|Title||Foster-feeding and polygamy in the Purple Martin|
|Publication Type||Journal Article|
|Year of Publication||1959|
|Journal||The Wilson Bulletin|
While conducting homing experiments with Purple Martins (Progne subis) in the vicinity of the University of Michigan Biological Station, Cheboygan County, Michigan, in the summer of 1958, I trapped, color marked, and released 16 adult martins at distant points. When periodically checking for the return of these homing birds I also observed behavior at the nests. Female 14 was trapped at 3:30 p.m., July 11, and was released near Sleeper Lake, Luce County, Michigan, at 9:00 p.m. the same day. She did not return to the nest until the afternoon of July 13. In her absence the female occupying the nest directly above made several trips to Female 14's nest with food for the young. This female also continued to care for her own young. Perhaps the begging notes of the young in the nest below induced her to bring food. Number 14's mate was also feeding his young. He accepted this help and did not attempt to drive away the assisting female. When Female 14 returned, the assisting female ceased this behavior and cared solely for her own brood. This was my only observation of foster-feeding, although 14 females were taken from the colony for periods of a few hours up to approximately three days. I also recorded an instance of possible polygamy. Females 9 and 10 were removed from the colony for homing trials. The nest compartments of these two birds were side by side. During their absence, a single male cared for both broods of young. Often he brought several insects to the nests and fed some to each brood. Sometimes all of the food was givem to one brood of young and a fecal sac removed. No challenging martin came to either of these nests. Female 9 was absent from the nest for eight hours and No. 10 was gone for 25.5 hours. The male was successful in his attempt to care for two broods because young fledged from both nests.