North American Crane Working Group

 

Date of this Version

2001

Document Type

Article

Citation

Bergeson, Douglas G., Bradley, Mark, and Holroyd, Geoffrey L. Food items and feeding rates for wild whooping crane colts in Wood Buffalo National Park. In: Ellis, David H., ed., Proceedings of the Eighth North American Crane Workshop, 11–14 January 2000, Albuquerque, New Mexico (Seattle, Wash: North American Crane Working Group, 2001), pp. 36-39.

Comments

Reproduced by permission of the North American Crane Working Group (NACWG).

Abstract

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.