Passive external transport of freshwater invertebrates by elephant and other mud‐wallowing mammals in an African savannah habitat

1. Recent findings hint at the potential importance of mammals affecting the spatial dynamics of aquatic organisms in areas where mammals live in close association with water. Perhaps the most iconic example of such an environment is the African savannah. 2. We investigated dispersal patterns of freshwater organisms among a set of temporary ponds in SE Zimbabwe to test the hypothesis that large mammals, and particularly African elephants (Loxodonta africana), can be important vectors of aquatic organisms. Dispersal kernels were reconstructed by hatching mud collected from ‘rubbing’ trees located at increasing distances from a set of isolated ponds. To assess the relative importance of other mammalian vectors, the vertical distribution of mud on rubbing trees was mapped and related to the body size of candidate vector species. 3. Laboratory hatching of mud samples revealed large numbers of propagules of 22 invertebrate taxa as well as some aquatic macrophytes. Dispersing communities reflected source communities and diverged with increasing distance from the source. Both dispersal rates and richness of transported taxa decreased significantly with dispersal distance. No indications for differences in dispersal capacity among propagule types were detected. Instead, common propagules were more likely to travel greater distances. Most mud was attached to trees at heights >1.5 m, implicating elephants as the dominant vector. Vertical distributions of tree mud, however, also revealed clustering at heights up to 50 cm and 90–120 cm corresponding to the height of warthog, rhinoceros and buffalo, respectively. Finally, variation in the vertical distribution of mud on trees in combination with differences in vector vagility suggests that local differences in vector species composition may affect passive dispersal dynamics of aquatic organisms. 4. Based on vagility and vector load, mud‐wallowing mammals emerge as highly effective vectors that, in some areas, may be more important in transporting aquatic organisms than traditionally recognised vectors such as waterbirds. Since most large‐ and medium‐sized mammals currently have restricted geographic distributions, it is likely that mammal‐mediated dispersal was more important in the past.     

Invertebrate dispersal by aquatic mammals: a case study with nutria Myocastor coypus (Rodentia,Mammalia) in Southern France

Many freshwater invertebrates rely on vectors for their passive dispersal. A wide array of vectors has already been investigated, but dispersal mediated by aquatic mammals remains largely unknown. Since nutria (Myocastor coypus Molina, 1782) live in a variety of aquatic habitats and frequently move around between these water bodies, they have the opportunity to transport hitch-hiking aquatic invertebrates along with them. We investigated the presence of aquatic invertebrates in their fur to evaluate this hypothesis. This study demonstrates the feasibility of ectozoochory in a broad array of freshwater invertebrates by nutria on a local scale. More than 800 invertebrates of 14 different taxa were retrieved from the fur of 10 nutria specimens, including cladocerans, copepods, ostracods, rotifers, bryozoans, dipterans, nematodes, annelids and collembolans. Many of these freshwater invertebrates could survive at least 30 min in the moist fur of nutria. Therefore, we can state that besides modifying aquatic habitats physically by clearing vegetation or digging, nutria may also alter invertebrate communities by introducing new species or genotypes.     

Soil seed banks near rubbing trees indicate dispersal of plant species into forests by wild boar

Current knowledge about processes that generate long-distance dispersal of plants is still limited despite its importance for persistence of populations and colonization of new potential habitats. Today wild large mammals are presumed to be important vectors for long-distance transport of diaspores within and between European temperate forest patches, and in particular wild boars recently came into focus. Here we use a specific habit of wild boar, i.e. wallowing in mud and subsequent rubbing against trees, to evaluate epizoochorous dispersal of vascular plant diaspores. We present soil seed bank data from 27 rubbing trees versus 27 control trees from seven forest areas in Germany. The mean number of viable seeds and the plant species number were higher in soil samples near rubbing trees compared with control trees. Ten of the 20 most frequent species were more frequent, and many species exclusively appeared in the soil samples near rubbing trees. The large number of plant species and seeds – more than 1000 per tree – in the soils near rubbing trees is difficult to explain unless the majority were dispersed by wild boar. Hooked and bristly diaspores, i.e. those adapted to epizoochory, were more frequent; however, many species with unspecialized diaspores occurred exclusively near rubbing trees. As opposed to plant species closely tied to forests species which occur both in forest and open vegetation and non-forest species were more frequent near rubbing trees compared with controls. These findings are consistent with previous studies on diaspore loads in the coats and hooves of shot wild boars. However, our method allows to identify the transport of diaspores from the open landscape into forest stands, where they might especially emerge after disturbance, and a clustered distribution of epizoochorically dispersed seeds. Moreover, accumulation of seeds of wetness indicators near rubbing trees demonstrates directed dispersal of plant species inhabiting wet places among remote wallows.     

