1. Dabbling ducks (Anatinae) are omnivorous birds that are widespread, numerous, highly mobile\udand often migratory, and therefore have great potential for (long distance) dispersal of other organisms,\udincluding plants. However, their ability to act as plant dispersal vectors has received little\udattention compared to frugivores and is often assumed to be relevant only for wetland species.\ud2. To evaluate the potential for plant dispersal by dabbling ducks, we collated and analysed existing\uddata. We identified all plant species whose seeds have been recorded in the diets of the seven dabbling\udduck (Anas) species in the Western Palaearctic, as reported from gut content analyses. We then\udanalysed the habitats and traits of these plant species to identify general patterns, and related these\udto data on gut passage survival and duck movements.\ud3. A large number of plant species (> 445 species of 189 genera and 57 families) have been recorded\udin the diet of dabbling ducks. These plant species represent a very wide range of habitats, including\udalmost the full range of site fertility, moisture and light conditions, excluding only very dry and deeply\udshaded habitats. The ducks prefer seeds of intermediate sizes (1–10 mm3), which have good chances to\udsurvive gut passage, but also ingest smaller and larger seeds. Ingested seeds represent a wide range of\uddispersal syndromes, including fleshy fruits. Many species (62%) were not previously considered animal-\uddispersed in plant data bases, and 66% were not identified as bird-dispersed. Rarefaction analyses\udsuggest that our analysis still greatly underestimates the total number of plant species ingested.\ud4. Synthesis. Dabbling ducks do not exclusively ingest seeds of wetland plants, which make up only\ud40% of the ingested species. Rather, they feed opportunistically on a wide cross-section of plant\udspecies available across the landscapes they inhabit. Given the millions of ducks, the hundreds to\udthousands of seeds ingested per individual on a daily basis, and known gut passage survival rates,\udthis results in vast numbers of seeds dispersed by ducks per day. Internal seed dispersal by dabbling\udducks appears to be a major dispersal pathway for a far broader spectrum of plant species than previously\udconsidered
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