Long-term environmental influences on the ecology and conservation of river birds

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Covering less than 1% of Earth's surface, freshwater ecosystems host around 10% of the Earth's species and a third of all vertebrates. This includes almost 2000 bird species - roughly 20% of the global total - that depend on inland waters or their margins for all or part of their life cycle. Simultaneously, however, many of these species are exposed to multiple, global environmental stressors on freshwaters that are now responsible for rates of extinction and impairment faster than in any other ecosystem. There is a need to understand the processes, assess the consequences for ecosystems and ecosystem-services, and for management strategies to halt or reverse adverse effects. In the UK, Dippers Cinclus cinclus and Grey Wagtails Motacilla cinerea are associated closely with streams and rivers, but now have respectively 'amber' and 'red' conservation status following population decline since the 1970s. Research over 35 years has shown that 1) these species are connected integrally to the quality/quantity of invertebrate production in freshwaters (Ormerod & Tyler 1991) 2) their distribution, abundance and life histories are affected by freshwater ecosystem stressors such as pollution, persistent contaminants, plastics, climatic variation and physical habitat character (Vaughan et al. 2007; Windsor et. 2019). As a result, these species are recognised globally as indicators of the quality of rivers and their surrounding catchments. This project will use this detailed knowledge to assess factors responsible for variations in the distribution, abundance and demography of Dippers and Grey Wagtails areas of their upland range - specifically Mid/South Wales Focusing mostly on rural rivers, we will pay attention to growing concerns about the influence of intensifying agriculture on the ecology of rivers and river birds to ask: How do the distribution, abundance and demography of river birds relate to land use in space/time, and through what freshwater ecological processes? Specifically:i) How does land use affect the breeding performance, demography and fitness of river birds?ii) How does land use alter freshwater prey availability and prey use for river birds?iii) How do land use effects on water quality and physical habitat affect river birds?iv) How does land use affect pollutant exposure in river birds?v) Is there any evidence that mitigation strategies in catchments or riparian zone can offset any adverse effects revealed by i) to iv)?