Invertebrate community patterns in Mediterranean temporary wetlands along hydroperiod and salinity gradients

1. Temporary aquatic habitats often are inhabited by a unique fauna and flora and contribute significantly to regional diversity. Temporary wetlands around the world are disappearing rapidly. The individual and interacting impacts of factors influencing community structure and dynamics in temporary wetlands are not always well known.
2. Camargue wetlands are mainly characterized by variable salinity and hydroperiod. The individual and combined impacts of these local factors, together with regional variables, on invertebrate communities remain unknown. We therefore characterized and sampled invertebrates in 30 temporary wetlands along salinity and hydroperiod gradients in the Camargue (Southern France) 3, 5 and 7 months after inundation.
3. Over the three sampling occasions, a total of 17 cladoceran species and 49 macroinvertebrate taxa were identified. Hydroperiod and salinity were the most important variables explaining variation in taxonomic composition and can be considered key factors shaping the invertebrate communities in Camargue wetlands. The impact on taxon richness was significantly positive for hydroperiod but significantly negative for salinity. Regional factors had no significant effect on the structure of the studied invertebrate communities, suggesting that dispersal was not limiting and that species sorting was the most important structuring process.
4. The results of this study suggest that the combined and interacting effects of salinization and hydrological modification of Mediterranean temporary wetlands (due to water management, climate change, etc.) can result in reduced diversity in large numbers of Mediterranean wetlands and induce a considerable decline in regional diversity of aquatic invertebrates.     

A potential role for overland dispersal in shaping aquatic invertebrate communities in arid regions

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Assessing invasion risk across taxa and habitats: life stage as a determinant of invasion success

Aim Many aquatic invertebrates produce dormant life‐history stages as a means to endure inhospitable environments and to facilitate natural long‐distance dispersal, yet we have little understanding of the role of dormant stages as a mechanism for human‐mediated introductions of non‐indigenous species. We explore the survival of invertebrate dormant eggs in collected ships’ ballast sediment over a 1‐year period to determine relative invasion potential across taxa (i.e. rotifers, copepods, cladocerans and bryozoans) and different habitats (freshwater, marine). Location Canadian Atlantic and Pacific coasts and Laurentian Great Lakes. Methods During 2007 and 2008, 19 ballast samples were collected as a part of a larger study. The degradation rate of dormant eggs was assessed by enumerating dormant eggs and by conducting viability hatching experiments. Results Taxa examined included rotifers, copepods, anomopods, onychopods and bryozoans. Dormant eggs of rotifers degraded at the highest rate of all taxa examined, with no viable eggs remaining within 10 months. Copepods showed a less rapid degradation rate than rotifers. The degradation rate of anomopod dormant eggs was significantly slower than that of both rotifers and copepods. Onychopods and bryozoans did not visibly degrade at all over 12 months. Viability hatching experiments were successful for rotifers, copepods, and anomopods. Onychopods and bryozoans did not hatch during any of the three hatching trials. Main conclusions Dormancy is not equally beneficial to all invertebrate taxa. Our results indicate that dormant eggs of rotifers and copepods degrade at a rapid rate and may not pose high invasion risk. In contrast, the slow degradation rate of anomopod dormant eggs and the lack of degradation of onychopod and bryozoan dormant eggs could result in high invasion risk because of their accumulation in ballast tanks. Species having resistant dormant eggs mostly belong to freshwater taxa making freshwater habitats at higher invasion risk by dormant invertebrates than marine habitats.     

Dispersal of aquatic organisms by waterbirds: a review of past research and priorities for future studies

1. Inland wetlands constitute ecological islands of aquatic habitat often isolated by huge areas of non-suitable terrestrial habitats. Although most aquatic organisms lack the capacity to disperse by themselves to neighbouring catchments, many species present widespread distributions consistent with frequent dispersal by migratory waterbirds.
2. A literature review indicates that bird-mediated passive transport of propagules of aquatic invertebrates and plants is a frequent process in the field, at least at a local scale. Both endozoochory (internal transport) and ectozoochory (external transport) are important processes.
3. The characteristics of the dispersed and the disperser species that facilitate such transport remain largely uninvestigated, but a small propagule size tends to favour dispersal by both internal and external transport.
4. We review the information currently available on the processes of waterbird-mediated dispersal, establishing the limits of current knowledge and highlighting problems with research methods used in previous studies. We also identify studies required in the future to further our understanding of the role of such dispersal in aquatic ecology.     

