The Diffusion of Useful Knowledge

Having a first degree in history I have always had an interest in how our understanding of bats has developed down the years (see "An 1892 bat-worker", January 2009). Today's post brought me a copy of "The Penny Magazine of the Society for the diffusion of useful knowledge", published on 7 January 1843.

My first thought was what a wonderful-sounding title and what a sign of the times that there existed a Society for the Diffusion of Useful Knowledge. The Victorian moneyed classes were incredible busy-bodies and loved trying to enhance people's lives, often in rather idiosyncratic ways. (Strangely, paying people enough to live on was rarely considered a way of enhancing lives!)

A regular feature of this paper is a series entitled "Curiosities of British Natural History" and this issue's feature is about bats. Sadly, the author's name is not given but it was either someone who knew the subject or who did a good deal of research as it contains several pages of detailed description of the subject.

Above the start is a gorgeous engraving, showing a Noctule, a Pipistrelle and a Long-eared Bat. The latter has a thoroughly cheesy grin on its face and the Noctule looks too portly to fly, but some of the anatomy is surprisingly detailed: presumably they were engraved from dead specimens.

The article begins with the enticing statement "It may surprise some of our readers to be informed that sixteen or seventeen distinct species of bats are natives of the British Isles". What?! That is our current understanding (depending on whether you include the Greater Mouse-eared or not). In 1843 the two Pipistrelles had not been separated, nor had Brandts and Whiskered Bats. The finding of Nathusius Pipistrelles in Britain was long in the future and, although it had been described elsewhere, I don't think the Grey Long-eared had been discovered in Britain at that time.


So what were the other four species? Unfortunately, the anonymous author doesn't tell us. In fact he only describes eight species, dismissing all the others as "extremely rare and restricted to certain localities". Was he guessing? Was he reading a foreign book and assuming the same species were here? Was he including some long-dismissed sub-species or perhaps bats found in part of the Empire? How frustrating!


The species he describes are: The Common Bat (Pipistrelle); The Great Bat (Noctule); The Long-eared Bat; The Barbastelle; The Reddish-grey Bat (Natterer's); the Whiskered Bat and the Greater and Lesser Horseshoe Bats. The obvious missing species is the Daubenton's, which must surely have been known at that time and would have been relatively easy to distinguish.

As with all writing of the era, wordsmithing was a priority and some of the descriptive text is fantastic: "Often during warm summer evenings have we seen numbers, perhaps several scores, of the Common Bat flitting over pools, in chase of gnats and similar insects, or gambolling with each other in a mazy dance, ever and anon uttering sharp shrill cries of exultation and delight..." The shill calls were presumably social calls, which are sometimes just within the range of human hearing. Incidentally, a score at that time was an innocent number twenty, in case you think the author was using dried bats for questionable purposes.


The piece includes a surprising amount of scientific detail, for example listing the species found to hibernate in caves as Natterer's, Whiskereds, Barbastelles and Long-eareds, though again Daubenton's are conspicuously absent (could it be they confused them with Natterer's at this time?). Given that this was a popular paper, not a scientific journal, there is a remarkable amount of detail: something today's press could learn from.


As with today's press however, the author just can't resist a lurid story and describes bats stealing bacon from chimneys and eating meat in larders. Not perhaps as daft as it sounds, in an era when bacon was hung in chimneys to cure and when meat was kept open in a larder. Houses would have been quite porous to bats at that time and I can imagine a stray Pipistrelle within a house, finding itself next to a joint of raw meat, having a nibble, possibly for the water content.


Something exciting about old texts like this is when they describe the location of bat roosts. The author mentions a Noctule roost under the eaves of Queen's College Cambridge and Greater Horseshoes occupying caves "at Clifton and in Kent's Hole, near Torquay". If anyone reading this lives in those areas, it would be fascinating to know if these sites are still occupied, 166 years later!


At the time this paper was produced, people were still grasping to understand how bats found their way in the dark, and, reading the author's description one gets a sense of his frustration: they knew there was something special about it, but couldn't quite put their finger on it:


"There is a singular property with which the bats is endowed, too remarkable and curious to be passed altogether unnoticed. The wings of these creatures consist, as we have seen, of a delicate and nearly naked membrane of vast amplitude considering the size of the body; but besides this, the nose is in some furnished with a membranous foliation, and in others the external membranous ears are enormously developed. Now these membranous tissues have their sensibility so high, that something like a new sense somehow accrues, as if in aid of that of sight. The modified impressions which the air in quiescence, or in motion, however slight, communicates; the tremulous jar of its currents, its temperature, the indescribable condition of such portions of air as are in contact with different bodies, are all apparently appreciated by the bat." So near, yet so far!


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Alana or Envisage?

