Created April 2009
Last UpdatedaPRIL 2018
Myotis brandtii (Eversmann 1845)/ Myotis mystacinus (Kuhl 1819) , Myotis alcathoe
Brandt’s Bat
Photo Bob Cornes
Whiskered Brandt’s and Alcathoe bats are notoriously difficult to tell apart In the end it’s down to minutiae of dental features – and even then it isn’t necessarily conclusive. Trying to make out these features at the dead of night is a nightmare.Several years ago some one found a dead bat and we couldn’t decide what it was so sent in to Natural England expert Tony Hutson, who reported back that on one side of its mouth it was a whiskered and on the other a Brandt’s.
We have never found either species in hibernation, and have yet to find an Alcathoe’s bat.
( which seem to be confined to a small area in southern England).
In April 2010 it was announced that there was a new species, Alcathoe’s bat had been lurking in the UK. So the identification problem just got worse 2010-7-alcathoe’s bat
Alcathoe’s bat Photo Bob Cornes. Photographed in Hungary
Brandt’s are between 35 and 50mm long and weigh between 4.5 and 9 grams.
Whiskered bats tend to darker than Brandt’s and weigh between 4 and 8 g with a body length of between 35 and 48mm. They probably live for about 4 years but the oldest bat known was 19 years old. The peak frequency of their call is as around 50kHz
We know of only a few locations to date in Bedfordshire. We were mist netting in Kings Wood Heath and one night in 2005 and as we took our nets down at midnight a bat flew in It was only when we looked at the photo later that we realised what we had found.
Photo Bob Cornes
A year later to the day we were in the same wood and lightning struck twice in the same place when a second Brandt’s /whiskered flew into a net in exactly the same place. We are confident that this was not the same bat (The first one had very worn teeth)
In 2011 we returned an another bat in the same wood. This time we got a good photo of her dentition. You can also see that she really should have flossed more often
In 2013, again at the same place we caught another, which cooperated by leaving droppings in the holding bag. DNA analysis confirmed it was a Brandt’s bat’
The wood is close to the Buckinghamshire border and The North Bucks Bat Group takes delight in the fact it is probably ” one of theirs”.
Photo Bob Cornes
During our preliminary work for BatMap we were astounded to catch the pair shown below. We also caught another three whiskered bats
Whiskered bat is on the left, Brandt’s on the right
Brandt’s and whiskered bats are extremely similar and therefore easily confused. The teeth can be used to distinguish the two species. On the lower jaw of Brandt’s bats the third premolar (P3) is greater than half the size of the second premolar (P2). On the upper jaw the protocone of P4 is large and taller than P3. This is nightmare to see in the dark. Thank heavens for DNA analysis.
Image from Bristol Bioacoustic lab
Another feature is a difference in penis structure , which is helpful as long as the bat is a male. A whiskered bat has a whiskered penis and the Brandt’s bats penis is bulbous.
Brandt’s are woodland bats and fly and forage in the lower part of the canopy picking insects and spiders of eaves ( gleaning).
We caught a female Brandt’s on BatMap and were able to radiotag her and trace her to her roost, which was firmly in Bedfordshire.
More information
http://www.bats.org.uk/pages/uk_bat_species.html
http://www.bio.bris.ac.uk/research/bats/britishbats/index.htm