Volume 16
Issue 2

Protecting horseshoe and Leisler’s bats in Ireland is a continual adventure that never fails to include history, heritage, and some degree of hazard . . .

By Kate McAney

It is my first day in the office following a few nights’ fieldwork, and the message log on my answering machine registers double figures. I never know what to expect when I make the return call, but when the telephone is answered by a young voice that says, "Mum, it’s the bat lady," I tend to breathe a sigh of relief, as signs are the conversation will be an amicable one, and the caller will agree to let bats stay in their home rather than excluding them. I never introduce myself as "the bat lady," but I suspect that I shall bear the title for some time to come.

My involvement with Irish bats dates back to the summer of 1981. I was living with my parents when late one Saturday night, my Mum called out to me that there was a bat flying around the kitchen. As is often the case, we searched high and low before we found what was probably a pipistrelle, hiding in a fold of the curtain. That was the first time I had ever seen a bat, and as I examined it at close range, marvelling at how fast its heart was beating, a new world opened up for me–a world that has engaged me, in one way or another, ever since.

I am now in the extraordinary position of being the only person in the Republic of Ireland whose job is dedicated solely to the conservation of bats, which constitute a quarter of the mammals of the country. Since 1991 I have worked as a field officer in Ireland for The Vincent Wildlife Trust, founded in London in 1975 by Vincent Weir. The Trust is an independent, charitable body engaged in wildlife research and conservation. A major part of the conservation work undertaken by The Trust centers on protecting the declining populations of both greater and lesser horseshoe bats (Rhinolophus ferrumequinum and R. hipposideros). Worldwide there are 69 species belonging to the family Rhinolophidae, but only the lesser horseshoe is native to Ireland, where it is at the northern and western limits of its European range. Although it is one of the smallest and most vulnerable of Irish mammals, the population is currently estimated to be 12,000, making Ireland a European stronghold for the species. Its endurance here is mainly due to the lack of intensive agriculture and industrialization along Ireland’s Atlantic seaboard where its habitat is found.

A major portion of my work is locating, monitoring, and safeguarding this population. These tasks are made relatively easy by a number of factors. First, it is impossible to mistake a horseshoe bat for any other bat species. Horseshoes have a circular flap of skin surrounding their nostrils in the shape of a horseshoe, hence their name. They always hang freely from a surface rather than clinging to a wall or burrowing in a crevice. Second, their choice of winter and summer sites is well known. Early scientific writings about the lesser horseshoe in Ireland date back to the 1800s. While these Victorian accounts resemble natural history essays rather than scientific reports, they are nonetheless accurate. One of my favorite pieces, penned by Frederick J. Foot in March, 1859, describes the hibernation habits of the species:

The favorite haunts of these bats are dry, vertical nooks in the rock, from the top of which they hang suspended by their claws, head downwards and completely enveloped in their wings, so much so that not even their ears are visible. Two are rarely seen near each other and never more than one in the same nook. In selecting a position to hang, they appear to be regardless of its distance from the ground, as they may be seen at different heights. On the candle being held near them, they wince slightly from the light, changing their vertical position into a curve.

More than a hundred years later, my winter field notes are similar, except I now illuminate the lesser horseshoes by battery-operated light.

Considering the difficulties some bat researchers experience in locating and recognizing their study species, I would appear to have it easy. However, before 1991, my only experience of caves was as a shorts-clad tourist to Chateau Beycheville in France, where I witnessed the maturation of that fine wine. I soon realized that monitoring bats in caves would require a little more effort and expertise, so in October 1992, I enrolled in a caving course. Over two weekends I slowly mastered the skills which would enable me in the years that followed to repeat the experiences of the Victorian explorers.

Such thoughts were far from my mind, however, as I stumbled underground for the first time in an ill-fitting wet suit with heavy and unfamiliar equipment strapped to my body. The majority of the caves in my work area were formed relatively recently, and the streams that originally formed them are still flowing along their lengths, dictating that a wet suit soon became an important addition to my winter wardrobe.

Thanks to help from a team of experienced British bat workers/cavers, I have now completed hibernation surveys in all the major limestone areas where the lesser horseshoe is known to occur in Ireland. In all, 204 sites have been searched, yielding 810 lesser horseshoe bats. Caves and mines were the preferred hibernation sites, although I visited other underground roosts as well. Fewer bats were recorded in southern caves, probably because the internal temperature of some of these was 53°F (11.8°C), too hot even for horseshoes.

