#23 Alcathoe Bat by John Altringham

Meet John Altringham, Emeritus Professor of Animal Ecology and Conservation at the University of Leeds!

John Altringham is Emeritus Professor of Animal Ecology and Conservation at the University of Leeds and an advisor to a wide range of conservation organisations. He is interested in all aspects of nature, but his primary research interest is bats. He is the author of three books on bats and numerous scientific papers and magazine articles. You can contact him via email at j.d.altringham@leeds.ac.uk and find him on Twitter at @JohnAltringham.

John’s chosen species is the Alcathoe Bat Myotis alcathoe, a small and cryptic species very similar to whiskered and Brandt’s bats. It was formally described in 2001 from studies in Greece and neighbouring parts of Hungary. Initially it appeared to be a rare and geographically restricted species but is now known to be widespread across Europe. It does appear to be rare, being largely restricted to old, deciduous, riparian woodland, where it feeds on small insects taken in the air and other invertebrates gleaned from vegetation.

Alcathoe bat © Cyril Schönbachler.

The first Alcathoe Bat recorded in Yorkshire was captured in 2003 during John and his colleagues’ studies of autumn swarming at Slip Gill, a cave near Rievaulx Abbey in Ryedale. Swarming is a pre-hibernation mating behaviour seen at cave entrances in late summer and autumn. It is common to Myotis, Plecotus and Barbastella species that hibernate in caves and mines. However, they did not know they had recorded Alcathoe Bat until 2009 when they studied the genetics of a very large number of bats from swarming sites across Europe. Genetic analysis was completed using 3 mm diameter disks of wing membrane, taken when the bats were first caught. It is a painless procedure, and the small hole rapidly heals. It is a valuable technique in ecology, behaviour and conservation studies.

‘In 2003 Alcathoe bat was a rare and recently discovered species from the other side of Europe, a species we did not expect to find in Yorkshire – it was barely on our radar’ explains John. ‘When several bats turned out to be Alcathoe we immediately analysed all the samples we had collected from small Myotis bats at UK swarming sites. A small but significant percentage of those from Ryedale were not whiskered or Brandt’s (as identified in the hand) but Alcathoe. Most of the small sample from sites in Sussex were also Alcathoe bats.’

In 2009, soon after this discovery, as they continued their studies in Ryedale, John and his team fortuitously recaptured that very first Alcathoe Bat (all bats caught at swarming sites were being ringed to estimate population sizes and catchment areas). Now knowing what to look for, they were able to identify the subtle morphological features that separate it from other Myotis bats. The differences are small and reliable identification needs care. Knowing of its habitat requirements in Europe, some speculative survey work was completed in some of the well-wooded dales along the southern edge of the North York Moors. Flying individuals were picked up by acoustic survey from their distinctive echolocation calls. Several individuals were caught, and one was fitted with a radio transmitter that led to the discovery of a nursery colony in a riverbank tree in Sleightholmedale.

Is Alcathoe Bat a newcomer to the British Isles, perhaps expanding its range in response to climate change? Or has it always been here, a rare species hiding among other rare and similar species? We don’t yet know, but John suspects it’s a long-standing resident given its breeding status in Yorkshire and the significant numbers recorded in the south-east of England. Its distribution in the British Isles is patchy, not surprising for a rare and recent discovery and the fact that few people have been looking for it. Since it uses a conveniently distinctive echolocation call it should reveal itself in acoustic surveys, particularly as automated identification software is becoming more reliable and more widely available.

Until we know more about its distribution and population status, as well as its ecology, we can say little about its conservation status with any confidence. However, all the signs point to a rare bat largely dependent upon old riparian woodland, a scarce habitat. As a priority habitat for many other species, it is to be hoped that future conservation efforts are likely to favour it.

So there we have it - a Yorkshire species discovered by accident during a Europe-wide research project on bat swarming. A species ‘new to science’ but probably a long-standing resident in the county. A species so like some of its relatives that it needed genetic analysis to confirm its separate status. A species that will always be tricky to identify in the hand but should be readily identifiable by its echolocation call. A ‘data-deficient’ species waiting to be properly surveyed and studied. A species that shows that even in these small, overcrowded, wildlife-depleted islands there are still new species to be recorded…and some of them may even be mammals!

Monitoring

Along with other bat species, Alcathoe Bat is being surveyed as a component of the Heritage Lottery funded Ryevitalise project, led by the North York Moors National Park.

Further information and acknowledgements

NEYEDC would like to thank John for his time and expertise in helping to create this blog.