Bat-friendly lighting

The intensity of bright light can cause a high contrast between the lit area and the surrounding darkness; this is known as glare. Glare can impair bats and invertebrates, therefore low output or dimmable fittings will be beneficial to surrounding wildlife.

Colour temperature is a measurement to describe the appearance of white light. This is typically referred to as warm, neutral and cool. Blue light can be harmful to wildlife, especially bats and invertebrates, therefore the warm-white spectrum should be adopted.

LED products, in comparison to other light sources, boast a multitude of bat-beneficial attributes. These include no UV element, sharp cut-off, good colour rendition and dimming capability. LED is the light source of choice for most local authorities (ILP 2018).

Automatic lighting controls can conveniently turn off a light fixture when it is no longer required. It is advisable for external lighting to be programmed to switch off, or dim down, shortly after use.

The height (from the ground) at which a light is positioned should be carefully considered, to minimise light pollution. Generally speaking, the closer to the floor a light fitting is placed, the less obtrusive the light will be.

Optics are components of a light fitting which control the direction of the light beam. These include reflectors, refractors, and protectors. Such accessories can be used to reduce light spill by directing it only to where it is needed.