Individual study: Food-supplemented male Carolina wrens sing significantly more than non-supplemented males
Strain J.S. & Mumme R.L. (1988) Effects of Food Supplementation, Song Playback, and Temperature on Vocal Territorial Behavior of Carolina Wrens. The Auk, 105, 11-16
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Provide supplementary food for songbirds to increase adult survival
A replicated, randomised, controlled study from December-January in 1985-1986 in 8 experimental and control (rotated) pairs of Carolina wrens Thryothorus ludovicianus in a woodland study site in Tennesse, USA (Strain & Mumme 1988), found that male wrens supplemented with food sang significantly more than unsupplemented males. Food supplementation, but not song playback, significantly increased both the song rate and the rate of song-type change (89.4 and 51.2 songs / hour; 1.3 and 0.7 song changes / hour for food supplemented and control males respectively). The authors point out that, because foraging and singing are mutually exclusive behaviours in Carolina wrens, the increase in vocal territorial behaviour associated with food supplementation may reflect a decrease in the time required for foraging. Wren pairs were allocated to food supplementation treatments randomly. Food supplementation consisted of 2 cans filled daily with 100 mealworms / territory. Daily observations began approximately 30 min be-fore sunrise and continued for 4 hours.