English
On lowland wet grassland sites in England and Wales there were significant declines of 38% for Lapwing Vanellus vanellus, 61% for Snipe Gallinago gallinago, 40% for Curlew Numenius arquata and 29% for Redshank Tringa totanus between 1982 and 2002. Oystercatcher Haematopus ostralegus increased significantly by 47% in the same period.
The number of Oystercatchers (Haematopus ostralegus) in the Dutch Wadden Sea has declined by 40% during the last two decades. The number of breeding pairs declined 4.6% annually. Reproductive output was virtually zero in the last 7 years, which was associated with a dramatic decline in summer of two prey species for raising the young, i.e. ragworm and Baltic tellin. Oystercatcher numbers have also declined on the Wash, England since the late 1980s, due to changes in winter survival, which was related to cockle and mussel abundance. Poor recruitment of juvenile shellfish to the Wash populations was implicated in the decline in both mussels and cockles. American Oystercatchers are also at risk in coastal ecosystems. The number of Oystercatchers breeding on barrier islands in Virginia has decreased by more than 50% in the last 20 years.
A recent study indicates high toxicity of imidacloprid to the non-target terrestrial arthropod P. scaber when compared to birds and mammals. Imidacloprid affects isopods at similar exposure concentrations as insects.
The new GABA-disrupting insecticide fipronil may pose a high risk to copepod production in estuarine systems. Copepods are the most abundant arthropods on earth and often the most important secondary producers in estuarine/marine food webs.
Imidacloprid can be applied as a systemic insecticide to trees by direct stem injections or by soil injections and drenches, and be indirectly introduced to aquatic systems via leaf fall or leaching, which may pose a risk to natural decomposer organisms. When applied directly to aquatic microcosms to simulate leaching from soils, imidacloprid was shown to be highly toxic to aquatic insects. Imidacloprid at realistic field concentrations in maple leaves had adverse effects on aquatic insects and earthworms. Imidacloprid at realistic concentrations in leaves can inhibit leaf litter breakdown through adverse effects on decomposer invertebrates. When imidacloprid is applied as a systemic insecticide to the soil around trees it may cause adverse effects on earthworms.
A quarter of the total UK landmass (6,000,000 ha) received annual treatment with insecticides between 1990 and 2003. The overall weight of active ingredients used has declined due to newer compounds with greater intrinsic insecticidal activity.
There are eight species of bat in Northern Ireland all of which are insectivorous. Bat populations have declined dramatically in recent years throughout Northern Ireland.
Once the lesser horseshoe bat was known to be widespread and common in Switzerland. In the past 50 years their overall population has undergone a severe decline, as in most countries of Central Europe. The most threatening factors are thought to be pesticides, changes in the structure of habitats and food shortage.
The effect of a single pulse contamination with the neonicotinoid insecticide thiacloprid on invertebrates was investigated in mesocosms designed to realistically mimic communities in small streams within the agriculural landscape. The contamination resulted in long-term alteration of the overall invertebrate community structure. One species, the stonefly Nemoura cinerea, was affected at the lowest tested concentration, 70 times below the lowest known median lethal concentration (LC50).
A study of the species composition of seven calcareous grassland remnants in south-western Germany in 1972 and 2001 revealed a strong change in the community composition and a severe decline in species richness of butterflies.
In general, the incidence of the autochthonous non-ubiquitous species declined by more than 50%, whereas ubiquitous species showed no significant difference in numbers during this period. Especially affected by the decline were those species which need structured habitats, those which are poor dispersers, species which need habitat sizes of 16 ha and more, monophagous species, K strategists and Red Data Book species.