The Swainson’s hawk (Buteo swainsoni) is a state-listed threatened species in California and is a Covered Species under the Natomas Basin Habitat Conservation Plan and the Metro Airpark Habitat Conservation Plan. As part of the implementation of both HCPs, the Swainson’s hawk nesting population is monitored annually throughout the entire Natomas Basin in order to assess the status of the population and the effectiveness of the HCPs. To date, monitoring has indicated a fairly stable nesting population with the number of active nesting territories ranging from 43 to 62 between 2001 and 2011 Reproductive effort has also remained relatively stable during this period ranging from 1.38 to 1.67 young per successful nest. In 2011, 62 nesting territories were confirmed active, representing the largest number of active territories since monitoring began. However, due largely to inclement spring weather and possibly disturbance from levee construction and other disturbances in the Basin, only 23 of these successfully produced young for a reproductive effort of 0.60 young per occupied nest.
