Individual study: A review shows that colour dyes deter birds from taking poisoned rodent-baits
Kalmbach E.R. & Welch J.F. (1946) Colored rodent baits and their value in safeguarding birds. The Journal of Wildlife Management, 10, 353-360
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Use coloured baits to reduce accidental mortality during predator control
A review of three replicated, controlled trials in Day County, South Dakota, USA, and another in Routt County, Colorado (Kalmbach & Welch 1946), in 1945, found that bird assemblages (mainly songbirds and doves) took a higher proportion of uncoloured grain (88% taken) than of yellow (73%) or green (23%) grain, and when uncoloured was not available, birds took more yellow (87% and 15% in two sites) than green (39% and 9%). In addition, more dead birds were found with uncoloured poison grain in their stomachs than with yellow. Very few birds were found with green grain.