Shown in the article photograph is a rugged tablet computer with a cattle tag reading wand. Bluetooth is probably used for the link between the wand and the tablet, so the audience is already familiar with that use of Bluetooth.
Written about in the article is an animal tracker device, which uses actigraphy. Bluetooth would be able to read this device directly from the tablet.
The article doesn’t say where the device comes from, best would be to ask Beth Paganoni at the Department of Primary Industry and Regional Development; but there are many such devices now from China that have a sealed case, a battery, an accelerometer, a data logger, and are accessed over Bluetooth. Sort of like a simplified FitBit tracker.
I wrote about a children’s tracker on my blog. See end of the page for photographs.
While you could make something from components at Little Bird Electronics, your best bet will be to find a source in China of these trackers, especially rugged ones designed for rain and sheep droppings.
So how to do it …
As lambing approaches, you’d charge each tracker at the farm house, and wipe the data.
At lambing begins, you’d power-up and tie a tracker to each ewe and lamb, especially noting if the ewe and lamb were seen together at birth.
Some time later, you’d remove the trackers, but not before you add a standard industry RFID tag or plain plastic tag, depending on your state and regulations. Somehow you’d have to link the tracker number to the permanent tag.
Then the data sets from each of the trackers would have to be processed to look for periods of simultaneous movement. For which you’ll need a good coder who understands signal processing maths. That would give you a list of likely pairings, and a probability of each pairing.
I’ve spoken with sheep farmers around where I live, and the pairings don’t always remain constant, so the analysis will be quite interesting.
A step up in cost is to add GPS receiver to the tracker. Adds bulk, reduces running time. But does have the advantage of removing ambiguity; a lamb and ewe that spend time together will show up in GPS data much more reliably than trying to correlate simultaneous movement.
Hope that helps!