For this study, published in the journal Wetlands Ecology and Management, the researchers approached a variety of duck, grebe, egret, ibis and other bird species in wetlands along the the Darr and Thompson rivers until the birds fled. Using a laser rangefinder, they recorded how far away they were from the birds when they took off, known as the starting distance, and how far the birds flew.
Birds spooked by canoes flew an average of 108 feet, while those set off by walkers flew an average of 156 feet. The results varied depending on species, with the Pacific black duck having the greatest average escape distance at 236 feet from canoes and 354 feet from walkers. White-plumed honeyeaters, on the other hand, flew an average of just 23 feet from canoes and 55 feet from walkers. The Australian darter and intermediate egret both bucked the trend, fleeing farther from canoes than walkers.
Those two species aside, the trend makes sense. The distance of escape flights cane influenced by the speed, noise and shape of the intruder, according to the study. “Most (unmotorised) canoes are slow, quiet, used by non-consumptive recreationists (some are used by hunters), and presumably represent little risk to birds,” the authors write.
If wildlife managers were to use data gathered in this study as a guideline to restrict access and protect the birds, the study would recommend a set-back distance of around 300 feet. But that is “wider than most waterbodies in the study area,” according to the study area, suggesting that some disturbance from boats may be inevitable.