Vleermuizen

Herbicides and insecticides can both affect the abundance of insect prey available to bats

Bats are intriguing animals – the world’s only true flying mammals and one of the most diverse mammal groups on Earth – second only to the rodents in number of species, they occur on every continent except Antarctica. Throughout Great Britain and Northern Ireland – as elsewhere in western Europe – bat populations have declined dramatically in recent years. Several species of bats are now seriously threatened, and in the last decade one species – the greater mouse-eared bat – became extinct as a UK breeding species. Even the more common bats have suffered dramatic declines. Pipistrelle numbers, for example, are estimated to have dropped by about 70% during the 15-year period 1978-1993. In the UK, bats eat only insects and changes in agricultural practices appear to be an important factor in declining bat numbers. Herbicides and insecticides can both affect the abundance of insect prey available to bats. Hedgerows and ponds, both widely used by bats, have been lost from the countryside at an alarming rate – even in recent years. For example 23% of hedgerows and 75% of ponds were lost during the period 1984 to 1990. Woodland habitats, including old trees, have declined also.

Het aantal hondsdolle vleermuizen neemt toe

Er worden jaarlijks gemiddeld zo'n 120 gevonden vleermuizen bij diverse opvangplekken binnengebracht. Het aantal zieke en gewonde vleermuizen dat de laatste jaren is gecontroleerd steeg van 107 in 2011 naar 133 in 2012. Sinds 2010 hadden ze bij de Stichting Vogelklas Karel Schot geen hondsdolle vleermuizen gezien, maar eind vorig jaar, zaten ze er ineens met twee opgescheept.

Dode bij, stille lente

Het instorten van bijenkolonies in heel de Verenigde Staten en Europa. De massale sterfte van kikkers in meertjes in de Sierra Nevada. De woekering van infecties onder de Japanse rijstvis. De kaalslag onder vleermuizen. De dramatische daling in het aantal weidevogels. Al dit leed brengt de Nederlandse toxicoloog Henk Tennekes in verband met een nieuw type pesticiden, de neonicotinoïden. Deze middelen zijn sinds de jaren negentig big business. Hun grote voordeel voor boeren en tuinders: je hoeft ze niet over het land te spuiten, maar je kunt ze als coating op plantenzaadjes aanbrengen. Maar volgens Tennekes is de grootschalige verspreiding op gewassen en in het oppervlaktewater de opmaat tot een ecologische ramp. De toxicoloog uit Zutphen vond een werkingsmechanisme dat ervoor zorgt dat chronische blootstelling aan neonicotinoïden al bij zeer kleine hoeveelheden fnuikende gevolgen heeft. Neurologisch onderzoek zou uitwijzen dat het zenuwgif zelfs de ontwikkeling van de menselijke foetus kan aantasten. Samen met wetenschappers uit Engeland en Australië publiceerde Tennekes onlangs een alarmistisch artikel in het Journal of Environmental Immunology and Toxicology (bijlage). 'Dit artikel is een wake-upcall voor de wereldautoriteiten, milieuagentschappen en wetenschappers,' besloten de auteurs.

Bats recovering from white-nose syndrome (WNS) show evidence of IRIS, a condition that is experienced by HIV-AIDS patients

According to a hypothesis proposed by the U.S. Geological Survey and collaborators at National Institutes of Health, bats recovering from white-nose syndrome show evidence of immune reconstitution inflammatory syndrome (IRIS), a condition that was first described in HIV-AIDS patients. IRIS is a syndrome in which an organism's immune system, which has been suppressed, reactivates and, perceiving a serious infection around it, goes into overdrive resulting in severe inflammation and tissue damage in infected areas. In both human patients with HIV-AIDS and bats with WNS, the functioning of the immune system is severely reduced. For humans, this occurs when the HIV virus attacks the patient's white blood cells. In bats, this occurs during normal hibernation. IRIS can be fatal to both humans and bats.
"The potential discovery of IRIS in bats infected with white-nose syndrome is incredibly significant in terms of understanding both the reasons for bat mortality and basic immune response," said USGS Director Marcia McNutt. "This discovery could also prove significant for studies on treatment for AIDS."

