Information transfer on the whereabouts of food in colonies of pigeons
- Ecology Division, DSIR, Goddards Lane, Havelock North, New Zealand
[Abstract of a paper read at the Ecological Society Conference, 1983.]
The hypothesis that communal roosts and breeding colonies of birds act as information centres for food-finding was tested using pigeons, Columbia livia. The birds roosted and bred in lofts, but were free each day to search for food in the surrounding fields. Two out of three experiments showed that naive pigeons could learn the location of a patch of food when in the presence of knowledgeable birds that already had the information. A fourth experiment showed that the mechanism of information transfer was simply that naive birds followed knowledgeable ones to a good feeding area. Pigeons returning from a successful foraging trip did not transfer information on the distance and direction of the food to other members of the colony. banded. By July 1982, 184 adults and 171 juveniles had been reported short. The mean annual survival rate of adults was 58% (95% conf. into 53-64%) and those surviving their first year after banding had a mean expectation of further life of 1.8 (1.5-2.3) years. The mean annual survival rate of juveniles in their year of banding was 50% (37-64%). To maintain a stable population, each breeding pair is required to raise 3.4 young to fledging; limited field studies suggest an average annual production of 3.6 young. Some slender evidence indicates a tendency toward ancestral breeding but otherwise shovelers demonstrated a pattern of high mobility throughout the country.