Tools for managing invasions: acceptance of non-toxic baits by juvenile Nile monitor lizards and Burmese pythons under laboratory conditions

Abstract

Nile monitor lizards (Varanus niloticus) and Burmese pythons (Python molurus bivittatus) are large, invasive, predatory reptiles, which are now well established in south Florida. Acetaminophen was recently shown to be lethal to both animals and therefore has potential for inclusion in an integrated pest management effort to control these species. However, acceptable bait matrices for both species are still needed to deliver the toxicant. We tested nine candidate bait matrices on juvenile Nile monitor lizards and Burmese pythons in the laboratory. Baits were tested fresh and also after aging at 30°C and 50% relative humidity for 24 h. Six of the nine baits were well accepted by the monitors in both fresh and aged conditions (dead neonatal mouse, dead quail chick, ground turkey, chicken liver, tilapia, and zebra finch egg). Only the fresh dead neonatal mouse and fresh dead quail chick were well accepted by the pythons. As far as we are aware, these tests are the second of such bait matrix preference tests conducted for reptiles. The implications of our results are discussed regarding further development and testing of baits in a natural setting.

Keywords:

• integrated pest management
• invasive species
• Python molurus bivittatus
• toxicant delivery
• Varanus niloticus

Acknowledgements

We thank the Animal Care Staff at the National Wildlife Research Center for their efforts in accommodating and caring for these animals. We appreciate the efforts of G. Gathright and D. Gossett during the post-mortem examination of the animals. We thank W. Shockley and T. Hairston for information on Nile monitor trapping methods on site visits at Homestead Air Reserve Base, Florida. We also thank H. Phillips for Nile monitor trapping information at Cape Coral, Florida.