Musings on the Wild

Sunday, 13 July 2025

PippyG - A new way to record Bats?

One of the challenges I have set myself is to create a complete species list for my patch. One taxon that is currently under recorded is Bats. I have made a few visits to the site in the summer with a handheld detector; I am currently using an Echo Meter Touch 2 from Wildlife Acoustics. This device fits on to an iPhone and is remarkably easy to use. However, what I needed for a more systematic survey of bat abundance was something I could deploy in the field and leave, a kind of trail camera for sound.

This is not as strange as it sounds and there are devices out there that make devices for recording sound. Wildlife Acoustics are obviously the leader in this technology and produce a number of models for this purpose with their song meter range. This range allows for a range of species identification and their MiniBat records ultrasonic sounds. These devices, however, range from £160, up to £1300, a little pricey for me but very tantalizing.

The more I researched the more interested I became the more I found, the Titley Chorus is about £462 and AudioMoth offers a low cost build your own version although assembled devices cost about £69.63.

During my searches I came across the BTO acoustic pipeline. This section of the British Trust for Ornithology’s website enables you to upload recordings from audio equipment that it will analyse and present the data. There is a cost to this, but for a non-commercial operation like mine its pretty cheap with many facets of its access free or purchasable via credits that can be topped up as needed by payment.

This solved one of my problems, I am in no way an audio engineer nor am I skilled at interpreting Bat sonograms, I am even shaky on bird song to be honest. The question of how I could analyse the information is what was holding me back the most. There are bat call analysis software but this represented an additional cost.

As I investigated the pipeline I looked at what hardware was being used by the website and stumbled across PippyG. PippyG is one of a range of inexpensive bat detectors developed by Phil Atkin, which like AudioMoth can be assembled from scratch. Phil is a hardware designer and software developer, and his models are based around the Raspberry Pi the small, affordable single board minicomputer that can be used for a range of micro electronic devices. The benefit is that the addition of a microphone to such a device makes a very cost-effective detector. PippyG and the whole range of the pipistrelle family of products is now being sold by the Dutch company Apodemus and in the UK by NHBS.

Now I do warn you, the device is very barebones. Do not expect a fancy case or easy to flick switches or an extensive manual. The PippyG is a device in its rawest form and right at the edge of my technological understanding. It arrives in an unassuming box, and I struggled for a while on how to ‘reflash’ the device to install software updates. It is not intuitive, and you do need the accompanying free app to make it work but slowly I started to understand it. Phil Atkin has several YouTube clips available and Apodemus is starting to develop its support resources. I was at one point very stuck and frustrated and contacted Apodemus by email, they were incredibly responsive and helpful even replying in the evening and weekend to ensure that I was able to get the device to work. If you’re not familiar with reflashing then it’s all very confusing.

With the software updated and an understanding of how to use that app I was ready to field test in it the garden. The device lacks any waterproofing and despite the hot weather I was concerned about damage and so I set the device out in my garden under a plastic strawberry Punnett. To set the device you use the Pipistrelle app, this codes the location of the device via GPS, identify the device and sets the wake and sleep times. You can then select the trigger sensitivity and the frequency you wish to record. The device offers Bats – 384kHz and Birds 48kHz. You then select the length of recordings, I would recommend the 5 second option as it is much easier for analysis and then you press configure. Like a bat itself the information is transmitted to the device via a chirp.

With the device primed you switch it on and walk away. The files are recorded on the microSD card which can later be uploaded on to your computer. I would recommend you purchase the model of SD card that Apodemus suggest, I bought a different one first and had difficulty.

Using the BTO Acoustic Pipeline you can upload your data and the software on the website will process the data giving you a list of species identified with a probability of certainty percentage.

It took a couple of attempts to test it, I obviously needed bats to be present to get a positive result and on the second night of trying I obtained some results. On Test 4 76 detections were made resulting in 5 species being recorded. Unidentified bird, Soprano Pipistrelle, Common Pipistrelle, Noctule and Pygmy Shrew. All had a maximum probability of correct identification of 91 or greater except the shrew which was 46%. The discussed level of acceptance is 50% however given my lack of understanding of the software, hardware and general innate cynicism I will only be accepting 90% probability going forward, at least for awhile.

The shrew record is very interesting, whilst I doubt it was a shrew it does indicate how useful the device could be in identifying other ultrasounds and could be useful in future mostelas studies I carry out when differentiating between common and pygmy shrews is difficult.

Clicking on any species reveals a time plot revealing when this species was recorded.

