I am glad to see more programmers coming into the conservation field.  The first big project I did that really got me involved with conservation work, was taking the path finding algorithms I used from learning game programming, and using them to detect and measure the distance of routes that turtles traveled up and down streams in a river drainage.  

Wolves, cool!

Will this then need collared wolves ?

Hi Kristof!

It's been quite some time since you made this post, and I hope you're doing well.

I'm an environmental scientist currently working on a project to teach children living near a national park the basics of game development through conservation science focused on the biodiversity of the atlantic forest. I came across your post and thought it would be wonderful to chat with you, if you're still available and interested.

Let me know—I’d love to hear from you!

Hi Akio!

Is there any more extensive documentation for Loko than what I see on the website in the link you sent? I'm curious to learn more, such as what the mean and median positional errors are, and how long the battery would last at various fix intervals (such as 5 minutes fixes vs 15 minute fixes), whether the device is capable of taking more than 6,500 consecutive fixes if it is able to regularly connect to the ground device, how it handles failed fixes (i.e. there are no satellites detected), etc.

I'm working on a project in which we are deploying GPS receivers on gopher tortoises. As with many devices, one of our biggest challenges is finding a device that can store a lot of fixes so that we can leave it out for long deployments (we have been looking at devices with pure receivers, and no transmission option), and as someone else mentioned, ruggedness is very important as well- the turtles can be very hard on trackers. These animals present some unique tracking challenges because they spend much of their time underground, meaning that the device will be unable to detect satellites and/or get a good fix most of the time. We also value customizability- someone else pointed out that we biologists have been known to open up devices and DIY them for our own uses- and we are wont to do the same with software as well, if able. For example, for my study we are interested in options where we can choose an adaptive fix interval, for example, every 5 minutes but only during daylight hours, to save on battery as well as memory space. I know triggered firmware is a common request as well- various groups will use different sensors, such as light, temperature, moisture, float, accelerometer, etc. to tell a device when it's appropriate to take a fix (when the animal moves, when it surfaces, etc.).

Best,

Jocelyn

Great discussion — the trade-offs you're navigating with Loko are exactly the right ones for open-source wildlife tracking.

A few thoughts on the points raised, particularly for large animal tracking in Africa with limited budget:

On waterproofing the LoRaWAN antenna — the antenna does need to protrude or be positioned at the surface of the enclosure, but this doesn't have to compromise IP rating. A simple approach is to use a helical or meandered trace antenna on the PCB itself (no external stub needed) and cast the entire PCB in epoxy or use a conformal coating, with the enclosure providing the mechanical protection. For collar deployments on large mammals, the antenna is often routed along the collar belt itself as a flexible element, which also improves radiation pattern.

On geofencing for large animals with infrequent fixes — I'd agree with the caution raised earlier. For animals with large home ranges like elephants or lions in Africa, a 1-4 hour fix interval means an animal can travel 10-30km between fixes. Geofencing only works reliably when you can predict where the base station receiver will be relative to the animal's trajectory. For open savannah, a LoRaWAN gateway on a fixed elevated point (a termite mound, a tree, a ranger station) with 10-20km range is more practical than trying to download when the animal passes close.

On memory — 6,500 records at hourly fixes gives about 270 days of logging, which is enough for most large mammal deployments. The limiting factor in practice is usually battery rather than storage.

I work with LoRaWAN-based tracking systems and have field experience in southern Africa — happy to discuss specific deployment scenarios.

Hi Travis — good question, and one where the practical answer is often different from what the theory suggests.

The fundamental challenge with solar on GPS collars is that the power budget is dominated by the GPS fix, not the idle current. A modern GNSS module during a fix pulls 15-30mA for anywhere from 5 seconds (hot fix) to 60+ seconds (cold start or poor sky view under canopy). A typical small solar cell on a collar — say 2-3cm² — generates perhaps 1-5mA in full sun in Africa. So solar is not replacing GPS power; it's offsetting the baseline quiescent current and helping during long inter-fix intervals.

