Escape behaviour in Estonian birds: differences in flight initiation distance (FID) between urban and rural populations
This data contains 2129 observations of escape behaviour from 57 bird species from Estonian urban and rural habitats. Data was collected in 2015-2016 by Kunter Tätte. Flight initiation distances are accompanied by starting distances, alert distances and various other covariates. This data contains observations from four studies (but not observations collected by other authors): 1) Samia, D.S.M., Blumstein, D.T., Díaz, M., Grim, T., Ibáñez-Álamo, J.D., Jokimäki, J., Tätte, K., Markó, G., Tryjanowski, P., Møller, A.P. (2017). Rural-Urban Differences in Escape Behavior of European Birds Across a Latitudinal Gradient. Frontiers in Ecology and Evolution, 5: 66. 2) Tätte, K., Møller, A.P., Mänd, R. (2018). Towards an integrated view of escape decisions in birds: relation between flight initiation distance and distance fled. Animal Behaviour, 136: 75-86. 3) Morelli, F., Benedetti, Y., Díaz, M., Grim, T., Ibáñez-Álamo, J., Jokimaki, J., Kaisanlahti-Jokimäki, M.L., Tätte, K., Marko, G., Jiang, Y., Tryjanowski, P., Møller, A.P. (2018). Contagious fear: Escape behavior increases with flock size in European gregarious birds. Ecology and Evolution, 9(10), 6096-6104. 4) Unpublished data. Mainly for a discontinued project titled "Effects of winter weather and latitude on escape decisions" in 2015 by Anders Pape Møller. There is also excluded data from the first three studies (i.e. either species with too few observations, or species not of interest in a particular study, or repeat observations) Some remarks: * All distances are in meters, but snow cover in cm * Temperatures are in celsius. * This data set is good for urban-rural comparisons because (a) I always collected observations from both habitats on the same day, (b) starting distances between urban and rural habitats are very similar, (c) there is a large overlap between species composition * Most birds were located on the ground (initial_perch_height = 0) * Whenever a column name has "repeat_..." as prefix, it indicates a second subsequent approach to the same individual. After the first approach I moved back to a starting distance of about 30 m and then recorded alert distance and FID again. This repeat data has not been analyzed or used anywhere. * In the column titled sex, M=male, F=female. I am not very certain about how well I was able to sex Motacilla alba, but observations from other species should be fine. Sex data has not been analyzed. * approach_speed "normal" indicates a walking speed of 1.3 m/s, while "fast" was about 2.6 m/s. However, note that some observations were made during wintertime with snow, meaning that the approach speeds might have been slower then. I would treat winter data with caution. There is also a column "bird_feeder_nearby" that indicates whether a bird feeder was in sight, but it does not necessarily mean that the bird was feeding there. * Column on flock size does not discriminate between same-species groups and mixed-species groups.
Steps to reproduce
Please see the published papers mentioned in the description for details on methods. Here is a general description of the basic methods used: Having located an unalarmed adult bird, I approached it to measure parameters related to escape behaviour. A standard protocol for measuring FID was followed (e.g. Blumstein, 2003; Møller, 2008), where the focal bird is approached at normal walking speed until it escapes. First, the initial distance between the observer and the focal bird was recorded as the starting distance. Second, the distance between the two at the moment when the bird became visibly alert of the approaching human (i.e. discontinues its current behaviour to orient towards the observer and/or freezes) was recorded as the alert distance. Third, the distance between the observer and the individual when it began to flee was the FID. These distances were measured by counting steps and were later converted to metres by multiplying by the average step length of the observer.