birds – Richard Mudhar

the sound of starlings massing

Winter is coming, and that means that millions of starlings are on the move, from the deep cold of Continental Europe to the relative mildness of Britain’s winters. We are surrounded by the sea, which buffers the temperatures reducing the cold in the depths of winter. They join our resident starlings to roughly double the population in winter, according the the RSPB.

A starling is nothing that special individually, but in winter they roost communally in reedbeds¹ these days. They group together in massive billowing clouds called murmurations², this is thought to be trying to confuse birds of prey, who can’t home in on individual birds.

The unquiet sound of massed starlings

Once they’ve settled in for a while a massive racket starts to built up, this is a binaural recording best on headphones. The slight dread at 4:30 is when a bird of prey came along, it silenced the starlings closest to me but most of the roost was still rapping away to each other.

I managed to get myself to within fifty yards of one of their roosts on Ham Wall, in the Avalon Marshes complex of nature reserves, sited on only peat extractions. Although the starlings tend to roost somewhere on the reserves, which site they favour varies from day to day. When you’re that close to the roost, you get to hear the damnedest noise from these guys. A starling roost is not a peaceful place – they charge around low in the reedbeds, and as the day gave way to twilight I saw a bird of prey strafe in low over the water, though I couldn’t make out whether it won its supper for the night.

It was a slight challenge to stand my ground as I was buzzed by wave upon wave of birds incoming on all points very low. They didn’t go for me, although The Birds³ movie did come to mind.

Some tips if you are going to visit a starling roost

Choose a still day, the starlings take more time about their murmurations if they don’t have to fight the wind or rain
Go early in the season – November or December. The season persists often through to March, but starling shit is a pretty noxious smell. The hum builds up to an acrid stench as time passes
For the same reason, keep your mouth closed if you look up at phalanxes of starlings passing overhead 😉
Go on a weekday – fewer people and dogs with all that goes with that…
Avalon Marshes has a Starling Hotline 07866 554142 that tells you where the birds roosted last night. That doesn’t tell you where they will be tonight, but it lifts the odds. It’s a dead cert if you fancy the early morning sight when they leave, however.
Take a torch. It’s very dark when the birds pack it in, and the cold comes as the sun goes down.

In the early parts of the 20th century when the starling population was much higher and we hadn’t killed off most of the insect population they had massive urban roosts in London. ↩
You can find a roost near to you on the Starlings in the UK site to see murmurations for yourself ↩
Hitchcock could have done very well with the electric, eerie sound of starlings, but he synthesised the soundtrack using a Trautonium. ↩

A good year for Nightingales, locally

First I hear a pair at Newbourne Springs, then one at Orwell Country Park

Orwell Country Park, not really classic Nightingale habitat of low scrub

and finally one at Mill Stream Nature reserve

Three separate places with a fair amount of human and dog interference in less than a week.

The BTO doesn’t seem to agree that it’s a good year countrywide – Nightingale reporting seems lower than the historical average

Nightingal reporting seems down accordign to Birdtrack

Olympus LS-10 remote control success

I’d experimented with the wired remote for the Olympus LS- series recorders before. I have an Olympus LS-10 and an LS-14, and previous experiments showed I could make this work in principle. There’s a big gap between making it work on the bench and getting it to work in the field, however. This is the next step of boxing it up and making it stand alone.

16F628 PIC is fitted into the space of two batteries in a 4-way battery box, giving me a small box with battery holder and on/off switch. A 32kHz watch crystal gives an easy integer divide down to seconds and then hours, and reduces the power drawn by the PIC and lets me drop down to 2V Vcc and stay in spec over the industrial temperature range.

Either my LS10 is knackered or it never was compatible with Olympus’s wireless remote, it doesn’t provide 3.3V power on the plug tip, so I have to power the PIC 16F628 from two NiMH cells, which means I am short of headroom for 3.3V because there’s a 0.9V difference. I’d expect the PIC to drag the remote control line, which rests at 3.3V down to ~ 3V (2.4V VCC + 0.6V input protection diode drop)

I used a diode for the stop command pulling to ground, which still works with that diode drop, so the drive circuit is

RA4 is an open-drain connection, I figured I would chance the forward-biasing of the input protection diodes via the 100k. It works fine, at least at room temp – a 100ms pull to gnd via RA4 starts the recording, and then a 100ms pull to ground of RA2 stops the recording. Pins are switched to hi-Z inputs when not active. I guess the 3V3 from the LS10 has to go through two diode drops now to get to the 2.4V rail (diode shown and the input protection diode), and this is enough to let it float OK.

