Average values of #animal group sizes are prone to be overestimated in traditional #fieldstudy, because small groups and singletons are easier to overlook than large ones. This kind of bias also applies for the method of locating groups by tracking previously radio-collared individuals in the wild. If the researcher randomly chooses a collared animal to locate a group to visit, a large group has higher probability to be selected than a small one, simply because it has more members.
The question arises whether location of groups by means of finding collared animals has smaller or greater bias than searching for groups by visual observation. If the bias is smaller or same, this method can be recommended for finding groups. However, such a comparison cannot be made by speculation, only by empirical investigation.
Authors compared the two methods empirically, by statistically comparing group size measures (mean, median, quantiles, frequency distribution, and 'typical group size') between two data sets. These data sets comprise of Rocky Mountain mule deer group size values collected in the same area during the same period of time, referring either to groups located by the traditional ‘search and observe method’ or located by tracking formerly collared individuals.
Reiczigel, J., Mejía Salazar, M., Bollinger, T., et al. (2016). Comparing radio-tracking and visual detection methods to quantify group size measures. European Journal of Ecology, 1(2), pp. 1-4. doi:10.1515/eje-2015-0011
Download Open Access
