myotis – Grantham Ecology

2017 Retrospective – The Rest!

December 31, 2017Grantham Ecology1 Comment

I like to take the opportunity which the end of the year presents to look back over what I’ve seen and encountered. Some fall nicely into groups so do check out trees, wildflowers, butterflies, bees and invertebrates on their own posts!

The remainder are individual species or places which don’t form a group, but which are an important part of the year just passed. I hope you enjoy!

Easegill Bat Surveys

I was lucky to be invited along to a hibernation check in the caves in Easegill, Cumbria by a friend in the bat group there. We found a number of hibernating myotis and brown long-eared bats in the various cave systems, along with the tissue moths, herald moths and cave spiders which use the same habitats over winter. It was a great day out in some stunning scenery, and the opportunity to do a spot of caving whilst searching for wildlife was a real treat! You can read more, and watch a short compilation video, on this post from January 2017.

Snowy walk along Stanage Edge

It takes around an hour and a half for us to get to some of the most stunning walks in the Peak District; a bit of a trek but always worth the visit especially if there’s snow to line the fields and de-mark the landscape with its series of hedges and stone walls. I love too how the hills in the far distance can give an illusion of mountains when they become snow-covered!

Smooth newt – Lissotriton vulgaris

I couldn’t resist this photograph when we were undertaking translocations at the beginning of the year. The legislative driver behind the translocation is the great crested newt, but we take the opportunity to move any species we encounter to a place of safety. With the juveniles, such as this little smooth newt, you need to keep a sharp eye to make sure you spot them all!

Common frog – Rana temporaria

Spring is one of the most rewarding times to have a garden pond – when the croaking begins and the surface is a mass of calling frogs. This was taken on a cool March day when the frogs had decided that spring had sprung! In this photo, I tried to capture the turbulence of the water which these amorous amphibians bring to a placid garden pond.

Slow worm – Anguis fragilis

We encountered this slow worm under a piece of corrugated metal in the woods near Woodhall Spa in the early summertime. There had been a rainshower which caught us out and the slow worms too had taken shelter. As the sun came out and the corrugated metal began to warm, the chances of catching one reduced significantly as they are anything but slow when they want to be! These reptiles are in fact legless lizards rather than snakes. Their habit of sheltering beneath these artificial refugia forms the basis of the reptile survey technique we use in ecological consultancy to find out whether reptiles are present on a particular site.

Dandelion seedhead before the full moon

The was taken at Muston Meadows at midnight when the moon was full and I couldn’t resist a walk. The dandelion seedheads glowed white against the dark grass but I was struggling to capture this in a photograph – then I thought this might make an interesting angle!

Shropshire Hills

We spent a few days over the May bank holiday in Ireland for a wedding, coming back via Anglesey and spending a night in Shropshire on our way back east. We walked over the Long Mynd at dusk, heading back towards our campsite, and this was the view as we began to descend.

Church of Saint Mary, Whitby

A weekend camping near Robin Hood’s Bay in the summer found us in Whitby before walking back along the coast. This is the taken at the Church of Saint Mary – set above the town and referenced in Dracula. I was struck with this view of the tombstones dark against the long meadow grasses and wished this was a more common sight – cemeteries and churchyards can be beautiful places full of life after death, if they’re managed sensitively for wildlife rather than manicured as bowling greens!

Curbar Edge, Derbyshire

We had a survey site which saw me out in the Peak District until 7pm one evening in August – after which I took the opportunity to see the heather and take a walk along Curbar Edge at sunset. This is the view out across from the Edge as the sun was sinking low on the horizon.

Vancouver Island

The following are a few photographs from Vancouver Island this year – we encountered some spectacular wildlife and were amazed by the scenery. You can read more in my blog posts here, but below are a few highlights.

