An evening with the horseshoe bats at Orielton, Pembrokeshire

Greater Horseshoe Bat 6
Lesser Horseshoe Bat 38

A remarkable evening watching the bats at Orielton. Probably less than 20m from my bedroom door, I counted at least 38 lesser horseshoe and 6 greater horseshoe bats emerge from their roost in a storage room at the side of the stables. At about 9pm, in still reasonable light, one by one they started to emerge through a doorway, and there was definitely a difference in the method of emergence used by the two species, to such an extent  that you could confidently identify them by how the left the room.

The lessers, broadcasting on a frequency of 110khz, flew around in the room for a minute or two before coming right up to the entrance, but then turning back at the last second and going back into the room. They would repeat this for a further minute or two, and each time they came to the door they would come out a little bit further, almost as if they were checking how dark it was. Sometimes they would fly 10m or more beyond the doorway, before returning to the room. At last though they would go, they would come out at the top of the doorway and would fly up and away over the roof.

On the other hand, the greaters, on 80khz, flew out like a rocket, low across the ground, and remaining no more than 0.5m above the ground until lost to sight in the fading light.

Amazingly, virtually all of the lessers went over the same bit of roof to the left of the door, whilst all of the greaters came out of the doorway and went right, all following the same route.

Very difficult to capture any of this on camera, and even if I could it wouldn’t tell the story. All I can do is put it into words and leave you with the consolation of a photo of lesser horseshoe bat poo.