Some of the most interesting sites used by these bats are artificial cave-like structures called souterrains, a term borrowed from the French for "underground." The Irish souterrains date back to some time between 500 and 1200 AD, when they served as a refuge during times of raiding. The design of souterrain passages varies from a "restricted" type (hardly three feet square yet up to 65 feet long), to a "roomy" type (up to seven feet high and four feet wide), which can be straight, angled, or curving, with one or more spacious chambers along its length. Their most interesting feature is the many holes in the passages, usually between chambers. These openings were built to impede movement, and they certainly have this effect on me, given my fear of either falling through one or missing one leading to more hibernating bats.

One souterrain now has a protective gate on its entrance to prevent disturbance. Eight caves have been fitted with gates as well. Bat numbers in Irish caves are small compared with other countries; the most important cave contains 400 bats in winter. In all cases where sites have been protected, numbers have slowly increased.

There’s a well-used phrase in Britain and Ireland to describe the summer roosting habits of this species: it is termed "a bat of the aristocracy," on account of its preference for the attics of castles, mansions, or their associated buildings, such as coach houses or stables. In such places they are relatively undisturbed, seeking out warm roof spaces in which to rear their young, and large apertures such as open windows or doorways for entrance to and exit from the building.

My tried-and-tested method for finding horseshoe bat roosts is as follows. First, I consult old maps for evidence of large estates that might still provide suitable roosting sites. Once these have been identified, I take to the road, driving slowly through the countryside and keeping a watchful eye for walled areas with a gateway. The gateway usually marks the beginning of a long and winding driveway, lined by mature deciduous trees, which sometimes leads to an intact building, usually more than 100 years old. Even if bats are no longer present, the owners usually still remember the plum-sized creatures that once hung in the stables. Lately, however, I have seen many bats forced to abandon their preference for the historical end of the real estate market. As these buildings are restored or collapse from neglect, bats are forced to move into suboptimal accommodation– typically small, abandoned cottages, often with leaking roofs.

The traditional approach for conserving a species such as the lesser horseshoe is to locate important sites–usually defined as the largest hibernation and breeding sites–and to protect these, generally by gating access to underground sites and by repairing any buildings used in summer. Historically, little thought has been given to whether these sites are linked. However, in keeping with trends in many other fields of interest, bat conservation is now following a more holistic approach. Not only the key sites are being protected, but also sites used intermittently by smaller numbers of bats, as well as landscape features such as hedgerows and trees that are used as commuting routes for bats.

In March 1997, I set out, with help from my colleague Henry Schofield, Frank Greenaway of the British Natural History Museum, and Irish researcher Niamh Roche, to band 22 lesser horseshoe bats at three winter sites, with the aim of finding where these bats bred. I was a little concerned about handling the bats because of their reputation of being sensitive to disturbance; Henry, having handled many horseshoes during his studies in Britain, assured me that with due care they would suffer minimal stress. As we crawled through a low, narrow passage (wet, of course) to our first bat, I was more concerned with the stress I was undergoing.

"Okay, Kate, unhook that bat and carefully place it in this holding bag," Henry instructed. Even though I had been associated with the species for fourteen years, I had never handled a live lesser horseshoe. With a mixture of anticipation and anxiety, I closed my fingers around it, unhooked its claws from its roost, and began my day’s work.

That cool March day gave way to a warm and wet Irish summer, and I began the search for the summer haunts of "my" banded bats along with rangers from National Parks and Wildlife (NPW)–the government body responsible for protecting all bats under the 1976 Wildlife Act. We scanned maps of the areas surrounding the hibernation sites, mystified many householders by seeking permission to search their farm buildings, and placed numerous bets with each other that, yes, this building is definitely going to have them, only to have to set off again. And then, during one memorable week in August, we found three sites with banded bats as well as juvenile bats: the corresponding breeding sites for the known winter sites.

Immediately my thoughts switched from that of wildlife tracker to that of conservationist. Who owned these buildings? Did they know about the bats? How could the roosts receive the protection they obviously needed? Two of the sites were small, derelict cottages in need of repair, and the remaining site was not going to be available to the bats in 1998 because of restoration work. Since this discovery, we have spoken to all the owners, who, I am grateful to say, have agreed to allow The Vincent Wildlife Trust to undertake the repair work. Similar work at two sites in 1992 has resulted in an increase in the numbers of bats, so we are hopeful that history will repeat itself. I am also optimistic that the hedgerows and trees connecting these winter and summer sites will receive protection under the Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora (known as the Habitats Directive), a European Community Directive to which the Republic of Ireland is a party.

Ireland holds not only an important lesser horseshoe population, but also a significant Leisler’s population. Leisler’s bat (Nyctalus leisleri) is distributed all over Europe but considered rare outside Ireland. This is unusual, as Leisler’s is considered to be a woodland bat, yet Ireland’s principal natural climax vegetation–deciduous woodland–comprises no more than one half of one percent of the landscape.

