These transmitters have not disappointed and continue to impress! I ordered Holohil RI-2D (with a mortality sensor) transmitters per my advisor’s suggestion for my graduate research on small mammal and Burmese python interactions in the Greater Everglades Ecosystem. We’ve attached them to cotton rats to look at cause-specific mortality and survival in areas with pythons compared to areas without pythons. So far, we’ve had our cotton rats die from snakes, birds, and mammals. Our signal range is 150-470 meters depending on the type of antenna employed and the vegetation thickness. The transmitters work from inside of snakes that are underground, inside piles of huge boulders, and underwater with amazing signal strength. We’ve also had a snake end up in an alligator after consuming a tagged rodent and we STILL got a signal through the alligator that was 8-12 feet underwater. Birds of prey and some mammals (raccoons likely) move their rodent kills (with attached radio collar) up to a about a kilometer away from the kill site and typically consume them in super dense sugarcane or other vegetation. The transmitter’s signal strength works amazingly well in these difficult conditions and so far we’ve managed to find and analyze all kill sites. We’ve also re-deployed these collars up to 3x and the signal strength and battery life are still working like new. We are ~5 months into the project and continue to be impressed with how well the transmitters perform given the harsh conditions (including reptilian and mammalian stomachs!) they endure.

Transmitter signal strength is absolutely incredible!
Marina McCampbell
University of Florida