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In melissopalynological studies, the investigation of pollen composition in honey samples reveals the geographical and botanical origin of the samples and links them to the regional climatic conditions. Honeybees (Apis mellifera), collect pollen and nectar for their nutritional requirements based on the seasonal availability of surrounding flora. In this study, pollen content in honey was temporarily investigated for seasonal differences of the bee foraged plants. A melissopalynological investigation was applied to honey samples harvested from 13 beehives located in the Greater Kruger National Park, South Africa. Multivariate statistics (NMDS and Rarefaction curves) were used to show spatial and temporal clustering of the samples. The melissopalynological data were then compared to the species’ flowering season and a botanical survey of the surrounding area. The turnover in pollen composition for different seasons signifies seasonal variation in pollen types. For example, during summer, bees foraged from fewer floral sources. The highest species richness was observed during winter, suggesting a higher dependence on a diversity of floral resources during the driest months. Various seasonal pollen spectra were characterised by a pollen turnover from numerous species, including Combretum type, Sclerocarya birrea, Poaceae, Harpephyllum caffrum and Lannea schweinfurthii but also neophytes such as Medicago sativa. Therefore, honey samples from the Lowveld region in South Africa reflected the seasonal patterns of the surrounding flora although pollen from taxa such as Combretum spp. (average 56%) and Sclerocarya birrea (average 14%) were continuously sought after by bees throughout the year.

1. We review progress in our understanding of the importance of waterbirds as dispersal vectors of other organisms, and identify priorities for further research. 2. Waterbirds are excellent for long-distance dispersal (LDD), whereas other vectors such as fish and mammals disperse similar propagules, but over shorter distances. Empirical studies of internal and external transport by waterbirds have shown that the former mechanism generally is more important. Internal transport is widely recognised for aquatic plants and aquatic invertebrates with resting eggs, but also is important for other organisms (e.g., terrestrial flowering plants not dispersed by frugivores, bryophytes, tardigrades, fish eggs). 3. Waterbird vectors also are important in terrestrial habitats, and provide connectivity across terrestrial–aquatic boundaries. There are important differences in the roles of different waterbird species, especially those using different habitats along the aquatic–terrestrial gradient. Early attempts to predict zoochory based on propagule morphology have been found wanting, and more research is needed into how the traits of vectors and vectored organisms (including life history, dormancy and growth traits) explain dispersal interactions. Experimental studies have focused on the potential of propagules to survive internal or external transport, and research into factors determining the establishment success of propagules after dispersal is lacking. 4. Recent spatially explicit models of seed dispersal by waterbirds should be expanded to include invertebrate dispersal, and to compare multiple bird species in the same landscape. Network approaches have been applied to plant–waterbird dispersal interactions, and these are needed for invertebrates. Genetic studies support effective LDD of plants and invertebrates along waterbird flyways, but there remains a lack of examples at a local scale. Next Generation Sequencing and genomics should be applied to waterbird-mediated dispersal across the landscape. More studies of biogeography, community ecology, or population genetics should integrate waterbird movements at the design stage. 5. Zoochory research has paid little attention to the dispersal of non-pathogenic microbes (both eukaryotic and prokaryotic). Nevertheless, there is evidence that dispersal via avian guts can be central to the connectivity of aquatic microbial metacommunities. More work on microbial dispersal by waterbirds should explore its implications for biogeochemistry, and the interchange with gut flora of other aquatic organisms. In the Anthropocene, the role of migratory waterbirds in LDD of plants and other organisms is particularly important, for example in compensating for loss of large migratory mammals and fish, allowing native species to adjust their distributions under global warming, and spreading alien species along flyways after their initial introductions by human vectors. Recent technological advances have opened exciting opportunities that should be fully exploited to further our understanding of dispersal by waterbirds. AJG was supported by projects from the Ministerio de Ciencia e Innovación (PID2020-112774GB-I00/AEI/10.13039/501100011033) and Ministerio de Economía y Competitividad (CGL2016-76067-P). ESG received the grant RYC2019-027216-I funded by MCIN/AEI/10.13039/501100011033 and from ESF Investing in your future. GGS received a postdoctoral fellowship from CNPq (grant no. 150887/2022-1) ÁLK was supported by a János Bolyai Research Scholarship of the Hungarian Academy of Sciences, New National Excellence Programme of the Ministry of Innovation and Technology ÚNKP-21-5-DE-457, NKFIH FK-138698 grants.

