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

  • Scientists say restoring the lush habitats would boost wildlife, protect coasts and store carbon

    The UK has lost more than 90% of the lush seagrass meadows that once surrounded the nation, research has found.

    Scientists described the decline as catastrophic, but the latest analysis also shows where the flowering plants could be restored. A resurgence of seagrass meadows would rapidly absorb the carbon dioxide that drives the climate crisis and provide habitats for hundreds of millions of fish, from seahorses to juvenile cod.

    Continue reading...

  • Equivalent falls in emissions over a decade required to keep to safe limits of global heating, experts say

    Carbon dioxide emissions must fall by the equivalent of a global lockdown roughly every two years for the next decade for the world to keep within safe limits of global heating, research has shown.

    Lockdowns around the world led to an unprecedented fall in emissions of about 7% in 2020, or about 2.6bn tonnes of CO2, but reductions of between 1bn and 2bn tonnes are needed every year of the next decade to have a good chance of holding temperature rises to within 1.5C or 2C of pre-industrial levels, as required by the Paris agreement.

    Continue reading...

  • Cross-party environmental audit committee welcomes decision but urges Treasury to go further

    The chancellor has changed the remit of the Bank of England’s interest rate-setting monetary policy committee to include a duty to support the government’s net zero carbon ambition alongside its longstanding responsibility to keep inflation in check.

    Rishi Sunak made the change to reflect the importance of environmental sustainability, he said.

    Continue reading...

  • The pygmy hog is still endangered but a reintroduction programme in Assam, India, has given it a greater chance of survival

    The greyish brown pygmy hog (Porculasalvania), with its sparse hair and a streamlined body that is about the size of a cat’s, is the smallest wild pig in the world, and also one of its rarest, appearing on the International Union for Conservation of Nature (IUCN) red list as endangered.

    Named after the sal grasslands where they were first found, they once thrived in the lush plains of the sub Himalayas from Nepal to Uttar Pradesh. But today, there are thought to be less than 300 in the wild, in Assam, India.

    Continue reading...

  • Ojok Okello is transforming his destroyed village into a green town where social enterprises responsibly harness the shea tree

    The village of Okere Mom-Kok was in ruins by the end of more than a decade of war in northern Uganda.

    Now, just outside Ojok Okello’s living-room door, final-year pupils at the early childhood centre are noisily breaking for recess and a market is clattering into life, as is the local craft brewery, as what has become Okere City begins a new day.

    Continue reading...

  • The energy industry is like a smoker who goes from one pack a day to two – but claims they’re quitting because they switched to filtered cigarettes

    The United Nations campaign Race to Zero recently published a paper identifying 20 pathways to reach net zero carbon emissions. In December, the British Oil & Gas Authority published a requirement that oil and gas development be “consistent with net zero” (despite approval of new offshore permits). BP, Shell and other multinational companies have all now published their “net zero” pathways.

    Related:The climate crisis can't be solved by carbon accounting tricks | Simon Lewis

    Continue reading...

  • Drivers of decline likely to be habitat loss, intensive farming, climate change and light pollution

    Moths in Britain have declined in abundance by a third over the past 50 years, according to a new study.

    The declines of 39% in the abundance of larger moth species over southern Britain and a 22% fall across northern Britain add to the picture of calamitous declines in flying insects in the industrialised world.

    Continue reading...

  • Government reversed a ban on a neonicotinoid earlier this year - but says chemical was not needed

    A pesticide which reduces bee populations and was to be used in England’s sugar beet fields this year will not be used after recent cold weather killed off virus-transmitting aphids.

    The government broke an explicit pledge earlier this year when it reversed a ban on a product containing the neonicotinoid thiamethoxam, sanctioning its emergency outdoors use this year because of the threat posed by a virus after pressure from the National Farmers’ Union and British Sugar.

    Continue reading...

  • Area to be seeded with 70 grass and flower species and planted with native trees to create wood pasture

    A “rewilding” of arable fields by HS2 will create 127 hectares (314 acres) of wood pasture, wetlands and flower-rich grassland using chalk taken from tunnelling under the Chilterns.

    The new wildlife haven will be founded upon all 3m tonnes of chalk that are to be excavated from the high-speed railway’s 10-mile Chilterns tunnel, with construction starting in May.

    Continue reading...

  • Confining rivers creates valuable agricultural land but can lead to greater flood risk downstream

    For many of us across the UK it has felt like another wet winter; yet again homes have flooded and politicians are under pressure to improve flood protection. Engineering our rivers and building defences might bring reassurance, but recent research shows that doing nothing is often more effective at reducing flooding.

    George Heritage and Neil Entwistle from the University of Salford studied the River Caldew in Cumbria; responsible for three major floods in Carlisle since 2010. Their results, published in the journal Water, show that the straightening, deepening and widening of the river has increased the rate at which sediment whooshes downstream, dumping its load in Carlisle and increasing the chances of overflow there. But where this upstream river maintenance has been relaxed they found the river has reverted to wandering, depositing more sediment upstream and reducing the clogging up in Carlisle.

    Continue reading...

Eco Health News feeds

Eco Nature News feeds

Feed not found.