PUB - Publikationen an der Universität Bielefeld

Animal collective patterns such as group size frequency distributions often show substantial intraspecific variation, suggesting low species-specific consistency. Here, we dissect intraspecific vs interspecific components of colony size variation to estimate the repeatability (R) of colony size frequency distribution (CSFD) statistics for seabird species breeding in at least two out of four distant geographic areas of the Northern Hemisphere (21 species; 57 populations; 21 665 colonies; 9 326 479 breeding pairs). Colony sizes were highly variable both within and between species. We estimated the proportion of between-species variation using the repeatability statistic. Colony size-related statistics of CSFDs (e.g. geometric mean) showed high repeatabilities (R = 0.73–0.88), and shape-related measures ranged from null (kurtosis), moderate (fit to a log-normal distribution, R = 0.62) to highly repeatable (e.g. skewness, R = 0.74–0.87). We thus show that species collective patterns can be at the same time highly variable within species and a robust species-specific trait that bridge ecological spatio-temporal heterogeneities.