Differences in dispersal- and colonization-related traits between taxa from the freshwater and the terrestrial realm

The aquatic and terrestrial realms differ in many physical properties that not only require specific physiological adaptations but also cause differences in dispersal options. We thus expect that life-history traits related to dispersal and colonization are under selection pressure because freshwater habitats are more isolated and thus more difficult to reach. We compared traits from European databases of three taxonomic groups along the passive–active dispersal gradient: plants (Plantes), snails (Mollusca: Gastropoda: Prosobranchia et Pulmonata) and hoverflies (Diptera: Syrphidae), all of which have both terrestrial and freshwater species (plants and snails) or early life stages (hoverflies). Aquatic taxa seem to be more successful long-distance dispersers than are terrestrial taxa. Our analysis also revealed lower numbers of seeds or eggs produced in the aquatic habitats. However, aquatic taxa often allocate resources to offspring guarding (vegetative propagules in plants, egg capsules in snails) and breeding-site selection (syrphids). Colonization of the aquatic realm is reinforced by increases in life span (plants), clonal spread (plants), shorter generation times (snails), selfing ability (marginal effect in pulmonate snails) or paedogenesis (two incidences in hoverflies, needs further studies). Probably, the variety of strategies reflects the different evolutionary backgrounds that elicit different combinations of trade-offs, but all traits also might increase invasibility of species.     

Relative importance of different dispersal vectors for small aquatic invertebrates in a rock pool metacommunity

The extent and frequency of passive overland dispersal of freshwater invertebrates as well as the relative importance of different dispersal vectors is not well documented. Although anecdotal evidence subscribing the feasibility of individual vectors in various aquatic systems is abundant, dispersal rates have rarely been quantified for different vectors in one study system. Earlier studies also usually investigated dispersal potential rather than actual dispersal rates. In this study we have estimated passive dispersal rates of invertebrate propagules within a cluster of temporary rock pools via water, wind and amphibians in a direct way. Overflows after heavy rains mediated dispersal of a large number of propagules through eroded channels between pools, which were collected in overflow traps. Taking into account model based predictions of overflow frequency, this corresponds with average dispersal rates of 4088 propagules/channel yr^?1. Wind dispersal rates as measured by numbers of propagules collected on sticky traps mounted between pool basins were very high (average dispersal rate: 649 propagules m^?2 in one month) and were positively related to the proximity of source populations. Finally, invertebrate propagules were also isolated from the faeces of African clawed frogs Xenopus laevis caught from the pools (on average 368 propagules/frog). The combination of short distance wind and overflow dispersal rates likely explain the dominant species sorting and mass effect patterns observed in the metacommunity in a previous study. Amphibian mediated dispersal was much less important as the Xenopus laevis population was small and migrations very rare. Based on our own results and available literature we conclude that both vector and propagule properties determine local passive dispersal dynamics of freshwater invertebrates. Accurate knowledge on rates and vectors of dispersal in natural systems are a prerequisite to increase our understanding of the impact of dispersal on ecology (colonisation, community assembly, coexistence) and evolution (gene flow, local adaptation) in fragmented environments.     

Influences of riparian logging on plants and invertebrates in small,depressional wetlands of Georgia,U.S.A.

We studied 12 small, seasonally flooded, depressional wetlands on the Atlantic Coastal Plain of Georgia, U.S.A. Each wetland was embedded in stands of managed plantation pine. The pine trees surrounding each wetland had been harvested and replanted beginning in 1997 (2 sites), 1995 (2 sites), 1993 (1 site), 1988 (2 sites), 1984 (2 sites) or 1975 (3 sites). Regressions of various environmental variables with harvest histories indicated that those wetlands surrounded by smaller trees had greater light levels, water temperatures, pH, herbaceous plant cover and biomass, terrestrial invertebrate diversities and numbers, and water flea numbers, and lower water electrical conductivities and aquatic oligochaete numbers than those wetlands surrounded by more mature trees. Detected variations in hydroperiod, water depth, dissolved oxygen levels, sediment inputs, macrophyte diversity, periphyton biomass and densities of most aquatic invertebrates were not clearly correlated with past histories of peripheral tree harvest. This study suggests that harvesting trees around small wetlands initiates physical and ecological changes within the embedded habitats and that changes can persist for up to 15 years.     

