Captive starlings were studied to see how their stress hormone levels change throughout the day and across different seasons. The researchers found that stress hormone levels in starlings vary depending on the time of day, with higher levels at night. They also discovered that the birds release more stress hormones during the night in response to stress. Additionally, the study showed that starlings have different stress hormone levels during different seasons, with lower levels during molt. This research provides insight into how stress hormones fluctuate in starlings and can help scientists understand how these birds cope with stress in different situations.