Heuristics for unrooted, unranked, and ranked anomaly zones under birth-death models

•We consider three types of gene trees: ranked, unranked, and unrooted.•Probabilities that species trees are in anomaly zones increase with the number of taxa and the speciation rate.•Species trees can be in different types of anomaly zones simultaneously.•Probabilities that species trees are in anomaly zones can be quite high for moderately high speciation rates.