Red-tailed Hawk

August 24, 2023

Question: What was the cause of death for the young red-tailed hawk that was taken by an eagle to its nest in Santa Clara County?

Answer: In late May, two red-tailed hawk nestlings were taken by an eagle to its nest where the eagle and its mate were caring for an eaglet. The hawk nestlings were likely taken as prey items for the eaglet, said CDFW Raptor Coordinator Shannon Skalos. It is common for raptors to take nestlings of other birds to feed their own nestlings. One of the hawk nestlings was eaten by an adult eagle. However, the other one spent time in the nest with the eaglet and adult eagle pair. The hawk nestling was initially fed and cared for by the adult eagles. But as the hawk got older, the eaglet and the adult eagles were aggressive with it causing the young hawk to suffer injuries. Eventually, the hawk was no longer fed, and its condition began to deteriorate. The hawk was found dead in early July near the nest in Santa Clara County.

CDFW’s Wildlife Health Laboratory conducted a necropsy on the hawk and determined it died due to trauma likely sustained from the eagles. The hawk was also emaciated and had almost no fat reserves and atrophied muscles. It had likely not eaten for several days up to a couple of weeks. The findings in CDFW’s necropsy report are consistent with public observations of activity at the nest such as the hawk not being fed regularly, competition with the eaglet and physical altercations with at least one of the adult eagles, said Skalos.