20 research outputs found
Birds, bogs and forestry: the peatlands of Caithness and Sutherland
NCC’s Upland Bird Survey had surveyed a significant area of the Flow Country between 1979 and 1986, and the 1987 report analysed and published the data from those surveys, together with those obtained from eight sites in Caithness surveyed by RSPB in 1985 using NCC methods.
The results highlighted losses of up to 19% of the populations of Golden Plover, Greenshank and Dunlin in the Flow Country area as a result of then widespread and rapidly occurring afforestation of the peatlands. NCC considered that this land-use change represented “perhaps the most massive single loss of important wildlife habitat in Britain since the Second World War.”
Although Birds, bogs and forestry also included summary results from other NCC surveys in Caithness and Sutherland, these studies of peatland vegetation were reported in more detail in the complementary report The Flow Country, published by NCC the following year.
As a result of the case made by Birds, bogs and forestry and The Flow Country, a substantial proportion of the extent of these peatlands was designated as a Ramsar site and also classified under European nature Directives as a Special Protection Area and Special Area of Conservation
Change in the distribution of a member of the strand line community: the seaweed fly (Diptera: Coelopidae)
1. Coastal organisms are predicted to be particularly susceptible to the impact of global warming. In this study the distribution and relative abundance of two coastal invertebrates, Coelopa frigida (Fabricius) and C. pilipes are investigated. 2. Coelopa pilipes has a more southerly distribution than C. frigida , and prefers a warmer climate. Coelopa pilipes is less resistant to sub-zero temperatures than C. frigida and its northerly distribution is probably limited by cold winter days. 3. The most recent distribution map of C. frigida and C. pilipes in northern Europe was published a decade ago and showed the northerly extent of the distribution of C. pilipes reaching the north coast of mainland Scotland but its complete absence from the Western and Northern Isles. 4. C. pilipes has now spread throughout the Western Isles and the Orkney Islands but is still absent from Shetland. There has also been an increase in the relative frequency of C. pilipes at sites harbouring coelopids on the British mainland. A similar pattern of distribution change along the west coast of Sweden is reported. 5. It is proposed that these changes have occurred primarily as a result of global warming and in particular due to the recent increase in winter temperatures. A number of other indirect effects may have also contributed to these changes, including a probable change in macroalgae distribution. The implications of these changes for the wrack bed ecosystem and at higher trophic levels are considered
Day-night activity of intertidal invertebrates and methods to estimate prey accessibility for shorebirds
Competition for feeding in waders: a case study in an estuary of south temperate Europe (Mondego, Portugal)
The loss of feeding areas may pose a threat to many wintering waders because increased competition arising from reduced foraging space may force birds either to emigrate or to die. This has been demonstrated to occur in northwest European estuaries, but virtually no studies have been performed in the estuaries of southern Europe, where the loss of supratidal habitats (salines and saltmarshes), rather than intertidal habitats, are currently the main threat to waders’ habitats. If these habitats are lost, waders may be forced to move to the intertidal mudflats, perhaps increasing competition between individuals and ultimately leading to starvation or emigration. We tested this hypothesis in the Mondego estuary, a small estuary on Portugal’s west coast, which is presently under heavy human pressure. We used indirect methods to test for the occurrence of both components of intra-specific competition: interference and prey depletion. We found no evidence that either interference or depletion competition was occurring at present, either on the mudflats or in the salines. Overall, the results suggest that the intertidal mudflats may still be able to accommodate birds displaced from the destroyed supratidal salines, but modelling is required to predict the effect that the combined loss of feeding area and foraging time that this would entail would have on their fitness, and thus numbers