Overall I am impressed by this piece of kit and the BTO software. It is opening up another avenue of research for me and I look forward to deploying it on my patch once I have decided how to protect it from the elements.

This seems at present to be a very cost effective way to record species and I look forward to experimenting over the next few weeks in its use.

Sunday, 1 June 2025

Zombies are real and ‘living’ in Warwickshire

Nature really is both amazing and horrific and always has the power to surprise me. I have been recording wildlife on my patch for 23 years and even after this time I am still discovering new things. In recent years feeling fairly secure on my bird, mammal, butterfly dragonfly and damselfly recording I have been trying to build up a list of what other invertebrates can be found.

Today I was out on my patch trying to count the clouds of Banded Demoiselle damselflies, trying to get a picture of juvenile Great Tits, hoping that the resident swans cygnets had hatched watching Perch in the mill race and composing my next blogpost something had caught my eye.

I was planning on writing about the abundance of Scarce Chasers on my patch. These dragonflies are… well scarce but seem to be doing well on my patch where we seem to be on the northern edge of their range for the river Avon. I was watching a male hunting over the meadow hoping to see it catch something and then photography it with its prey when I noticed a strange fly or wasp. It had an elongated white and black abdomen but fly like eyes. I took a quick snap of the individual hoping to ID it later.

I finished my weekly survey and stopped at the local pub for a soft drink and then had a look at the images I had taken. Superficially it looked like a fly, not your average bluebottle or flesh fly, I mused as to whether it was a solitary wasp, but no ovipositior and assumed it was one of the many thousand species of fly, perhaps a robber fly? That would be interesting, robber flies have an interesting ecology. Not having any books on flies and aware that my insect books wouldn’t have too many flies in them, I opted for AI.

Artificial Intelligence and machine learning are powerful tools but with great power comes great responsibility and one must always understand the limitations and problems in their use. Any AI derived identification must be crosschecked with reliable sources. I use the Merlin Bird Song App, its great but occasionally throws up a strange species, if I am at all suspicious, I will only record that species if I then subsequently see it and confirm it.

The AI I used this time was Google Lens, a subscription image search function of google that I had been using to ID plants and invertebrates. I use it mainly to point me in the general direction, perhaps to the family or genus level before diving deep into books or websites. In this case I uploaded the image and waited whilst the wheels turned. Shortly it had an answer for me, it had a few but number one was weird. It thought what I was looking at was a fungus. It was clearly a fly; it was clearly wrong. So, I uploaded another image and again it came up with a fungus. I did it to a third image and again the AI model found for me a fungus.

It wasn’t just any fungus, it was the same fungus each time, and the images it showed did look similar to my image, so I read a little deeper. The fungus was Entomophthora muscae. Interesting the term muscae relates in Latin to house flies. Entomophthora is also known as the Fly Death Fungus and is a pathogenic fungus focused on various fly species. Fascinating.

I started to research a bit more and discovered that Entomophthora have a unique life cycle. They require a fly host to live. Infectious spores land on a fly and penetrate their skin and enter the flies basic blood system known as haemolymph. Here the spores form cell-wall-less (protoplastic) cells within the body cavity. They use up the body’s fats and other nutrients to survive. Once it has drained the fly it has two options, if it was too quick and the fly dies the cells turn into resting spores remaining in the decaying carcass or if the fly is still alive it hijacks the fly causing its behaviour to change. The fly will move to a higher position where the fungus produces a mass of fruiting bodies called conidia that burst from between the segments of the fly’s abdomen, hence the striking black and white markings I saw. These conidia then spread spores that hopefully land on a passing fly and the infection starts all over again.

See at bottom to reference to the paper this was taken from.

On closer examination it was clear that the white parts of the abdomen were a non-fly related mass, and it was possible to see the fungal structures. The zombie nature of fungi is not unknown and is quite topical with the release of the second season of the Last of Us which revolves around a human infection of the Cordyceps fungus (something that Entomophthora does not do, it is only focused on flies). Cordyceps fungi infect a range of insects such as ants and control its behaviour to improve the chances of infecting another host. This turns its hosts into a kind of zombie unable to fight against the fungal mind control.