For years Alana Ecology have been the benchmark supplier for wildlife survey equipment. They were never the cheapest supplier, but their catalogue always drew together kit from a huge range of manufacturers. It always seemed to include the very best equipment and this was coupled with excellent advice: if you called you always found yourself speaking with someone who actually understood what you needed and knew the best solution.

Not surprisingly, for me and for many other people who work with wildlife, both professionally and as a hobby Alana became the standard supplier for everything: a reliable source of advice and good kit.

Over the past couple of years there seems to have been a disappointing deterioration in the standard of service provided by Alana: late and missing deliveries; failure to keep the customer informed, failure to call back etc. After several instances of this kind of poor service I started looking around to see who else is out there and a colleague told me about Envisage Wildcare. Their catalogue isn't quite as comprehensive as Alana's (and irritatingly, you have to download it, you can't simply view it on the web), but most of the key equipment is there.

When I needed a new endoscope I decided to give Envisage Wildcare a try. I phoned at 4pm and spoke to someone who took my order. Pushing my luck, I asked if it would be possible to have it delivered the next day? "Erm, yes, but the van is arriving so I'll need to put the phone down now and run". That is the kind of service that attracts attention and true enough, next morning the endoscope arrived.

Since then, I have heard about several other examples of this kind of thoughtful, professional service, experienced by others. I do think that we would be best served by two good companies in competition: that way they keep each other up to the mark and keep prices low. Having heard a couple of people say recently that had gone elsewhere, I hope that Alana recognise and address their service. They have great expertise and I certainly haven't written them off.

If I were to send messages to both companies it would be this:
Alana - sort out your service, keep your customers informed about their orders and lose the complacency.
Envisage - keep doing what you're doing, but for heaven's sake set up a proper on-line shop, instead of the irritating pdf download.

Take a look and decide for yourself:
http://www.alanaecology.com/
http://www.envisage-wildcare.co.uk/

My website: http://www.plecotus.co.uk/

Noctules, Boxes and dangling bat-workers

During 2007 and 2008 I spent some time on investigating the distribution of Noctules (Nyctalus noctula) in south-east Scotland, a region where the species was traditionally considered scarce and probably beyond it's natural range. I gathered together incidental records from many bat-workers (thanks!), some focussed car surveys and records from commercial bat surveys carried out by a number of consultants, including me.

The result was a clear indication that Noctules are widespread in the Borders and Lothians regions and probably at a greater density than was previously realised. The results were presented in a poster at the B.C.T. Scottish bat Conference in November 2008. If you're interested you can download a copy as a .PDF file here: http://www.plecotus.net/Noctule-poster.pdf (You are free to distribute this information, in the interests of bat conservation, but please attribute it)

One evening in September I was relaxing in the bar at Preston Montford Field Centre, near Shrewsbury during a training course. My phone made one of the irritating noises that mobiles make, to tell me I had received a text from Carol and Nigel, both active members of Lothians Bat Group. They attached a photo, with the tongue-in-cheek message "do you know what this is?!" You're probably ahead of me here - it was a Noctule, of course. To rub my nose in it, they had found it in a bat box at a country park 2 miles from my home. If I hadn't been on the course I would probably have been there when the boxes were checked. Grumpy wasn't the word for my response....

To their credit, Carol and Nigel had found the first ever Noctule in a bat box in Scotland and it resulted in some positive press coverage for bat conservation. Fast forward two weeks when I was checking bat boxes at another country park, also in Midlothian and believe it or not, there was another Noctule. Like Nigel and Carol's this was an adult female, squeezed into a slim bat box. She was a delight to handle: very relaxed, even when I placed her on a log to photograph her, before returning her to her box. She was also kind enough to give up some Spinturnix acuminatus mites (well, I was happy about it, even if my companions were a little taken aback).

To put this in context, these two animals were both found in boxes in a county where I can count previous records of Noctules in flight on my fingers. Was it coincidence (or was it the same bat, with a sense of humour?) or does this tie in with our new knowledge of the spread of Noctules? It was certainly a surprise in an area with many bat box schemes and two decades history of only ever finding Pipistrelles in them. By coincidence, in 2007 and 2008 a small colony of Natterer's Bats were found in a West Lothian bat box, so these Noctules seemed too good to be true.

Stuart Smith, chairman of Lothians Bat Group (and one of the grandees of Scottish bat-work), came up with an unusual plan to respond to these new records by installing some new bat boxes, higher than normal, something he had seen at a Vincent Wildlife Trust site in Dorset. Most bat boxes in the Lothians are between 12 and 20 feet (3.7-6.1m ) above ground. Noctules are tree-roosting bats, with a tendency to roost in tree holes, often high up, so higher boxes makes sense. The problem is that 20 feet is the maximum height for access by ladder, without extra safety measures and skills.

