In which I learn I need a new approach to seeing bats

Last year I had quite a few bat adventures. I (eventually) managed to see five different species of bats, but frequently struggled with not being able to distinguish the calls captured by my bat detector. I could tell it was a species that I didn’t have ticked off my list, but not which one. So this year, I decided I needed to learn more about bats to help me in my quest.

This week I attended a Bat Ecology course, hosted by Surrey Wildlife Trust and taught by a member of Surrey Bat Group.The course was fascinating. A particular highlight was getting to see some bats up close, as there were a few captive bats present (who can’t be released back to the wild as they can’t fly properly). I learnt a lot about the different species of bats, and how to distinguish between them if I get a good view of them (when they’re not flying about in the dark). I was also reassured to learn that it’s not just me being rubbish at interpreting the sounds from my bat detector – even experts can’t tell distinguish between the Myotis bat species (Daubenton’s, Bandt’s, Whiskered, Alcathoe, Natterer’s, and Bechstein’s) using just a basic detector like mine.

So, having been reassured that it’s not (just) my incompetence that’s stopped me being able to identify some of the bats I’ve come across, I need to come up with a new way of seeing those species that I haven’t yet ticked off my list. I think I may need to start volunteering on some bat surveys.

But that’s not going to stop me walking around at night waving my bat detector in the air. Surrey’s a great place to see bats, as most of the 17-18 (it’s complicated!) British bat species are resident here. And using a detector to eavesdrop their hunting is a good way of getting a glimpse into their night time audio world, so different from our own.

More about my bat adventures:

• Bat Girl
• Bat Girl Strikes Again
• Bats of Nutfield Marsh
• More enigmatic bats
• Going bats?

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Bat girl strikes again

At last some success with bats! In fact, 3 new species (and 2 old ones) in one night!

You may have noticed that I have been struggling with identifying bats. When I go out with a bat detector without expert help I detect new species, but can’t pin down which ones. And my previous bat walk with an expert found nothing but common pipistrelles. Still, I can persevere when needed, so I went on another bat walk.

This time I headed down to Winkworth Arboretum. This National Trust site is bat heaven, including woodland and lake, and is home to seven species of bats. And they weren’t all in hiding!

About 17 people gathered just before dusk, to listen to a short talk by an expert from Surrey Bat Group. Armed with detectors we then headed into the woods.

The first species to show up were common pipistrelles, feeding over our heads, silhouetted against the still light sky. Soprano pipistrelles soon joined them. As we walked over a bridge our guide was disappointed not to see Daubenton’s bats, and I worried I wouldn’t find any new species.

We then came out of the wood, to the shore of a small lake. That’s where things really got exciting. Soprano and common pipistrelles flitted over head. Skimming the water, Daubenton’s bats scooped up insects, emitting fast clicks. Then, tuning the detector lower, we picked up serotine bats at 25khz. Finally, we picked up the deep signal of Britain’s largest (and loudest) bat, the noctule. It’s just as well we can’t hear high frequncies, as noctule bats calls can be louder than a rock concert. Imagine the complaints from neighbours!

It was amazing seeing (through occasional torch flashes) so many different bats in one place, and watching their acrobatic manoeuvres. It was particularly satisfying being able to distinguish between the species, as they had quite different call patterns and frequencies.

So, five down, 11 more to go!

British Animal Challenge: August update

I’ve been making the most of the summer this month, spending lots of time watching wildlife. I have been focusing on trying to see some new bat species, and a water shrew.

I have had mixed success with bats. A bat walk led to no new species, while an unaccompanied expedition in Devon found two new species, only one of which I could identify (soprano pipistrelle). A more recent bat walk was more successful, with three new species – more on that next week.

As for water shrews, I have spent quite a bit of time looking for them at a site I know they inhabit, but no luck so far. I think I may have heard one, but I haven’t seen one.

Apart from new species, I have also seen:

• A hare
• Common pipistrelles
• Woodmice
• A pygmy shrew
• Rabbits
• Hedgehog
• Frog
• Dormice

As for next month, I’m not going to have so much time for wildlife watching, as a work trip is taking me out of the country. But I do have a trip to the West Country planned, where I will try my luck with more bats and cetaceans.

More enigmatic bats

The mad bat woman has been at it again, wondering the streets at night, waving a badly tuned radio around. This time it was a small Devon village that looked on, bemused, at my antics.