In practice, solar works well when: your fix interval is long (hourly or less), the animal spends significant time in open sun, and you're optimizing for months-long deployments rather than high-frequency tracking. For large savannah species — elephants, lions, giraffes — where the animal is often exposed and fix intervals of 1-4 hours are acceptable, solar can meaningfully extend collar life, sometimes doubling it.

Where it tends to disappoint: dense canopy species, nocturnal animals with low daytime activity, or applications requiring fixes every few minutes. In these cases the extra weight, cost, and mechanical complexity often outweighs the benefit.

A few practical notes: lithium primary cells (LiSOCl2) have higher energy density than rechargeable lithium-ion and don't need solar management circuitry — worth comparing before assuming solar is the right route. If you do go solar, a small MPPT circuit like the BQ25504 from Texas Instruments handles the variable input from small panels very efficiently at minimal quiescent cost.

What species and fix interval are you targeting? That would help narrow the recommendation.

Hello @robbiemp  

My method may not be the best at the moment, but I’ll share the results from my previous tests. Here’s what I’ve tested: “DIY using SDR connected to a smartphone as a radio telemetry receiver.”

I have a VHF receiver that works with SDR and an Android smartphone. I’ve tested it with a VHF tag that I built myself, "My VHF Telemetry Tag Building Project From Scratch."

It depends on whether you need data or just audio. If you need data, SDR may not perform very well. But if you’re just after audio signals, it can work similarly to a regular VHF receiver. By using a Yagi antenna and connecting the SDR to the smartphone, it can work for any frequency range you want. I used 148-151 MHz, but you can use more than that.

Please understand that it works similarly to a commercial VHF receiver, but it may not be as good as the ones available in the market due to various limitations. However, it can still be used. I tested it with a Yagi antenna that I made myself (but if you already have an antenna, you can use it too), and I was able to detect my VHF tag from a distance of about 1.2 kilometers and 800 meters for the VHF tag I received from @Rob_Appleby  . This is just a rough test.

If you need a receiver that can operate across a wide range of frequencies, I think the RTL-SDR would be a good option as well.

This may not be the best method, but it works just fine. Thank you, and if you have any questions, don’t hesitate to ask me.

Hi Ravi

If you’re still looking for VHF receivers to track wildlife you could check out multi-frequency receivers. These can track 500 frequencies simultaneously (with no need for frequency scanning), and provide automated geo-location (with no need for triangulation).

They are ideal for aerial (drone or aircraft) and ground tracking.

For more info please see our website:

https://altitudeconservation.com/

Good luck with your fieldwork!

Kind regards

Chris

HI

This what I am trying currently todo

https://wildlabs.net/en/discussion/looking-collaborators-ai-powered-backyard-bee-monitor-citizen-science?language_content_entity=en

I have already some algorithms and some monitoring set up in development

feel free to reach me maybe we could join forces

That's a great idea @MandyEyrich ! Similar to your idea, I wrote up an article with geospatial highlights from ICTC 2026: https://wildlabs.net/en/article/wildlabs-geospatial-group-ictc-2026. 

Is the Human-Wildlife Coexistence article available yet? Would love to read it and share it with colleagues at Fauna & Flora.

Hi Simon, this sounds so interesting and is something I've been thinking about for my work in the past.
My team tracks Temminck's pangolins in Malawi using VHF and satellite tags. These animals have been rehabbed and released so we conduct welfare checks on them following release.
Our biggest challenge is that sometimes the satellite tag dies prematurely and then we struggle to pick up VHF signal without knowing an approx sat location. If the terrain is especially hilly then the distance we can pick up VHF signal from is really reduced, especially if the animal is in a burrow. I've previously wondered if a VHF monitoring system is possible with our drone (DJI Mavic 3T).

Your system sounds great and I'm definitely interested in learning more. A 50-100m real-time estimate would work well for us.

Hi Stephanie, We are manufacturing an innovative AI-powered trail camera called DeterCam, and we are based in the UK: https://innovfactory.com/ 

The camera is equipped with our Edge AI technology, which allows it to detect only animals and send media (pictures/videos) only when an animal is present in front of the camera. This significantly reduces false triggers and power consumption.

