond network five years before the demographic explosion. Also, we found that the spatial spread fits an accelerating trend that causes complete invasion of the network in six years. Such dynamics noticeably match field observations and confirmed patterns previously detected in other invaders characterized by high dispersal abilities. Sensitivity analysis suggests that it would have been preferable to quantify initial propagule size and post-metamorphic survival in the field; both timing and modes of invasion are par-ticularly sensitive to these parameters. We conclude that the model has potential to forecast amphibian invasion dynamics and test management countermeasures.