BEHAVIOR OF 'GOONEY BIRDS' ON MIDWAY ISLANDS.
Abstract
Four trips were made to Midway Islands during the early part of 1962: January 27-31; February 27 - March 3; April 12-17; and June 13-16. These were spaced so as to give opportunity to observe development of the young Albatrosses, particularly the sound signals. A fifth visit, to test the possibility of scaring flying birds with recorded sounds was made on December 8-15. Observations on the Albatrosses during the early part of the year revealed that the populations of the two species were about the same as in 1958. There was some reduction in Laysans generally in the housing area, but not serious. The first sounds produced by hatchlings of both species are juvenile-type, high-frequency Nest Calls, which are like those of the adults. Within a short time, the characteristic peeping used for food-solicitation develops, and for a few months these two calls represent the repertory of calls of the babies. Shortly after hatching, the babies exhibit defensive beak-snapping, and, as in the adults, the Black-foots also 'growl' while snapping. Within about a month, the babies throw up the head and attempt the Sky Call, but usually the motion is silent, and the true call does not appear until they are a few months old. When almost fully fledged, ready to leave the islands, the babies have the following calls: Nest Call, Food Peeping, partial Sky Call, and, in the Black-foots, defensive growling.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 16, 1964
- Accession Number
- AD0608578
Entities
People
- Hubert Frings
Organizations
- University of Hawaiʻi System