BRANTA — Jennifer Smart
Strategies of sea-level rise mitigation for breeding Redshank
Institution: University of East Anglia, Norwich, UK
Supervisors: AR Watkinson, WJ Sutherland, JA Gill
Details: PhD 2005 (Completed)
Address: School of Environmental Science, University of East Anglia, Norwich, NR4 7TJ (Oct 2005) Email
Subject Keywords: breeding shorebirds, saltmarsh, grassland, stable isotopes, chick growth, chick survival, productivity
Species Keywords: Common Redshank Tringa totanus
Abstract
Amongst the key conservation implications of sea-level rise are reductions in the extent of saltmarsh and coastal grasslands, habitats which both have important nature conservation interests. This creates a situation in which (1) a trade-off between increases in saltmarsh at the expense of coastal grassland will exist, (2) options for mitigation are likely to be limited in the coastal zone and (3) improvements to inland habitat management could provide compensatory habitat. For species supported by these habitats, the relative quality of coastal and inland habitats is unknown. This thesis uses the redshank, Tringa totanus, a wading bird species that breeds on saltmarsh, coastal and inland grasslands, to address these issues. Redshank populations are declining across many countries and on all breeding habitats but declines inland have been most severe. Comparisons of breeding densities and breeding success between habitats give contrasting results. Breeding densities are highest on saltmarsh and coastal grassland but breeding success is very low, due to a combination of low hatching success resulting from predation and tidal flooding, and poor chick survival. On inland grassland, where breeding densities are lowest, breeding success is much higher than on either saltmarsh or coastal grassland. Despite extensive use of intertidal habitats for foraging by coastal breeding birds, access to intertidal foraging areas did not improve breeding success. Schemes aimed at creating saltmarsh are unpredictable in their outcome and likely to have significant time-lags (> 80 years). In contrast, grassland rehabilitation can be both rapid and effective because management can be optimised by providing shallow wet features and suitable vegetation. Thus, the higher success of inland grassland populations coupled with the success and potential for large areas of grassland rehabilitation to occur means that this could provide the best short-term solution to conserve breeding wader populations. In the long term, these populations may then act as centres for population expansion once saltmarsh creation schemes realise their biodiversity potential.
Published Papers
Smart, J., Sutherland, W.J., Watkinson, A.R. & Gill, J.A. 2004. A new means of presenting the results of logistic regression. Bulletin of the Ecological Society of America 85: 100-102.
Smart, J. & Gill, J.A. 2003. Climate change and the potential impact on breeding waders in the UK. Wader Study Group Bulletin 100: 80-85.