Relationships Between Winter and Spring Weather and Northern Goshawk (Accipiter Gentilis) Reproduction in Northern Nevada

Ecological factors, such as weather, play important roles in raptor population dynamics. We used logistic and Poisson regression analyses to investigate relationships between late winter, spring, and early summer temperatures and precipitation and Northern Goshawk (Accipiter gentilis) breeding, failure, and productivity in northern Nevada from 1992-2002. We also examined weather data for possible patterns that could explain reported trends in goshawk reproduction. Declines in occupancy of nesting territories by breeding goshawks were related to colder February and March temperatures and increased April precipitation. Warmer April temperatures and decreased precipitation in April-July favored reproductive success. Of all significant weather variables, only February and March temperatures had significant temporal trends. Although adverse weather is known to affect goshawk reproduction by decreasing nestling growth and survival, it is unlikely that direct weather effects were responsible for reported reproductive trends in our study area. Weather may have operated indirectly, influencing reproduction through changes in goshawk hunting behavior or food supply