Summertime and the survey’n ain’t easy

Setting out the bat detectors again for the next round of surveys means I was up early to collect, check and deploy them all. Early so that I can finish sooner but also to try to avoid the stifling heat of the mid-day sun. What with traffic, a small detour round a road closure and some battery problems (always always take spare batteries on field work!!) I missed the cool morning and was working through the heat of the day. Everything about planning and risk assessments had gone out of the window – my water supply was getting hot in the car (and quickly running out), the suncream was acting as a glue, keeping seeds and bugs and dirt trapped on my skin and I was far too hot to wear my full leg trousers out to the survey points. Striding through long grasses and undergrowth without anything to protect my skin I felt a million scratches, bites and stings tingling my skin. While one nettle sting is painful it seems that a whole leg full numbs the pain – not that I recommend this of course, but after the first few the rest didn’t really matter. Thistle thorns, grass seeds and other burrs work their way down into my boots and prickle my feet with every step. Meanwhile the sun shines on, unflinching, unrelenting. I am exhausted and I still have two sites to go.

My last farm is something of a problem child. The first crop failed this year – a disaster for the farmer, no small part played by the unusually cold winter we had this year. On top of the loss of income from the cropping, the farmer now needs to use labour and products to return the field to use. He opted to spray it with herbicide, which will add a new field treatment to my survey plan (best made plans and all that…).

Sun-drenched fields. Photo Credit: Em

As I returned to my car after setting the last detector, a small piece of eggshell caught my eye. I’m not exaggerating, this was tiny. Creamy, with specks of brown, the shell finish was almost glossy. It crumbled in my palm, so thin and so delicate. Without knowing anything about shell colours I guessed wren. After a sneaky google it still fits the bill. A nice little extra today. Now I’m off to cool down.

Wren eggshell. Photo credit: Em

Em

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Messing About on the River

I don’t forget how lucky I am to live where I do, and with nothing on the diary I set out with the kayak and went for the river equivalent of a stroll.

Being on the surface of the water gives you a different perspective on the wildlife that lives there, you can sneak up on the sulky herons on the strand line. With their shoulders hunched and their beaks pulled in they look studiously unimpressed with the weather. Perhaps they prefer it drab and grey.

The water erupted in a burst just ahead of me. Breaking the surface a cormorant emerged, fish in beak, droplets falling from its wing tips to its tail. Up close it’s quite a stocky bird, it’s tail more of a wedge and it’s bill a fairly substantial weapon. Given the presence of a large-ish boat the cormorant recovered itself quickly enough and flew off to an emerging sand bank.

Early though I was, it was shaping up to be a very hot day again and the double assault of the sun and salt water was prickling my skin. Turning home, this time against the tide, I paddled slowly, admiring the colours in the hills – it’s a lovely time to be in Devon.

Em

BioBlitz Bugs

I will freely admit that I like to include wildlife in my day, everyday, I have not kept pace with the 30 Days Wild Blogging, such is the way of things sometimes. If you are too busy noticing, enjoying and relaxing to write a blog then so be it. What with this lovely weather we are having at the moment, it seems a shame to sit indoors and watch that blinking cursor taunt you…

Nonetheless, last Saturday I participated in what must be the ultimate #30DaysWild of activities – a Bioblitz! For the uninitiated this is a short, focused period of ecological surveying designed to produce a ‘list’ of the species present. It draws on experts from a range of fields to identify the rare and easily confused species but is also a great way for anyone to get involved as there is a great deal of work involved in surveying even the smallest of areas.

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Clennon Lakes, Photo Credit: Em

I took part in the Clennon Lakes Bioblitz, near Torquay. This rich wetland habitat is an absolute paradise for surveying, including lakes, grasslands, woodlands and open fields. It was fantastic to meet some local experts as well and to learn more about survey  methods, ID tricks and recommendations for field guides (more to follow in a future blog post). I especially enjoyed sweep netting and investigating the teeming trays of insects that we caught. Here are a few of my favorites:

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Yellow ringed dragonfly, Photo credit: Em

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Crab spider, Photo credit: Em

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Spider with parasitic wasp larvae, Photo credit: Em

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Ground beetle, Photo credit: Em

And the find of the day? Theridiosoma gemmosum – a ray spider that is rare in Europe and Britain. For what it’s worth this is a really tiny spider so maybe we have been overlooking it for a while?

Em

30 Days Wild: Day 12 – Horseshoes

Stop press people – big news! We have Horseshoe bats on the detectors! This is extremely exciting as it is the species that I set out to survey so their presence is, if not entirely unexpected, it is somewhat of a relief. The exact locations of their maternity and hibernation roosts is something of a closely guarded secret – to protect them against disturbance. But thankfully, when they are out foraging it can be relatively straight forward to get them on a detector – if you live in Devon that is. This is the Greater Horseshoe – the biggest bat you are likely to see in the UK (outside of a zoo). It is found all across Europe and is relatively common on a global scale, but here in the UK it has a very restricted range – covering the south-western corner of the UK up as far as South Wales and across as far as Hampshire-ish. Naturally the bats do not respect administrative boundaries so it’s something of a wobbly patch but you get the general idea.