I got it to start the recorder at 4am, which is too early, but recording for two hours got me this recording at about 5:30 am of the local birds. I hear Great tit, Robin, Blackbird, some sort of gull, Wren, Woodpigeon, Crow, in that lot.

Using a 3.5mm socket as a workaround for the fiddly 4-pole 2.5mm jack plug – it’s a lot easier to wire a socket than a 4-pole plug, and I got a 4-pole 3.5mm jack to 4-pole 2.5mm jack cable from Ebay. Wiring the 4-way socket is dead easy now, and saves having a flying lead from the box.

In search of microphone weatherproofing ideas

I need to now find a way to get a reasonably weatherproof microphone. Looking at how B&K do this in the manual for the UA1404 the way to go is to use a small raincover just over the mic capsule

Their mention of birds makes me thing this is very close to a mesh nut feeder – I could put horticultural fleece around the mesh and use the top cap as a rain guard. Another option is to go minimalist, recess an omni electret capsule in something like a plastic bottle cap. I’d have thought that the cavity of the raincover would cause dreadful resonances, but if it is say 2cm diameter that would be a wavelength of 330/.02 ~ 16kHz – perhaps theirs is 0.5cm keeping this down to ¼ wavelength. Where this would score is it’s small, and electret mic capsules are cheap so I could afford to lose some. I can take the line that I’ll omit the big foam guard and use a piece of horticultural fleece across the cap, this makes a reasonable wind baffle, and I’m not going to get a good recording if the wind is over 5 mph anyway because of the hiss of the wind in the trees even if I were to keep wind blast out of the mics.

I am thinking of using a small Dribox to rig the recorder and timer, and sample some birdsong from other places. A pair of AAs run the timer for at least three days and the power drain of the LS10 on standby is also low, probably good for a couple of days, but I don’t have more than four hours of recording time on the LS10, it is 2Gb. So I can live with that – the Dribox has enough room for a bigger battery if that starts to look necessary.

Ipswich Sparrow Survey topping out and press event

RSPB Ipswich Local Group leader Chris Courtney and a group of our surveyors met up today at the Brunswick Road Recreation ground for a press event to celebrate the completion of the survey in 2016. (above pic is Chris (L) with Joe Underwood, Ipswich Parks and Wildlife ranger)

Heatmap showing the density of sparrows in Ipswich

Naturally if you’re in the group being photographed you don’t get to take pics of the group 😉 It was good to meet up and put some names ot the faces of our sparrow surveyors from last year and talk with the rangers, who have improved this rec for wildlife.

Alanna, intrepid surveyor of seven Ipswich squares in 2016. Behind is the part of the rec that has been made more wildlife friendly by the rangers and another sparrow colony has been established.

The Sparrows of Ipswich 2016 report.

Sparrows of Ipswich survey 2016 results

The RSPB Ipswich Local Group surveyed the town’s sparrows last year, and we have the results now in. It’s a little bit better than I had thought – strongholds to the north-west and south-east. It’s tough to compare this with the 2006 survey because that wasn’t controlled-effort, although at first glance they still seem to be losing the fight around the Valley Road area relative to the earlier survey.

A short survey of sparrows in Glastonbury

I was in Glastonbury, Somerset, and the house sparrows have started calling at nest sites there, They haven’t started in Ipswich. So I tried the audio recorder/GPS track surveying method. Each of the flags is where there was a male calling, or a male was sighted, along the lines of the BTO survey protcol [ref]Protocol for censusing urban sparrows, DeLaet, Peach and Summers-Smith, British Birds, 104, May 2011, p255 ff[/ref]

I covered a decent area, but not as thoroughly as I thought I had done. The sparrows seem in good heart, however, a more continuous coverage than I feel they are in Ipswich, where the colonies strike me as more fragmented. We will see.

My general impression was that sparrows are doing better in Glastonbury than many parts of Ipswich. The route I took left residential areas for the high Street, I know there are sparrows in Northload street so the two clusters might join.

Bird surveying in the field using GPS

The Ipswich RSPB Local Group is looking at surveying Ipswich’s house sparrows, ten years on after I took part in the first Ipswich Sparrow Survey. Most bird surveys cover a wide, fairly homogeneous area and avian subjects that are mobile over several hundred metres, or specific colonies. Surveying sparrows in the heterogeneous urban environment, with subjects that stay within 70m of the nest site when feeding young are a different kind of challenge.

