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.
John Pickrell in England for National Geographic News
February 2, 2004
Bat activity may be up to 60 percent greater on organic farms than conventional farms in the United Kingdom, according to a new report. The study also revealed that one endangered European bat was completely absent on non-organic farms tested. A second study, published in the science journal Conservation Biology, reveals that insect families which are key to British bat's diets are significantly more abundant and diverse on organic farms.
In the last few decades bat populations have been declining at alarming rates worldwide. Bats remain the most endangered land mammal in the United States. An important factor could be increased use of pesticides, both in agriculture and in the treatment of building materials against pests. Bats are the primary predators of night-flying insects and will live or relocate to areas where there are lots of insects.
BY SONIA SHAH
For decades, toxicologists have accrued a range of evidence showing that low-level pesticide exposure impairs immune function in wildlife, and have correlated this immune damage to outbreaks of disease. In the past dozen years, three new diseases have decimated populations of amphibians, honeybees, and — most recently — bats. Increasingly, scientists suspect that low-level exposure to pesticides could be contributing to this rash of epidemics. The recent spate of widespread die-offs began in amphibians. Scientists discovered the culprit — an aquatic fungus called Batrachochytrium dendrobatidis, of a class of fungi called “chytrids” — in 1998. Its devastation, says amphibian expert Kevin Zippel, is “unlike anything we’ve seen since the extinction of the dinosaurs.” Over 1,800 species of amphibians currently face extinction. There is a strong correlation between pesticide use and declining amphibian populations. Six years after scientists discovered the fungal assault on amphibians, a mysterious plague began decimating honeybees.