I’ve been spending a lot of time this year looking at the bats of what some of the locals call the Holbrook Valley in Walsall. (The Holbrook runs through the old Great Barr Hall estate, so the valley to the west of Barr Beacon and east of the Daw End Branch canal is the general area I’m looking at – in green in the map below – orange is Sutton Park and blue is the wider north east countryside area.)
- Three years of bat box checks at Merrions Wood, Lime Pits Farm & Park Lime Pits
- Bat surveys at Chapel Farm and Linley Woods
- Batlas tetrads at SP09J (Arboretum & Lime Pits Farm) and SP09N (Holbrook Valley)
- NBMP Waterways Survey of the Daw End Canal adjacent to the Grange
- Mist netting at Merrions Wood and Cuckoos Nook & the Dingle
- A a driven transect of Chapel, Noose & Skip lanes
After the survey work, I’m slowly building up a picture of the bat species assemblage in the valley.
(5 confirmed; 2 unconfirmed)
Bat box checks have shown Soprano Pipistrelle and Brown Long Eared bat (This week’s bat box checks confirmed that BLEs are breeding in the woodland, as we found a maternity roost of 23 females and subadults – result! – Photos below!) Bat walks and surveys have indicated the possibility of Natterer’s, Common and Soprano Pips, Leisler’s and Noctule. Mist netting also turned up Whiskered and confirmed Noctule for us.
(2 confirmed; 2 unconfirmed)
Anecdotal records from the 1980s exist for Lesser Horseshoe bat here – I would ordinarily dismiss this sort of thing but the farmer had the bat in hand and said he knew what it was because of the distinct flap of skin around the nose of the bat, which he had in hand. We surveyed the farm buildings and recorded Common and Soprano Pips, and a suspected (yet very short) Serotine call – this is not enough to confirm the species in the area but is a tantalising thought! – Below is a sonogram of the call, peak frequency at around 32kHz. You can click on the image to hear the sound file- about 10 seconds in…
Cuckoos Nook & the Dingle
(6 confirmed, 1 unconfirmed)
Mist netting at the northern end of the Dingle turned up just 7 bats (it was quite breezy and cool) but it was a matter of quality over quantity, as there were 6 species: Soprano Pip, Common Pip, Noctule, Whiskered, Natterer’s (fantastic to have the species confirmed for the valley!) and our first confirmed Leisler’s bat for the valley – one of only 3 sites in the county that we know of (so far) for the species! – also my favourite bat!) Detectors also picked up BLEs.
Park Lime Pits & Lime Pits Farm
Bat boxes were put up at Park Lime Pits 3 years ago, but most have been vandalised, so we moved the remainder to other sites, but the ones at Lime Pits Farm have been left untouched, so are still there, and are due to be checked this week. Previous surveys have shown Common and Soprano Pips and Daubentons Bats.
Linley woods is a privately owned woodland and cave that BrumBats are assessing for its value to bats. The woodland itself has Common and Soprano Pips and Noctules (from bat detector surveys) and we left a remote bat detector during the spring (I have yet to go through the files). We are hoping to return during September for another detector survey. There is significant potential to hibernating bat species such as myotis bats, including daubentons, so we hope to continue surveying into the future on this site. I should stress that this site is not open to the public, and is a protected geological SSSI so it’s a no-go zone, I’m afraid.
Daw End Canal
The NBMP Waterways Survey is a national survey run by the Bat Conservation Trust in which you adopt a 1km stretch of canal to survey every August. My kilometre is from Longwood Locks down to the bridge at the back of the Grange (Arboretum extension). There is plenty of potential for roosting sites (bridges, culverts, etc), and so far we have recorded Common and Soprano Pips, Daubenton’s and Noctules.
Batlas Tetrads and Driven Transect
(Watch this space!)
I’m going to report on these in a couple of weeks when the surveys are complete. The driven transect is a roughly circular 10km route – I am still hashing out the methodology – an amalgamation of techniques from iBats and Butterfly Transect stuff, so I’ll be refining it this month and hopefully do the monthly survey April – September 2016.
In the remaining month of the 2015 survey season, I plan to do my second Batlas tetrad, repeat my driven transect, survey Holly Wood and return to Linley Caverns, check bat boxes at Lime Pits Farm and again at Merrions Wood, more mist netting at Sutton Park, and if I can squeeze it in. to look at surveying what I believe may be important commuting routes into the valley from sutton park and the wider countryside to the north east (the pale circles on the map below). So I’ll have my work cut out for me for the next few weeks!