Pishing is an imitated alarm call frequently used by birders and ornithologists to attract birds and provide close-up views. However, despite the widespread use of pishing in the field, data on the success of this technique are still scarce. Here we tested the effectiveness of pishing as an attracter of birds in a subtropical savanna in South Africa, using a randomised controlled trial design. Over a period of 12 months, repeated silent observation and pishing treatments were randomly applied across 30 preselected savanna sites to test the response to pishing of both the bird community and individual species. Overall, significantly more individual birds were recorded during the pishing treatment than during the silent observation control treatment. Furthermore, the observation rates of eleven species, from seven passerine families, were significantly higher during pishing treatments. Robins in the Muscicapidae were especially responsive. Pishing does increase visibility of arboreal passerines in African subtropical savanna. This finding confirms that the technique is an effective tool for increasing bird observations in the field and informs current discussions on the ethics of pishing in the South African birding community. Keywords: birds; alarm call; pishing; playback

High human population growth and rapid urbanisation, particularly in Africa, have led to an increased interest in the impacts of this land-use change on bird communities. The African Bird Atlas Pro...

Concentrations of organochlorine pesticides have been extensively monitored in birds, particularly from higher trophic guilds such as raptors. While monitoring of raptors has been ongoing for decades, patterns from monitoring activities have never been summarised on a global scale. In this study, we undertake a review to better describe the monitoring of two widespread organochlorine pesticides monitored globally in raptors, DDT and dieldrin. We provide a historical retrospective on the monitoring effort of a global environmental issue. Sampling was heavily biased geographically to the global north, with more than 90 % of studies conducted in this socio-geographic region, most from Europe and North America. Although monitoring occurred from at least 114 species, most samples came from relatively few species, with three species (Eurasian Sparrowhawk Accipiter nisus, Bald Eagle Haliaeetus leucocephalus, and Peregrine Falcon Falco peregrinus) comprising 50 % of samples. The types of raptors sampled have changed over time, with avian and mammal specialists dominating samples until the 1970s, but more diverse dietary guilds monitored in later decades, and greater proportions of samples coming from generalist species. The three most sampled tissues (egg, liver, and plasma) comprised 84 % of all samples. Eggs were the earliest tissue examined and the only tissue sampled in all decades. The geographical bias in monitoring effort and relatively narrow species focus, suggests that patterns in these pesticides are unlikely to be fully representative of all global environments occupied by raptors. While DDT has been banned throughout most of the global north, it remains in use in the global south, yet monitoring effort in the south, does not match that of the north. While monitoring remains prevalent in the global north, contemporary monitoring is limited in the global south with less than 10 % of raptors sampled in Asia, Africa, and South America, over the last 3 decades.

Hybridisation between invasive and native species represents a significant threat to biodiversity. The Mallard Duck (Anas platyrhynchos) is known to hybridise with numerous closely related Anas species in regions where they have been introduced, threatening the genetic integrity of native ducks and in some instances contributing to their extinction risk. Mallard Ducks were introduced into South Africa in the 1940s and are now naturalised and widespread in the country. It has been speculated that Mallard Ducks are hybridising with native Yellow-billed Ducks (A. undulata) in South Africa, but evidence for this remains observational or purely anecdotal. Here we use data from nuclear microsatellite markers and mitochondrial DNA sequencing to show that hybridisation is indeed occuring between these two species. We found evidence for the occurance of hybridisation, mostly as crosses between Mallard Duck hens and Yellow-billed Duck drakes. Surprisingly, our results suggest that introgressive hybridisation is primarily occuring into the invasive Mallard Duck population (mostly Mallard Duck backcrosses were detected), evidenced by directionally-skewed gene flow and sex-biased mating. Whether these findings reflect true assortative mating or a case of Haldane’s rule remains unknown. We also found evidence of high connectivity between Yellow-billed Duck populations, as far as 1000 km apart, in South Africa. Taken together these results suggest that hybrid genotypes can disperse over vast distances between populations and lead to genetic pollution, even in the absence of invasive Mallard Ducks. Active management of Mallard Duck populations has been met by public resistance in some areas in South Africa, partly because of a lack of evidence showing clear impacts by these birds. This study provides some of the first scientifically-documented evidence for such impacts.

