discussion / Biologging  / 23 March 2023

RFID Tech for small animals?

Hi All,

I'm working on a project that might require some tech work and as of yet am not a 'tech person' so have been pointed in this direction. It's a pretty common problem that some animals are too small for certain tracking tech; my study species is a lizard SVL 60-90mm, weight 6-11g. RFID came up as an option with studies using tags on very small animals such as wasps - though detection range was limited to around 3cm. 

More context; we know very little about the species ecology as they are currently living in remnant, non-native habitat, and cryptic so hard to observe. We'd like to do a semi-wild experimental set-up in the field investigating which native habitat types they might be happy to live in if translocated - probably offering small patches of temporary plantings - and as they're known to spend most of their time below vegetation it's difficult to observe, and fluro-powder tends to get rubbed away/becomes difficult to follow in dense vegetation. Considering setting up some kind of detecting array that could monitor the movements of lizards temporarily fitted (glued) with small RFID tags; issue is largely what tech to go for and how effective it would really be, especially if the range is very limited? Can we just get a big aerial or cable-grid/strips similar to use in fisheries or is the issue all in the tag size? I've had contradictory chats with people about how the tech actually works and what is possible so I'm getting a bit confused...

Any insight welcomed, even if to say we're barking up the wrong tree entirely... thanks!

Hi Emily, 

Signposting a few other convos and resources that might be useful while we wait for some folks to chime in!  

Vikram's work might be helpful, he's super lovely and I'm sure he'd be happy to answer questions or speak with you if you think it's a path to go down 

If you decide to go down the RFID route, there are quite a few convos if you drop RFID into our search - here's one with lots of advice that might be helpful:  

I also swear there was someone in Kate Jone's lab who was popping tiny tags on locusts, @TaliaSpeaker who did that photo belong to? 



Hi Emily, I think, as you've pointed out, the read range of any tag you use is going to be pretty small. For example, the tags from Sparkfun linked to below have a read range of about 'one inch'. Alternatively, given the weight of your lizards (soooo tiny!) you could potentially consider very small VHF tags like the LB-2X from Holohil. Looking at about 2-3 weeks of battery life, but it would mean you could potentially, more easily track their movements (for example). Happy to discuss and all the best for your research.


Hi again Emily,

@tom_august just pointed to this PhD thesis in another post that could be of interest to you also:

All the best,