Joanna Skwarska
Ornis Polonica 2012, 53: 209–221
https://doi.org/10.12657/ornis.2012.3.4
Summary: The ratio of the heterophils and lymphocytes (H:L ratio) is known as a reliable stress indicator in free-living birds. It is considered that H:L ratio allows to assess body reaction to long-term stress caused by ecological and physiological factors. Results of studies of many authors indicate that particular factors can influence the stress index of young and adult birds in a different ways. The H:L ratio is affected by physiological mechanisms of the stress reaction. The level of corticosterone and heat shock proteins result in increase in the H:L ratio. A change in the H/L ratio is detectable within hours following exposure to a stressor. Thus, in contrast to corticosterone (its level increases 2–3 minutes after capture), the H/L ratio is not affected by handling or blood sampling stress what is advantageous in the field studies.