The Luxury Effect hypothesizes a positive relationship between wealth and biodiversity within urban areas. Understanding how urban development, both in terms of socio-economic status and the built environment, affects biodiversity can contribute to the sustainable development of cities, and may be especially important in the developing world where current growth in urban populations is most rapid. We tested the Luxury Effect by analysing bird species richness in relation to income levels, as well as human population density and urban cover, in landscapes along an urbanization gradient in South Africa. The Luxury Effect was supported in landscapes with lower urbanization levels in that species richness was positively correlated with income level where urban cover was relatively low. However, the effect was reversed in highly urbanized landscapes, where species richness was negatively associated with income level. Tree cover was also positively correlated with species richness, although it could not explain the Luxury Effect. Species richness was negatively related to urban cover, but there was no association with human population density. Our model suggests that maintaining green space in at least an equal proportion to the built environment is likely to provide a development strategy that will enhance urban biodiversity, and with it, the positive benefits that are manifest for urban dwellers. Our findings can form a key contribution to a wider strategy to expand urban settlements in a sustainable way to provide for the growing urban population in South Africa, including addressing imbalances in environmental justice across income levels and racial groups.

Supplementary material for the paper, including details regarding the study methods, definitions and illustrations of the subjective variables used, results of the validation of scores and shape analysis, and all supplementary tables and figures (Tables S1-S4 and Figures S1-S6), to be published along with the main manuscript.

Set of appendices containing catalogue ID numbers and URLs of all photographs analysed in this study, to be published along with the main manuscript.

Urban animal ecology is a rapidly growing research area, yielding fascinating insights into the patterns and processes that shape biodiversity in the city. However, much of this research has focused on cities in the developed world, where the mechanisms affecting biodiversity might be very different to those in the developing cities of the Global South. Here we detail how the contemporary cities of the Global South diverge from their Global North counterparts and explain how several key differences in pattern can have important consequences for urban animal diversity and ultimately ecological function and ecosystem services. Our focus in this chapter is on several key taxonomic groups, including, birds, mammals, herpetofauna and invertebrates, and incorporates a case study on urban predators, as well as some views on novel insights that can be gained from studying urban animal diversity in the Global South. Additionally, we synthesise the available urban animal diversity research from the Global South and explore how varying landscape patterns, distinct abiotic conditions, and vastly different socio-economic contexts can lead to greatly different outcomes for biodiversity in Global South cities.

Diverse freshwater biological communities are threatened by invasive aquatic alien plant (IAAP) invasions and consequently, cost countries millions to manage. The effective management of these IAAP invasions necessitates their frequent and reliable monitoring across a broad extent and over a long-term. Here, we introduce and apply a monitoring approach that meet these criteria and is based on a three-stage hierarchical classification to firstly detect water, then aquatic vegetation and finally water hyacinth (Pontederia crassipes, previously Eichhornia crassipes), the most damaging IAAP species within many regions of the world. Our approach circumvents many challenges that restricted previous satellite-based water hyacinth monitoring attempts to smaller study areas. The method is executable on Google Earth Engine (GEE) extemporaneously and utilizes free, medium resolution (10–30 m) multispectral Earth Observation (EO) data from either Landsat-8 or Sentinel-2. The automated workflow employs a novel simple thresholding approach to obtain reliable boundaries for open-water, which are then used to limit the area for aquatic vegetation detection. Subsequently, a random forest modelling approach is used to discriminate water hyacinth from other detected aquatic vegetation using the eight most important variables. This study represents the first national scale EO-derived water hyacinth distribution map. Based on our model, it is estimated that this pervasive IAAP covered 417.74 km2 across South Africa in 2013. Additionally, we show encouraging results for utilizing the automatically derived aquatic vegetation masks to fit and evaluate a convolutional neural network-based semantic segmentation model, removing the need for detection of surface water extents that may not always be available at the required spatio-temporal resolution or accuracy. The water hyacinth species discrimination has a 0.80, or greater, overall accuracy (0.93), F1-score (0.87) and Matthews correlation coefficient (0.80) based on 98 widely distributed field sites across South Africa. The results suggest that the introduced workflow is suitable for monitoring changes in the extent of open water, aquatic vegetation, and water hyacinth for individual waterbodies or across national extents. The GEE code can be accessed here.

Connectivity has long played a central role in ecological and evolutionary theory and is increasingly emphasized for conserving biodiversity. Nonetheless, connectivity assessments often focus on individual species even though understanding and preserving connectivity for entire communities is urgently needed. Here we derive and test a framework that harnesses the well-known allometric scaling of animal movement to predict community-level connectivity across protected area networks. We used a field translocation experiment involving 39 species of southern African birds to quantify movement capacity, scaled this relationship to realized dispersal distances determined from ring-and-recovery banding data, and used allometric scaling equations to quantify community-level connectivity based on multilayer network theory. The translocation experiment explained observed dispersal distances from ring-recovery data and emphasized allometric scaling of dispersal based on morphology. Our community-level networks predicted that larger-bodied species had a relatively high potential for connectivity, while small-bodied species had lower connectivity. These community networks explained substantial variation in observed bird diversity across protected areas. Our results highlight that harnessing allometric scaling can be an effective way of determining large-scale community connectivity. We argue that this trait-based framework founded on allometric scaling provides a means to predict connectivity for entire communities, which can foster empirical tests of community theory and contribute to biodiversity conservation strategies aimed at mitigating the effects of environmental change.