The British Wildlife Trusts Position Statement on Neonicotinoids

There is a growing body of evidence that shows that neonicotinoids have a detrimental effect at sub-lethal doses on insect pollinators. For this reason, The Wildlife Trusts believe that until it can be categorically proven that neonicotinoids are not adversely impacting pollinator populations, and by extension ecosystem health, Government should adopt the precautionary principle and place a moratorium on their use on all outdoor crops.

Review of what is known about White-nose syndrome and Geomyces destructans

White-nose syndrome (WNS) is a newly emergent disease that potentially threatens all temperate bat species. A recently identified fungus, Geomyces destructans, is the most likely causative agent of this disease. Until 2009, WNS and G. destructans were exclusively known from North America, but recent studies have confirmed this fungus is also present in Europe. We assembled an international WNS consortium of 67 scientists from 29 countries and identified the most important research and conservation priorities to assess the risk of WNS to European bats. Here, we review what is known about WNS and G. destructans and detail the conservation and research recommendations aimed at understanding and containing this emerging infectious disease.

Pflanzenschutzmittel gefährden Fledermäuse

Fledermäuse sind eine hochbedrohte Tiergruppe. Die gesamte Tiergruppe steht in Europa unter Schutz. Zehn von 19 in Deutschland beheimateten Fledermausarten werden bereits auf der Roten Liste der bedrohten Tierarten geführt. Umso bedenklicher ist es, dass beim EU-weiten Zulassungsverfahren von Pflanzenschutzmitteln die Auswirkungen auf Fledermäuse nicht überprüft werden. Eine Studie der Universität Koblenz-Landau zeigt nun, dass die Pestizidbelastung der Nahrung zu Langzeiteffekten bei Fledermäusen führen kann.

Stay away from bats

Rabies is a virus that affects the nervous system of humans and other mammals. Humans can get rabies after being bitten by an infected animal. Rabies can also be contracted when saliva from a rabid animal gets directly into a person’s eyes, nose, mouth or a wound. People usually know when they have been bitten by a bat, but bats have very small teeth and the bite mark may not be easy to see. If you find yourself in close proximity to a bat and are not sure if you were exposed, for example – you wake up and find a bat in your room, do not kill or release the bat before calling your doctor or local health department to help determine if you could have been exposed to rabies and need preventive treatment. Any wild mammal such as a raccoon, skunk, fox, coyote or bat, can have rabies and transmit it to humans.Bats are the primary carrier of rabies in Illinois and already this year, 52 bats have tested positive for rabies in 24 counties. In 2011, 51 bats tested positive for rabies in Illinois.

Starving bats in search of food

THE Tweed's bats are going through tough times and a lack of food has forced the animals to invade people's backyards in search of something to eat. A Bat Conservation and Rescue Queensland spokesperson said a prolonged period of wet weather resulted in nectar and pollen being washed from flowers, and has made it nearly impossible for bats to find the food they desperately need. Tweed Valley Wildlife Carers bat coordinator Connie Kerr said the situation was improving as winter was coming to an end and more flowers were emerging. Although bats found or caught recently were underweight, their future looked a little rosier as more and more flowers bloomed and provided nectar and pollen to the animals. Ms Kerr said the bats were a very important part of the local eco-system and were capable of pollinating certain hardwood trees which could not be pollinated by any other animals including insects and birds. Bats also pollinated the Eucalyptus trees on which koalas depended, and without the bats koalas would be in an even more vulnerable position. Ms Kerr advised against feeding the bats and said the best way to help the animals was to plant native flowering plants and trees.

Mysterious illness killing bats – could it add to the West Nile threat?

In a season of growing concern about the West Nile Virus, a mysterious illness that has killed millions of mosquito-eating bats has added to the worry about that infection, and about bats in general. It’s called white nose syndrome, a fungal growth on the noses and wings of many species of bats, some of them already endangered. It was first observed in a cave in New York in 2006 and has spread throughout much of the northeastern United States. “It moved into Virginia in ’09. We have our first two documented caves in ’09,” said Jeff Trollinger, Deputy Director for Statewide Resources, Bureau of Wildlife Resources at the Virginia Department of Game and Inland Fisheries. “It has been growing extremely fast. “We don’t know what causes it and we’re not even sure the fungus itself is what is actually killing the bats,” Trollinger added. Scientists believe the fungus may interrupt hibernation, leaving the mammals too weak and thin to survive.