Diving behaviour and diet of the blue-eyed shag at South Georgia

This paper describes a concurrent investigation of individual variation in diet, diving patterns and performance of blue-eyed shags Phalacrocorax atriceps breeding at South Georgia. Within one day individual shags exhibited 1 of 3 foraging strategies: Short diving (4 birds, all dives less than or eq...

Full description

Saved in:
Bibliographic Details
Published in:Polar biology 1992-12, Vol.12 (8), p.713-719
Main Authors: WANLESS, S, HARRIS, M. P, MORRIS, J. A
Format: Article
Language:English
Subjects:
Animal ethology
Aves
Biological and medical sciences
Fundamental and applied biological sciences. Psychology
Marine
Phalacrocorax atriceps
Psychology. Psychoanalysis. Psychiatry
Vertebrata
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This paper describes a concurrent investigation of individual variation in diet, diving patterns and performance of blue-eyed shags Phalacrocorax atriceps breeding at South Georgia. Within one day individual shags exhibited 1 of 3 foraging strategies: Short diving (4 birds, all dives less than or equal to 120 s), long diving (11 birds, all dives > 120 s) and mixed diving (15 birds, predominantly long but with a few short dives). The mean number of dives per day was significantly higher in shags that only made short dives (mean = 172.0, SE = 43.2) than birds with a mixed diving strategy (mean = 40.5, SE = 4.7) and birds that made only long dives (mean = 30.8, SE = 1.8). Diet was assessed using hard remains recovered from pellets regurgitated by the shags. Small nototheniid fish (c. 10 kJ per item) were by far the commonest prey but most pellets contained additional items.
ISSN:0722-4060
1432-2056
DOI:10.1007/BF00238872