Our Edge AI architecture allows the camera to operate for up to 1 year on battery power (assuming approximately 5 triggers per day). The system also allows full remote control from our cloud platform, including:

• Video duration
• PIR trigger settings
• Detection configuration
• Camera management and updates

The camera is equipped with a 4G module, allowing all media and detections to be uploaded directly to the cloud, meaning there is no need to physically collect data from the SD card.

We supply the complete solution, including manufacturing the battery packs ourselves. The total internal battery capacity can reach up to 32,500 mAh. To date, we have sold over 10,000 units worldwide.

Please let me know if you have any questions.

You can email me if you have any further questions: [email protected] 

Hi, are you looking to import these? Do you have any import tax considerations? This could impact which models you buy. I have been using Acorn models, very reliable and provide photo and 4K video with sound options.

Best wishes

Susan

I wrote a really simple app for Android phones that acts as a telemetry receiver using the RTL-SDL dongles.  First version was 5 years ago, and I will admit I didn't really understand what I was doing with the signal processing at the time.  I have improved it some, but haven't added all the features I have wanted quite yet.  A big change I made was integrating the RTL-SDR android driver directly into my code so a separate package doesn't have to be installed.  Some concerns have been brought up, that making a cheap receiver could lead to bad actors using it to find animals, and I have had to sit and debate that.  Still, the code for the projects is here:

https://github.com/donfbecker/Telemetry-Receiver

I saw mention of tracking BPM with AI, and I have to say, you don't need AI.  Code for this one will not be released until after we finished up a project or two using it (publishing is competative, sometimes you have to keep your advantage).  The hardware has a cellular modem in it, so we get updates on BPM (which translates to Body Temperature), every 20 minutes.  I had it at 5 minutes, but the solar panels don't keep up as well then.  Like I said, no code, but I can give you a teaser of what I have been watching the last few days as our snakes emerge from over wintering.

The main issue with the RTL-SDR is that with the 8bit sampling, you have a noise floor around around -50dB, so you have to have a signal stronger than that to detect it.  The built in amplifier amplifies it's own noise as well, so isn't always great.  The wideband LNAs that are sold for software radios amplifies EVERYTHING, which sounds great, but isn't.  Tracking frequencies often aren't too far off from local FM radio stations in my area, so the LNA amplifies them too.  If they get too strong, they saturation the amplifier, and the RF front end on the SDR, basically erasing your signal.  The solution is to put a good bandpass filter in front of the LNA, but I've never been able to find one for the frequencies we use, so had to resort to building my own.  I only recently figured out the black magic that goes into LC filters, and dealing with all the extra capacitance added by PCBs.  I finally have a filter working in the range I need, and will be testing it out on my hardware soon to see how it helps with range.

Overall there is a lot of utility in using the RTL-SDR dongles, but the more I get into it, the more I am trying to design my own SDR hardware.  I don't need it to be as capable as the commercially available hardware.  I've made a few basic ones already just feeding the output of mixers in to the ADCs on an STM32 microcontroller, using an SI5351 to generate an LO signal for direct converstion.  I am going to start playing with using a TLV320ADC audio codec chip to sample signals.  It does 32bit sampling, which lowers the noise floor down to -130dB or so, assuming I don't introduce a bunch of noise from my hardware.  The sampling rate wouldn't be as fast, but still plenty for picking up the CW pulses from wildlife transmitters.

--Don

P.S. I am recovering from the flu, please ignore typos

How far did you end up taking this project?

HI Chittakon, 

Have you tested the dB gain as that is a measurement of how sensitive the receiver is to pick up a VHF signal.  Most commercial grade VHF receiver from telemetry manufacturers are in the -150dbm with a maximum noise figure of 3 dB.  

What was the type of VHF transmitters you were using and what was the length of the antenna of the transmitter?  Was the transmitter on the ground or position above the ground and if so what height and polarization plane?

There are a lot of variables which determine field range.

Chris Kochanny

www.vectronic-aerospace.com

See the solution below. If the island is within Globalstar’s coverage area, this is definitely the cheapest option: https://interrex-tracking.com/flex-globalstar 

Greetings Lisa, it is interesting to see to the project you are working on.  If there's anything I can do to help with my skillset let me know.

Thanks, Mike