{"id":7484,"date":"2025-08-23T10:15:58","date_gmt":"2025-08-23T09:15:58","guid":{"rendered":"https:\/\/rdnhs.org.uk\/blog\/?p=7484"},"modified":"2026-04-28T10:20:01","modified_gmt":"2026-04-28T09:20:01","slug":"calcot-bat-walk-23rd-august-2025","status":"publish","type":"post","link":"https:\/\/rdnhs.org.uk\/blog\/calcot-bat-walk-23rd-august-2025\/","title":{"rendered":"Calcot bat walk – 23rd August 2025"},"content":{"rendered":"\n

Katie Jenks led a walk around Linear Park in Calcot on Saturday 23 August. It was a perfect evening for a bat walk \u2013 17\u00b0C, no rain and just a slight breeze. Nine members met at the Beansheaf Community Centre car park just before dusk at 8pm. Katie handed everyone a heterodyne bat detector, along with an information card highlighting which species of bat could be heard at the various frequencies. After an explanation of how to use the detectors and which species might be found, the group followed the path southwards in the direction of the Holy Brook. Dusk was at 8.07pm and the bats that were most likely to be encountered emerge just before or a little after dusk. The first path followed a treeline at the edge of woodland. The route then turned to continue with the woodland on the left and more open wet areas and ditches on the right. Purple-loosestrife Lythrum salicaria<\/em> was growing in the ditches and willow dominated the wetter open areas. The first bat of the evening was a Soprano Pipistrelle Pipistrellus pygmaeus<\/em>. Katie explained about the division between the Pipistrelle species in the 1990\u2019s when it was discovered that Common and Soprano Pipistrelles were two separate species. It was found that the Common Pipistrelle Pipistrellus pipistrellus <\/em>echo locates at 45 kHz and is slightly darker than the Soprano with a dark band across its eyes. The Sopranos which could be seen foraging amongst the oak trees could be heard on the detectors as a series of clicks at 55 kHz as they
echolocated. Every now and again, there was a raspberry sound on the detectors as the bats caught and ate an insect. Pipistrelles emerge 15-20 minutes after sunset to hunt for smaller insects, with the Sopranos favouring wetter habitats and being more common in the south of the UK. The ones we were watching would probably be roosting behind hanging tiles of nearby houses or in loft spaces. <\/p>\n\n\n\n

As the group moved on, the Sopranos were joined by foraging Common Pipistrelles. Three or four darted between the trees and up and down the tree-lined path, some getting very close to our heads. Arriving at a small open area of amenity grassland, those of us who had tuned our detectors to 25 kHz could hear a very different noise from the Pipistrelle clicks \u2013 a higher sounding \u2018chip chop\u2019 noise. This was a larger bat, the Noctule Nyctalus noctula <\/em>which favours tree holes and crevices to roost in and feeds on larger insects such as beetles and moths. Katie explained how the Noctule can commute around 7 km to hunt and that the echolocation noise on the detectors sounds slower because they fly higher than the Pipistrelles and do not have so many obstacles to navigate around. It was almost dark when we reached the small bridge over the Holy Brook. We settled here to wait for the \u2018water bats\u2019, the Daubenton\u2019s, Myotis daubentonii<\/em>, and were soon joined by three fishermen curious to know what we were looking for. Armed with a detector they were soon hearing the bats! We didn\u2019t have to wait long before the Daubenton\u2019s made an appearance. As we watched them below us, they zoomed under the bridge, catching insects on the water\u2019s surface with their big hairy feet. They seemed to have plenty of choice \u2013 moths were abundant as well as the usual mosquitoes and midges. Confusingly they also echolocate at around 45 kHz but sound like machine gun fire rather than clicks. Mindful of getting back to the car park before it was locked up, we slowly made our way back in the dark. It was fairly quiet with the bats either moving on to areas further away from their roosts or taking a break from hunting. We had seen or heard 4 out of the 18 UK bat species in a short space of time.<\/p>\n","protected":false},"excerpt":{"rendered":"

Katie Jenks led a walk around Linear Park in Calcot on Saturday 23 August. It was a perfect evening for a bat walk \u2013 17\u00b0C,…<\/p>\n","protected":false},"author":8,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_customify_content_layout":"","_customify_sidebar":"","_customify_page_header_display":"default","_customify_disable_header":"","_customify_disable_header_top":"","_customify_disable_header_main":"","_customify_disable_header_bottom":"","_customify_disable_page_title":"","_customify_disable_content_vertical_padding":"","_customify_disable_footer_top":"","_customify_disable_footer_main":"","_customify_disable_footer_bottom":"","_customify_breadcrumb_display":"","_customify_header_transparent_display":"","footnotes":""},"categories":[5],"tags":[61,63,62,49],"class_list":["post-7484","post","type-post","status-publish","format-standard","hentry","category-field-trip-reports","tag-bat","tag-beansheaf-centre","tag-calcot","tag-wildlife-walk"],"_links":{"self":[{"href":"https:\/\/rdnhs.org.uk\/blog\/wp-json\/wp\/v2\/posts\/7484","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rdnhs.org.uk\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rdnhs.org.uk\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rdnhs.org.uk\/blog\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/rdnhs.org.uk\/blog\/wp-json\/wp\/v2\/comments?post=7484"}],"version-history":[{"count":1,"href":"https:\/\/rdnhs.org.uk\/blog\/wp-json\/wp\/v2\/posts\/7484\/revisions"}],"predecessor-version":[{"id":7485,"href":"https:\/\/rdnhs.org.uk\/blog\/wp-json\/wp\/v2\/posts\/7484\/revisions\/7485"}],"wp:attachment":[{"href":"https:\/\/rdnhs.org.uk\/blog\/wp-json\/wp\/v2\/media?parent=7484"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rdnhs.org.uk\/blog\/wp-json\/wp\/v2\/categories?post=7484"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rdnhs.org.uk\/blog\/wp-json\/wp\/v2\/tags?post=7484"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}