Long necks enhance and constrain foraging capacity in aquatic vertebrates

Highly specialized diving birds display substantial dichotomy in neck length with, for example, cormorants and anhingas having extreme necks, while penguins and auks have minimized necks. We attached acceleration loggers to Imperial cormorants Phalacrocorax atriceps and Magellanic penguins Spheniscu...

Full description

Saved in:
Bibliographic Details
Published in:Proceedings of the Royal Society. B, Biological sciences Biological sciences, 2017-11, Vol.284 (1867), p.20172072-20172072
Main Authors: Wilson, Rory P., Gómez-Laich, Agustina, Sala, Juan-Emilio, Dell'Omo, Giacomo, Holton, Mark D., Quintana, Flavio
Format: Article
Language:English
Subjects:
Acceleration
Accelerometry
Animals
Aquatic Organisms - physiology
Ascent
Behaviour
Birds
Birds - anatomy & histology
Birds - physiology
Diving
Diving Birds
Energy conservation
Energy Expenditure
Energy Metabolism
Feeding Behavior
Forage
Heat loss
Models, Biological
Neck
Neck Length
Spheniscidae - anatomy & histology
Spheniscidae - physiology
Streamlining
Swimming
Vertebrates
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Highly specialized diving birds display substantial dichotomy in neck length with, for example, cormorants and anhingas having extreme necks, while penguins and auks have minimized necks. We attached acceleration loggers to Imperial cormorants Phalacrocorax atriceps and Magellanic penguins Spheniscus magellanicus, both foraging in waters over the Patagonian Shelf, to examine the difference in movement between their respective heads and bodies in an attempt to explain this dichotomy. The penguins had head and body attitudes and movements that broadly concurred throughout all phases of their dives. By contrast, although the cormorants followed this pattern during the descent and ascent phases of dives, during the bottom (foraging) phase of the dive, the head angle differed widely from that of the body and its dynamism (measured using vectorial dynamic acceleration) was over four times greater. A simple model indicated that having the head on an extended neck would allow these cormorants to half the energy expenditure that they would expend if their body moved in the way their heads did. This apparently energy-saving solution is likely to lead to greater heat loss though and would seem tenable in slow-swimming species because the loss of streamlining that it engenders would make it detrimental for fast-swimming taxa such as penguins.
ISSN:0962-8452
1471-2954
DOI:10.1098/rspb.2017.2072