This Commentary is a response to a Commentary published in the May/June 2020 issue: Nattrass N. Why are black South African students less likely to consider studying biological sciences? S Afr J Sci. 2020;116(5/6), Art. #7864, 2 pages. https://doi.org/10.17159/sajs.2020/7864 Responses to the Commentary in the May/June 2020 issue have been published collectively in a special issue of Volume 116.

Aspiring towards cities that are sustainable and equitable, as detailed by Goal 11 of the United Nations Sustainable Development Goals, has become increasingly relevant given the growing human population in urban areas. A key part of guaranteeing that cities meet Goal 11 is to ensure equitable access to urban green spaces, and the biodiversity that they support, for all residents. However, there is evidence from developed world cities of a Luxury Effect, where wealthier residents have greater access to urban biodiversity than poorer residents. To test for this Luxury Effect in a developing world city, we measured bird species richness and diversity in 27 urban green spaces in Johannesburg, South Africa, to examine how socio-economic and ecological drivers influence urban biodiversity. We found no evidence of a Luxury Effect with the median income of neighbourhoods surrounding the green spaces having no significant effect on bird richness or diversity. There were, however, ecological effects with surrounding natural land-cover negatively correlated to richness, and a positive influence of wetland connectivity on richness. The negative effect of natural land-cover is possibly due to the relatively low bird diversity of the natural grasslands surrounding Johannesburg. The positive effect of wetland connectivity and the lack of a Luxury Effect indicate that the use of waterbodies to historically separate populations has buffered poorer neighbourhoods from depreciated biodiversity within the selected green spaces. The effect of wetlands also further emphasises the importance of water availability on urban biodiversity. This indicates that historical land use decisions can still influence how biodiversity is distributed in urban landscapes.

Many falcons (Falcospp.) exhibit a distinct dark plumage patch below the eye, termed the malar stripe. This stripe is hypothesized to reduce the amount of solar glare reflected into the eyes while foraging, thereby increasing hunting efficiency in bright conditions. Here, we use a novel, global-scale correlative approach to test this ‘solar glare hypothesis' in peregrine falcons (Falco peregrinus), the most widespread falcon species, using web-sourced photographs from across the species' global range. We found that the size and prominence of the malar stripe were positively associated with average annual solar radiation, but not with other environmental variables, such as temperature and rainfall. Our results provide the first published evidence for the hypothesis that this plumage feature functions to reduce the amount of solar glare reflected into the falcon's eyes, thereby improving the ability to pinpoint and target agile prey in bright conditions.

The landscape heterogeneity hypothesis states that increased heterogeneity in agricultural landscapes will promote biodiversity. However, this hypothesis does not detail which components of landscape heterogeneity (compositional or configurational) most affect biodiversity and how these compare to the effects of surrounding agricultural land-use. Our objectives were to: (1) assess the influence of the components of structural landscape heterogeneity on taxonomic diversity; and (2) compare the effects of landscape heterogeneity to those of different types of agricultural land-use in the same landscape across different taxonomic groups. We identified a priori independent gradients of compositional and configurational landscape heterogeneity within an agricultural mosaic of north-eastern Swaziland. We tested how bird, dung beetle, ant and meso-carnivore richness and diversity responded to compositional and configurational heterogeneity and agricultural land-use across five different spatial scales. Compositional heterogeneity best explained species richness in each taxonomic group. Bird and ant richness were both positively correlated with compositional heterogeneity, whilst dung beetle richness was negatively correlated. Commercial agriculture positively influenced bird species richness and ant diversity, but had a negative influence on dung beetle richness. There was no effect of either component of heterogeneity on the combined taxonomic diversity or richness at any spatial scale. Our results suggest that increasing landscape compositional heterogeneity and limiting the negative effects of intensive commercial agriculture will foster diversity across a greater number of taxonomic groups in agricultural mosaics. This will require the implementation of different strategies across landscapes to balance the contrasting influences of compositional heterogeneity and land-use. Strategies that couple large patches of core habitat across broader scales with landscape structural heterogeneity at finer scales could best benefit biodiversity.