The solution? Suspended bat boxes! We used Schwegler woodcrete bat boxes, suspended from pulleys attached to high branches. Wire rope is used to pull the boxes up to full height -around 40-45 feet above ground (12.3-13.8m) - and tied off on bolts mounted on the tree trunk. These are at ladder height, to prevent the local "yoof" from reaching them. When we need to check and clean the boxes we will simply climb a ladder to normal height, unwind the wire rope from the bolts and lower the box to ground level. Once finished, we simply haul the box back to the top of the tree and tie off the wire rope once more. Ingenious!

Now, there is a chicken and egg problem here: how to get 40 feet up to mount the pulley? The Bat Group is lucky to have access to the services of a professional tree-climber, who also has an affinity for bats. George used his skills to climb the trees and install pulleys for us, making it look easy, as tree climbers always do. However, it's very hard work: you need to combine a high level of physical fitness with some somewhat counter-intuitive skills. Come to think of it, strolling about at the top of a tall tree as about as counter-intuitive as it's possible to be!

Watching a bat-box being hauled 40 feet into the top of a tree was quite exciting. Whether they will attract Noctules remains to be seen...

With work over for the day, George offered a couple of group members the opportunity to try out tree climbing techniques (at very low height) and so, trussed up and roped to the tree, we took our turns at making fools of ourselves. I had tried my hand at this in the past, so probably should have known better, but didn't.

An advantage of this being my blog is that you won't get to see my feeble attempt at tree climbing. However, this seems a good moment to wreak revenge on Carol for last year's Noctule text message. You have to hand it to her: she's enjoying herself, even if she isn't making much progress up the tree!

Any comments: blog@plecotus.co.uk

My website: http://plecotus.co.uk/

The Anabat PDA Bracket

Last year I described a home-constructed bracket for attaching a PDA over the face of an Anabat SD1 bat detector (Ana...nother thing or two about the SD1, November 28 2008)

Although not as strong as the brackets sold by Titley Electronics, my bracket has the advantage that, if dropped during a survey, the bracket is likely to give way and protect the PDA and its precious data. It also cost roughly a 50th of the price of buying theirs, which is handy in the current economic climate.

Several people have contacted me to ask about the design. It's very simple, virtually "Blue Peter" construction, though without the sticky-backed plastic (I could never put that stuff on without bubbles anyway!)

For anyone who wants to try making one, I have put the details onto a .PDF file, accessible here: http://plecotus.net/Anabat-PDA-bracket.pdf

If you make one please let me know how you get on: mailto:blog@plecotus.co.uk

My website: http://www.blogger.com/www.plecotus.co.uk

An early spring...maybe?

Last night I took a group of ecology undergraduates to a 200 year-old kirk (that's church to those without a Scottish education) in East Lothian, to watch for bats. I had my fingers firmly crossed on the way there: although I know the church and churchyard to have plenty of summer bat activity it is still very early in the season for bats to be at all dependable.

In the summer the kirk has a Soprano Pipistrelle (Pipistrellus pygmaeus) maternity roost within the roof structure and also has Brown Long-eared Bats (Plecotus auritus) inside the kirk itself - during the summer there is usually a light scattering of droppings over the pews. Last year I watched one flying up and down inside the kirk, warming up before going out to forage.

The most I could really hope for was that there might be one or two individual Pipistrelles foraging around the kirkyard - it's in a secluded, tree-lined valley, alongside a burn (or stream if you prefer), so it's good foraging habitat, even this early in the season.


When we arrived and walked round there were no droppings inside the kirk, althought there were some on the exterior, making me hope that at least a few of the Pipistrelles may be present.

At sunset a few Soprano Pips overflew the kirk at first, commuting from other locations in the valley. Then there came an excited squawk over the radio, announcing that someone had seen a bat emerge from the edge of the kirk roof and we watched about 30 Sopranos emerge from the same spot where I watched several times that number come out in the autumn last year.



I am sure that there will be many more than 30 bats in that roost in mid summer, when Soprano Pipistrelle females gather in large numbers to rear their young - these are probably the first arrivals. Interestingly, we also heard a male Soprano in songflight, the string of mating calls designed to attract mates. This is primarily an autumn activity, but seems to occur a little in spring as well.

It's not hard to see why the bats are active so early in April. The chart below shows night-time temperatures at the Met Office's Gogarbank station, near Edinburgh. There have been two weeks of fairly consistent temperatures around 7 to 8 degrees, which seems to be the level at which bat activity in this area picks up. As a happy coincidence, last night was also the warmest night of the year so far.



However, this might not be the end of the story. It's still very early in the year and weather is never as reliable as we would like. As you can see below, last year April started off warm like this and then went into a cold period for a couple of weeks, causing bat activity to fall away until nearly the end of the month. Only time will tell what will happen this year.



My website: plecotus.co.uk
Contact me: mailto:blog@plecotus.co.uk