Anna’s Hummingbird in Victoria

American red squirrel at Long Beach, Tofino

Black squirrel in Stanley Park, Vancouver

Orca’s from Victoria

Grey heron reflection against the vending machines on the marina in Vancouver

Slow worm – Anguis fragilis

This tiny slow worm was one of this year’s juveniles – we were surveying a site in Somerset and this was one of seven young ones which appeared under a single survey mat where the sun warmed a bank at the edge of the site. When I picked it up, it wrapped itself around my finger but was so small that the nose and tail didn’t quite meet!

Sunrise on the day of Storm Ophelia

This photograph was taken of the countryside in Warwickshire on the day Storm Ophelia swept across the UK. At that time, I didn’t realise what was causing the effect but was just taken by the colours – it turned out that the day was to be filled with the pseudo-apocolyptic light brought on by the Sahara sands.

Cattle at Muston Meadows

Muston Meadows is an ancient haymeadow and a National Nature Reserve in Leicestershire. The site is managed with a late-summer hay cut and is grazed in the winter by cattle. I visited one frosty morning in December and they were delighted to have a visitor, charging over before stopping and checking me out. They then accompanied me all the way off the site so perhaps their role is security as well as site management!

Icicles under Burbage Bridge

On a snowy cold day in December, I took a walk through the white from the Longshaw Estate in Derbyshire, through woodland and across tors and encountering these beautiful icicles hanging beneath the bridge which takes the road over Burbage Brook.

Clematis seedhead – Clematis vitalba

These are also commonly known as old man’s beard and it’s easy to see why! I came across these seedheads in a hedgerow on a survey site in Bedfordshire where the wind had left them with this shape over time – I liked the feeling of motion which they held even when still. It seemed appropriate for seeds which are waiting for their time to take to the wind and begin a new plant elsewhere in the landscape.

Teasel seedheads – Dipsacus fullonum

On the same site as the clematis above, I also found an amazing stand of teasel seedheads. These striking plants are excellent for wildlife – in the summer they provide an abundance of nectar for pollinators such as bees and butterflies, and the winter seedheads will play host to flocks of goldfinches foraging for the seeds.

Easegill Caves Hibernation Surveys

January 24, 2017Grantham Ecology1 Comment

The Cumbria Bat Group kindly let me come along on a hibernation survey at Easegill Caves in January 2017. We hiked up to Upper and Lower Kirk Caves to see what we could find, then descended using ropes and caving ladders into Link Pot to explore an underground cave network some 15m down.

We found good numbers of myotis species including Daubenton’s, Natterer’s and whiskered/Brandt’s/Alcathoe – these last three are grouped as it’s very difficult to distinguish these three without disturbing the bats. We also found a small number of brown long-eared bats hibernating too.

It’s important to note that disturbing hibernating bats is illegal without a licence from Natural England – this survey was led and supervised by licenced bat workers who ensured that disturbance was kept to a minimum whilst allowing the bats to be identified and counted. If you find a bat in roosting you should take great care not to disturb it especially during the winter as they may rouse from torpor at an inappropriate time and be unable to then survive the winter. If you do find a roosting bat – let your local Bat Group know! More details at the bottom…

The video below shows a summary of the seven hours we spent out in the hills, in just under three minutes!

The following photographs show a few of the hibernating bats we identified on the surveys.

It’s not only bats we found in the caves – plenty of cave spiders and hibernating moths too including herald and tissue moths.

If you would like to get more involved with your local bat group and help out on hibernation surveys such as these, you can find your nearest here. Many thanks to the South Cumbria Bat Group, and Rich Flight in particular, for a great opportunity to explore the caves and see plenty of roosting bats!

Life after Light – Bats along Grantham Canal

October 20, 2014July 31, 2017Grantham Ecology1 Comment

It’s very nearly Halloween – what better time to introduce you to the bats which haunt Grantham Canal when darkness falls…

I spent several nights this September cycling along Grantham Canal with an EM3 bat detector connected to a GPS unit, recording the bats in flight between the A1 to the east and Hickling Basin to the west. Bats use echolocation to navigate and hunt and the bat detector converts this ultrasonic sound into something we can hear. The sound emitted by the detector tells you when a bat is there, often which species it is and sometimes even what it is doing.

