Electroretinography in the Collared Scops Owl (Otus lettia)

Electroretinography (ERG) is a non-invasive technique used to assess retinal function via electrical responses to light stimuli. We established baseline ERG parameters and a standardized recording protocol for collared scops owls (Otus lettia). Twelve eyes of six owls were evaluated. In addition to the pre-release assessment, ocular reflex tests and basic ophthalmic examinations were performed before the induction of anesthesia. Routine radiographic and hematological examinations were performed under general anesthesia, followed by ERG recordings. Under scotopic -20 dB conditions, the a-wave amplitude was 1.78 ± 0.53 μV (implicit time: 37.83 ± 5.52 ms), and the b-wave was 41.59 ± 10.71 μV (100.88 ± 10.9 ms). For scotopic 0 dB mixed responses, the a-wave amplitude was 27.98 ± 5.9 μV (27.64 ± 2.71 ms), and that of the b-wave was 175.51 ± 13.82 μV (97.02 ± 7.01 ms). Under photopic conditions, the a-wave and b-wave amplitudes were 2.88 ± 2.06 μV (28.67 ± 2.77 ms) and 25.53 ± 10.61 μV (77.78 ± 16.18 ms). To the best of our knowledge, this is the first study to establish species-specific baseline ERG parameters for collared scops owls. These findings provide a valuable tool for assessing retinal function in raptors and may serve as a baseline framework for ERG evaluation in other avian species.