Bats at Whetsted Wood

It's 8.35pm on Saturday 7th May, the sun has just set on another lovely warm and sunny day. For the last week everyday has got warmer and it feels like summer. So different from the previous week, when for much of the time it was colder than during the Christmas week.

Maybe it's just my perception, but for the last few years I have noticed that the weather patterns appear to get ‘stuck’ for weeks, if not months, at a time. December 2015 - Late February 2016 was the warmest winter ever recorded in the UK. Then in the last week of February the wind switched to the north and north east and for much of the next two months the weather was cold and spring was delayed. 1st May arrived and all changed, summer arrived almost overnight ! This current warm spell is forecast to continue, but maybe a little cooler and I am enjoying typing this post under a sunshade, drinking a cool beer, looking out across the garden at butterflies and bumble bees visiting the flowers in the garden. Is it climate change, or just part of the Earth's changing weather patterns? Time will tell. 

Anyway back to Saturday night. I am standing on the edge of Whetsted Wood looking south across a grass field, awaiting the arrival of the local bats, as they visit to feed along the woodland edge and the Tudeley Brook. The air is full of tiny midges and gnats, hovering above my head, the ground vegetation and newly unfurled tree leaves. A smorgasbord of aerial insect nibbles, irresistible to any bat making a beeline to this ‘picnic spot’.

Bats often have their ‘favourite’ feeding areas, places they know they can rely on to have a regular supply of food. For many years I have known about this bat ‘picnic spot’ on the edge of Whetsted Wood, used by local bats, as they awake from a daytime spent asleep.

 8.43pm and the first bats arrive, two pip 45’s (common pipistrelle) flying along the Tudeley Brook from a southerly direction. One minute later and both pip 55’s ( soprano pipestrelle) and pip 45’s are in the air above me, feeding on the gnats and midges. They are flying fast, high and covering a large area of the wood and surrounding fields, but don't seem that determined to stay. Maybe this is just a quick ‘snack stop’! More pips, both 45 & 55’s arrive over the next ten minutes. The aerial display is fast and furious. I have the bat detector tuned to 45 KHz, and with my headphones plugged in I can pick up both the 45 & 55 pips clearly. I am all alone in a warm field with a darkening skyline, lost  in my own soundscape of repeating clicks and occasional buzz’s as I watch an old fashioned style aerial dogfight between the bats and midges above me. The buzz sounds are feeding buzz’s, a rasping sound, as the bat speeds up its sonar echo location system, to home in on a midge and as the buzz ends, so does the midge’s life !

 By 9.05pm many of the first arrivals have moved on, flying away in a northerly direction, following the Tudeley Brook towards the River Medway, about 2 kms away. Left behind are two pip 45’s who for the next 20 minutes hoover up as many insects as they can catch.

The best way to see them as the light fades is to lie low and look towards the West, where the light remains for the longest. Silhouetted against the sky, the bats can be picked out. They are flying slower now, in a more determined pattern. This is their feeding area and they know the landscape well. They can pick out every tree, shrub & bush. They hug the edge of the wood and trees along the stream. Flying where the midges are densest, the pair of pip 45’s feeding buzz’s and loud and frequent. Flying between 4 - 8 feet above the ground and at a lower speed, it's helpful that I am sitting on the ground, as I marvel at their aerial skills. My own private air show, however their flying skills are far superior to any human pilot and all the time the soundscape of clicks and buzz’s is ringing in my ears.

 At 9.14pm two robins suddenly start singing from either side of the field. A last minute declaration to each other to keep to their own territory, their own side of the fence so to speak. This verbal spat lasts for about two minutes and then they stop and presumably turn in for the night.

The pair of pip 45’s frantic feeding is drawing to a close now and eventually at 9.30pm they are no longer around. It's dark now and I cannot tell in which direction they headed, but they will be moving on to another favoured food stop, before they have full tummies. Feeding contniues for about two hours after sunset, before bats tend to take a break, to digest their night time meal. Feeding then starts again later, just before dawn and then they return to their daytime roosts to sleep during the day.

I leave now, heading back to civilisation, but as I look back I see a dog walker, torch in hand, patrolling the footpaths around Whetsted Wood. I wonder if this person knows that above them a nightly duel is taking place.