Ecological theory predicts that if animals with very similar dietary requirements inhabit the same landscape, then they should avoid niche overlap by either exploiting food resources at different times or foraging at different spatial scales. Similarly, it is often assumed that animals that fall in different body mass modes and share the same body plan will use landscapes at different spatial scales. We developed a new methodological framework for understanding the scaling of foraging (i.e. the range and distribution of scales at which animals use their landscapes) by applying a combination of three well‐established methods to satellite telemetry data to quantify foraging patch size distributions: (1) first‐passage time analysis; (2) a movement‐based kernel density estimator; and (3) statistical comparison of resulting histograms and tests for multimodality. We demonstrate our approach using two sympatric, ecologically similar species of African ducks with quite different body masses: Egyptian Geese (actually a shelduck), and Red‐billed Teal. Contrary to theoretical predictions, the two species, which are sympatric throughout the year, foraged at almost identical spatial scales. Our results show how ecologists can use GPS tracking data to explicitly quantify and compare the scales of foraging by different organisms within an animal community. Our analysis demonstrates both a novel approach to foraging data analysis and the need for caution when making assumptions about the relationships among niche separation, diet, and foraging scale.

Novel syntheses of both the benzo[b]phenanthridine and the 6H-dibenzo[c,h]chromen-6-one motif are described. Reaction of (2-(3-bromo-1,4-dimethoxynaphthalen-2-yl)phenyl)methanamine with PIFA afforded benzo[b]phenanthridine-7,12-dione, while the related nonbrominated precursor, (2-(1,4,5-trimethoxynaphthalen-2-yl)phenyl)methanamine on treatment with PIFA, furnished the ortho-quinone 1-methoxybenzo[c]phenanthridine-11,12-dione. Unexpectedly, treatment of related oxygen analogs such as (2-(1,4-dimethoxynaphthalen-2-yl)phenyl)methanol with NBS under an O2 atmosphere, afforded a chromenone, 12-methoxy-6H-dibenzo[c,h]chromen-6-one.

SummaryRudd’s Lark Heteromirafra ruddi is a globally threatened species endemic to eastern South Africa’s highland grasslands, where climate envelope modelling has predicted a dramatic reduction in its already small and fragmented distribution. Here we assess recent changes in one of its last strongholds, the Wakkerstroom grasslands. We assessed changes in Rudd’s Lark population and habitat condition over 12 years, within a core section of an area intensively surveyed in 2002–2004. Our 2016 survey found lower absolute numbers of Rudd’s Larks (five transects with Rudd’s Lark present compared to nine in 2002; nine individuals compared to 32), as well as a lower probability of encounter. Transects with shorter grass and higher altitude had a higher probability of Rudd’s Larks occurrence, consistent with findings in 2002. Point locations where Rudd’s Larks were recorded had shorter grass, higher forb cover and more bare ground cover, and tended to be at higher altitudes than random locations in the surrounding grassland. Remotely-sensed fire data showed that late-season fires, which pose a threat to Rudd’s Lark nestling survival, are generally uncommon. Field observations indicated that seven transects (of which two previously contained Rudd’s Lark) that had previously been grassland had been converted to intensive crop production. While Rudd’s Lark may be affected by direct loss of grassland habitat through conversion to crops, the species has also declined within remaining grassland habitat. The drivers of decline remain unclear but this recent observed local decline of Rudd’s Lark in the immediate Wakkerstroom area supports the species’ recent IUCN uplisting to globally ‘Endangered’, given that its previous downlisting was based on habitat requirements and breeding success from this area.

Although wildlife production is widely considered beneficial for semi-arid environments, few studies have reported on the long-term environmental effects of converting from livestock production to game ranching. Asante Sana Game Reserve in South Africa was stocked with domestic livestock for centuries. However, after 1996 game ranching was adopted in the reserve. We investigated the long-term (1987–2017) spatial and temporal change in vegetation productivity and type on the reserve using Landsat multispectral data and soil adjusted vegetation index (SAVI), and explored the relationship between changes in vegetation productivity and the potential drivers. The results show that while Thicket has decreased overall, it has expanded into parts of Grassland and Shrubland, and Bare-ground has expanded into parts of Shrubland and Thicket. Overall vegetation productivity increased over time, with the greatest increases in Thicket and Grazing lawn and the lowest in Shrubland and Bare-ground. Changes in rainfall, fire and stocking rates were all significant predictors of the observed changes in vegetation productivity, but rainfall had the strongest effect. This research highlights some of the complex responses that arise in semi-arid vegetation when domestic livestock production is replaced by game ranching, and points towards key issues that can be addressed by management.Keywords: land-use change, remote sensing, semi-arid rangeland, vegetation index, wildlife impact