Entomophthora promote a series of behaviours that is known as “summit disease”. The stricken fly immediately seeks elevated locations. If it is too weak to fly it will climb. At the top of a plant or object it will cease moving. Its legs will grip the surface. Its proboscis will extend, and a droplet of liquid will be exuded that sticks the fly to the surface ensuring it cannot be dislodged or fall. Next the wings will raise and spread out and its limbs will straighten; death usually occurs then. Secure and high the fungus now releases it spores that can then rain down on any flies beneath them. The full cycle lasts between 5-7 days

There are about 22 species of Entomophthora that infect 8 families of flies including Mosquitos, Hoverflies, House Flies, Fruit Flies and Flesh Flies. They are most active in May and June and September and October. So keep an eye out for Zombie flies being controlled by fungi.

For more information,

Carolyn Elya and Henrik H De Fine Licht (2021) The genus Entomophthora: bringing the insect destroyers into the twenty-first century. IMA Fungus 12 (1) DOI:10.1186/s43008-021-00084-w

Sunday, 4 May 2025

Sigma 150-600mm F5-6.3 DG OS HSM: A review

Buying a new camera lens can be a bewildering affair, there are so many makes, models and types, do you want macro, prime or telephoto. The last lens I bought was a grey series Canon EF 100-400 mm F4.5-5.6 l IS USM lens. It was a gamble, this is an expensive (to me) lens, and I chanced my arm on a damaged lens from eBay. My gamble was that I could get a cheap repair to the autofocus motor. The gamble paid off and paired with a 1.4x teleconverter became my everyday lens and helped me to get some amazing shots.

Following a small pay rise I wondered about perhaps investing in something new. I started by checking out my go to online store - WEX - and explored the canon lenses available there. Even with a little more money there did not seem to be a better lens out there for a reasonable price that I could afford and so I put the idea from my mind.

Of course, Googles AI had spotted my interest and started to flood my Facebook, Instagram and YouTube feeds with possible lens to buy. I like to think that I am wise to their ad games and do not fall for them, but I know the truth and my curiosity got the better of me and I started clicking links. Thats half googles job done, halfway to a sale. I was weak and succumbed.

One particular lens caught my attention - the Sigma 150-600 mm F5-6.3 DG OS HSM Contemporary black lens. Once I started looking it seemed to crop up everywhere (good old google AI). Now, I’m not a complete chump and so I started my own research. I found that Amazon sold the model for a cheaper price than most, but price alone wasn’t enough, was this lens worth the investment. I started to devour online reviews and watched a slew of YouTube videos - one in particular was very informative. It swung me round to purchasing, despite this I still waited 24 hours before making the purchase.

With next day delivery I very soon had it with me and I was excitedly unboxing it. The lens comes well protected with shoulder straps and lens bag. The construction, although plastic seems robust. First impressions were good but how would it perform in the field. Weight was the most worrying aspect to me. I almost exclusively shoot from the hand. My style of wildlife watching and photography is mostly casual. I am usually out birding or wildlife watching and the camera is there to document this. I very rarely go out with the aim of taking a photo of a particular subject. In essence I’m too lazy and distracted to sit for hours for one shot, too many other interesting birds and animals catch me off sending me off down another rabbit hole, sometimes literally. In essence I am an opportunist. Trudging about carrying a zoom lens camera, binoculars, note pad, bird seed, drink and chocolate bar means weight is an issue. My canon lens weighed 1380g and this new lens was 1927g.

I was pleasantly surprised. The lens is heavier than most, despite its plastic casing it does have some hefty glass in it but out in the field it did not feel appreciably heavier. I noticed it slightly when poised, braced on one knee waiting for a Blue Tit to come back to its nest box. My arms fatigued fractionally faster than normal but that could just be age creeping up on me.

What about the image quality? Before going out I watched a few more videos regarding suitable settings. I increased the shutter speed (I always shoot with shutter priority) to 1/1000 and to compensate with the loss of light upped the ISO level to 6400. My Camera is a Canon 90D and its CMOS APS-C sensor x1.6 multiplier factor means that in real terms the zoom lens is actually 240mm to 960mm. I experimented with this magnification of the zoom. A Whitethroat was bobbing about in the hedgerow a little too quickly for my liking and refused to pose properly but the two shots below illustrate the two extents of the lens.

Whitethroat on a bush 150 mm (effective 240mm)

Same Whitethroat at 600mm (effective 960mm)

As for quality, I was impressed, the images were crisp and sharp, better than my old lens. Some reviews described problematic issues with the autofocus, it would often lose lock and then be searching too much in the view. I found no issues; I shoot with a single point of focus and had no issues whatsoever other than the normal issues of a windy day pushing leaves and branches across the view. The optical stabilising was excellent, I have used Sigma OS before, and this is just as good. focus is fast and whisper silent. I do think I need a little more time with the lens but on day one I was very pleased. The only downside was something that was not the lenses’ fault but my own. It goes back to an ongoing problem I have, Looking after lens caps. I seem incapable of keeping hold of them. I even took special care to keep hold of this one and reattach it when finished but I still managed to lose it.

