Behavior of Loons in Response to Predators
Anusha Pahari ’21, Kathmandu, Nepal
Majors: Ecology, Evolutionary and Behavioral Biology; Anthropology
Waterfowl birds display a variety of behaviors like making various noises, making postures, diving and swimming. I wanted to investigate whether any of these behaviors are associated with the threat of predators. To test this hypothesis, I did an observational study on the behavioral patterns of common loons (Gavia immer) found in the Low Lake of Northern Minnesota located in the Boundary Waters. I observed the behavioral patterns of loons when they were approached by predators, in this case, humans approaching them in a canoe. I recorded the various calls, postures, diving patterns and the frequency of a swim escape. I observed loons doing the vulture pose and making three calls – the whale note, the tremolo and the yodel. I had seven observations in which a male-female pair had one or two chicks. We also observed one single loon and one male-female pair without chicks. I compared the behavior patterns of the pairs with chicks, the pair without chicks and the single loon to determine anecdotally if any of the behaviors were more prevalent for the loons with chicks as a protective response. I did have a limited amount of data since I collected seven cases of loons who had chicks but only one case each of a single loon and a loon pair who did not have any chicks. The conclusion mostly was that the alarm calls were only made by loons who were partnered up and more so if they had chicks with them, since 100% of loons with chicks made those noises. The postures were seen more frequently in loons with chicks too, since this was found in 5 out of 7 cases. However, the diving time was higher among single loons with it being 31.5 seconds among single loons and 30 seconds average among loons with chicks.