Nature Natters (4) Batty About Warrington

Imagine being able to fly at speed, day or night, weave in and out of natural or structural objects, detect, catch and eat food as you go and communicate with others whilst doing so?  Tricky maybe but not if you are a bat!

Bats are amazing creatures, a warm-blooded mammal that truly flies and often only noticed at dusk but which can be active throughout the night consuming thousands of insects in the process.  Most insects are eaten on the wing and although bats have good eyesight they prefer to hunt in the dark using a specialized form of sonar known as echo location, a high-pitched signal emitted by the bat which not only enables it to locate and avoid objects from the ‘echo’ it receives back from its calls but also as to where its prey is and even what size it maybe.

Although echo location is generally inaudible to most adult’s young ears can sometimes pick up the bat calls whilst the rest of us must rely on a piece of technology called a bat detector, a device which converts the high frequency sound of the bat to our level of hearing which in the process and with practice, allows us to identify the bats moving around us.

Of the 18 species of bat recorded in the UK, 17 species are known to breed here with a further 6 species regarded as rarities or vagrants.  Previous records show that in 1986 there were just six species of bat recorded in Cheshire with a further four species being added to the list by 2012 (The Mammals of Cheshire) and additional species being added since.

Species to look out for around the Warrington area include the Noctule one of the largest British species and usually the first to appear and easiest to recognize as they feed out in the open, often above tree top height where they are frequently noted going into sudden steep dives when chasing insects.  The Leislers is a bat of similar size and characteristics which also emerges before sunset and feeds in a similar manner to the Noctule.  Although Leisler’s bats are found throughout the UK there have only been a handful of records in Cheshire.

Other bats widespread in the region and most likely to be seen include the fast weaving flights of the Common and Soprano Pipistrelles, Daubentons and Natterer’s bats and in contrast the slower butterfly like flight of the Brown long Eared bat.  Two other species found around us include Whiskered and Brandt’s, both of which are similar in appearance and frequency of their echo location and only really identifiable in the hand or by use of sophisticated computer programs analysis of their calls.  In addition, albeit with limited data of its status and distribution, is the Nathusius Pipistrelle, a migrant species which appears to be on the increase in the UK generally and has been recorded on few occasions in Cheshire in recent years.  The Lesser Horseshoe is known to hibernate in the county and possibly recorded on rare occasions whilst there have been unverified records of two further species the Serotine and Barbastelle.

Although our knowledge of bats in the UK and Cheshire is continuously improving we still get the odd surprise and additions to the list when – through DNA analysis, a new species of bat is found to be present among similar types of bat as for example the Nathusius pipistrelle being separated from the Common and Soprano pipistrelle and more recently, the Alcathoe from Whiskered and Brandt’s.

You are never quite sure where you are going to find bats but generally if you venture out on a warm, calm night they can be seen and heard as they forage for insects in various locations such around barns, buildings, gardens, hedgerows, tree lined canals and waterways, ponds and lakes and where it is possible with the aid of a bat detector to listen too several individuals and species feeding there.

Although bats are warm blooded and very active between early spring and late autumn they are an insectivore and as such are dependent on temperature and especially the availability of insects.  Once temperatures fall and insects disappear bats are forced to go into hibernation which they might do so in caves, trees, tunnels or cavities in buildings during the winter period but may reappear for short periods during this time to drink or change location before going back into hibernation.

Sadly over the past 100 years the UK bat population has declined dramatically due in part to loss of roosting, hibernation and maternity sites, fragmentation and loss of habitat and in particular hedgerows which form important links between roosting and foraging sites but also the use of pesticides on crops which not only kill the insects but often the bats themselves whilst some timber treatments and roofing materials can also be harmful to bats.   Added to this is that UK bats also have a slow reproduction rate and only produce a single pup each breeding season as such population increase is slow and more long term but which can be quickly undone if they or their maternity sites are lost.

As a result, bats are now designated as a European Protected Species and are protected under the Wildlife and Countryside Act (1981) which not only gives individual bats and their roosts legal protection from harm or destruction.  Where building works are likely to impact on roosting or breeding bats then there is a legal and licensing process to follow as determined by Natural England, a necessary precaution in this day and age of fast change.

Bats are harmless mammals which do a great deal of good in the environment and cause no damage to property but if you are looking for more information and advice on bats check out the Bat Conservation Trust web site or ring the National Bat Help Line on 0345 1300 228.

You can also send Warrington Nature Conservation a message via our website http://www.wncf.co.uk/

Rob Smith is a founder member of the Warrington Nature Conservation Forum and a Consultant Ecologist.

 

Rob Smith

May 2017

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