Abstract
one of the most perilous times in a bird's life is the period imme- diately following fledging. "Depart- ure from the nest increases vulner- ability to predators and the elements. Unable to . fly well, the baby bird cannot easily escape predators, and the mortality rate during this period is high." (Gill 1990, p. 383). If fledglings can survive the first few days out of the nest, their survival rate improves with increasing age and strength (Skutch 1976 ).
While chicks fledging in captivity don't have to contend with predators their inexperience and general dum- siness can still get them into trouble, particularly in large planted aviaries or other mixed-species flight cages. While learning to fly (and land) safely chicks can get themselves into predicaments easily avoided by their parents, particularly if the aviary con- tains pools of water. Chicks are wizards at getting themselves wedged in plants, trapped behind food plat- forms, or tangled in hanging plants.
In addition, overly curious, friendly, or "helpful" birds in the same aviary can frighten fledglings into accidents or just keep them moving until they become exhausted. Their beleaguered parents can spend large amounts of time protecting the new fledglings, or just trying to find them. This time could be better spent feed- ing the chicks, teaching them how to get around the aviary, or getting themselves back into condition for their next breeding attempt.
References
Gill, Frank B. 1990. Omitbologv, W. H.
Freeman & Co., New York.
Skurch, Alexander F. 1976. Parent birds and their young, University of Texas Press, Au sun.
de Hamel, Richard and Ian G. McLean. 1989. Caging as a technique for rearing wild passerine birds. Journal of Wildlife Management 53:852-856. ~