You might imagine that this is quite a sinister place to be, surrounded by bats on a moonlit night, but there really is nothing to be afraid of! As the detector tapped and pattered away to announce their, I could see bats flying before me in the darkness. But even though I was cycling towards them, they elegantly avoided me every time, never making contact and certainly never tangling in my hair. This is one of the most enduring myths about bats but their fantastic echolocation abilities mean that they can ‘see’ and avoid obstacles on even the darkest of nights.

I recorded at least five species in September, some calls with ‘buzzes’ indicating foraging and some with ‘song flight’ where male soprano pipistrelles emit lower frequency social calls to attract mates. These are just on the edge of human hearing and can be heard without a detector – you may have heard the very high frequency chirrups if you walk outside at dusk in the autumn.

Common Pipistrelle

The common pipistrelle is our most abundant species in the UK, and was encountered throughout the route of the canal, particularly where there are more trees as this species specialises in hunting along ‘edge’ habitat which is typically along hedges, tree lines and other landscape features.

The orange bat symbols in this map indicate the locations where common pipistrelle bats were identified. The A1 which dissects the canal is at the far eastern end with Hickling Basin marking the western extent

Soprano Pipistrelle

The soprano pipistrelle is very similar morphologically and was not even identified as a separate species until 1992. Now they can be told apart confidently in their hand, and with fair reliability acoustically as the soprano pipistrelle calls at 55 kHz compared with the common pipipstrelle at 45 kHz. In England, the soprano pipistrelle is often found associated with water and so it was no surprise to find them along the canal. An interesting observation however is that there appears to be much more activity to the east, near to larger water bodies. Denton Reservoir lies just beside the canal towards the eastern end and is likely to be an important foraging resource for this species.

aaaa — The blue bat symbols in this map indicate the locations where soprano pipistrelle bats were identified. The A1 which dissects the canal is at the far eastern end with Hickling Basin marking the western extent

The vast majority of the recordings related to these two pipistrelle species – the other bat species were found at much lower frequencies.

The yellow bat symbols in this map indicate the locations where Natterer's bats were identified; black represents whiskered/Brandts; purple represents brown long-eared; and green represents noctule. The A1 which dissects the canal is at the far eastern end with Hickling Basin marking the western extent — The yellow bat symbols in this map indicate the locations where Natterer’s bats were identified; black represents whiskered/Brandts; purple represents brown long-eared; and green represents noctule. The A1 which dissects the canal is at the far eastern end with Hickling Basin marking the western extent

Noctule

The noctule bat is our largest species and tends to fly high and early, often the first bat to appear around sunset and can be seen in the skies as the swifts are still on the wing. Only one noctule was heard during the transects, between Denton and Woolesthorpe and picked up again near Muston. This bat is large and the sky was light meaning I could watch it flying my way, foraging as it flew to the west. This is a widespread species which favours roosting in trees, but numbers are generally lower than the pipistrelles.

Brown long-eared bat

Brown long-eared bat is one of our quietest but most charismatic bats. Their large ears make them quite charming to behold, and they are frequently found roosting in barns and other buildings. I only picked up a single instance of this bat, but their very quiet echolocation means they are generally under-recorded.

Myotis bats

The myotis bats are considered to be some of the most difficult to identify from sound alone. Daubenton’s bats are the myotis species most frequently associated with water as they specialise in flying low over still waters and taking insects on the wing or from the water’s surface. Natterer’s bat is another myotis species and some of the calls recorded along the canal in September are characteristic of this species. Whiskered and Brandt’s bats are the other two myotis species which are likely to be present in this part of the country. These two bats are very similar to one another and are difficult to separate even in the hand. Some of the calls have the characteristics of one (or both) of these two species. Whilst these species are not commonly associated with aquatic habitats, the canal also boasts hedgerows, copses and grass bank margins which provide great terrestrial habitat as well.