Following my recent bat walk, where only common pipistrelles came out to play, I thought I might have better luck ticking off new species from my list away from home. So I jammed my bat detector and id chart into my bag, along with a change of clothes, and jumped on a train heading west.

I was fairly confident that I would see bats, and, after dusk I was proved right, spotting my first one just a few metres from the gate of where I was staying. This time the bat detector issued a slapping, clicking sound, different to a pipistrelle. Horay, a new species to tick off my list! But what was it? My BatLib app helped to narrow the options down to three, but I really couldn’t differentiate between them, even with the help of recordings, descriptions of flight patterns and habitats. So, once again, I have seen a new species, but don’t know what it is.

A few metres round the corner I picked up some more bats. The detector made the familiar babbling, squelching sounds of common pipistrelles, but this time at a higher frequency – it was a soprano pipistrelle. Horay, a new species that I can tick off my list!
With that, I decided to call it a night. I am going to need some expert help with identifying bats. Luckily I have another bat walk with experts booked. I hope that they don’t all go into hiding like last time!

Do you have any top tips for distinguishing between bat species, using a heterodyne detector?

Bats of Nutfield Marsh

Those of you who’ve been following this blog for a while will know that I’ve set myself the challenge of seeing every species of British animal in the wild. One group that are proving particularly tricky at the moment are bats. There are 16 species of bat resident in the UK, 14 of which live in my home county of Surrey, so it really shouldn’t be that hard. I have a bat detector, an identification chart and an app on my phone that lets me hear recordings of different bats, as played through a heterodyne bat detector. But despite all this, I’m still not making much progress. Lots of bats sound very similar to each other, and live in similar habitats, making distinguishing them hard.

In an effort to deal with this, I thought I’d get some expert help. So Dr C and I went along to a Surrey Wildlife Trust bat walk on Nutfield Marsh, led by someone who knows their bats. It was a beautiful summers day, and the clear skies meant it didn’t get dark til late. A group of around 30 people (including lots of kids) gathered in the car park, watching flocks of ring-necked parakeets. Nutfield Marsh is a nature reserve on the site of former sand pits (not the sort kids play in). It’s now been transformed into a wonderful mix of ponds, lakes, grasslands and woods. Ideal bat habitat, and home to 5 different sorts of bats (Common and Soprano Pipistrelles, Daubenton’s, Serotine and Noctules).

A common pipistrelle bat weighs about the same as a 2p coin

 Armed with bat detectors we wandered round the reserve, and as the dusk deepened we picked up our first bats – common pipistrelles. Common pipistrelles, as their name suggests, are the most widespread and numerous of Britain’s bats. They’re also one of the smallest, weighing the same as a 2p coin.

While it’s always good to see and hear bats, I had already crossed them off my list in May, so I was really hoping to see some new species.

We headed to the largest of the lakes, and waited as the last hint of light faded, hoping to see Daubenton’s bats feeding on the insects that flitted just above the surface of the water. We did see a few more bats, but the detectors revealed them to be common pipistrelles. Eventually, the call of bed could no longer be ignored, and we headed back to the cars.

It was a little disappointing not to see some new bats, but it was very pleasant to take a stroll round Nutfield Marsh in the cool of the evening. It’s inspiring to see how an industrial landscape can be transformed into a haven for wildlife.

British Animal Challenge: July update

Progress on my British Animal Challenge slowed somewhat in June, mainly due to me being distracted by football, tennis and music.  I have seen (and heard) a couple of new bat species, thanks to my new bat detector. But I’m not quite sure which species, as I find it hard to distinguish them. This month I have a bat walk planned with an expert, so hopefully I will pick up some tips.

In addition to bats, I am also hoping to see a yellow necked mouse, and maybe some other small rodents when I go out dormousing.

Sleeping like a dormouse

After years of monitoring dormice, I have now had a taste of what it’s like to sleep in a dormouse nest. Last week we went camping, and stayed in a remarkable tent, suspended from oak trees.

The tent was made of a spherical wood and aluminium frame, covered in canvas. The design was inspired by harvest mouse nests, but I prefer to think of it as a dormouse nest, since dormice live in trees.

It was an exciting experience. The tent had two windows, looking into the branches. Every so often we could feel the tent move gently, like being in a boat.

It was also a comfortable experience, as it comes with proper beds and a tiny woodburner.

