Natterer's bat (Myotis nattereri)
Ialtóg natterer
The Natterer's bat is a medium sized species with relatively long ears. Its face also appears long and is pinkish due to sparse hair growth. The upper fur colour is greyish and the lower is noticeably white. This species can be confused with whiskered or Daubenton’s bats but the former is much darker and the latter has larger feet and lacks a distinct fringe of hairs along the trailing edge of the tail membrane. Another distinctive feature of the Natterer’s bat is an ‘S’ shaped calcar - the spur that leads from the foot along the edge of the tail membrane. This is much straighter than in the other species.
This species has a slow to medium flight speed and is found hawking and gleaning insects in woodlands, along treelines and hedgerows and over water. Natterer’s bat is highly maneuverable and can hover for short periods. The prey consists of flies, caddis flies and moths.
The species is often recorded during hibernation in underground sites such as caves, mines and tunnels. However, their summer roost sites are less frequently encountered. Those that are known are usually in very old stone built buildings, trees or bat boxes. Maternity roost numbers are usually between 30 and 200.
Natterer’s bat emerges later than other bat species and it is often quite dark before they exit the roost. They sometimes share their roosts with other species. The echolocation calls are extremely quiet and easily missed in the field.
The status of the bat in Ireland has not been determined but it is classed as threatened and listed in the Irish Red Data Book.