They roost upside down – in classic bat style, hanging from the ceiling like little bat baubles. Their thin skin wings fold around their bodies hiding their fur – unlike crevice dwelling bats where the fur is visible and, if ID-ing, can be a useful guide.

Greater Horseshoes are not the first bats to emerge in the evening. If you can still see and are debating whether or not it qualifies as ‘dusk’ any bats you see are probably pipistrelles – the least picky of the bats. The ‘pips’ do not need old buildings, crumbling cool mines or ancient tree cavities to roost, they can cope fine with modern architecture (providing they can find a way in). The house on the other side of the close from us has bats in the roof. These are most definitely pips and they may well be the ones I say flying around outside my house in a previous blog post.

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Horseshoes in Devon. Photo credit: Em (and AnalookW software – thanks Analook)

As I mentioned (here in my blog post) the visual representation of bat calls using the AnaBat detectors and AnalookW software helps you to ID the bats as they tend to have fairly distinct shaped calls. This graphic is of the horseshoe that my detector picked up over the weekend. With a flat, long call and static frequency there is only one other bat that makes a call like this – the Lesser Horseshoe Bat. Thankfully, it does so at a different frequency (around 110kHz). The shape of the bat call tells us something about the bat and how it navigates (remembering that these vocalisations are for echolocation). The constant call at a static frequency matches the larger, heavier, slower body of the horseshoe – they need a picture of the environment at a coarse scale if you like. The smaller bats call at a range of frequencies and break up their calls into smaller segments as they navigate more cluttered environments – information at a finer scale.

The Greater Horseshoe Bat populations in the UK have been recovering in recent years, though this has not always been the case and it is thought that the Europe wide population is as low as 1% of the population in the 1950s. This is largely due to increased intensification of agriculture (or whatever euphemism you prefer), resulting in fewer insects as prey, habitat for roosting and barriers to migration. This bat, like all UK bats, is a protected species in the UK, you need a licence to handle, disturb or manage bats – this is for their protection and  it is important that those who are in a position to support the local bat populations do. That’s why I am so pleased to be surveying with three local farmers who love and appreciate their bat tenants. And just in case you were wondering, my detectors are passive and do not disturb the bats so I am not harming them by recording their voices.

Em

PS I am not on commission from Analook or AnaBat but I am extremely grateful for the loan of these detectors from the Devon Bat Project and Devon Wildlife Trust to support my project work.

30 Days Wild: Day 10 – Garden Wildlife

As is so often the case, the inspiration for this blog comes from our modest sized garden in South Devon. While I was eating my lunch outside in the sunshine, the buddleia behind me was providing a sizeable buffet to several brightly coloured caterpillars. I am not in any way bothered by this – the buddleia could do with being taken down a peg or two and it will take something far hungrier to make a dent on the aggressive growth plans of this fast growing plant.

It seems to be the caterpillar of the mullien moth (Shargacucullia verbasci) and will grow up into a brown moth with a skill for impersonating twigs – take a little look at some photos (on another blog) if you don’t believe me. This is quite a remarkable change of strategy – from using warning colours in the pupae to cryptic body outlines and camouflage in the adult – isn’t nature amazing?

While I have my camera in my hand I spot a bee with bulging pockets. Unlike me, this bee is clearly working hard today.

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Bulging Bee Pockets. Photo Credit: Em

Em

30 Days Wild: Day 9: I do pick ’em.

Navelwort. This is a pretty ugly name. I don’t want to over sell this plant but really the name sets the expectations rather low so there’s really only one way to go from here. Thankfully it is quite pretty.

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Navelwort in it’s preferred habitat. Photo credit: Em

This plant grows in the dead spaces – between little gaps in walls, between the pavement and nearby wall, on the upended roots of a fallen and dying tree, even on a decaying log. With less competition for space the small succulent disc shaped leaves can grow comfortably. If that was all that you had to go on you could confuse it for the marsh pennywort. Thankfully the flowers are suitably different – the navelwort produces spears of flowers, a bit like floxgloves. The marsh pennywort’s flowers are below the leaves, tiny and inconspicuous.

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Navelwort flowers. Photo credit: Em

The belly button reference in the name isn’t random, the leaf really does look like a navel. Something that helped me when IDing this little plant in the field – keep an eye out for it – it is in full flower at the moment and looks like little waterfalls down the wall.

Em

30 Days Wild – Day 8: Field Work

Today was all about ecology. As I mentioned in yesterday’s post, I am starting a survey of Greater Horseshoe Bats in West Devon and tonight will be the first night of data collection. To make sure I can interpret the data correctly, I have also completed surveys of the habitat and vegetation immediately around where the detectors have been placed. I am particularly interested in the impact of fine scale habitat features such as wildflowers, hedgerows and animal dung. What this means is a series of transects, some quadrats, a 20m length of fluorescent guy rope and counting cow pats. It’s a glamorous job but someone has to do it. So here you are – this is what field ecology looks like:

Covering six different survey sites across three farms there is a lot of leg work involved.  Swimming through waist high grasses, climbing steep fields and lugging the kit across river and valley I definitely did an honest day’s work today! Despite being overcast, it has been close and warm today and if it hadn’t been for all the flies this would have been a nice day for shorts and t-shirts. Of course I can’t be too upset about the flies – after all a fair few of them may end up as bat breakfast – the very reason I am surveying in the first place.  Still, I wish they wouldn’t fly in my ear.

