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

Eco Environment News feeds

  • Six-year-old Xanda was shot and killed by hunters when he roamed outside the protected area of the Hwange National Park in Zimbabwe

    A son of Cecil the lion has been killed by trophy hunters in Zimbabwe, meeting the same fate as his father whose death in 2015 caused a global outcry.

    Xanda was six years old and had fathered a number of cubs himself. He was shot on 7 July just outside the Hwange National Park, not far from where Cecil died, but news of the death only became public on Thursday.

    Continue reading...

  • Pangolins are the world’s most trafficked wild mammal and decimated Asian populations have sharply shifted the focus of exploitation to Africa

    The true scale of the slaughter of pangolins in Africa has been revealed by new research showing that millions of the scaly mammals are being hunted and killed.

    Pangolins were already known to be the world’s most trafficked wild mammal, with at least a million being traded in the last decade to supply the demand for its meat and scales in Asian markets. Populations of Asian pangolins have been decimated, leaving the creatures highly endangered and sharply shifting the focus of exploitation to Africa’s four species.

    Continue reading...

  • Hotels and local government in Cancún will pay premiums, and insurance industry will pay out if the reef is damaged by storms

    A stretch of coral reef off Mexico is the testing ground for a new idea that could protect fragile environments around the world: insurance.

    The reef, off the coast of Cancún, is the first to be protected under an insurance scheme by which the premiums will be paid by local hotels and government, and money to pay for the repair of the reef will be released if a storm strikes.

    Continue reading...

  • Summer’s here, and so are bees. These new macro images by Alejandro Santillana are being showcased in the Insects Unlocked project at the University of Texas at Austin

    Continue reading...

  • Photographer Matthew Staver and writer Oliver Milman visited the US National Wildlife Property Repository, where illegal wildlife products, from stuffed tigers to worked ivory, are stored and counted

    If the US had a national house of horrors, it would probably be the federal government compound that lies on the fringes of Denver, Colorado, incongruously set within a wildlife reserve where bison languorously dawdle against a backdrop of the snow-crowned Rockies.

    The National Wildlife Property Repository, operated by the US Fish and Wildlife Service (FWS), is a warehouse of the macabre. It’s a Noah’s ark of protected deceased biodiversity that smugglers attempted to get into the US before being caught by FWS staff at airports and ports.

    Continue reading...

  • The endangered wild dogs are well adapted to high temperatures but a warming world means pup survival is plummeting, study shows

    Rising temperatures are making it too hot for African wild dogs to hunt and the number of their pups that survive is plummeting, according to a new study. The research is among the first to show a direct impact of increased heat on wildlife that appears well adapted to high temperatures.

    There are only 7,000 African wild dogs left in the wild and they have lost 93% of their historic ranges to humans. Research earlier in July suggested that a “biological annihilation” of wildlife in recent decades means a sixth mass extinction in Earth’s history is already under way.

    Continue reading...

  • First global analysis of all mass–produced plastics has found humans have produced 8.3bn tonnes since the 1950s with the majority ending up in landfill or oceans

    Humans have produced 8.3bn tonnes of plastic since the 1950s with the majority ending up in landfill or polluting the world’s continents and oceans, according to a new report.

    The first global analysis of all mass–produced plastics has found that it has outstripped most other man-made materials, threatening a “near permanent contamination of the natural environment”.

    Continue reading...

  • The vast majority of newly built stations in Indonesia relied on export credits agencies or development banks, says study by Market Forces

    The much-discussed boom in coal-fired power in south-east Asia is being bankrolled by foreign governments and banks, with the vast majority of projects apparently too risky for the private sector.

    Environmental analysts at activist group Market Forces examined 22 deals involving 13.1 gigawatts of coal-fired power in Indonesia and found that 91% of the projects had the backing of foreign governments through export credit agencies or development banks.

    Continue reading...

  • Brexit department warns EU counterparts it will ‘return waste to its country of origin’ if an agreement on nuclear cooperation cannot be reached

    Britain has warned the EU that it could return boatloads of radioactive waste back to the continent if the Brexit talks fail to deliver an agreement on nuclear regulation.

    In what is being taken in Brussels as a thinly veiled threat, a paper setting out the UK position for the negotiations stresses the right “to return radioactive waste … to its country of origin” should negotiations collapse.

    Continue reading...

  • Catholic order builds chapel in middle of cornfield in attempt to use religious freedom protections to block Atlantic Sunrise pipeline

    Catholic nuns in Pennsylvania are resisting plans to build a $3bn pipeline for gas obtained by fracking through its land by creating a rudimentary chapel along the proposed route and launching a legal challenge, citing religious freedom.

    The Adorers of the Blood of Christ order has filed a complaint against the Federal Energy Regulatory Commission (FERC) in a bid to keep the pipeline off their land. The nuns’ lawyers argue in court papers that a decision by FERC to force them to accommodate the pipeline is “antithetical to the deeply held religious beliefs and convictions of the Adorers”.

    Continue reading...

Eco Health News feeds

Eco Nature News feeds