We will be banding, taking coloration measurements, and conducting behavioral assays on Dark-eyed Juncos. Banding: Mist netting will take place from April to June with IACUC, federal, and state permission. One or two nets (mesh size 35 mm) will be assembled and opened soon after sunrise 3-7 times per week between January and August. Banding will continue until either 11 AM or until it becomes too hot to safely mist net. Spectrometry: During the breeding season from March to July 2025 I plan to collect data from [ ] Reserve. I will only be sampling from male juncos to keep general behavior and plumage coloration consistent. To band juncos, I will audio-lure them into mist nets. I will take standard morphological measurements, blood samples, and pictures of birds’ white tail feathers to calculate tail white area. At the end of the banding process, if the junco did not show any signs of stress (prolonged closing of the eyes, accelerated breathing), I will use an OceanOptics Flame Miniature Spectrometer to collect plumage reflectance data. One researcher will hold the bird, while another researcher will use the spectrometer probe to lightly touch the surface of the bird at a 90º angle against the surface of the plumage for the specified region for reflectance data. We will take three measurements from each area and average them. This will last 5-10 minutes, and after the scans, the bird will be immediately released. Behavior: During the banding process, I will first measure agonism by quantifying breaths per minute in hand. This will involve holding the junco directly below my face immediately after I remove it from the bird bag, and measuring the amount of time passed by the bird’s 30th breath. I will also measure the aggression of males within their territory by setting up a testing arena. This will consist of a 3 meter radius arena with a model male junco atop a speaker playing a junco song in the center of the circle. Once the male junco enters the vicinity I will take note the following behaviors and environmental aspects: latency to enter the arena, latency to sing, number of chip calls, nearest distance to the speaker, number of attacks on the model junco, number of fly-overs, amount of time spent within 1m radius in the arena, amount of time spent in the the 1-3m radius of the arena, singing duration, and number of passing pedestrians. I will implement an at least a week-long waiting period between banding and aggression assays of the same individual to avoid bias.

Approved