Abstract
This research was designed to study growth patterns of the Tree sparrow Passer montanus. Body mass, as well as tarsus and natural wing lengths, were measured for two nestlings from the day they hatched to a time just before fledgling. The nestlings studied were in a nest box placed on a tree at the Ikebukuro campus of Rikkyo University. The research was conducted from April to July 2010. The data from the three measured traits were tested against three growth curve models; Logistic, Gompertz, and von Bertalanffy; and the results showed that the Logistic curve provided the best fit. In addition, feather growth was also recorded, and the data indicated that the growth pattern can be used for estimating the age of nestlings.
