Daubentonís bat / Myotis daubentonii / Ialtóg dhaubenton

Photo © Phil Richardson

The Daubentonís bat is one of the most widespread species in the country. It is frequently seen as it skims the surface of a river, pond or other water body. Looking like a small hovercraft as it circles close to the surface, its wings quivering, as it hunts for emerging caddis flies, mosquitoes and midges. In this environment, it is very easy to identify as no other species behaves in this manner. However, the species can also be found in woodlands where it can be confused with whiskered and Nattererís bats.

Feeding on emerging insects and surface flies, this species often falls foul of fly fishermen; becoming impaled on fishing hooks. Often, itís a wingtip or the tail membrane which gets caught so the damage is limited and the bat can be released immediately. These wing and tail areas are used to channel food towards the mouth. The feet are over-sized compared to other species as the Daubentonís bat uses these to trawl through the water to intercept any emerging insects or those struggling on the surface. The food is then transfered to the mouth and consumed while on the wing.

In summer, this species prefers to roost in trees, buildings and beneath bridges. In winter, they are frequently found in caves and other underground sites. They are seldom found very far from a source of water. As the Daubentonís bat secretes itself into cracks beneath bridges, it is often overlooked and perishes when the bridge is renovated. This is usually accomplished using pressure injected concrete which doesnít allow the bats time to escape and they are often entombed or drowned. This pointless killing could be avoided by a little foresight and the batsí roost could be incorporated within the plans to stabilise the structure. Bridges should always be surveyed for the presence of bats before beginning any works.

The echolocation calls of this species are fast and sharp. On a detector, they resemble the sound of a Geiger-counter, peaking at 55kHz.

The species mates throughout autumn and winter and the single young is born in June or July. All juveniles have a black Ďchin spotí which begins to fade as the bat grows. It finally disappears completely during the second year. Daubentonís bats are known to live to 20 years.

The species is classed as internationally important and is found throughout the county.

 

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