Long-term monitoring of a successful recovery program of Peregrine Falcons in Virginia

• Published in: Ornis Hungarica
• Main Authors: Watts, Bryan D., Byrd, Mitchell A., Mojica, Elizabeth K., Padgett, Shawn M., Harding, Sergio R., Koppie, Craig A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Walter de Gruyter GmbH 2018
• Subjects: Falco peregrinus; peregrine falcon
• Online Access: http://dx.doi.org/10.1515/orhu-2018-0018; http://content.sciendo.com/view/journals/orhu/26/2/article-p104.xml; https://www.sciendo.com/article/10.1515/orhu-2018-0018

Abstract The Peregrine Falcon (Falco peregrinus anatum) was believed to be extirpated as a breeding species in Virginia by the early 1960s. An aggressive restoration program was initiated in 1978 that involved the release of captive-reared birds totaling 115 on the Coastal Plain (1978 – 1985) and 127 in the Mountain physiographic region (1985–1993). The first occupied territory was established and the first breeding attempt was documented in 1979 and 1982, respectively. We have monitored the size, distribution, reproductive rate, and substrate use of the resulting breeding population (1979 – 2016). The population proceeded through an establishment phase (1979–1993) driven by releases with an average doubling time of 3.8 yrs to a consolidation phase (1994–2016) with an average doubling time of 23.1 yrs. The state supported 31 breeding pairs by 2016. Per capita reproductive rates have increased significantly over the study period from 0.89 (1979 – 1993) to 1.86 (1994–2016). Average nesting success increased from 67.1% to 82.7% over the same period. Nesting attempts (n = 469) have been documented on dedicated peregrine towers (52.1%), bridges (26.1%), buildings (4.1%), and various man-made structures (13.0%) with only 4.7% documented on natural cliffs. The population appears to be self-sustaining with reproductive rates exceeding 1.5 young/pair every year since 1999. An ongoing management concern is that only 8.9% of known territories (n = 45) identified since introductions and 4.7% of documented breeding attempts (n = 469) have occurred within the historic mountain breeding range.