The bat population is declining and scientists have found that it could be partly due to constant exposure to metals.
In recent years, the number of bats has seen a rapid decline. Several factors have been found to contribute to it, including deforestation, loss of food and water source, climate change and intensified agriculture. Just recently, thousands of bats invaded an Australian town to hunt for food.
Researchers from the University of York, however, have found that a large population of bats has high levels of metals that are now causing toxicity.
Majority of bat habitats in the UK, particularly those previous mining sites, have had high metal concentration since the Industrial Revolution. Bats get the metals into their system via ingestion of the flora and fauna that has accumulated the metals coming from the soil.
About 190 dead pipistrelle bats found across Wales and England were studied, their organs and tissues analyzed for presence of metals. Researchers have found that the levels of metals are comparable to what is considered toxic for mammals.
As much as 21 percent of the bats have at least one metal residue high enough to cause toxicity. Lead, in particular, was found in as much as 11 percent of the dead bats. Researchers also found cadmium, copper and zinc in high concentrations.
"The percentage of bats in which concentration of metals exceed toxic thresholds suggest that a significant proportion of the bat population in England and Wales may be affected by metal exposure," said Professor Alistair Boxall, who mentored the researchers.
Boxall went on to say that many of the bats are in constant exposure to a variety of stressors in the environment. Further research focused on understanding the interactions among stressors could significantly help in conserving the bat population. He believes that studying sediments and water would help them determine how these sources of metal pollution affect accumulation. Boxall added that it is also important to study how these metals affect the bats' immune system.
The results of the study are published in Environmental Pollution.
Bats For Ecosystem
Why is there a need to preserve the bat population? Simple. Bats are important.
Bats, all 1,300 species of them, play major ecological roles that are important in maintaining the health of the natural ecosystem and human economics.
Their consumption of insects, particularly the disruptive agricultural pests, brings balance to the ecosystem. They are also very good pollinators. As a matter of fact, even their droppings are good fertilizers.
Without the bats, the ecosystem will collapse. For this reason, bats are often referred to as "keystone species."
Photo: Gilles San Martin | Flickr