The campsite itself is a wildlife haven. The pitches are mown areas of grass in a meadow. There’s a pond, and the site is surrounded by woods. The owners are keen to keep it wildlife friendly. Later this month they are hosting a wildlife weekend with Sussex Wildlife Trust.

We didn’t have any dormice visit us during our stay, but it was lovely watching (and listening to) the common pipistrelle bats as we sat by the campfire after dark.  We also saw three deer at dusk, crossing into the woods. And there are plenty of bunny rabbits, birds and bugs around.

 

Have you come across any particularly wildlife friendly campsites you would recommend?

Bat girl

Since my first taste of bat detecting last month, I’ve splashed out on a bat detector. It’s a fairly basic heterodyne model that tuns the ultrasound emitted by bats into sounds audible to humans.

Different bat species emit ultrasound at different frequencies, and with different patterns (or tunes), so a bat detector can help you work out what the black silhouette flitting past you might be.

Since the bat detector arrived, any time that I’ve been out in the evening I’ve taken it with me. I’ve been walking around after sunset, waving what appears to be an untuned radio.

For my first expedition with it, I tried the local park. I thought the mill pond might attract bats, but no luck.

Expeditions 2, 3 and 4 involved wondering round some of the quieter roads in town, as they were on my way. Still no luck.

Finally, walking down an alleyway in town, I saw a dark shadow whizz past. I pointed the detector at it, tuned to 45khz, and started picking up some rapid clicks.

Determining which species it was is harder than I anticipated. The phone app BatLib helped narrow it down, by providing a list of bats that emit at that frequency, descriptions of their appearance, habitat and flight patterns, and recordings of what they sound like through a heterodyne detector.

Based on this, I think it’s either a Brandt’s or a Whiskered bat. But I have no idea which. To progress with my British Animal Challenge, I am going to have to find some expert help…

British Animal Challenge: May Update

May has been the most successful month so far for my British Animal Challenge. I’ve seen two new species of amphibians: smooth newts and great crested newts. I’ve also ticked off common pipistrelle bats from my list as well.

More generally, I’ve seen quite a few species that were already ticked off my list, but it’s always good to see them again:

• Adders
• Slow worms
• Woodmice
• Roe deer
• Common frog
• Dormouse
• Water voles

Sadly I haven’t managed to cross any new reptile species off my list, although I do have a plan. I also failed in my second attempt to see water shrews, but I’ve found out a bit more about where I could see them. I’ve also heard rumours of natterjack toads in Surrey, which I’ll have to investigate more.

So, what are my target species for June? Well, my new bat detector should be arriving any day now, so I’m keen to try that out and see some more types of bats. I’m also going to be keeping my eyes peeled for moles, as this is the time of year when they could be dispersing from where they were born. I’m also hoping to see a yellow-necked mouse.

Going bats?

They’re not the most popular of Britain’s wildlife. I know many people, who, while keen on wildlife in general, quail at the thought of bats. It’s hard to see why they inspire such fear. None of the species native to Britain would cause humans any harm (preferring insects instead). And most bats are happily hibernating by the time halloween comes around, with tacky bat images everywhere.

Having said that, they are quite mysterious – nocturnal mammals with crazy flight patterns, only glimpsed as silhouettes against the night sky. And some look downright weird (take horseshoe bats as an example…)

Britain is home to 16 different species of bat, and given their nocturnal nature I’m going to need some help finding them (and working out which species they are). While many mammals can be distinguished with a good look, telling the difference between bats usually requires specialist equipment to record or transpose their distinctive calls.

I have seen bats before. They nest in the eaves of my parents house, and I’ve seen them flapping around our house as well. One memorable holiday with friends we stayed in a 15th century manor house, and at dusk each day long-eared bats would fly round inside the Great Hall before heading off to feed. This was a bit of a surprise the first time it happened, but it was fantastic to get a view of them in good light. A different species of bat inhabited the outbuildings as well, so we could see them roosting upside down. But despite these close encounters, I don’t know which species I have seen. It will be interesting to find out.

While some species of British animal will require lots of travel, it turns out I’m ideally placed for bat spotting. Surrey is home to 14 bat species, so, with the help of people who know what they’re doing, hopefully I should be able to see most without having to travel too far.  Luckily, Surrey Wildlife Trust and other conservation groups organise bat walks led by experts with detectors, so this seems like a good way to start.