Acquisition of Homeothermy in the Black-eared Kite, Milvus migrans lineatus

The development of homeothermy was investigated in a hand-reared black-eared kite, Milvus migrans lineatus. The 20-day-old nestling was capable of thermoregulating at about 95% of the adult ability at the ambient temperature of 20℃. In effect, the kite which is one of large altricial birds acquires the homeothermy in an earlier growth stage than do small altricial ones, Such precocious development of homeothermy in the kite appears to be caused by the large body mass resulting in decreased surface to volume ratio and in increased heat production, and it allows the parents to increase the foraging time early in the nestling period. In other words, the precocious development of homeothermy plays an important part in the growth and survival of the kite nestling which requires more food and energy than do the nestlings of small altricial birds

Food Habits of the Black-eared Kite, Milvus migrans Zineatus, in Nagasaki Airport and Its Adjacent Areas

Food habits of the black-eared kite Milvus migrans lineatus were analysed based on the stomach contents obtained from 241 kites, which were shot to reduce strike damage to aircraft or hit by aircraft at Nagasaki Airport, Nagasaki Prefecture, during the five-year period from 1977 to 1981. Most of the samples were collected in summer and autumn when the number of the kites was large. The kites fed mainly on fishes and insects in this period : especially in August and September, the former was their main diet. This fact was presumed to be related to the following two factors : 1) a mass death of fishes due to both an outbreak of a red tide and a lack of oxygen dissolved in bottom waters, and 2) abandonment of a quantity of worthless fishes, which thronged into well-conditioned environments owing to deterioration in water quality and consequently became easily captured by fishermen. In October and November the kite chiefly preyed on locusts. During this period, a large number of them inhabited green belts in the airport ; thus the kite seemed to eat preferentially locusts which were easy to catch. It was concluded that the black-eared kite fed on prey animals obtained easily according to habitats and/or seasons

Food Habits of the Black-eared Kite, Milvus migrans Zineatus, in Nagasaki Airport and Its Adjacent Areas

Food habits of the black-eared kite Milvus migrans lineatus were analysed based on the stomach contents obtained from 241 kites, which were shot to reduce strike damage to aircraft or hit by aircraft at Nagasaki Airport, Nagasaki Prefecture, during the five-year period from 1977 to 1981. Most of the samples were collected in summer and autumn when the number of the kites was large. The kites fed mainly on fishes and insects in this period : especially in August and September, the former was their main diet. This fact was presumed to be related to the following two factors : 1) a mass death of fishes due to both an outbreak of a red tide and a lack of oxygen dissolved in bottom waters, and 2) abandonment of a quantity of worthless fishes, which thronged into well-conditioned environments owing to deterioration in water quality and consequently became easily captured by fishermen. In October and November the kite chiefly preyed on locusts. During this period, a large number of them inhabited green belts in the airport ; thus the kite seemed to eat preferentially locusts which were easy to catch. It was concluded that the black-eared kite fed on prey animals obtained easily according to habitats and/or seasons