discussion / Biologging  / 6 October 2023

Project Update: Improving satellite ear tag transmitters for Polar Bears

I was just delighted that WWF's Sybille Klenzendorf and Mistywest's Tony Jackson joining us to talk about the polar bear ear tag they've been working on for the past few years. Together, they gave us a fantastic insight into the innovation and design process they've been going through, the current development status of the tags, and they talked through their current challenges and next steps. They were keen to get feedback from our community and to find potential partners for next phases, so we're hoping this is the start of the conversation. They got a lot of supportive feedback and some good ideas during the session, and they are hoping this recording will kick off a longer conversation with folks who weren't able to attend as they catch up. if you have ideas, feedback or suggestions, they'd love to hear from you. 


How the a, b, c, d, e and f did I miss this!? I was registered and everything!! I am an idiot! My apologies for missing the session and it looks like a really promising design, and the ergonomic shape looks really impressive and should improve welfare and deployment outcomes I reckon. 


To me, this suits an open model of development and I'd certainly be interested in helping, if I can at all. @Alasdair from Arribada is also definitely worth chatting to.  


A few questions/comments:

I am actually surprised you are able to source the Tadiran 1550s. I have a lot of trouble in Australia at least. Am I correct that these have limited capacities (e.g. 300mAh-550mAh)? That seems like a pinch point re: available capacity to deployment time. You are probably already across all of this but just in case, have you considered a hybrid lithium cell with a super capacitor to handle the high current draw requirements? Tadiran has a range of low temp. compatible batteries that have higher capacities:

that could potentially be combined with a super capacitor for transmission bursts. 

Re: the antenna, and you may already be doing this (apologies, I haven't read the article), our in-house tests suggest that an 'air gap' between the potting material and the antenna markedly improves signal. Specifically, we use a thin (~2mm) layer of non-conductive, closed-cell foam to provide an air gap that sits between the antenna and the potting material. Definitely helps with our ear tags, albeit in dramatically different temperatures, so not sure if this contributes to signal issues!


Lastly, I couldn't see exactly how the tag joins through the ear, but I am assuming it's a standard male-female mating design. I also assume that the inner side of the tag (the part on the inside of the ear) has to be quite low profile and small so it doesn't impede hearing? Does this inner side have any componentry, or is it just plastic? We've considered trying to make tags that spread the componentry more evenly to both 'sides' of tags, such that the connector links them electronically. Could help to distribute the weight. 


Anyhow, it's a very nice design and happy to help/discuss if there's anyway I can be of use.