Dr. Nova Silvy has been actively involved in efforts to control a screwworm outbreak in the endangered Florida Key deer. Silvy first worked with Key deer during his doctoral research over 49 years ago. Prior to this, there had been no screwworm outbreaks in the U.S. for the past 30 years. However, one began last July on Big Pine Key. Over the following months, screwworms infested the Key deer population, which is spread across multiple islands in the Lower Florida Keys and it led to 135 Key deer deaths, mostly males which sustained wounds during the rut. Screwworm fly larvae feed on warm-blooded animal tissue, so the open wounds from the deer rut provided an environment for screwworms to infest and lay eggs. The screwworms eat the flesh around the wound until the deer becomes incapacitated or dies.
To help control the outbreak and assess the survivability of the Key deer, Dr. Silvy along with Drs. R Roel Lopez and Israel Parker and others from the Texas A&M Institute of Renewable Natural Resources have traveled to the Florida Keys to conduct deer population estimates and projections. With the U.S. Fish and Wildlife Service as the lead agency, they have been researching screwworm impacts and spatial distribution, as well as deer population density based on sex ratio and age. Dr. Silvy noted that while interagency efforts to date have been highly successful in halting the outbreak, further concern over screwworm infestations may appear in the spring as Key deer does start giving birth. Therefore, Dr. Silvy and the rest of the team also have placed radio collars on 30 Key deer does to help find if they may be vulnerable to screwworm flies while giving birth. Through use of antiparasitic medications and the U.S. Department of Agriculture releasing over 140 million sterile male screwworms flies to mate with wild female flies (female flies only mate once,) the screwworm fly population has been significantly reduced and further screwworm infestation has been stopped.