Environmental heterogeneity,dispersal mode,and co‐occurrence in stream macroinvertebrates

Both environmental heterogeneity and mode of dispersal may affect species co‐occurrence in metacommunities. Aquatic invertebrates were sampled in 20–30 streams in each of three drainage basins, differing considerably in environmental heterogeneity. Each drainage basin was further divided into two equally sized sets of sites, again differing profoundly in environmental heterogeneity. Benthic invertebrate data were divided into three groups of taxa based on overland dispersal modes: passive dispersers with aquatic adults, passive dispersers with terrestrial winged adults, and active dispersers with terrestrial winged adults. The co‐occurrence of taxa in each dispersal mode group, drainage basin, and heterogeneity site subset was measured using the C‐score and its standardized effect size. The probability of finding high levels of species segregation tended to increase with environmental heterogeneity across the drainage basins. These patterns were, however, contingent on both dispersal mode and drainage basin. It thus appears that environmental heterogeneity and dispersal mode interact in affecting co‐occurrence in metacommunities, with passive dispersers with aquatic adults showing random patterns irrespective of environmental heterogeneity, and active dispersers with terrestrial winged adults showing increasing segregation with increasing environmental heterogeneity.     

Strong spatial influence on colonization rates in a pioneer zooplankton metacommunity

The magnitude of community-wide dispersal is central to metacommunity models, yet dispersal is notoriously difficult to quantify in passive and cryptic dispersers such as many freshwater invertebrates. By overcoming the problem of quantifying dispersal rates, colonization rates into new habitats can provide a useful estimate of the magnitude of effective dispersal. Here we study the influence of spatial and local processes on colonization rates into new ponds that indicate differential dispersal limitation of major zooplankton taxa, with important implications for metacommunity dynamics. We identify regional and local factors that affect zooplankton colonization rates and spatial patterns in a large-scale experimental system. Our study differs from others in the unique setup of the experimental pond area by which we were able to test spatial and environmental variables at a large spatial scale. We quantified colonization rates separately for the Copepoda, Cladocera and Rotifera from samples collected over a period of 21 months in 48 newly constructed temporary ponds of 0.18–2.95 ha distributed in a restored wetland area of 2,700 ha in Doñana National Park, Southern Spain. Species richness upon initial sampling of new ponds was about one third of that in reference ponds, although the rate of detection of new species from thereon were not significantly different, probably owing to high turnover in the dynamic, temporary reference ponds. Environmental heterogeneity had no detectable effect on colonization rates in new ponds. In contrast, connectivity, space (based on latitude and longitude) and surface area were key determinants of colonization rates for copepods and cladocerans. This suggests dispersal limitation in cladocerans and copepods, but not in rotifers, possibly due to differences in propagule size and abundance.     

Late Maastrichtian small-sized herpetofauna from Valencia province,eastern Spain

A Late Maastrichtian microvertebrate assemblage which includes amphibian remains was recovered from continental deposits of the palaeontological site of La Solana, Valencia Province, Spain. This site is composed of variegated mudstones, pedogenically modified, interbedded with fluvial sand bodies and freshwater limestones lenses, and has also yielded plant debris, freshwater and oligohaline invertebrates, abundant fish remains (isolated bones and scales), turtle plates and archosaur bones. This fossil assemblage, dominated by aquatic forms, also includes semiaquatic and terrestrial elements, and may be interpreted as the palaeofauna of a wetland environment with terrestrial environs. The new material described here consists of fragmentary remains of an indeterminate albanerpetontid, a salamandrid and two anuran taxa (an alytid and a palaeobatrachid). The amphibians from La Solana are typical Laurasiatic taxa. This faunal association shows broad similarities to other coeval faunas of the Iberian Peninsula and contrasts with the Upper Campanian–Lower Maastrichtian sites where Gondwanan elements are frequent.     

