Bats are nocturnal mammals which, in Ireland, exclusively predate insects. Their range varies with species, from the Common Pipistrelle which is widespread throughout the island, to Brandt’s bat, which has to date only been identified from a few counties.
There are 10 species of bats in Ireland, nine of these belong to the family known as vesper bats (the 10th species – the lesser horseshoe bat - is not found in N. Ireland and so is not covered by this all-island SAP).
These nine species are:
- Daubenton’s bat (Myotis daubentionii)
- Whiskered bat (Myotis mystacinus)
- Natterer’s bat (Myotis nattereri)
- Leisler’s bat (Nyctalus leisleri)
- Nathusius’ Pipistrelle (Pipistrellus nathusii)
- Common Pipistrelle (Pipistrellus pipistrellus)
- Soprano Pipistrelle (Pipistrellus pygmaeus)
- Brown Long-eared bat (Plecotus auritus)
- Brandt’s bat (Myotis brandtii).
Bats provide a valuable pest control service. They emerge from hibernation in late spring and early summer to forage for insects. A single bat can consume thousands of insects every night.
Bats are not blind, but use a type of sonar, called echolocation, to locate their prey. In early summer female bats get together in a suitable nursery roost. They each give birth to a single baby that they can identify by its smell and sound. The mother feeds it milk for several weeks at which point the baby is able to fly and learns to echolocate and catch its own prey. By 6-7 weeks after birth the young are independent.
The females usually leave the maternity roost in August and avail of the late summer’s insects to build up a store of body fat to help them survive the winter. Females then seek out males who have set up mating territories by mid-August. Mating takes place from August onwards. Then as temperatures drop further during the approach of winter and insect numbers decline, males and females move into hibernation roosts.
Hibernation takes place from October/November onwards during which time a hibernating bat uses very little energy and its body temperature drops to 8-9°C. Individuals may wake up occasionally during mild spells to eat and to drink water. By spring bats gradually wake up to begin the yearly cycle again. The average lifespan of the Irish bat species is thought to be 7-8 years although some have been found over 15 years old.
Habitats especially used by bats include woodland edges and wetlands. Destruction and infilling of these habitats has led to local population declines in some areas. Bats use a variety of roost over the year, choosing warm places such as the attics of churches, stables and occasionally houses for summer nursery roosts, but preferring cool, humid locations like caves and cellars for hibernation.
Loss of foraging habitat can arise from a change in land use resulting in a loss of invertebrate habitat, land management measures which reduce the number of invertebrates present and a loss of habitat corridors which link roost sites to foraging sites.
For information on conserving bats, see the downloads at the bottom of this page.
Bat Conservation Ireland
Bat Conservation Ireland (BCI) is a charity dedicated to the conservation of Ireland’s bats.
The charity receives funding from various State agencies and sponsors to carry out specific bat education, monitoring or other bat conservation work.
Reports have been published for certain projects that Bat Conservation Ireland has been involved in.
Bat Mitigation Guidelines (Irish Wildlife Manual No. 25)
These guidelines have been developed by the Department of Environment, Heritage and Local Government to assist those involved with land-use planning and development operations where bats are known or suspected to occur.
Although the emphasis is on developments that fall within the remit of the planning system, the guidelines apply equally to other sorts of developments and contain elements of good practice that apply to a wide range of situations
To view a copy of these guidelines, please visit http://www.npws.ie