I encountered a whole host of other species whilst cycling along in the afterglow of sunset including barn owls, tawny owls, hares fleeing down the towpath and badgers snuffling in the hedgerows. The canal is stunning in the daytime but at night it comes alive with a whole host of new species – a walk around sunset might reveal creatures which you would not normally be privileged enough to watch.

If you are looking to commission bat surveys in the Midlands area, check out Landscape Science Consultancy’s website here!

Bat Swarming Site – first trial of Bushnell Trail Cam

October 28, 2013Grantham Ecology3 Comments

My last professional bat survey of the season was completed last week – at a railway tunnel which is a swarming site for a small number of bats. Swarming sites are locations, often caves, mines or tunnels, where bats – particularly the myotis species – gather in the autumn to mate. We stayed until 5h after sunset to monitor the usage of the tunnel and recorded around 5-6 bats at this site. They are most likely to be Natterer’s bats, judging by the calls, although myotis species are notoriously similar acoustically, and can be difficult to tell apart from sound alone.

This is an extract from the echolocation files from the tunnel survey. The calls which are very long and straight (known as FM of Frequency Modulated calls) are distinctive of myotis species. This is probably Natterer's bat because the start of the call is at such a high frequency and the end is at such a low frequency. For reference, most people can hear upto about 18 kHz which would be a very high pitched sound. These calls are from well above 100 kHz and end around 30-40 kHz. — This is an extract from the echolocation files from the tunnel survey. The calls which are very long and straight (known as FM of Frequency Modulated calls) are distinctive of myotis species. This is probably Natterer’s bat because the start of the call is at such a high frequency and the end is at such a low frequency. For reference, most people can hear upto about 18 kHz which would be a very high pitched sound. These calls are from well above 100 kHz and end around 30-40 kHz.

The bats were using the tunnel entrance – a great, ominous opening onto blackness surrounded by shrubs and trees – but they spent most of their time flying in tandem within the tunnel and especially around the vertical air vents – circular ‘chimneys’ some 5m wide – which are spaced out down the length of the tunnel.

I’ve recently bought a trail cam and this seemed like a good opportunity to try it out and answer the first question – can it be triggered by bats? I’ve spoken to people who have said that they can, but that the lag between the detection and the shutter closing means that the bat has been and gone before you can get a good photo.

I’ve opted for the Bushnell Trophy Cam Max HD, largely because of the no-glow LED’s which would hopefully reduce the risk of it being spotted and interfered with, but I wasn’t sure how the different cameras available would compare on their sensitivity. It can certainly spot a greenfinch hopping about on the lawn which suggests it is reasonably sensitive to small creatures, but my first test on bats suggested that flight ~6m away was not detected.

I placed the trail cam face-up beneath one of the air vents and there were no ‘triggers’ but I also used the ‘field scan’ setting to automatically take a 10 second video every 5 minutes, regardless of whether the camera detected something to monitor. The result was lots of empty shots, with only dripping water to reveal movement, but I did record one brief pass of two bats flying close together. It’s not great footage – very far from something you might have seen on the BBC recently using their high quality night vision kit – but it is enough to show that the bats are there and it could potentially be a way to monitor the presence of bats in a site such as this over a period of time.

The use of automated bat detectors has really taken off in recent years – this is a great supplement to surveys where ecologists walk or watch and detect bats using hand held devices. A static unit can sit in the field for a week, record every bat which goes past, and be picked up and analysed at your convenience. It lacks the qualitative element which can be gained from an actual surveyor in the field – where did the bat fly, which direction, what behaviour – but it is invaluable to assess the assemblage of bats present, picking up species present at low densities or passage use by rarer species.

In a similar way, I am hoping that the trail cam will be a great way to gather a census of the species of mammals in an area or at least using a trail, even if they only pass that way once a week. With any luck, watch this space for further updates and footage which are hopefully a little better than this!

If anybody has any experience of catching videos of bats in flight using a trail cam, I’d love to hear about it!