The following images were taken today. I only edit my images slightly - I adjust the levels, add a little contrast and sharpen if required using a high pass filter.

I will continue to work with this lens to see how it performs and update you if anything changes.

Full details of the lenses specifications are:

Lens Construction	20 elements in 14 groups
Angle of View (for SD1)	16.4 – 4.1 degrees
Number of Diaphragm Blades	9 (rounded diaphragm)
Minimum Aperture	F22
Minimum Focusing Distance	280cm / 110.2in
Maximum Magnification	1:4.9
Filter Size	Diameter 95mm
Dimensions	105mm x 260.1mm / 4.1in. x 10.2in.
Weight	1,930g/100.9oz. (1,830gwith protective cover PT-11)

I bought the lens from Amazon

The lenses official page is at Sigma

Sunday, 27 April 2025

A little Beetle with possible world changing abilities.

Whilst on a floral survey this weekend we came across some bright yellow orange eggs laid in clusters on the underside of dock leaves. Also on the dock plants were large numbers of metallic green beetles. All of the pieces of this puzzle were there and a surprising story.

The eggs on the dock were laid by the metallic Dock Beetle.

The Dock Beetle (Gastrophysa viridula) is a small stunning looking metallic green beetle that is common throughout the United Kingdom. It feeds on dock plants (Rumex sp.) and sorrels eating a series of 1 cm holes in the leaves. There is no sexual difference between male female beetles however in the breeding season the females black abdomen beneath the metallic wing cases swells immensely, making it seem almost round in shape.

They breed from March to October producing as many as 6 generations per year but usually 2. Each female will lay over 1000 eggs in clusters of 20-45 eggs on the underside of the leaves of its host plant the Broad Leaved Dock (Rumex obtusifolius). These eggs are cream or yellow when they are laid and turn orange as they mature over 3-6 days.

When they hatch, the larvae that emerge are greenish-grey to dark brown. They undergo 3 growth phases (instars) before dropping to the ground and burrowing into the earth where they pupate for 6-9 days.

Adults will feed on docks and sorrels and can fly to new hunting grounds, they are also able to hibernate and thereby persist in a habitat year on year.

Dock beetles have a special anti-predation response, when threatened the roll up creating a tight tiny ball and roll off the leave to the ground or into the nook created at the node of the leaf intersection.

The dock beetles voracious appetite and specifity to dock make it perfect for biological control particularly in the Beef industry where it can be used to combat climate change! Trials in Ireland have used the introduction of dock beetles on beef pasture to reduce and control the amount of dock in the sward. Dock whilst not actively negative to cattle does out compete and supress clover. Clover is nutrient and protein rich and so contribute significantly to the cows diets it also has the secondary effect of reducing bovine methane emissions. Bovine methane is one of the things that makes beef such a carbon intensive food source and this innocuous beetle could lead the way in lowering the cows carbon footprint.

Sunday, 30 March 2025

NSFW Mallard Activity

Today is Mother’s Day in the UK and so it was somewhat apt that whilst birdwatching on my patch I observed the process of Mrs Mallard starting to become a mother herself. Mallard reproduction can be a somewhat brutal affair, they have a reputation for aggressive and violent mating. The ratio of males to females is often skewed towards the males and so when it comes to mating many males will target one female and will fight one another over the female and can drown the female in the process.

Today’s mating was much gentler. The pair of Mallard had been feeding together for most of the morning, dabbling around the edge of the mill pond. The female broke away swimming away from the banks and signalling her intent by assuming a receptive posture. She bobbed her head a few times and then lowered her head on to the surface of the water, arching her back. The drake took little persuasion quickly grabbing her by the neck and mounting her. Normally this is where things become dangerous, by holding the nape and with the weight on the duck the copulation occurs with the female completely submerged.

When other males are involved, the female can often be kept underwater by the throng and in the worst cases drown in the attempt. In this relationship it may appear that the female has a rough deal, and they certainly do, males will often force themselves on the female, however they have a trick up their sleeve.

The males have corkscrew shaped penises, which is unusual in the bird world where males generally lack external genitalia, that match anticlockwise vaginas in the female. Females can use muscles to restrict this anticlockwise passage and block the entrance of the male, this gives them some measure of control of who inseminates them.

