Recently, several zoos have aimed to improve the welfare of captive animals by adopting certain feeding enrichments, particularly to address oral stereotypy in giraffes. Research has revealed that the utilization of certain feeding enrichments, such as browsing enrichment, is effective for preventing oral stereotypy. However, feeding of browsing enrichment may be difficult in winter, although its effect is not evident in this season based on previous studies. Therefore, the weight of tree feed foraged by the giraffes and their behavior, including oral stereotypy, was observed in all seasons of tree feeding. Three giraffes were observed in the Kyoto City Zoo. No significant change was observed in the weight of foraged tree feed throughout the seasons, with a similar weight of food intake observed in all seasons. Although all giraffes expressed oral stereotypy, the behavior increased significantly in winter. Furthermore, the oral stereotypy frequency was not significantly correlated with the weight of foraged tree feed, suggesting that some other factor strongly influenced the frequency, such as the climate differing from that of the giraffes’ original habitat. Therefore, further research is required to elucidate the factors that cause oral stereotypy.