A review and synthesis of bird and rodent damage estimates to select California crops

A comprehensive literature review was conducted to identify the magnitude of bird and rodent damage to 19 economically important crops in California. Interviews with agriculture experts provided additional information about damages. Monte Carlo simulations were used to derive summary estimates of damages to each crop. A meta-analysis indicated that summary damage estimates from expert interviews were higher than estimates from field studies and surveys. It was also found that there has been a downward trend over time in damages to almonds and grapes. The results of our study indicate that damages from bird and rodents remain high for many crops and are likely to be economically significant within the state of California.

► A downward trend in pest damage was found, potentially due to better pest control.
► Bird and rodent damage remains significant despite the use of pest control methods.
► Many valuable crops were damaged heavily and the economic impact was likely large.