Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.07.22.216481v1?rss=1 Authors: DeNicola, A. J., DeNicola, V. L. Abstract: Overabundant suburban deer (Odocoileus spp.) are a source of human-wildlife conflict in many communities throughout the United States. Deer-vehicle collisions, tick-borne pathogens, impacts on local vegetation, and other negative interactions are the typical reasons cited for initiating a deer management program. Social attitudes, legal constraints, and perceived safety concerns lead many communities to examine nonlethal management options. Surgical sterilization is currently the only nonlethal method available to permanently sterilize females with a single treatment. There are limited data demonstrating methods and outcomes in management programs that sterilize a high percentage (>90%) of the population, particularly in terms of the impact of immigration on non-isolated populations. We present data from 6 surgical sterilization sites with open populations (not fully enclosed or island environments) in California, Maryland, Michigan, New York, Ohio, and Virginia, USA. From 2012 to 2020, we sterilized 493 deer primarily via ovariectomy. Annual or periodic population estimates were conducted using camera surveys, road-based distance sampling, and intensive field observations to assess population trends. Initial populations ranged from 6 - 63 deer/km2. For all 6 sites combined, we noted an average reduction in deer abundance of approximately 25% from Year 1 to Year 2. Four years after first treatment at sites managed with only surgical sterilization, we noted an average total population reduction of 45%. These projects demonstrate that significant reductions in local deer densities using high percentage surgical sterilization programs can be achieved in non-insular locations. Copy rights belong to original authors. Visit the link for more info