ContextThe disruption of normal activities by humans (i.e. ‘anthropogenic disturbance’) can have important behavioural, physiological and population effects on coastal birds. These negative effects include increased vigilance, increased energy expenditure and reduced nesting success. To overcome this, separation distances (e.g. buffers and setbacks) are often used to separate threatening stimuli, such as humans, from wildlife. However, in most instances the determination of separation distances are based on little empirical information. This is particularly true for Africa, which supports huge populations of Palearctic migrant shorebirds. AimTo determine suitable separation distances that will reduce anthropogenic disturbance to the coastal bird community at West Coast National Park, South Africa. MethodsThe distance at which a behavioural response (i.e. flight initiation distance, FID) occurred among 15 common coastal bird species when presented with an approaching human was measured. Linear mixed-effects models were used to determine the relationship between FID and body size, migratory status, intraspecific flock size, flock species richness, foraging behaviour and several environmental covariates. Key resultsBody mass was significantly and positively correlated with FID, indicating that larger birds are more sensitive to the anthropogenic stimulus. Furthermore, it was shown that migratory birds had longer FIDs, suggesting that they are less risk tolerant compared with resident birds. The distance at which the approach was initiated (i.e. the start distance, SD) was also significantly and positively correlated with FID, supporting the hypothesis that birds will flush early to avoid the potential negative consequences of fleeing too late. Finally, there was a novel significant effect of increasing wind speed on increasing FID, suggesting a thermoregulatory trade-off. There was no effect of foraging behaviour, flock size or flock composition on FID. ConclusionBased on these data, buffer distances for tidal habitats at West Coast National Park should be set at ~170 m. ImplicationsImproved understanding of FID, and the morphological and behavioural predictors thereof, will enable West Coast National Park and other protected areas to designate separation distances or buffer zones that reduce the negative effects of anthropogenic disturbance on shorebird communities.

Recent years have seen considerable advances in ecological understanding of the functional role(s) of biodiversity and the connections between biodiversity, ecosystem function and ecosystem service provision. Functional approaches have become important tools for simplifying biodiversity–ecosystem function relationships, but they also have some obvious weaknesses. In particular, since analyses that use functional groups treat members of a group as ecologically interchangeable, functional groups must be defined at a level that simplifies ecological complexity yet retains key ecological distinctions between groups of species. We developed a data-driven approach to functional group definition and applied it to a case study of 16 species of seed-dispersing Afrotropical waterfowl for which we created seed dispersal functional groups using both a priori categories, as typically done in previous studies, and a hierarchical clustering approach. Relevant functional differences and similarities occur among the waterfowl, particularly in the types of plant family dispersed. We found evidence for at least five functional groups of seed disperser. The different groupings have important implications for both wetland and terrestrial plant dispersal. Our analysis suggests that even for a relatively data-scarce study system, using a data-driven approach to generate functional groups offers a feasible and ecologically rigorous approach and is a useful alternative to simple a priori classification schemes. Our approach is capable of capturing variation across several functional traits and suggests that existing datasets may be useful in exploring variation in biodiversity–ecosystem function relationships. Since functional classification schemes may affect our conclusions about biodiversity, ecosystem function and ecosystem service provision, considerable care should be given to ensuring that functional groups are not defined in such a way as to mask important ecological differences among supposedly similar species.

Summary Patterns of seed dispersal are strongly influenced by disperser and propagule traits. However, the relative importance of these characteristics for dispersal outcomes is unclear. We investigated differences in the potential dispersal of wetland plants between Egyptian goose (Alopochen aegyptiaca) and red-billed teal (Anas erythrorhyncha), two southern African Anatidae. The seeds of seven wetland plants with varying traits were fed to the birds and the dispersal parameters of gut passage time, recoverability and germinability of ingested seed were determined. We tested the effect of disperser species and seed traits on dispersal parameters. In addition, we determined whether increased retention times lead to lower recovery and germination of ingested seed. We predicted that the seed traits of small size and increased hardness would be better at mediating the trade-off between retention time and recoverability and germination, but that this might differ between vectors. The dispersal parameters varied significantly between Egyptian goose and red-billed teal. In particular, Egyptian goose had longer average and maximum retention times of seeds, but also higher recoverability. Furthermore, short seeds had significantly longer average retention time and were also recovered in the highest numbers. Short seed length potentially facilitates endozoochory by two complementary mechanisms. First, short seeds are less digestible, leading to higher recoverability. Second, due to lower digestibility, short seeds are able to survive at longer retention times to be dispersed further, similarly to hard seeds (with hardness positively correlated with seed mass). Our results suggest that small seed length and hardness are optimal seed traits facilitating endozoochory in wetland plants. Dispersal parameters were also influenced by the bird species and indicate that differences in vector morphology and digestive physiology may likely have important consequences for seed dispersal. Hence, vector characteristics should be given more explicit consideration in future studies of seed dispersal in aquatic systems.

