I must be batty!
End of 2020 National Bat Monitoring Programme. (NBMP) That’s another season done! The last of the NBMP surveys is the Waterways Survey in the first and second halves of August each year. This survey counts the number of Daubenton’s Bat passes, as heard on a bat detector, as one stands beside the water, for each of 10 four-minute periods along a kilometre of water, be it lake or stream or river. One of the characters of Daubenton’s Bats is that they feed by skimming the surface of water, picking off insects that are emerging from the water or just hovering over it. (When seen on an infra-red night-sight they look like ice skaters.) By counting the number of passes at each station along the bank one gets an idea of how many bats are feeding in the area. So year on year one builds up a picture of the population changes for this bat. A typical section of the Tamar where I record. I do three sites for this survey; two on the River Tamar which separates Cor...