Shedding light on bat behaviour: conservation research project

Foraging behaviour

LesserhorseshoebatLesser horseshoe bats forage in woodlands feeding mainly on diptera (flies and midges) (Knight 2006). They are very flexible in their foraging behaviour feeding by aerial hawking (catching insects on the wing), gleaning (picking insects from vegetation) and pouncing on prey close to the ground (Jones and Rayner 1989). They are very specialised with constant frequency echolocation calls at around 110 KHz allowing them to navigate and hunt in cluttered environments. They fly low to the ground often no more than 5 metres high (Russ 1999), and close to vegetation (Jones and Rayner 1989). Lesser horseshoe bats fly an average of 2km per night from roosts during the summer, with an average home range of 147-177ha (Knight 2006). They fly for just over 50% of the night, resting after each foraging bout in night roosts.

Commuting behaviour

hedgeLinear landscape features such as hedgerows, river banks and canals are important for bats (Walsh and Harris 1996; Verboom, Boonman & Limpens 1999). Some species use them for foraging (Limpens and Kapteyn 1991), shelter from wind or predation (Verboom & Spoelstra 1999), or orientation during commuting (Downs & Racey 2006). Such features are fundamental to the ecological functionality of an area and provide a crucial link between key foraging areas for many bat species, including lesser horseshoe bats which use linear features as corridors along which to commute and forage (Schofield 1996; Motte and Libois 2002). Lesser horseshoe bats emerge on average 30 minutes after sunset (Stone, Jones and Harris 2009) and during emergence they often fly in and out of the roost repeatedly before leaving. This behaviour is often interpreted as "light sampling", bats are assessing light levels before emerging.