Bat emergence survey

A batty visit to St Denis’, 17th July 2021


Brown long-eared (plecotus auritus) bat – photo / Rachel Bates.

By our bat correspondent, Nicola Jenkins

Rachel Bates of the Cambridgeshire Bat Group organised a survey of bats emerging from St Denis’ church on the evening of  Saturday, 17th July – a beautiful balmy evening with the church lit by a half moon. She kindly supplied the photos on this page – click on each one for a larger image.

Barbastelle bat – photo / Rachel Bates.

Barbastelle bat – photo / Rachel Bates.

Soprano pipistrelle bat – photo / Rachel Bates.

Soprano pipistrelle – photo / Rachel Bates.

Rachel also invited local residents to take part in the survey – Sarah Brennan, John O’Sullivan, Ruth Chan, Alastair Smith, Linda Hudson, Sofie, Jeremy, Ali and Thomas Hooper and Nicola Jenkins joined in.

Rachel collected samples of bat droppings from the church floor for analysis (see below) and set up a camera and bat detector inside the church for the duration of the survey. She gave a brief talk to the group and distributed tally counters and bat detectors, describing how to distinguish bat species and movements.

Common pipistrellea – photo / Rachel Bates.

Common pipistrellea – photo / Rachel Bates.

Brown long-eared (plecotus auritus) bat – photo / Rachel Bates.

Brown long-eared – photo / Rachel Bates.

Participants sat in pairs round the church and, with Rachel, and counted any bats emerging from the church between 9.00 pm and about 10.15 pm. Activity outside the church was dominated by common pipistrelle and a few soprano pipistrelles and inside by multiple brown long-eared and a few passes of a barbastelle bat inside. At least 16 brown long-eared bats emerged from between the tiles and the guttering of the vestry; three bats came out from the guttering in the nave on the north side of the church.

No bats were observed to emerge from the south side. Everyone enjoyed seeing plenty of bats foraging around the churchyard all evening, mostly common pipistrelles, some coming from surrounding trees. Ali and Thomas were particularly good at spotting them.

A short report is on Cambridgeshire Bat Group’s Facebook page.

The results of the DNA analysis of the bat droppings from the church floor show they were all from brown long-eared bats (plecotus auritus).


The churchyard

St Denis’ churchyard is a quiet open space and still consecrated.  It is also a local nature reserve.

Post created 20th July 2021; updated 7th September 2021.