We didn’t have the benefit of this BTO House Sparrow Survey protocol [ref]Protocol for censusing urban sparrows, DeLaet, Peach and Summers-Smith, British Birds, 104, May 2011, p255 ff[/ref]. As such the results show sample bias from the observer locations, survey effort and the difficulty to getting negative reports. However, it did answer the question ‘where are there sparrows in Ipswich?’, although not the question ‘where are all the sparrows in Ipswich’. It also answered the question ‘where are there no sparrows’ although the sparrowless areas were not exhaustively surveyed. Proving a negative is hard, though the BTO paper shows the way.

In the intervening time I solved the need to create waypoints on a handheld GPS and announce them to tie the audio to the location. Modern audio recorders contain clocks and timestamp the recording, this can be synchronised with the GPX tracks created by the GPS handheld. Smartphone applications like viewranger can also create GPX tracks. However, although a smartphone does many things it doesn’t do any of them very well.

The same trip tracked using Viewranger on a Samsung Android phone versus a Garmin Vista HCx. each machine was in different outside pockets of a coat at the same height above ground. The lighter red tarce is the Garmin which follows the paths better — The same trip tracked using Viewranger on a Samsung Android phone versus a Garmin Vista HCx. each machine was in different outside pockets of a coat at the same height above ground. The lighter red trace is the Garmin which follows the paths better

I set the Samsung to give the most precise location. The issue doesn’t seem to be as simple as the Viewranger Samsung app updating slower than the Garmin, there are enough points, but they aren’t in the right place, particularly when the border trees by the road and railway line

The aim of all this was to write a web app to record sparrows in the field. However, it turns out that the Location API is very hit and miss. Sometimes I got 20m accuracy. Sometimes I get 3km accuracy, and I can’t easily see how to fix that, having already selected high geolocation accuracy. If I can’t do that for myself, I certainly can’t support other people using it on two different operating systems and on some mobiles that may not actually have a GPS receiver.

Curlew at Melton Riverside

I love curlews – they may be common as muck round these parts but the beautiful plumage, strange down curved bill and haunting bubbling call make them special.

The little nature reserve at Melton has a free car park and you can get a view of the riverside mudflats near Wilford Bridge

It’s a pleasant walk along the river into Woodbridge, there is another small level crossing to get into the town. On the other side to Wilford Bridge going north there is a footpath toward Broweswell reedbeds and it’s worth a look at the birds on the riverside there too

[osm_map lat=”52.102″ lon=”1.335″ zoom=”15″ width=”100%” height=”450″ marker=”52.10401,1.33903″ marker_name=”wpttemp-green.png” type=”Mapnik”]

Raspberry Pi Camera and Motion out of the box – Sparrowcam

The idea is simple enough – a bird feeder camera on the network, using the Pi and associated camera. Using motion detection software I can pick out the birds. Of course I will also get the feeders swinging in the wind 😉

Although this is about running motion I can use videolan instead to stream the video as a netcam and use motion on a second machine. Videolan streaming

cvlc v4l2:///dev/video0 --v4l2-width 640 --v4l2-height 480 v4l2-chroma h264 --sout  '#standard{access=http,mux=ts,dst=0.0.0.0:8082}'

is nice on the Pi, because it seems the camera can do the h264 in some sort of hardware/accelerated mode in the V4l driver. I can then watch the birds with realtime update rates on my LAN. That’s for another day…

Up to about mid 2014 it used to be a load of hurt to run Motion and the Raspberry Pi camera because there were no videoforlinux drivers for the camera. That way you don’t get a /dev/video0 for the Pi Camera and needed workarounds for Motion.

Now there is a driver which you’ll already have on a Raspbian install, and it’s easy to use. right out of the box. Continue reading “Raspberry Pi Camera and Motion out of the box – Sparrowcam”

Lackford Lakes ringing with the sound of Teal calls

Tucked away off the A1101 it’s easy to overshoot the turnoff because the bend of the road means the sign isn’t visible till you are nearly on the turn – even knowing that it caught me out. The low winter light was a treat on the leafless trees, painting them this lovely golden colour.

A lot of the water was still ice-bound, with a few channels of open water. All over the sailing club lake there was a marvellous ringing sound of teal. Not worth recording however since it sounded like the RAF were warming up their afterburners at RAF Honington.

The island only seemed to hold about twenty teal but their calls rang out over the water sounding like many more. I had the reserve largely to myself, with only a couple of photographers with hardy camo gear in the morning.

Visitor centre - newly upgraded in January — Visitor centre – newly upgraded in January

Monday seems to be the quietest day – the visitor centre wasn’t open though Suffolk Wildlife Trust did leave access to the toilets which is a kindness 😉 The small birds were staking out territories in the hazel coppice which was alive with the sound of competing great tits, which seem early to me – they haven’t started seriously marking out territory nearer home.

Lackford Lakes SWT