Summary Waterbirds are important seed dispersers and may play a vital role in maintaining connectivity among isolated aquatic communities. Whilst considerable progress has been made in our understanding of the dispersal function of waterbirds, the number of studies is still limited and is largely focused on migratory waterbirds in Europe. We present the first detailed study of seed dispersal by waterbirds in Africa. We quantified and compared endo- and ectozoochory across six waterfowl species at three widely dispersed sampling locations in South Africa and tested for differences between dispersal agents and sampling sites. We also tested for differences in the plant communities dispersed by endo- and ectozoochory. All intact and germinating propagules found in freshly collected faecal samples (N = 313) and feather brushings (N = 422) were counted and identified. A total of 1585 propagules from 48 plant taxa were recovered from the samples. Thirty-seven per cent of all external brushings and 27% of all faecal samples contained at least one intact propagule and 15 and 8% of the samples contained at least one germinating propagule, respectively. Sampling site had a strong influence on the presence, abundance and germination of propagules recovered from both external and faecal samples. Additionally, sympatric waterfowl showed differences in the abundance and germinability of plant propagules transported by endozoochory. The presence of at least one propagule was highest in the external samples, but propagule abundance and germination were highest in faecal samples. The community composition of propagules transported by each of these two modes was significantly different, suggesting that endo- and ectozoochory are complementary dispersal mechanisms. Our results indicate an important role for waterbirds in the dispersal of aquatic plants in Africa. While ectozoochory can be an important dispersal mechanism, its effects may be heterogeneous and unpredictable relative to endozoochory. Endozoochory appears to be the more effective and dominant mechanism. Our results also point to a high capacity for the dispersal of exotic species via both ecto- and endozoochory.

It is generally suggested that invasive alien plant species (IAPS) negatively affect livelihoods. However, there is a need to find more generalisable patterns of IAPS impacts on livelihoods, which are useful for decision making at broad scales. Here we test the hypothesis that across South Africa poorer communities with high reliance on provisioning ecosystem services are more at risk from IAPS. To do so, we integrate two national-scale datasets; 1) The South African Plant Invaders Atlas, and 2) the National Census Data, which provides details on household income and selected provisioning ecosystem service use. Our analysis revealed that the potential impacts of IAPS increased as household income decreased, confirming that IAPS had greater negative effects in poorer landscapes. Furthermore, IAPS had the potential to be more impactful on selected provisioning ecosystem services where households were more reliant on them. Taken together, our results confirm that across South Africa, landscapes with poorer households and high reliance on the selected provisioning ecosystem services are likely the most negatively affected by IAPS. This novel broad-scale approach revealed landscape-scale patterns of the potential socio-ecological impacts of IAPS and will help decision makers direct resources for IAPS management to where they may be most effective.

Aim: To review existing literature on the ability of waterbirds to spread aquatic alien and invasive species, and to assess the relevance of bird-mediated dispersal for the conservation of freshwater ecosystems. Location: Global. Methods: Literature Review. Results: A systematic review of the literature revealed that quantitative studies investigating dispersal of alien organisms by waterbirds are rare (n = 14). Most studies citing waterbird dispersal rely on anecdotes or inferences from morphological dispersal syndromes. However, evidence from each stage of dispersal (i.e. emigration, transport and immigration) shows that waterbirds can carry alien plants and invertebrates internally and externally; transport them between water bodies at a variety of spatial scales; and deposit viable propagules in sites suited to aquatic invasive species. Main conclusions: Our review suggests that waterbirds can and do act as important dispersal vectors for freshwater invasive species. Further experimental and field based research on the numbers and viability of moved alien propagules, and the roles of different species in the bird community, is needed. Furthermore, consideration of the spatially explicit manner in which birds move is imperative to understanding invasive spread. Populations of alien aquatic species in seemingly isolated wetlands can no longer be considered contained if they are able to be spread through waterbird-mediated dispersal, and containment measures must recognize such opportunities for further spread. Changing waterbird movement patterns, driven by climate and land use change, further add to the challenge of managing invasive species and offers an interesting opportunity for future research. The study of waterbird-mediated dispersal of aquatic alien invasive species provides insights not only into species invasions, but more generally into movement ecology, population ecology and biogeography.

