Swarming Survey at Luton Hoo

Hi All,

On Friday 5 of the team headed up to Luton Hoo to check for Autumn swarming around the hibernation site.

We know from past surveys that the site is used for this type of bat behaviour.

Two mist nets were put up, the first a 6m approx. 3m from the hibernation sites entrance and the second a 9m approx. 10m from the entance at a right angle to it.

In past surveys there has been almost constant activity around the small block of woodland that the hibernation site is situated in, however this time bats were lacking.

At about 20.35 a male brown long eared (BLEB) bat was caught in the 9m net. This gave Aidan the chance to remove the bat, as he is training for his licence. At around 21.35 another BLEB was caught, this time a female. Laura Gravestock extracted this one.

                                          BLEB extracted by Aidan, Photo: M O'Connor

All in all it was a bad night although Myotis bats were lacking from the site this year.

Another session is scheduled for the 4th Oct so with any luck the mytois bats will be about this time.

M

Confirmed Brandts Bat

 

As we said in a, it is very hard distinguish between Brandt’s, whiskered and Alcathoe Bat. So we were pleased to be able to take advantage of modern technology and get a DNA analysis done on some droppings. The results came back yesterday (that was quick) and we are delighted that our identification was correct. We can now confirm that the bat pictured below is a Brandt’s Bat.

Photo Bob Cornes Brandt’s Bat

Box Boxes Checks

 

Photo Bob Cornes

We got round 32 of the boxes on Sunday before the rain came in.

Two of the boxes were occupied, both for the first time. One had 6 Soprano Pips
(five females and a smug male) and the other had 18 BLEs (9 females and
9 males).

It had begun to rain hard by the time we checked the last box which had the brown long eared bats in. So we took measurements and put then back in the box before they got wet and so took no photos. The plan is to check the remaining boxes tomorrow, if it will just stop raining.

Additional info on the Geofforys bat

The bat was a male and was caught during a survey of autumn swarming bats near the Sussex coast.

Autumn swarming is a phenomenon which occurs at some (but not all) hibernation sites. Bats fly, sometimes over significant distances, to a hibernation site and fly around the entrance for a while. The name 'swarming' is not entirely appropriate because the number of bats flying at any one time can be quite small.

Males spend longer at swarming sites than females do, so that captures of bats usually show a preponderance of males even though probably similar numbers of females and males are involved overall. The functions of autumn swarming behaviour are not entirely clear, but probably include mating between individuals from different colonies (resulting in reduction of inbreeding), scouting out hibernation sites in advance of winter, and allowing juveniles to locate regularly used hibernation sites.

Bat species involved in this behaviour are the Myotis species, long-eared bats, Barbastelles and horseshoe bats. Recent work in Bedfordshire by the Bat Group has shown that several of our better-used hibernation sites have swarming activity of Natterer's, Daubenton's and Brown Long-Eared Bats and Barbastelles.

Geoffroy's Bat has not previously been recorded in Britain as far as I know, but it is present in coastal regions of northern France and southern Belgium.

The presence of a male at a swarming site in coastal Sussex is therefore not too surprising. Geoffroy's joins a list of European bat species which have been found in mainland Britain on one or more occasions - Kuhl's Pipistrelle, Savi's Pipistrelle, Parti-Coloured Bat, Northern Bat, Greater Mouse-Eared Bat (declared extinct in Britain in 1991, but still regularly recorded as a single male in a hibernation site in Sussex), Pond Bat and European Free-Tailed Bat.

There is no evidence at present of any of these species being resident in Britain. On the other hand, this was exactly the view taken of Nathusius' Pipistrelle until the discovery in the 1990s that it was breeding in both Britain and Ireland (and we have records of flying bats in Bedfordshire). The Alcathoe Bat was even more startling, with no British records until it was found, in 2010, to be present in both Sussex and Yorkshire. Also, with the effects of global warming on bat distribution extremely difficult to predict, it could well be that some European bat species could move into Britain in the next few years.

It's also worth noting that we have evidence of behavioual changes in Myotis bats in Bedfordshire woods very recently - Natterer's Bat, for example, has been notably absent during woodland surveys in the last few weeks at sites where it is usually found very easily. It could be a result of the unusual weather patterns this year, but who knows what to expect in the next few years?

Bob Cornes

National Trust Press Release

National Trust Press Release

 

For immediate release – 12.09.2012

 

Species of bat discovered for the first time in the UK

 

A species of bat normally found in continental Europe – the Geoffroy’s bat - has been identified in the UK for the first time ever on National Trust land in West Sussex.

 

Ecologist Daniel Whitby was conducting surveys in early September when he caught a male Geoffroy’s bat (Myotis emarginatus), a small species which weights between six and nine grams and has woolly fur with a foxy red tint to it. 

 

Daniel Whitby, a Consultant Ecologist and bat specialist, said:

 

“It was a real surprise to catch this bat. Geoffroy’s bat is nicknamed the Notch-eared bat because it has a distinctive notch in the top part of its ear, with this, along with other identification features; I quickly realized what an interesting bat I was holding”

 

“Bats are an amazingly diverse group with over 1200 species worldwide and 17 species known to be breeding in the UK, making up over a third of our native British mammals, yet we still know surprisingly little about them.

 

“This is the second new species recorded in the UK in the past few years after Alcathoe’s bat was also discovered in Sussex and through research we are slowly learning about the habitats of these fascinating but misunderstood creatures”

 

The National Trust is currently working closely with other conservation organisations on the South Downs to improve its habitat management for bats in woodland and on downland.

 

Dr David Bullock, the Trust’s Head of Nature Conservation said:

“This is great news and shows the importance of the bat survey and monitoring work we do. Geoffroy’s bat is found in continental Europe, including northern France, where it can be found foraging for insects over scrub and grassland.

 

“It may be that this individual is part of a colony or it may be another example of a new species moving in from the Continent as we improve our habitat management and as our climate warms. Like all other bats, it has protected status”

 

ENDS