Publication Date:
2020-10-26
Description:
The squids (Teuthoidea), alone of the Cephalopoda, are important foods of albatrosses and many petrels (Procellariiformes). Yet the biology of squids is poorly known, since they are difficult to catch with mechanical devices. Cephalopod beaks dominate the food remains in stomach contents and regurgitations of many procellariiform seabirds, and can be used to identify the species of cephalopods, and to estimate their body masses. Differential digestion of smaller and less resistant beaks overemphasizes the importance of larger squids in the diet and hence overestimates mean prey mass. Mass of cephalopod prey is positively related to procellariiform body mass. There is a wide overlap in the squid prey of three albatrosses at Marion Island (46 54S, 37 45E) : the Sooty Phoebetria fusaa, Lightmantled Sooty P, palpebrata and Wandering Diomedea exulans Albatrosses. The dominant squid families in the diet of various procellariiform seabirds are listed. Procellariiform seabirds apparently feed at the sea surface at night, detecting live squid that are bioluminescent, or nonbioluminescent squid that disturb bioluminescent organisms. Dead or moribund squid scavenged at the ocean surface may be an important food source for many procellariiform seabirds. Although squid distribution is poorly known, the distribution of both squid and procellariiform seabirds may be deduced from diet analyses. Diet analyses are providing valuable data on procellariiform predator:squid prey ecology and with refinement of techniques, will allow investigation of species composition, distribution and seasonal abundance, and even growth and reproduction of squids.
Type:
Book chapter
,
NonPeerReviewed
Format:
text
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