To study the time course of feeding-induced thermogenesis (heat increment of feeding, HIF) in an avian species with a crop, we measured HIF induced by a bout of feeding in domestic pigeon (Columba livia). Birds were fasted for 23 h and then allowed to eat for 40 min by illuminating an otherwise darkened metabolic chamber. In thermoneutrality (23°C), feeding was followed by an increase in oxygen consumption (VO2) and respiratory quotient (RQ), which then remained elevated for several hours without showing a clear peak. In cold (0.5°C), feeding did not change VO2 although RQ increased. Such results generally indicate that HIF substitutes for facultative heat production (shivering) in the cold. However, we found no difference in shivering (pectoral muscle electromyograms) between fed birds and non-fed controls in the cold. This suggests that actual substitution of cold thermogenesis did not occur. We conclude that HIF does not follow feeding as a clear peak in thermogenesis in birds that have a crop and raise the question whether the increased VO2 after feeding at thermoneutrality is true HIF or a shift in basal metabolic rate triggered by neuroendocrine signals induced by the presence of food in the crop.