34

Storks, which weigh 2 to 3 kg, require a daily food intake -

of approximately 570 kcal (95 g dry weight of fish), of

which 79 percent is assimilated. Nesting activities of the

individual pair of storks extend over approximately 130

days. Table 1 (from Kahl, 1963) shows the period of time

spent in each phase of reproduction.

 During the 60-65 day nesting period (from hatching to

fledging) observed by Kahl (1962), each young stork

required a total of 2.81 kg dry weight (16,802 kcal) of

fish. As the nestlings grew, relative metabolic rates

decreased from 425 kcal/kg.day during the first and second

weeks to 80 kcal/kg.day during the ninth week (Kahl, 1962).

 Kahl (1964) calculated that approximately 220,000 kcal

of food (34 kg dry weight of fish) are required by an

average Wood Stork family (2 adults and 2.25 fledglings)

during the breeding season. During the 1960-61 breeding

season, when the Corkscrew colony had 6,000 active nests,

the birds must have consumed approximately 200,000 kg dry

weight (1,200,000 kcal) of fish, which the adults collected

from ponds throughout the southwest Florida area.

 Wood Storks range up to 130 km from their rookery on

daily food gathering flights. Whenever possible, the birds

conserve energy by taking advantage of local convection

currents from which they gain altitude for gliding, or

powerless flight. Thermal lift carries Wood Storks to 1500

m In south Florida during the latter months of the dry

season.