In an experiment conducted from 1948 to 1964 in the Forest of Dean in Gloucestershire, two hundred and fifty nest boxes were carefully recorded for their locations and then analyzed for their inhabitance. The median breeding dispersal (the distance between successive nests) of the European pied flycatcher ranges from about , with the average distance between nest sites being about . This distance typically depended on the breeding density in each year. The study found little evidence to suggest a difference in breeding dispersal between years or between monogamous and polygynous males. As a result, the data for the separate categories could be combined. The breeding dispersal over longer distances could result in both mate fidelity as well as mate change, the latter of which occurs either while the previous mate is still alive, or following the death of the mate. The breeding dispersal distances of birds that survive more than three breeding seasons were studied, and the results showed that the site fidelity increased with more successive breeding attempts. The same long-term study also found that older European pied flycatchers, both male and female, were more likely to move shorter distances between breeding seasons than younger birds were. When mates were observed to re-establish their pair bond, they tended to occupy certain areas that were near the nest site established in the previous breeding season. In addition, female birds were less likely to return to a former breeding site following the death of, or divorce from, their former partner. When a pair divorces, the females have been observed to move greater distances away than the males. As a result, females that keep the same mates from year to year end up moving shorter distances for each mating period than those that divorce. Divorce has little influence on the likelihood of males moving away from their original nest site. The study found that males that keep the same mate do not move significantly smaller distances than males that divorce.
