Long Breeding Season and High Frequency of Multiple Brooding in Great Tits in Northern Japan

The Great Tit Parus major is one of the most intensively studied birds and such studies have contributed greatly to the current understanding of the evolution and ecology of natural populations. However, despite its wide geographic distribution and high variation in life history traits among regions, most ecological studies are concentrated in Europe, and there are relatively few studies elsewhere. We studied the breeding ecology of a Great Tit population in northern Japan and compared their breeding parameters to those described previously for European populations. This population was characterized by a long breeding season, up to four months from May to as late as the end of August (egglaying to fledging), and a high frequency of multiple brooding (≥60%) including two occasions of third broods. In addition, clutch size was large with a mean of over ten, compared to less than eight in European populations at the equivalent latitude. The high productivity of the studied population may be a consequence of ...