Using a 20m (pre-measured) rope as my guide I surveyed regular quadrats within  the radius of the detector. If I encountered a hedge I sampled the size, density and diversity at regular intervals. If I encountered dung I made an estimate of the percentage cover of the survey area and if I encountered grazing or fallow land I surveyed the wildflowers.

The bat data collection is done by some very clever detectors, loaned to me by the Devon Wildlife Trust as part of the Devon Bat Project. This work will help us to learn more about these enigmatic little mammals but is just a drop in the ocean compared to the amazing work these people do with farms, local communities and their partners. Meeting with, and speaking to, the land owners has been a wonderful experience and has filled me with hope that in the hands of these custodians our wildlife is valued, respected and protected.

I’m looking forward to getting the detectors back next week to see what we have!

Em

PS – look what was just around the corner of my survey site – I am on the edge of Poldark country here (aka Cornwall).

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Mine. Photo credit: Em

 

30 Days Wild – Day 7: Reading Bat Calls

There is more to the wild world than what we can see and hear with our own senses. True they are good, but when you enhance their capabilities through technology you are introduced to a new range of experiences. This includes the use of data loggers and recorders that we can leave running in one location busily recording away in our absence so we can, well, sleep. A bat detector is a great example of this.

I am starting a new bat survey project this weekend and, like all good scientists (and pessimists) I am testing the kit. Having put the detector in a distinctly average location in my garden I wasn’t exactly expecting much. Really, what you want is an uncluttered landscape, with hedgerows or trees but our garden really isn’t big enough to be described as ‘clutter-free’.

Handily this does not seem to have mattered – the bats came anyway:

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Analook file – Common Pipistrelle (using AnaBat Express, courtesy of Horseshoe Bat Project, Devon Wildlife Trust). Photo credit: Em

What we seem to have in our garden is a common pipistrelle – You can tell from the backwards facing hockey stick shape with a peak frequency of around 45kHz (cycles not visible in this view). What is really neat is that most bat calls ‘look’ quite different when displayed like this so it is a valid way of identifying the bat species present. You can even see different types of calls, such as social calls and hunting activity (known as a feeding buzz) in the way the calls change in frequency and duration.

The project I will be working on is looking at the impact of very fine scale habitat features on the Greater Horseshoe Bat here in South Devon. The Horseshoe Bat call is very distinctive (when represented visually in Analook) and I am hoping to pick them up at a couple of the sites selected for surveying.

While the software is free the detectors are very much not and I am very grateful to the Greater Horseshoe Bat Project and kind people from the Devon Wildlife Trust for the loan of these detectors.

With the test complete I am ready to start deploying them for the first survey window later this week 🙂

Em

30 Days Wild – Day 6: What’s wild in Devon?

If you wanted to guarantee a good ‘wild’ day out, Devon would be an excellent place to start. I’m not paid by VisitDevon but I am completely biased – I love living in Devon. Incidentally, I do quite like a quote they use on their website:

“I have never before been gifted with such an abundance of natural beauty” – Steven Spielberg, Director

Well said Steve. In the spirit of this, I have made a list of the kind of wild activities that are really good to do here. I will begrudgingly accept that it is possible that some of these might also apply to other places too :p

All these ideas are free and require few skills or equipment, though you might occasionally need a little patience and sense of adventure.

  • Watch cormorants fishing on the river and try to predict where they are going to come up.
  • Go wild swimming in the sea (but PLEASE remember to respect the water)
  • Take a stroll down an un-metalled roads to visit the wildflowers and butterflies
  • Watch out for bats emerging (tip: start looking just after sunset and use the sky as a backlight to spot them against)
  • Go for a run, settle into your stride and focus on your surroundings – I promise, the run goes much quicker than if you focus on how you legs or your lungs feel
  • Defend your ice cream from seagulls
  • Admire the abundance of flowers that grow right out of the stone walls
  • Listen out for bird song
  • Read a nature book – need a recommendation? See my earlier blog post
  • Rummage in the hedges for lizards (morning or evening is best – when they are not fully warm)
  • Join in with a Bioblitz – Clennon Valley in Paignton has one on 23 June – it’s free!
  • Go walking on Dartmoor
  • Roll a ball of red clay in your hand
  • Go looking for seals on the rivers and coast- Hope’s Nose is pretty good.
  • Get inspired and paint a favorite scene or animal or plant
  • Pursue a butterfly and try to photo it
  • Admire the leaflets within a leaf on the ferns
  • Poke about in a rockpool
  • Look for animal tracks or paths – if it passes a fence or thorny hedges look out for fur caught there
  • Sit back in a deck chair and watch the swifts, swallows, gulls, crows and buzzards  overhead.

Em