With so few remaining trees, it’s no surprise that this species now lives in buildings; a breeding colony of more than 200 animals in a house is not unusual. I monitor three such colonies, more to maintain a good relationship with the homeowners than to record population dynamics. Two hundred Leisler’s mothers and young can be noisy and smelly. As the largest Irish bats, they produce copious amounts of droppings. The householders allow the bats to return annually to their homes if I periodically remove the droppings. While vacuuming up droppings at midnight does not represent the glamorous side of conservation, it does work. I am, however, trying to find a better answer for this problem. With help from a broad-minded architect, a gifted carpenter, and the bemused goodwill of one family, I have installed a wooden bat box in their attic in an attempt to isolate the large colony within the roof space and so solve the problems of noise and smell. It’s too early yet to say how successful this solution has been. However, the colony successfully bred there in 1997, and I had no complaints from the family for the first time in years.

Besides fieldwork, my job entails a variety of educational work: delivering lectures, contributing to radio and television programs, organizing training courses, writing articles for magazines, composing information leaflets and . . . dealing with the press. At one time I thought caving was my most dangerous task, but I have since revised that to telephone conversations with journalists! A brief talk with a British journalist in November 1996 about bats in Irish churches led to my being under siege from reporters worldwide for several weeks. For some strange reason, a comment made years ago by an NPW member about the preference of long-eared bats (Plecotus auritus) to roost in Catholic churches and that of Natterer’s bats (Myotis nattereri) to inhabit Protestant churches suddenly became news. The originator of the comment assured me that I was the best person to deal with the publicity and thus began my love-hate relationship with the media. Although some of our most important breeding colonies of Natterer’s bats are indeed found in Protestant churches (such as the splendid Gothic Church at Kylemore in the west of Ireland), both species are found in many other types of buildings, sometimes even together. But try telling that to a journalist who has already penned his "Irish bats are sectarian" headline! All I can hope is that some practical information about bats survived the "sound bite" treatment.

Despite being able to report that Ireland still retains a healthy lesser horseshoe population, I believe there is no room for complacency. The Irish landscape is changing quickly. Since 1983, I have witnessed the loss of several major breeding sites, through the collapse of abandoned buildings or as a result of restoration, the latter leading to exclusion of the bats.

Only through an integrated program of site and habitat protection will we avoid the mistakes made by other European countries where the species has undergone a dramatic population decline. As we all know, conservation measures succeed only when individual citizens appreciate the intrinsic heritage value of their wildlife, and such appreciation is born out of education. Back in 1981, when I saw my first pipistrelle in my parents’ home, few people shared my excitement at the encounter. Now I have hundreds of queries each year from people seeking information on bats and constant requests for educational materials on Irish species. My educational work complements that undertaken by NPW and other voluntary groups. We are united in the hope of creating an environment in which all households enjoy sharing an attic or stable with bats.

Kate McAney has been working for The Vincent Wildlife Trust in the Republic of Ireland since 1991. Her work centers on the conservation of the lesser horseshoe bat, a species she has been studying since 1983, and on which she wrote her Ph.D. dissertation at University College, Galway, in 1987.

Back at the surface after banding bats in the narrow tunnel below, the author takes time to catch her breath and make notes on the status of this hibernation site.

Wrapped in their wings like cocoons, these lesser horseshoe bats hang freely in hibernation at one of the sites in Galway, Ireland, where the author has done banding studies.

A wing band identifies this greater horseshoe bat for researchers who make regular visits to its hibernation site.

The author surveys the underside of a bridge for bats. Being a bat conservationist in Ireland means she rarely has the luxury of dry feet.

The author has studied this nursery colony of lesser horseshoe bats for 16 years. The bats’ attic home was recently purchased and turned into the first bat reserve
in the Republic of Ireland.

Loss of much of their natural woodland habitat has increasingly brought Leisler’s bats to roost in buildings. This species is rare outside of Ireland.

The author had this scaled model built as an exhibition piece to show how bats use buildings. Here she explains bat roosting habits to a government minister and the director of the Government Environmental Information Centre.

Thoor Bally Lee Castle, once home to Irish poet and playwright William Butler Yeats, is the author’s favorite example of how history, heritage, and unlikely habitat merge in her job. Despite the invasion of 25,000 visitors to the castle each summer, a small group of 25 horseshoe bats reside in a chimney in the audiovisual room. These are definitely the most literary of all Irish bats: each day for the duration of the tourist season, they are subjected to the life story of the famous writer in English, German, and French.