Earth Notes: Bats Around our Home aka 16WW (2022)

I just witnessed a (juvenile soprano pipistrelle) release near 16WW at sunset (~20:13Z).

She had flown into someone's house nearby and not left for several days. So she was rescued and fed for about six days (weight up from ~3.5g to 4.5g).

On release after very loud chattering (audible, especially to my 16 year old daughter!) right up to 55khz, she circled a few times to get bearings, then found an insect-rich patch of airspace for a snack.

She should be able to find her way back to her roost. With luck she may live something like 15 years.

Walking back from the Spring Grove ~20:50Z, downstream side of Hogsmill bridge at Villiers had about 10 bats wheeling and feeding. Maybe two on the upstream side. Temperature ~17°C, with the day topping out at an overcast ~22°C I think.

The echolocation was loud enough even below ultrasonic to be picked up a little when recording video on my phone.

This evening with AF and MW saw again 10 to 20 (soprano) pips downstream of the bridge and two or three immediately upstream. Also plenty further along Hogsmill Lane, starting with a smitten pair, wheeling together. Maybe a common pip or two. No Daubenton's.

See AF's Flir E60 IR (infrared) videos of downstream of the bridge:

OK, not very near 16WW, ~1000km away on the Med, a dusk at about 9pm local time (~19:00Z), there are lots of bats among the trees at our campsite.

Maybe the size of a common pip or a little larger. Maybe slightly smoother, less jerky flight. (Common pips are apparently common here, so it could be them.) It is possibly to see some light through their wings!

2022-08-16: Pre-Storm

~9pm (~19:00Z) ahead of a forecast thunderstorm, the bats are back! (Sunset 20:48 local time, ie 18:48Z.)

And plenty more bats seen on subsequent dusks, including flying low (head height) above the beach.

I heard at least one loud cricket outside at ~9pm (20:00Z) from inside, well after sunset (18:55Z) and ~18°C, possibly under the white-ish lamp over the footpath behind us. I wielded the Pettersson detector hoping that it might detect cricket, but that attempt was rather swamped by at least one or two busy bats passing not far above my head. Maybe common pipistrelles as clearest at 45kHz. The cricket seems to be firmly non-ultra-sonic.

Yes, I missed #InternationalBatNight two days ago, though I doubt that they did!

On the way home ~9pm (20:00Z) at least three busy bats downstream of the Hogsmill bridge over Villiers road, coming quite close to me (feet away) while wheeling and whirling. At least one on the the upstream side.

At least one cricket busy from long before sunset until long after, audible from our back rooms and garden this evening!

Tonight as part of Kingston's "Sustainable September", Elliot Newton (RBK's Biodiversity Officer), is leading a bat walk in the cemetery and I'll be there as it is on my doorstep.

I am taking Alison's Pettersson detector, and several spare 9V batteries in case anyone's goes flat (9V seems to be common)!

Tonight sunset is 7:35pm (18:35Z). The bat walk starts a little before. The temperature will be ~17°C, there will likely be a gentle breeze, and we may get rained on.

And it must really be autumn, because I'm ditching my cargo shorts in favour of jeans...

...

Finished about 8:45pm (19:45Z).

Lots of common pips (45kHz), sopranos (55kHz) too, and the odd noctule flitting by!

An interesting evening, the first bat spotting jaunt for most attending. Well done Elliot! And no rain during the bat walk, hurrah!

As I was leaving the house this afternoon, I opened the front door to witness a flurry of feathers which appeared to be a sparrowhawk (I could see mainly talons and hooked beak and some yellow colour and beady eyes and the underside of a stripy tail) attacking a feral pigeon.

In the extra confusion that I introduced, the pigeon escaped into our porch and briefly hid in our recycling box, and the attacker flew away.

Pigeons like to congregate on our roof. They try to nest and lay eggs on our sloping roof: the eggs and sometimes young often roll off. Sometimes others meet their ends, decapitated, and we are not sure how. This predator may be part of the explanation.

(Yes, these are also not bats, though sparrowhawks do eat bats.)

Suddenly there are two cemetery bat walks in short order! This one is guided by Alison F, starting shortly after 7pm BST. Sunset is 7:17pm (18:17Z). Temperature is forecast to be ~17°C. No rain.

It was not a busy evening, but there were common and soprano pips, and maybe a noctule or two commuting over. All quiet before 9pm (20:00Z).

The noctule may have been a serotine in fact, it seems, detected by both Alison F and Mark W.

Mark F was recording throughout the bat walk, and provided these notes:

The first bat I got was a sop pip at 19:32.

Summary from 19:32:47 to 20:36:23 Bat passes 57 sop pips, 247 com pips, 2 serotine?, 1 Feeding Buzz, 6 Social Call

Walking back from the Spring Grove ~21:50Z, downstream and upstream sides of Hogsmill bridge at Villiers Road each had one bat (likely pip) feeding. Temperature ~13°. Sunset 18:03Z.

Walking back from the Spring Grove ~19:40Z, no bats obvious on either side of the Hogsmill bridge at Villiers Road. Temperature ~10°C. Sunset 17:49Z.

~17:37Z: detector at study window at 45kHz het on speaker. (Sunset 17:33Z, temperature ~17°C, some cloud.)

17:47Z and 17:51Z faint pip-like sounds. 17:53Z stronger. 17:57Z faint feeding buzz? 17:58Z faint. 17:59Z strong, bat sighted (visual contact). 18:00Z faint, visual contact. Het pushed to 55kHz: immediate strong signal suggesting soprano pips. 18:02Z faint. 18:06Z: close passes, visible, loud, feeding buzz. 18:10Z window closed.

Warmish night, sunset just before 6pm (17:00Z). Crossing Hogsmill at 17:09Z no bats seen on the usually-busier downstream side. Returning at ~22:10Z (~15°C) still no bats downstream, but one (likely pip) upstream!

Warmish evening, sunset 17:48 BST (16:46Z). Crossing Hogsmill at 17:05Z no bats seen nor detected on either side. Returning at ~20:00Z (~15°C) via Three Bridges Path immediately a couple of short passes near the university (likely common pip), then long loud extended pass (likely common pip) beside King Athelstan school including feeding buzzes I think. Then at Bonner Hill Road edge of cemetery and near main entrance more faint (likely common pip) passes.

A mixture of common and soprano pips at the cemetery in the evening. ~15°C.

Not Mr Musk and the bird site this time. Just after 6pm (18:00Z) I heard a series of owl calls from my study.

Just before 10pm I heard a series of owl calls from my study.