Activity rhythms and position preferences of domestic chicks which can see a moving object
The activity levels of isolated domestic chicks in home pens maintained at constant light and temperature were monitored for 4-6 days after hatching. The data were analysed using correlograms, spectrograms and multiple regression. Most chicks showed 24 h periodicities and also shorter periodicities of 1.5-4 h and about 30 min, but there was considerable individual variation. The importance of short-term rhythms in studies of responsiveness is emphasized. Chicks which could see a small, rotating ball from their home pens were more active than those which could not see a moving object and spent more time near it. The more pronounced 24 h periodicities, shown when a moving object could be seen, were partly due to greater activity, especially that near the object. © 1980.