For my birthday yesterday, David bought me a GPS tracking gadgetty thing that I will be able to use not only for my training with Jack but also on one of my wild ponies to see where they have been. In this way I should be able to collect a more accurate picture of the exact dimensions of their haunt and whether there are any distinct patterns to their orbit. (At present I know they involve daily attendance at the fence line to see if Sarah has put the hay out yet).
If only there was a device that would tell me where they ARE rather than where they have been. There are satellite tracking devices which can be fitted on a collar and logged at great expense (and the collar needs to be breakable - and is therefore lose-able - if the pony gets caught up) this still doesn't allow identification from a distance nor does it provide any deterrent to theft. Microchips are only worth anything if the police, ports and abbatoirs scan every pony.