Ecology and Physiology of Fasting in King Penguin Chicks
Abstract Captive King Penguin (Aptenodytes patagonica) chicks can fast for 5 months during the subantarctic winter with a 70% decrease in body mass. To investigate the adaptive value of this remarkable resistance to starvation, we compared captive chicks with free-ranging chicks in their colony at P...
Published in: | The Auk |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Oxford University Press (OUP)
1987
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1093/auk/104.2.254 http://academic.oup.com/auk/article-pdf/104/2/254/30081485/auk0254.pdf |
id |
croxfordunivpr:10.1093/auk/104.2.254 |
---|---|
record_format |
openpolar |
spelling |
croxfordunivpr:10.1093/auk/104.2.254 2023-12-31T10:01:40+01:00 Ecology and Physiology of Fasting in King Penguin Chicks Cherel, Yves Stahl, Jean-Claude Maho, Yvon Le 1987 http://dx.doi.org/10.1093/auk/104.2.254 http://academic.oup.com/auk/article-pdf/104/2/254/30081485/auk0254.pdf en eng Oxford University Press (OUP) The Auk volume 104, issue 2, page 254-262 ISSN 0004-8038 1938-4254 Animal Science and Zoology Ecology, Evolution, Behavior and Systematics journal-article 1987 croxfordunivpr https://doi.org/10.1093/auk/104.2.254 2023-12-06T09:08:34Z Abstract Captive King Penguin (Aptenodytes patagonica) chicks can fast for 5 months during the subantarctic winter with a 70% decrease in body mass. To investigate the adaptive value of this remarkable resistance to starvation, we compared captive chicks with free-ranging chicks in their colony at Possession Island, Crozet Archipelago. The chicks in the colony, from mid-April to beginning of September (i.e. all winter) were fed only every 39 days by their parents; some were not fed at all. In spring (October-December) the surviving chicks were fed every 6 days, and their growth was completed. Overall chick mortality in the colony during the winter and subsequent spring was about 50%. Mortality was highest in October, 6 months after the beginning of the winter, and may be attributed mainly to starvation. The decrease in body mass in the free-ranging chicks was remarkably similar to that for captive birds. In both groups, three periods were characterized according to the observed changes in the daily decrease in body mass per unit body mass (dm/mdt): dm/mdt dropped during the first period (I) of 5-6 days, was minimum and steady during period II, which lasted about 4 months, and increased in period III. Blood analysis of the captive chicks indicated the three periods correspond to modifications in protein breakdown. An initial decrease in uricacidemia indicates period I is a short period of transition, marked by a decrease in protein breakdown. In period II a minimum and constant uricacidemia, in parallel with a progressive increase in ketonemia, indicates efficient protein sparing while most of the energy is derived from lipids. Period III is critical because, from a rise in uricacidemia concomitant with a decreasing ketonemia, proteins are no longer spared. The extreme resistance of King Penguin chicks to starvation in winter may be explained partly by the ability to spare proteins for several months (period II). It occurs at a growth stage when the parents' feeding visits are rare. Other laboratory and field ... Article in Journal/Newspaper Aptenodytes patagonica Possession Island Oxford University Press (via Crossref) The Auk 104 2 254 262 |
institution |
Open Polar |
collection |
Oxford University Press (via Crossref) |
op_collection_id |
croxfordunivpr |
language |
English |
topic |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics Cherel, Yves Stahl, Jean-Claude Maho, Yvon Le Ecology and Physiology of Fasting in King Penguin Chicks |
topic_facet |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
description |
Abstract Captive King Penguin (Aptenodytes patagonica) chicks can fast for 5 months during the subantarctic winter with a 70% decrease in body mass. To investigate the adaptive value of this remarkable resistance to starvation, we compared captive chicks with free-ranging chicks in their colony at Possession Island, Crozet Archipelago. The chicks in the colony, from mid-April to beginning of September (i.e. all winter) were fed only every 39 days by their parents; some were not fed at all. In spring (October-December) the surviving chicks were fed every 6 days, and their growth was completed. Overall chick mortality in the colony during the winter and subsequent spring was about 50%. Mortality was highest in October, 6 months after the beginning of the winter, and may be attributed mainly to starvation. The decrease in body mass in the free-ranging chicks was remarkably similar to that for captive birds. In both groups, three periods were characterized according to the observed changes in the daily decrease in body mass per unit body mass (dm/mdt): dm/mdt dropped during the first period (I) of 5-6 days, was minimum and steady during period II, which lasted about 4 months, and increased in period III. Blood analysis of the captive chicks indicated the three periods correspond to modifications in protein breakdown. An initial decrease in uricacidemia indicates period I is a short period of transition, marked by a decrease in protein breakdown. In period II a minimum and constant uricacidemia, in parallel with a progressive increase in ketonemia, indicates efficient protein sparing while most of the energy is derived from lipids. Period III is critical because, from a rise in uricacidemia concomitant with a decreasing ketonemia, proteins are no longer spared. The extreme resistance of King Penguin chicks to starvation in winter may be explained partly by the ability to spare proteins for several months (period II). It occurs at a growth stage when the parents' feeding visits are rare. Other laboratory and field ... |
format |
Article in Journal/Newspaper |
author |
Cherel, Yves Stahl, Jean-Claude Maho, Yvon Le |
author_facet |
Cherel, Yves Stahl, Jean-Claude Maho, Yvon Le |
author_sort |
Cherel, Yves |
title |
Ecology and Physiology of Fasting in King Penguin Chicks |
title_short |
Ecology and Physiology of Fasting in King Penguin Chicks |
title_full |
Ecology and Physiology of Fasting in King Penguin Chicks |
title_fullStr |
Ecology and Physiology of Fasting in King Penguin Chicks |
title_full_unstemmed |
Ecology and Physiology of Fasting in King Penguin Chicks |
title_sort |
ecology and physiology of fasting in king penguin chicks |
publisher |
Oxford University Press (OUP) |
publishDate |
1987 |
url |
http://dx.doi.org/10.1093/auk/104.2.254 http://academic.oup.com/auk/article-pdf/104/2/254/30081485/auk0254.pdf |
genre |
Aptenodytes patagonica Possession Island |
genre_facet |
Aptenodytes patagonica Possession Island |
op_source |
The Auk volume 104, issue 2, page 254-262 ISSN 0004-8038 1938-4254 |
op_doi |
https://doi.org/10.1093/auk/104.2.254 |
container_title |
The Auk |
container_volume |
104 |
container_issue |
2 |
container_start_page |
254 |
op_container_end_page |
262 |
_version_ |
1786804946948063232 |