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.
Auteur: Eric
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Dramatic decline of bats in Northern Ireland
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.
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Severe decline of the lesser horseshoe bat in Switzerland
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.
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Long-term stream invertebrate community alterations induced by thiacloprid
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).
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Severe decline of butterflies on German calcareous grasslands during the last 30 years
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. -
Significant decline of Reed Buntings in England since the 1990s
A study identified two factors that may limit breeding productivity of the Reed Bunting Emberiza schoeniclus, which is in significant decline in England since the 1990s: ground vegetation providing concealment from nest predators and availability of invertebrate prey for chicks. The increased use of pesticides may have reduced invertebrate densities on most farmland.
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UK Tree Sparrow population crashed by 95% between 1974 and 1999
There has been a massive 95% decline in the UK Tree Sparrow Passer montanus population between 1974 and 1999. The nestling diet of Tree Sparrows is largely composed of invertebrates. It is possible that due to agricultural intensification in the late 20th century and increased use and effectiveness of insecticides there has been a decline in invertebrate prey, rendering large areas of farmland as suboptimal breeding habitat for Tree Sparrows.
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Starling in decline throughout Europe over the last two decades
Starling Sturnus vulgaris populations have declined throughout Europe over the last two decades. The Starling is commonest in urban and farmland habitats, though density in the latter is much lower. Soil and ground-dwelling invertebrates, particularly leatherjackets (tipulid larvae) and earthworms, are the main prey of Starlings. The use of insecticides on grassland is targeted partly at tipulids, which may have reduced foraging opportunities for Starlings.
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Large population decline of the song thrush in Britain
There has been a large population decline of the song thrush Turdus philomelos in Britain during the last three decades, which has reduced breeding densities on farmland by nearly 70% between 1968 and 1999. Survival of birds in their first year of life after fledging was shown to have a great impact on population changes. Changes in survival in the first winter are sufficient to have caused the song thrush population decline. Earthworms and other soil-dwelling invertebrates form a large component of the diet of song thrushes, particularly between December and May. Earthworms move deeper into the soil and/or become inactive during periods of cold weather and hence become less available as prey for song thrushes. Reduced availability of invertebrate food could explain reduced survival in the winter.
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Voor veel bedreigde vogelsoorten is de mestfauna een belangrijke voedingsbron
Ongewervelden die zich in de mest bevinden, zoals larven van vliegen en mestkevers, zijn een voedingsbron voor insectenetende vogels maar vaak ook een belangrijke eiwitbron voor de jongen van vogels waarvan de volwassenen zaadetend zijn: spreeuwen Sturnidae, kraaiachtigen (o.a. roek Corvus frugilegus, kauw Corvus monedula, zwarte kraai Corvus corone en ekster Pica pica), leeuweriken Alaudidae, gierzwaluwen Apus apus, zwaluwen (o.m. huiszwaluw Delichon urbicum en boerenzwaluw Hirundo rustica) en kwikstaarten Motacillidae (witte kwikstaarten Motacilla alba eten Sphaeroceridae).
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