Related
Recommended
Anna Allum

Volunteer Phil recounts a rather unusual wildlife sighting for February in his latest blog...

This day proved bright and very sunny, looking very like spring, but chilly and still feeling like winter.

Around lunchtime I was looking out over the North Brooks from the hairpin bend above Jupps View in the company of 2 visitors. We were discussing the presence of a ruff feeding close to the lapwings, seen here in this photo from Jupps View taken a little later.

At this point I noticed a small bird seen in silhouette against the sunlit background going directly away from us down the through the trees towards the water. It seemed to be gliding rather slowly and looked strange. Small birds don’t usually glide for long periods, tending to fly quite fast and direct. The bird proceeded to the main flood pool and then proceeded to fly around quite slowly very close to the water, behaving rather like a very stately swallow or martin and roughly the same size. However it certainly was not either a swallow or martin, presenting more the appearance and flight pattern of a tiny owl as seen in my binoculars.

After watching this performance for about 15 seconds it suddenly dawned on me that this was no bird at all but a bat! Just as the whole idea of swallows or martins hunting insects in the UK in middle of February seemed preposterous, the idea of a bat doing exactly that in broad daylight seemed even more so, and yet the watchers, all agreed that it must be a bat. 

We were shortly joined by a gentleman with a camera who proceeded to take a reasonable photo of this. So, despite me having discounted the idea of photographing such a small creature about 100m away, this encouraged me try to with my own camera. The result was not good, but here is my one usable photo to record this remarkable event.

This sighting gives rise to several questions.

  • Why would a bat be hunting in mid-February at a time it would normally be still hibernating?
  • Why would a bat be out hunting in the middle of the day when they are usually known as creatures of the night?
  • What species might it have been?
  • Where had it been roosting?

I must confess that I know very little about bats, but reporting this sighting to the Visitor Centre on the radio gave me an initial opportunity to talk to Anna Allum, who is much better informed than I am. We continued the conversation at the end of the afternoon, joined by Stephen, one of my volunteer colleagues who also seems well versed in the subject.

The answer to the first question may lie in the considerably warmer weather earlier in the week, and the fact that, despite the winter chill, the sun was out and lifting the temperature where it was shining. Anna said that if a bat had woken from hibernation due to the relative warmth, then its natural reaction would be to immediately seek food. And she also confirmed that, while very unusual, it is not unknown for bats to hunt in daytime. 

We had some discussion about what species it could have been. Stephen suggested a Daubenton’s bat, a species that specialises in hunting close to water, but Anna pointed out that any bat might do this if that was the main source of available food so its feeding behaviour may not be conclusive. With insect numbers being low in winter, there may well have been more available near the surface of the pools which were in bright sunshine, so it would make sense to try hunting there.

Anna commented that pipistrelle bats are the most common at the nature reserve (and across the country) where we have both common and soprano pipistrelles. Additional informational on the size and perhaps a hint of pale fur on the underside points to one of the myotis species and we do certainly have Daubenton’s bats on the reserve.

Without the help of a bat detector, or a very close-up view it’s incredibly tricky to provide a positive identification. Bat species are normally identified by the signature of their echolocation ultrasound picked up by a bat detector and analysed, but naturally none of the observers had one. Also it seems improbable that any type of sound from a bat would be detected at such a distance. 

I did wonder whether the bat would even have been using echolocation in broad daylight. One of the few things I do know about bats is that, contrary to the common myth, they are not blind. Anna tells me they can probably see as well as humans, so echolocation is an adaption to aid hunting at night and not a replacement for eyesight. 

The bat seemed to have travelled in a very deliberate straight line down through the trees to the water and I wondered whether that could be a clue to where its roost might be. The direction of travel might have been consistent with a roost at Wiggonholt Church. We have all heard the phrase “bats in the belfry” but, whereas active belfries are very noisy places and perhaps not suitable for roosting bats, other parts of church buildings can be ideal, and many churches do have populations.  There is even a project called simply Bats in Churches currently studying these roosts and more information can be found at the following link.

Project Home - Bats In Churches

Anna commented that a more likely explanation is simply that the bat was using tree holes for roosting as there are plenty of those nearby. 

It may not happen often, but Pulborough Brooks does have an astonishing way of producing complete surprises, and as a result I now know a little more about bats.