SOS: Bats Gone Missing!

Eco Hvar is not alone in being worried that bats are increasingly rare on Hvar Island.

Pipistrellus nathusii Pipistrellus nathusii Croatian Natural History Museum / Hrvatski prirodoslovni muzej

Once, not so long ago, they were plentiful. During the balmy summer evenings they would stream around any source of light, big or small, in the hunt for insects to feed on. I remember them milling purposefully around from my earliest days in Pitve over 25 years ago. In September 1993 there was one sleeping peacefully hanging from a beam in the wine-cellar. A friend remarked that having a bat on one's premises brought good luck to the house. This optimistic belief is not unique to Dalmatia. In traditional Chinese culture bats represent good fortune and blessings.

Colony, pipistrelli kuhlii. Photo courtesy of the Croatian Natural History Museum

In the last few years, bats have been less and less visible. In Pitve in 2016 I saw no more than a handful, and people in other places around the island have also reported seeing very few, if any bats, where once they were numerous.

Bats belong to the order Chiroptera, and are the only mammals capable of flying. There are over 1100 different types of bat in the world, making them the second largest group of mammals, after rodents. In Croatia there are 35 types, belonging to eleven families. Most of them feed on insects, while one, the rare giant noctule bat (Nyctalus lasiopterus) sometimes also catches smaller birds, while the long-fingered bat (Myotis capaccinii) can catch small fish.

Nyctalus noctula. Photo courtesy of the Croatian Natural History Museum

In Croatia Dr. Igor Pavlinić, Custodian of the Croatian Natural History Museum in Zagreb, has been involved in the study and protection of bats for many years. He is conducting a long-term project monitoring a colony of bats at Šćuza, including proposals for their protection. He has demonstrated how bats not only make their homes in woodlands, but also in the most diverse of places, from caverns, caves, abandoned mines and gaps in stones (mostly for winter hibernation), to loft spaces in houses and churches, chimneys, as well as spaces in the walls of bridges. Several colonies on Hvar bore this out. For example, over many years European free-tailed bats (Tadarida teniotis) nested in the belfry of the Church of Our Lady of Health above Jelsa. Sadly, following lengthy renovation works in the past few years, the bats disappeared and never returned.

Our Lady of Health, Jelsa, once a haven for bats. Photo Mirko Crnčević

Bats are said to be an 'index of health' in any given place. They do a good job, actually an essential service for human comfort. One bat can devour between 500 and 1,000 mosquitoes per hour; in the course if a night, it can consume prey equalling about one third of its body mass. Is it a coincidence that as bat numbers have fallen over the last few years, mosquitoes have become more and more of a problem, despite ever-fiercer desperate attempts to eradicate them with chemical poison sprays?

Bats are among the oldest surviving mammals, whose development probably began at the time when dinosaurs dominated the world. The evolution of bats gives rise to some of the most intriguing questions within the history of the evolution of today's mammals. The only thing the majority of scientists agree on is that the bat's early ancestor was a type of nocturnal insect-eating mammal which lived in trees. The latest molecular research has shown that the ape (homininoidea) arose in a later development from a common ancestor, providing a link to humans.

Eptesicus serotinus. Photo courtesy of the Croatian Natural History Museum

Eptesicus serotinus. Photo courtesy of the Croatian Natural History Museum

The decline of bats on Hvar is, sadly, not unique. Bats are under threat around the globe, some types are close to extinction. The Croatian State Institute for Nature Protection identifies several factors as potential causes of bat decline (brochure in Croatian):

1. LOSS OF HABITAT, including excessive felling of old established trees; adapting caves as tourist attractions; flooding of caves; renovation of old buildings without due care for bats' needs

2. LOSS OF NATURAL HUNTING GROUNDS

3. POISONOUS CHEMICAL TREATMENTS OF WOODEN RAFTERS

4. PESTICIDE USE

5. REDUCTION OF INSECTS (often through use of insecticides, and industrial-scale agriculture)

6. TOURISM IN CAVES

7. DISRUPTION TO NESTS AND WINTER COLONIES

8. WINDFARMS

9. DRYING UP OF SURFACE WATERS

10. POLLUTION OF WATER SOURCES

A monograph by I. Pavlinić published by the Natural History-Mathematics Faculty at the University of Zagreb places the blame for the bat decline squarely on inappropriate, careless human activity (article in Croatian).

