U.S. Department of Agriculture: Animal and Plant Health Inspection Service


Date of this Version



Proc. 23rd Vertebr. Pest Conf. (R. M. Timm and M. B. Madon, Eds.) Published at Univ. of Calif., Davis. 2008. Pp. 88-93.


U.S. Government Work


American crow populations have increased steadily since 1966 in many parts of the U.S. Large winter congregations of crows in urban environments have resulted in an increased number of requests for assistance in managing nocturnal roosts in New York. In 2002, the USDA APHIS Wildlife Services program initiated a large-scale non-lethal winter roost dispersal program in Troy, New York. Since that time, similar programs have been implemented in 4 other cities in New York to manage crow roosts ranging in size from 8,000 - 63,000 individuals. The goals of the programs were to minimize noise, accumulations of crow feces around residences, strong odors associated with droppings, property damage, clean-up costs, and potential threats to human health and safety. The primary management strategy relied on dispersing concentrated crow populations from high-impact high-conflict areas, to low-impact low-conflict areas. An integrated management program using pyrotechnics, amplified recorded crow distress calls, and hand-held lasers was implemented to successfully disperse local crow roosts, reducing populations at the majority of core roost sites each year by more than 98%. In some instances, significant reductions in crow numbers and associated damage persisted >8 weeks after management without additional interventions, although most sites required multiple additional “spot treatments.” High-profile urban wildlife management projects of this type require multiple meetings with key stakeholders and the public and often attract intense media interest, adding complexity to these programs. We provide summary information from 5 cities in New York documenting crow management techniques, intensity of effort, number of interventions required to relocate crow populations, and key lessons learned regarding science-based project documentation, project transparency, communication, and the need for long-term adaptive management strategies to meet project goals.

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