Ferruginous hawk nest monitoring
Below we explore the different stages in the ferruginous hawk nesting process in the NCA, from nest building to fledging. This specific nest is located south of Boise, Idaho, and contained four nestlings in the 2026 breeding season.
These photos and observations were made by Zoe Bonerbo as part of her Masters research. The photos were collected by Quantitative Conservation Lab in collaboration with Birds of Prey Partnership under scientific research permits.
Stage 1: nest building
This adult ferruginous hawk is building a nest. The platform in the photo is man-made and mimics their natural nesting habitat, and there are over 70 installed across the NCA to encourage breeding.
Sticks and other shrubbery are used to create a base for laying eggs and raising chicks. If you look closely you can see the bird is banded - it has a bracelet on its leg with a unique identification number that it will wear for the rest of its life. This helps us to track population survival and movement patterns.
Stage 2: up to 10 days old
As you can see from the first photo - it’s tiring being a newborn! This yawning nestling and its siblings are only 10 days old. At this stage, they still have spots of pink where their skin can be seen through their fluffy white downy feathers.
The adults are seen tending the nest together at night to keep the nestlings warm and protected.
Stage 3: 10-22 days old
The nestlings are growing up quickly! They are now able to thermoregulate, so the parents do not need to use their body heat to keep them warm.
Nestlings are fed multiple times a day and parents will stay close to the nest to protect them and shade them from the sun.
Stage 4: 22-30 days old
The nestlings are beginning to grow their flight wings. The colored feathers on their wings, face, tail, and body are their juvenile plumage, which will carry them through their first flights in just a few weeks.
During this time, nestlings are still tended to and protected by the parents but are now left alone for longer periods of time.