RTF biologist Celeste Carlisle recently took part in a roundtable discussion about the use of fertility control to manage wild horse populations on the range. For the record: RTF also opposes the use of IUDs based on past studies. IUDs used more recently by BLM are a newer technology but RTF remains opposed to their use until they are shown to be safe, humane and effective. Also, because the fertility control vaccine GonaCon affects the hormone system, it may cause other behavioral changes that would alter herd dynamics, so RTF believes more studies are needed to ensure that GonaCon meets the parameters of ethical and thoughtful wildlife fertility control.