'Man's activites to blame for bat decline'

Bats are strictly protected in Croatia, as in other European countries. According to the Law on the Protection of Nature (Zakon o zaštiti prirode - in Croatian), there are fines up to 200,000 kunas for disturbing, capturing, wounding or killing bats, and for damaging or destroying their habitats. There is also a separate fine of 1,000 to 4,000 kunas for each killed bat. Apart from the national law, since 2000 Croatia has also been party to the international agreement for the protection and conservation of European bats, entitled UNEP / EUROBATS. In the Sixth National Report on ther Implementation of the Agreement covering 2010 to 2014, the measures being undertaken in Croatia to monitor and protect bats were described. Most of the activity is on the mainland. Toxic timber treatments were given as a subject of special concern, but it seems there has been little specific study on the effects of pesticide use.

A single pipistrellus kuhlii. Photo courtesy of the Croatian Natural History Museum

The law takes into account deliberate and wilful damage caused to bats, but there is little in the way of an adequate system of control to prevent the harm done through pesticide use, building works and renovations, tourist developments and tree-felling. Bats can live for over 30 years, but they reproduce slowly, so any deaths of young bats in a colony causes a rapid decline in numbers. Protection measures are urgently needed. Every local council should initiate projects to provide adequate habitats for bats. Youngsters should be encouraged to observe bats and record their numbers, to raise awareness at local level.

We need these important and fascinating creatures. Their insect-eating capacities are an invaluable service to human health. With due effort and care, we can re-create the conditions which allow bats to thrive. They will repay the favour with infinite interest.

© Mirko Crnčević and Vivian Grisogono 2017

A Croatian version of this article by Mirko Crnčević was published in the magazine 'Dobra Kob', issue 184, January 2017, pp 52-55

Media

Bats hunting their prey BBC Earth
You are here: Home Nature Watch SOS: Bats Gone Missing!

Eco Environment News feeds

  • Freedom-of-information data reveals threat of drought that would devastate wildlife, with government slow to act on water management

    A quarter of England’s rivers are at risk of running dry, with devastating consequences for wildlife, according to data obtained by WWF under freedom of information rules.

    Fish are most obviously affected when rivers slow to a trickle, particularly those that migrate upstream such as salmon, trout, eels and lampreys. But animals such as water voles are also harmed, as they are unable to escape predators by fleeing into rivers to reach underwater entrances to their burrows. Birds such as kingfishers, sandpipers and dippers also suffer, as the insects and small fish they feed on die out.

    Continue reading...

  • Mayor of London wants urgent meeting with new environment secretary to press for action on toxic air quality

    The mayor of London, Sadiq Khan, has requested an urgent meeting with the new environment secretary, Michael Gove, to urge him to get a grip on Britain’s “life and death” air pollution crisis.

    This week, Khan activated the capital’s emergency alert system after experts warned toxic air in the capital had reached dangerous levels. Large parts of southern England and Wales were also affected on Wednesday.

    Continue reading...

  • Global warming will not affect everyone equally. Here we look at seven key regions to see how each is tackling the consequences of climate change

    It could have been the edge of the Sahara or even Death Valley, but it was the remains of a large orchard in the hills above the city of Murcia in southern Spain last year. The soil had broken down into fine white, lifeless sand, and a landscape of rock and dying orange and lemon trees stretched into the distance.

    A long drought, the second in a few years, had devastated the harvest after city authorities had restricted water supplies and farmers were protesting in the street. It was a foretaste of what may happen if temperatures in the Mediterranean basin continue to rise and desertification grows.

    Continue reading...

