Short-term physiological and behavioural effects of high- versus low-frequency fluorescent light on captive birds
Publication Type: |
Journal Article |
Year of Publication: |
2012 |
Authors: |
J. E. Evans, E. L. Smith, A. T. D. Bennett, I. C. Cuthill, K. L. Buchanan |
Publication/Journal: |
Animal Behaviour |
Keywords: |
captivebird, corticosterone, flicker frequency, fluorescent lighting, light environment, sturnus vulgaris, welfare |
ISBN: |
00033472 |
Abstract:
Experiments using captivebirds involve artificial lighting sources, which are often conventional low-frequency (LF; 100 Hz) fluorescentlight. Many bird species may be able to perceive the flicker emitted by these lights and this may have important consequences for their behaviour, physiology and welfare. We determined whether European starlings, Sturnus vulgaris, react differently to being housed under LF versushigh-frequency (HF; >30 kHz, a rate imperceptible to any animal) fluorescentlight. Birds were monitored and the lighting type changed half way through the experiment. While we found no difference in the mass or haematocrit levels of birds housed under HF and LF lighting, birds exhibited higher levels of myoclonus (involuntary muscle spasms) and preening but reduced jumping, eating, drinking and bill wiping under LF light. Birds also experienced lower basal corticosterone levels under LF light, suggesting that they are experiencing chronic stress, as prolonged exposure to a stressor is known to suppress corticosterone production. Birds initially exposed to LF light exhibited behavioural changes over the 3 weeks of the experiment, suggesting that this initial exposure to LF lighting had carryover effects on the birds’ behaviour. Our results demonstrate that starlings are sensitive to LF light and emphasize the importance of considering experimental lighting conditions. Our results also highlight the importance of ensuring the standardization of flicker rates as part of any study gathering behavioural or physiological data. From a welfare perspective, our results confirm that it would be better for wild birds to be housed under HF light.