Last year I heard a talk about the use the Botanical Society of the British Isles makes of historical records in order to understand changes in the distribution of vascular plants. Some of their impressive database comes from the notebooks of victorian botanists and the voucher specimens they made, which are often still to be seen in herbaria. Other records are found by trawling old natural history books and drawing out biological records from descriptions of species and their distribution.
Inspired by this I resolved to seek out any such data I could regarding bats in my part of Scotland. It took a while to find a suitable source of data: bats were not recorded anything like as much as vascular plants were, botany being a "suitable" occupation for those few Victorians and edwardians who had time to spare. However, I recently came across a copy of "The Mammalian Fauna of the Edinburgh District", written by William Evans in 1892. In it, Evans set out to record the distribution of mammals in Eastern Scotland between the Tay and the Tweed (a rather broad definition of "Edinburgh distict" by today's standards). He particularly wanted to record the distribution of bats and small mammals, as these were felt to be under-recorded at the time. Arguably then, Mr Evans was one of the first ever bat-workers in Scotland.
There are some fascinating distinctions between the work of this dedicated natural historian and modern bat-work, but some remarkable parallels too. Not surprisingly, the methods used are utterly different and at times seem a little barbaric to a modern reader. In a day when bat detectors were still 6 or 7 decades away, the art of finding bats was focussed on roosts and upon seeing and catching bats in flight. Whereas today we consider it appropriate to make biological records based on seeing (or hearing) a bat and recording the salient characteristics, in an age when conservation was unheard of and probably unnecessary, the true scientist's voucher specimen was a dead animal. Evans described removing bats from roosts, catching them in flight using butterfly and fishing nets, plus some less savoury approaches.
The Daubenton's Bat (then Vespertilio daubentoni, now Myotis daubentonii) seems to have come in for more of it's fair share of hasrh treatment: "During the summer of 1869 I observed a number of bats flitting above a still reach of the Esk above Penicuik, and one which I succeeded in striking down with a walking stick proved to be of this species." Three other specimens of this species were sent to him from the Dunbar area by a contact who, rather than battering them to death with a walking stick, chose the gentlemanly approach....and shot them!
In another section Evans describes how impressed he was with the nimble flight of a Pipistrelle he watched, though his methods of evaluating this were a little rough by today's standards: "In June last I watched one for fully a quarter of an hour flying in the bright sunshine at Broomhall, near Dunfermline and was much struck with its activity and the facility with which it evaded stones and other missiles thrown at it."
Lest you think too poorly of Evans, he also described caring for live bats (probably captures, rather than the sick and injured bats the modern bat-worker might deal with), in particular a Brown Long-eared Bat given to him by the gamekeeper at Dalkeith Country Park (where there is still a Brown Long-eared roost): "It delights in scrambling about the pictures, the window-blinds and even the chairs; and often settles on the floor, where it moves with considerable rapidity (indeed, it may almost be said to run), keeping the body practically clear of the ground. A more knowing little creature I have seldom seen; and, having discovered that there is sufficient space below the room-door for it to creep through, it's endeavours to overcome obstacles placed in the way of it's escape are most persistent and amusing."
Aside from the very limited equipment Evans had available by modern standards, the victorian understanding of bat taxonomy was rather different. He describes there being 12 species of bat nationwide, whereas today we accept there are 16 or 17 (depending on your views about the Greater Mouse-eared bat's status in the British Isles). The most obvious difference is the Pipistrelle. We now know that there are three Pipistrelle species in the UK, whereas in Evan's day only one was known, the splitting of Common and Soprano Pipistrelles being still a century away.
The most surprising thing about Evan's work and the thing for which he deserves to be remembered is the fact that, despite limited taxonomic understanding and huge limitations in method and equipment, compared with today, his description of the bat fauna of the area is remarkably in tune with what we know today. He described Brown Long-eareds as "by no means rare", Daubenton's Bats as "...locally at least, not uncommon" and Pipistrelles as "undoubtedly by far the most abundant and generally distributed." Ignoring the split of the Pipistrelle species, these three are the most abundant bat species in the region today.
More impressive still is that he was remarkably accurate about the rarer species too. He described a record of Natterer's Bats from near Dalkeith (the two known roosts of that species in the Lothians today are in the Dalkeith area) and goes on to hypothesise that Whiskered Bats are likely to be present in the region too. They are, but there are only three modern records of them in the Lothians. In fact, his only shortfall was his failure to mention the Noctule, which we now know to be present in the Lothians. Whether they were present 117 years ago is a moot point, but it's only in the past decade that they have been identified in south east Scotland. Were they here in Evan's time? We'll never know.
If you're interested in helping to put historical biological records to work, try visiting http://herbariaunited.org/atHome/ This project uses on-line volunteers to transfer information from thousands of old herbarium sheets onto a modern database. It's easy to do and rather addictive!
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