  • Bison, bluebells, bumble bees and beavers are among this week’s pick of images from the natural world

    Continue reading...

  • Six new vehicles including Land Rover and Suzuki are adding to air pollution crisis, despite stricter rules coming in months

    The latest diesel car models are failing to meet pollution limits when on the road, just three months ahead of stricter new tests, independent tests have found. Results show that none of six new 2017 diesel cars met the EU standard for toxic nitrogen oxides (NOx) pollution in real-world driving.

    The updated Equa Index, produced by the testing firm Emissions Analytics, shows that 86% of all diesel models put on to the British market since the 2015 Volkswagen emissions scandal failed to meet the official limit on the road, with 15% producing at least eight times more NOx emissions.

    Continue reading...

  • Nearly everyone other than science-denying Republican Party leaders understands the importance of a carbon pollution tax

    What do ExxonMobil, Stephen Hawking, the Nature Conservancy, and Ronald Reagan’s Secretary of Treasury and Chief of Staff have in common? All have signed on as founding members to the Climate Leadership Council, which has met with the White House to propose a revenue-neutral carbon tax policy.

    The group started with impeccable conservative credentials, bringing on cabinet members from the last three Republican presidential administrations (Ronald Reagan, George HW Bush, and George W Bush): two former Secretaries of State, two former Secretaries of Treasury, and two former chairmen of the President’s Council of Economic Advisors. It was founded by Ted Halstead, who explained the group’s proposed policy in a TED talk:

    Continue reading...

  • Although fracturing and surface melting on the Larsen C ice shelf might sound like indicators of climate change, these processes are natural

    Antarctica boasts a great many superlatives: it is the driest continent, the coldest, the remotest, the windiest and the highest on average. Right now, during midwinter, it is also the darkest. As a rift on the continent’s Larsen C ice shelf lengthens and gets closer to the ice front, we are anticipating the detachment of a large tabular iceberg within the next few weeks.

    This comes after observations of a waterfall on another ice shelf last summer, reports of extensive surface melting on several ice shelves and, in a report last week, indications of a widespread surface-melting event, which included rainfall as far as 82° south, during the 2015-16 El Niño. Are glaciologists shocked by any of this? Is Antarctica going to melt away? Is Larsen C about to collapse?

    Continue reading...

  • Damning report says nuclear project is bad for UK consumers and governments failed to assess alternative finance models

    Generations of British consumers have been locked into a “risky and expensive” project by the UK’s subsidy deal for a new nuclear power station at Hinkley Point in Somerset, according to a damning report by the spending watchdog.

    The National Audit Office said the contract sealed by ministers last September with EDF to construct the country’s first new atomic reactors in two decades would provide “uncertain strategic and economic benefits”.

    Continue reading...

  • A 20% shortfall in migrant workers relied on to pick fruit and vegetables is blamed on Brexit making the UK seem ‘xenophobic’

    Farms have been hit with a shortage of the migrant workers that Britain relies on to bring in the fruit and vegetable harvests, according to a series of new reports.

    There was a 17% shortfall in May, leaving some farms critically short of pickers, according to a new National Farmers Union (NFU) survey. The decline is blamed on Brexit, with the vote to depart the EU leaving the UK seen as “xenophobic” and “racist” by overseas workers, according to the director of a major agricultural recruitment company.

    Continue reading...

  • Deforestation in the Amazon is increasing amid cuts to protection, putting Norway’s financial aid in jeopardy, says minister

    Norway has issued a blunt threat to Brazil that if rising deforestation in the Amazon rainforest is not reversed, its billion-dollar financial assistance will fall to zero. The leaders of the two nations meet in Oslo on Friday.

    The oil-rich Scandinavian nation has provided $1.1bn to Brazil’s Amazon fund since 2008, tied to reductions in the rate of deforestation in the world’s greatest rainforest. The destruction of forests by timber and farming industries is a major contributor to the carbon emissions that drive climate change and Norway views protecting the Amazon as vital for the whole world.

    Continue reading...

Eco Health News feeds

Eco Nature News feeds