Erratum paru dans Landscape Ecology (2015) 30 p. 987. http://dx.doi.org/10.1007/s10980-015-0204-6. Context Landscape structure influences host-parasite- pathogen dynamics at multiple scales in space and time. Landscape epidemiology, which connects disease ecology and landscape ecology, is still an emerging field. Objective We argue that landscape epidemiology must move beyond simply studying the influence of landscape configuration and composition on epidemiological processes and towards amore comparative, systems approach that better incorporates social-ecological complexity. Methods We illustrate our argument with a detailed review, based on a single conceptual systems model, of geographic variation in drivers of avian influenza in Western Europe, Southeast Asia, and Southern Africa. Results Our three study regions are similar in some ways but quite different in others. The same underlying mechanisms apply in all cases, but differences in the attributes of key components and linkages (most notably avian diversity, the abiotic environment, land use and land cover, and food production systems) create significant differences in avian influenza virus prevalence and human risk between regions. Conclusions Landscape approaches can connect local- and continental-scale elements of epidemiology. Adopting a landscape-focused systems perspective on the problem facilitates the identification of the most important commonalities and differences, guiding both science and policy, and helps to identify elements of the problem on which further research is needed. More generally, our review demonstrates the importance of social-ecological interactions and comparative approaches for landscape epidemiology.

Despite a large literature on the impacts of micro-plastic pollution in marine ecosystems, very little research has focused on these pollutants in freshwater ecosystems. Recently, however, a few studies have demonstrated that micro-plastic pollutants are ingested by freshwater taxa, including birds. To explore this potential environmental threat in African freshwater systems we quantified micro-plastic pollutants in the faeces and feather brushings of seven southern African duck species. We analysed 283 faecal samples and 408 feather brushings, and found that 5% of faecal samples and 10% of feather samples contained micro-plastic fibres. The presence and abundance of micro-fibres differed between sampling sites, with significantly higher amounts recorded for the site that received effluent from a sewage treatment facility. Additionally, micro-fibre presence differed across duck species, indicating that foraging behaviour affects plastic ingestion. Our study confirms that African freshwater ecosystems and the biodiversity they support are under threat from micro-plastic contamination.

W. Solarz, K. Najberek, A. Pociecha & E. Wilk-Woźniak (2017, Diversity and Distributions, 23, 113–117) published a letter in Diversity and Distributions debating our view that waterbirds are important vectors of alien species (C. Reynolds, N. A. F. Miranda & G. S. Cumming, 2015 Diversity and Distributions, 21, 744–754; A. J. Green, 2016 Diversity and Distributions, 22, 239–247) and question whether future research into the mechanisms under-pinning this phenomenon can be advantageous for the practical management of alien species. Additionally, Solarz et al. suggest that human activities are the primary source of all alien species introductions and that waterbirds may only act as vectors of secondary dispersal. In this letter, we respond to several arguments raised by the authors surrounding the relevance of waterbird-mediated dispersal in the introduction and spread of alien species. We emphasize the partly deterministic nature of waterbird dispersal and the significance of long-distance dispersal events (and hence the potential for primary introductions of new alien species across political boundaries). Finally, we reaffirm the importance of further research into dispersal by birds to improve our capacity to foresee and manage invasions of those alien species with strong capacity to spread via avian vectors.

Male-male competition is recognized as a potent force of sexual selection. When intra-sexual competition is strong then selection theory predicts that alternative male phenotypes will evolve. Circellium bacchus is a large, hornless, ball-rolling dung beetle with extensive variation in size and subject to intense male-male contest competition. We proposed that small male C. bacchus, which are unlikely to be successful in male contest competition, would adopt the alternative reproductive tactic of sneaking copulations. This alternative tactic is likely to influence not only behavior, but morphology with an expectation that sneaking males would invest more resources in testes development. Investigation of testis allometry revealed that smaller male C. bacchus beetles had relatively larger testes than their bigger conspecifics. Furthermore, as resources may be limited during larval development, differential investment in testes development should result in adult male beetles either competing for fertilizations or for access to mates. This is seen in C. bacchus as two alternate male phenotypes; smaller beetles with a relatively low body mass invest proportionately more in testes development compared to larger, heavier form in which testes size does not scale with condition. To our knowledge this study provides the first investigation of alternative phenotypes in the reproductive tactics of a ball-rolling dung beetle species.