The effectiveness of Ramsar and IBA site designation for the conservation of migratory waterbirdsin Africa David Kleijn1, Szabolcs Nagy2, Simon Delany2, Oliver Nasirwa2, Tim Dodman2, Paul Goedhart1 Alterra and Wetlands International
Overview • Relevance • Data sources • Methodology • Results • Discussion
Relevance • WP3: Development of methods for the evaluation of the impact of the Natura 2000 network on conservation status and efficiency of the network • % of the resource • trends • conservation measures • African study, but the methodology can be adapted to evaluate the contribution of the Natura 2000 network to the conservation status of wintering waterbirds
The African Waterbird Census • Launched in 1991 • 197,043 records • 341 taxa • 1,631 sites • 44 countries • Counts • mid-January • mid-July
Methodology • Spatial overlay • International Waterbird Census (6326 plots) • Important Bird Areas (485 sites) • Ramsar Sites (252 sites) • Analysis • 1987-2007 • Retained only those species where • years of data: >7 AND • residual error degrees of freedom: >9 • Trend analysis on log-transformed data assuming normal error distribution • Linear mixed model with multipe error strata • Plot as random factor, • Basic model: Log(counts) = plot + country + trend • Designation model: Log(counts) = plot + country + IBA + Ramsar + trend + trend.IBA + trend.Ramsar • interaction term trend.IBA tests whether trends in count sites with IBA (but not Ramsar) designation differ from count sites without any designation
Results Figure 3. Across species average population trends observed in count plots located in Ramsar sites, IBAs and non-designated sites (regular). Bars indicate means ± se’s. • African wintering population trends estimated for 26 of 29 species • 8 species with significant positive trend; • 1 species with significant negative trend; • All species in higher numbers in Ramsar sites • 12 species in higher numbers in IBAs • Common Teal and Black-winged Stilt significantly more positive trends in Ramsar sites • Averaged over all species, trends did not differ significantly in Ramsar sites • Little Bittern, Black-tailed Godwit, Pied Avocet and Common Sandpiper significantly more positive trend in IBAs • Northern Shoveler and Caspian Tern were significantly more negative • Averaged across all species, winter population trends were somewhat higher in IBAs, but not significantly • The number of observed birds increased with increasing age of the Ramsar sites in case of ducks and waders, but not terns and gulls.
Discussion • No clear improvements due to Ramsar or IBA designations • Are these instruments ineffective? • Not necessarily • Castro (2002): Ramsar sites experienced strong increase in protection efforts • Buchanan (2009): 57% of IBAs in protected areas and vegetation in IBAs was less disturbed • Issues encountered • Methodological issues • limited statistical power (low sample size); • limitations of spatial analysis; • confunding effect of enhanced monitoring capacity and experience; • Data for designated and undesiganted sites are not independent • Process issues • variable degree of conservation measures even within categories; • conditions in designated sites might be not substantially different than in non-designated sites; • not all IBAs or Ramsar sites are key sites for all species; • Key improvement: monitoring also site conditions
Relevance for WP3 • There is a methodology is available, though it needs refinement; • As a site-based monitoring method, the IWC is very suitable to assess the contribution of the Natura 2000 sites to the conservation status of waterbird species; • The IWC data are much better in Europe than in Africa. Hence, the statistical power is expected to be better. • Long data series may allow before/after designation analyses; • Count data from other seasons are also available at national level in many Member States. • Such analysis can be linked with other components of WP3 (i.e. conservation measures and coverage).