Today’s pairing appeared completely consensual with the female taking the lead once the mating finished, which lasted only a few seconds they separated and began some vigorous washing and preening before hauling out on the bank for a nap.

Within the next 7-28 days if the female has allowed the semen into her vagina she will lay a clutch of 12-13 fertile eggs which themselves will hatch a further 28 days later. These ducklings will face an uphill struggle for survival for on my patch ducking mortality is very high. The number of pike, mink, otter, fox, and heron on this stretch that even if all 13 hatch only 1 or 2 will make it to adulthood.

Sunday, 16 March 2025

10-years Camera Trapping

On the 31st December 2024 it was 10 years since I started recording wildlife using Trail Cameras on my patch. In those 10 years a camera in the same hedgerow has been recording 24 hours a day for 7 days a week.

Having finally made sure all the data is recorded in an Excel database I can now start to analyse the information, this is going to take sometime so I thought in the short term I would share some of the data that I have collected so far.

In the 10-years the camera recorded 3033 days, a total of 83% of the time, creating 19073 separate data points based on 10 minute blocks in which animals were recorded.

	Percentage Active		No. 10 Min blocks
	Mammal	Bird	Mammal	Bird
2015	78	78	40752	40752
2016	89	89	47088	47088
2017	76	76	39888	39888
2018	90	90	47088	47088
2019	84	84	44352	44352
2020	92	58	48672	30528
2021	80	80	41472	41472
2022	70	70	36576	36576
2023	76	76	40176	40176
2024	96	96	50688	50688
			436752	418608

In total 51 Species were recorded, 31 bird species, 19 species of mammal and 1 reptile were recorded.

The most abundant species were Blackbird, Song Thrush, Woodpigeon, Wood Mouse, Grey Squirrel and Fox.

Taxa	Species	No. Blocks	Weighted	RAI K- Weighted
Bird	Blackbird	3595	3732	187.13
Bird	Song Thrush	1312	1339	67.14
Bird	Woodpigeon	691	937	46.98
Bird	Robin	743	750	37.61
Bird	Dunnock	422	450	22.56
Bird	Redwing	188	227	11.38
Bird	Magpie	180	188	9.43
Bird	Great Tit	156	164	8.22
Bird	Pheasant	115	126	6.32
Bird	Chaffinch	81	120	6.02
Bird	Wren	78	78	3.91
Bird	Jay	59	60	3.01
Bird	Goldfinch	22	25	1.25
Bird	Blue Tit	22	22	1.10
Bird	Bullfinch	19	21	1.05
Bird	Jackdaw	11	19	0.95
Bird	Woodcock	15	15	0.75
Bird	Water Rail	12	12	0.60
Bird	Treecreeper	11	11	0.55
Bird	Greenfinch	6	6	0.30
Bird	Moorhen	4	4	0.20
Bird	Blackcap	3	3	0.15
Bird	Stock Dove	3	3	0.15
Bird	Tawny Owl	3	3	0.15
Bird	Chiffchaff	2	2	0.10
Bird	Sparrowhawk	2	2	0.10
Bird	Carrion Crow	1	1	0.05
Bird	Great Spotted Woodpecker	1	1	0.05
Bird	Long-tailed Tit	1	1	0.05
Bird	Marsh Tit	1	1	0.05
Bird	Nuthatch	1	1	0.05
Mammal	Wood Mouse	3840	3960	198.57
Mammal	Grey Squirrel	2689	2737	137.24
Mammal	Fox	1656	1674	83.94
Mammal	Muntjac	1481	1622	81.33
Mammal	Badger	1166	1210	60.67
Mammal	Roe Deer	176	216	10.83
Mammal	Brown Rat	53	53	2.66
Mammal	Cat	39	39	1.96
Mammal	Rabbit	24	24	1.20
Mammal	Common Shrew	23	23	1.15
Mammal	Dog	21	21	1.05
Mammal	Weasel	20	20	1.00
Mammal	Field Vole	11	11	0.55
Mammal	Mink	3	3	0.15
Mammal	Bank Vole	1	1	0.05
Mammal	Hedgehog	1	1	0.05
Mammal	Mole	1	1	0.05
Mammal	Otter	1	1	0.05
Mammal	Polecat	1	1	0.05
Reptile	Grass Snake	1	1	0.05
		18968	19943

Over the 10 years there have been some winner and some losers.

In the analysis I want to explore each species fortunes, calculate species richness, relative abundance, species diversity and evenness, similarity, niche overlap and do a deep dive on the activity cycles of all the species that I have enough data for.

This may take me the rest of this year!!