Spatial context strongly affects community composition of both passively and actively dispersing pool invertebrates in a highly heterogeneous landscape

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Endozoochorous seed dispersal by free-ranging herbivores in an abandoned landscape

Seed dispersal is a crucial process for the dynamics and maintenance of plant populations. Free-ranging animals are effective dispersal vectors because they can move between similar habitats and transport seeds into favourable environments. Dung samples from two species of common free-ranging mammals—deer and wild boar—were used to study endozoochorous dispersal of seeds in a military training area in western Bohemia. The area was abandoned after WWII, and the military training area was established in 1953. The vegetation consists of shrublands and dry grasslands. Data on the local species pool of grassland herbs and forbs were collected to compare the characteristics of dispersed versus non-dispersed plants. Deer and wild boar dispersed 84 plant species; however, species composition of seedlings emerging from dung samples showed significant differences between dispersal vectors and notable change across the growing season. 80% of all seedlings extracted from the dung samples belonged to stinging nettle, Urtica dioica. From trait analyses, seeds of endozoochorous plants had a higher longevity index in the soil seed bank than non-endozoochorous plants and more often possessed a mucilaginous surface. Our results show that deer and boar are successful, though not substitutable dispersers.     

Mycophagy by invasive wild boar (Sus scrofa) facilitates dispersal of native and introduced mycorrhizal fungi in Patagonia,Argentina

Fleshy hypogeous fungi produce scents that enable mycophagous mammals and invertebrates to locate them and disperse their spores. The European wild boar (Sus scrofa) was introduced in central Argentina in 1900s and later expanded into Patagonia. Here, we determined the diversity and abundance of fungal taxa, and the frequency of hypogeous fungal spores in wild boar feces in Patagonia. We collected fecal samples on Isla Victoria, Nahuel Huapi National Park, and identified fungi using microscope and DNA metabarcoding of ITS2 rDNA. Hypogeous fungal spores occurred in almost all fecal samples. The most abundant species belonged to the genera Hysterangium, Melanogaster, Radiigera and Gautieria. In addition to the symbiotrophic hypogeous taxa, we also identified numerous pathotrophic and saprotrophic taxa. Not only diverse native hypogeous fungi, but also introduced ones are part of the diet of the wild boar in forests of Patagonia. If viable, introduced fungi are being dispersed as far as 2.5 km from the nearest plantation, highlighting how the introduced wild boar might alter the local distribution and composition of fungal communities.     

How did this snail get here? Several dispersal vectors inferred for an aquatic invasive species

1. How species reach and persist in isolated habitats remains an open question in many cases, especially for rapidly spreading invasive species. This is particularly true for temporary freshwater ponds, which can be remote and may dry out annually, but may still harbour high biodiversity. Persistence in such habitats depends on recurrent colonisation or species survival capacity, and ponds therefore provide an ideal system to investigate dispersal and connectivity. 2. Here, we test the hypothesis that the wide distributions and invasive potential of aquatic snails is due to their ability to exploit several dispersal vectors in different landscapes. We explored the population structure of Physa acuta (recent synonyms: Haitia acuta, Physella acuta, Pulmonata: Gastropoda), an invasive aquatic snail originating from North America, but established in temporary ponds in Doñana National Park, southern Spain. In this area, snails face land barriers when attempting to colonise other suitable habitat. 3. Genetic analyses using six microsatellite loci from 271 snails in 21 sites indicated that (i) geographically and hydrologically isolated snail populations in the park were genetically similar to a large snail population in rice fields more than 15 km away; (ii) these isolated ponds showed an isolation‐by‐distance pattern. This pattern broke down, however, for those ponds visited frequently by large mammals such as cattle, deer and wild boar; (iii) snail populations were panmictic in flooded and hydrologically connected rice fields. 4. These results support the notion that aquatic snails disperse readily by direct water connections in the flooded rice fields, can be carried by waterbirds flying between the rice fields and the park and may disperse between ponds within the park by attaching to large mammals. 5. The potential for aquatic snails such as Physa acuta to exploit several dispersal vectors may contribute to their wide distribution on various continents and their success as invasive species. We suggest that the interaction between different dispersal vectors, their relation to specific habitats and consequences at different geographic scales should be considered both when attempting to control invasive freshwater species and when protecting endangered species.     

