FOOD ITEMS AND FEEDING RATES FOR WILD WHOOPING CRANE COLTS IN WOOD BUFFALO NATIONAL PARK

Food habits of 5 whooping crane (Orus americana) colts in 4 nest ponds were recorded in the days following hatching in Wood Buffalo National Park (WBNP). In total, 93 hours of observations were made from blinds that were 60-80 m away from the nest. Spotting scopes and binoculars were used to identify food items. The adults were observed bringing the following items to the colts: adult dragonflies (Libellula sp., and Aeshna sp.), fish (Culaea inconstans), diving beetles (Rhantus binotatus, Acilius semisulcatus, Oraphoderus occidentalis, and Dytiscus alaskanus), damselflies (Enallagma sp., and Lestes sp.), snails (Lymnaea stagnalis, and Helisoma sp.), a vole (Clethrionomys gapped), a leech (unidentified), and a chorus frog (Pseudacris maculata). However, the food type most commonly consumed by the colts (88% of known items, n = 156) was dragonfly nymphs. Overall, females made most of the food deliveries (63% of deliveries for all nests, n = 194). Of the 4 nests, 2 hatched both eggs. Of these, 1 second hatched colt was preyed upon prior to being fed, and the other second hatched colt received fewer feedings than its older sibling when compared at equal ages. In addition, between 1998-99, 18 whooping crane colts had transmitters attached for a whooping crane colt mortality study. Five colt carcasses were located during the mortality study and necropsies revealed that 4 (1 was too decomposed) had only dragonfly nymphs in their digestive systems

MORTALITY OF WHOOPING CRANE COLTS IN WOOD BUFFALO NATIONAL PARK, CANADA, 1997-99

Twenty-two whooping crane (Grus americana) pairs with 2 young were monitored in Wood Buffalo National Park (WBNP) over 3 years to determine causes of colt mortality. The family groups were monitored from the ground, air, and with the aid ofradioteiemetry. We attached transmitters to 18 colts: 5 (28%) fledged, 5 (28%) succumbed to cumulative effects (head trauma, stress, exposure and/or infection), 4 (22%) were lost to unknown causes (3 of these went missing after they had lost their transmitters), 2 (11%) were taken by foxes (Vulpes vulpes), 1 (5.5%) was lost to raven (Corvus corax) predation, and 1 (5.5%) died of pneumonia. Of the 22 pairs we monitored, 16 young fledged. Of these, 2 (13%) were the younger sibling