Wildlife and SBI share these VHF repeaters, but I've not heard any SBI traffic on VHF in a long time. I suspect that some of it is on celluar & nextel. They do have some talkgroups on VIPER, but they would probably not be used much yet.
I worked with them providing medical for a meth lab bust a couple of months ago. Their tactical team responded. Some of them carried spectra hand helds, vhf for on scene use, but one of the guys said that all of their comms are on nextel.