The distribution and economic losses of alien species invasion to China

Invasive alien species have become one of the most serious environmental issues in the world. Data of taxon, origin, pathway, and environmental impacts of invasive alien microorganisms, invertebrates, amphibians and reptiles, fish, birds, mammals, herbs, trees, and, marine organisms in terrestrial, aquatic, and marine ecosystems of China were analyzed during 2001 and 2003, based on literature retrieval and field survey. There were 283 invasive alien species in China, and the number of species of invasive alien microorganisms, aquatic plants, terrestrial plants, aquatic invertebrates, terrestrial invertebrates, amphibians and reptiles, fish, and mammals were 19, 18, 170, 25, 33, 3, 10, and 5, respectively. The proportion of invasive alien species originated from America, Europe, Asia, Africa, and Oceania were 55.1, 21.7, 9.9, 8.1, and 0.6%, respectively. Methods for estimation of direct economic losses to agriculture, forestry, stockbreeding, fishery, road and water transportation, storage, water conservancy, environment and public facilities, and human health were established. Methods for estimation of indirect economic losses caused by invasive alien species to service functions of forest ecosystems, agricultural ecosystems, grassland ecosystems, and wetland ecosystems were also established. The total economic losses caused by invasive alien species to China were to the time of USD 14.45 billion, with direct and indirect economic losses accounting for 16.59% and 83.41% of total economic losses, respectively.     

Prioritising wetlands subject to secondary salinisation for ongoing management using aquatic invertebrate assemblages: a case study from the Wheatbelt Region of Western Australia

Secondary salinisation is recognised worldwide as a threat to aquatic biodiversity. Wetlands in the Wheatbelt Region of Western Australia are particularly affected as a result of clearing of deep-rooted native vegetation for agriculture. Between 1996 and 2001, the Western Australian government nominated six natural diversity recovery catchments (NDRCs), being catchments with high value and diverse wetlands in need of protection. One, the Buntine–Marchagee NDRC, supports approximately 1000 wetlands in varying states of salinisation. The challenge is to prioritise these wetlands for ongoing management. In this paper we propose an approach to prioritise representative wetlands using aquatic invertebrates. On the basis of hydrology, salinity and remnant vegetation, 20 wetlands covering a range of salinities were selected for sampling of water quality and aquatic invertebrates. Of the 202 taxa recorded, most endemic taxa occurred in fresh/brackish wetlands, while hypersaline wetlands supported predominantly cosmopolitan species. Taxa richness was greater in fresh/brackish than saline and hypersaline wetlands, with conductivity explaining 83 % of between-wetland variation in taxa richness. Classification using invertebrate assemblages separated fresh/brackish, saline and hypersaline wetlands, with greatest between-year variability within saline and hypersaline sites. Wetlands were ranked using taxa diversity, presence of conservation-significant taxa and temporal similarity. Mean rank across indices provided the final overall order of priority. Hypersaline wetlands were ordered separately to the fresher water wetlands (fresh/brackish and saline) so that priority for future management was detailed for both types of wetlands. The analysis indicated that although fresh/brackish sites support the highest biodiversity, naturally saline sites also supported wetland assemblages worthy of ongoing protection.     

The potential role of waterbirds in dispersing invertebrates and plants in arid Australia

1. The role of waterbirds as vectors of plants and invertebrates within and between arid‐zone wetlands is poorly understood. We present the first detailed study of passive dispersal by nomadic birds in Australasia. We investigated the numbers and types of invertebrate and plant propagules within freshly collected faecal samples as well as their viability. We compared dispersal among Grey Teal (Anas gracilis), Eurasian Coot (Fulica atra) and Black Swan (Cygnus atratus) in the Macquarie Marshes, a complex of temporary to semi‐permanent wetlands in New South Wales. 2. When faecal samples (n = 60) were inundated in the laboratory and monitored over 3 weeks, ciliates (75% of samples), nematodes (22%), ostracods (13%) and rotifers (5%) were recorded, with higher taxon richness in coot samples. Faecal samples (n = 71) were also sieved to quantify intact propagules, and ostracod eggs (70% of samples), large branchiopod eggs (31%) and bryozoan statoblasts (31%) were the most abundant invertebrates. Diaspores of 19 plant taxa were recorded, 14 of which were germinated in the laboratory or shown to be viable at the end of germination trials. The abundance and diversity of invertebrate propagules was highest in coot samples, whereas the abundance and diversity of diaspores was highest in teal samples. 3. One Australian Pelican (Pelecanus conspicillatus) sample was obtained and found to contain more taxa and far more propagules than any sample from other waterbirds, suggesting that piscivorous birds might have an important role in the indirect dispersal of propagules ingested by fish. 4. Our results support a role for birds in explaining the distributions of cosmopolitan plant genera such as Lemna, Typha, Myriophyllum and Nitella. The alien plants Ranunculus sceleratus, Medicago polymorpha and Polygonum arenastrum were recorded, demonstrating the potential role of waterfowl in the spread of exotic species. As the frequency and duration of flooding of arid‐zone wetlands decreases owing to human activities, the importance of waterbirds in facilitating recolonisation of temporary wetlands is likely to increase.