Lancashire Bats

The diversity of bats tends to decrease the further North you go in Britain, so not all British bat species are found in our area with only eight that are permanent  resident and two that were either recorded in the past and one that may have been transported from another area. The table on this page shows which of the species occur in Lancashire. and more information is given below on some of the more common bats. 

Of course, it has recently been discovered that Pipistrelles are two separate species. The main distinguishing feature is the peak frequency at which they call - either around 45kHz (now known as the Common Pipistrelle) or 55kHz (the Soprano Pipistrelle). There are some suspected minor differences in appearance, but by far the easiest way to identify them is by the use of a bat detector.

When the news broke about the discovery of the two species it was widely proclaimed that most Lancashire's bats were of the 45kHz type while 55kHz bats were commoner across the Pennines. Whilst there may be some truth in this, 55kHz bats have been found at many sites across the county - a recent survey of farm woodlands by MAFF Central Science Laboratory found 55kHz Pipistrelle at a third of sites, whereas 45kHz bats were found in nearly all the woodlands. 

As well as catching insects in free flight, brown long-eared are gleaners, picking insects off the foliage. Thus, they often fly against a background of dark trees, rather than against the sky, making them almost invisible. Their echolocation calls are extremely quiet, being only detectable when the bat is a few feet away, even in an enclosed space. Even where roosts are known, it is perfectly possible for the bats to slip out in the evening unseen. Only the lucky observer, catching a rare glimpse of the species flying away from a cluttered background, will see its large ears outlined against the sky.

Because of the difficulty of observing the species in the wild, especially with a bat detector, there are far fewer records of brown long-eared bats in Lancashire than of Pipistrelles. It is also impossible to separate the species from the grey long-eared bat, except in the hand, so although it is thought that the grey long-eared is very rare and confined to southern England, there must always be a doubt as to the identity of a long-eared bat in free flight. Most records, consequently, are of bats roosting in houses.

A number of roosts have been recorded over the years in locations around the Rossendale Area and more so in the Haslingden Areas of the Rossendale valley

One or two roosts are known in the county. A couple of years ago a roost in an ash tree came to light and as been used by Noctule over the last 15 years

Noctule bats preference for tree roosts dictates its need for mature and over mature trees. Consequently it is perhaps surprising that Noctule appear to be fairly commonly encountered hunting over the largely treeless areas. They are undoubtedly attracted by the quantities of insects to be found over this terrain

Many Daubenton's roosts are in bridges, canal tunnels and the like, from which they may fly up to 10km to feed. It can, therefore, be quite a challenge to find those roosts which are in tree holes nowhere near the water. Some roosts, mainly in bridges or old buildings, are known us and these have been the subject of regular monitoring over the years.

In winter, Daubenton's is one of the species known to hibernate underground. They are often solitary, but it is possible to find small groups in one cave. However, they are usually tucked in difficult to spot places such as tight crevices, or even among the loose scree and rock on the cave floor.

The echolocation calls as heard on a bat detector are rather like those of a Daubenton's bat, making identification in flight very hard. There are subtle differences in the calls, but while Daubenton's can be identified by listening and observing its hunting method over water, the Natterer's feeding behaviour in its preferred woodland edge habitat is less obvious.

A few Natterer's roosts are known and some have been established for many years. 

In hibernation Natterer's bats are mostly found singly, often near cave entrances, where they seem to prefer the cool conditions.

 

Whiskered/Brandt's Bat

Only in 1970 were Whiskered and Brandt's bats separated into two separate species. Therefore, it is not possible to establish the correct identity of bats previously recorded as Whiskered bats unless a specimen is available. Even since 1970, many records have failed to distinguish the exact species in view of the particular difficulties involved in separating these two species. In a few cases (usually roosts in buildings) it has is possible to confirm the exact identity of the species by careful examination of a specimen in the hand.

These species appear to be widely but thinly distributed across the county. Whilst they are certainly nowhere near as common as species such as the Brown long-eared bat, they are probably more widespread than is realized. In common with many Myotis bats they cannot be confidently identified in flight using a bat detector and there are still some disagreements among bat workers as to the identity of some specimens, even in the hand.

Although fairly widely distributed in England, its distribution appears to be rather patchy. In some places it is apparently quite common. We have only one record in the Blackburn and this may have come from afar as it was found amongst timber in a haulage contractors yard

Given the presence of Leisler's bat in neighbouring counties  it seems likely that this species is present, although probably in very low numbers. Hopefully, the increased interest in bats and growing expertise in the use of bat detectors and the interpretation of the sounds heard on them will soon enable us to confirm this species on the Counties list

Although everywhere rare, recent bat detector work in other parts of England has revealed hitherto overlooked Barbastelles. It would be very worthwhile for The Michael Birt Consultancy to organize a search for this species in Lancashire over the coming summers in an attempt to establish if it is  present.

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