TY  - THES
AU  - Agnès Lewden
PY  - 2017//
TI  - Stratégies de thermorégulation liées aux contraintes physiologiques et environnementales chez le manchot royal (Aptenodytes patagonicus)
N2  - The energetic cost of foraging activities in King Penguin (Aptenodytes patagonicus) consists to reach<br />favourable areas, realizes depth diving to attempt fish patch and resting in high latitude cold water.<br />Several studies have shown that resting in cold water could be represent a more expensive cost than<br />realized depth diving. Indeed, this paradox is probably linked with contrasting thermoregulation<br />processes. During daylight, a general hypothermia occurs and is believed to reduce energy<br />expenditure. At sunrise occurs a re-warming to normothermia, contributing to increase heat-loss<br />during the night. We hypothesise an energetic conflict between thermoregulation and digestive<br />processes. During daylight, the organism may be unable to assimilate the end product of prey<br />digestion (free fatty acids) inside the peripheral subcutaneous adipose tissues (SAT), because skin<br />is no more blood perfused. During the night, re-warming and re-connecting to blood circulation<br />peripheral tissues could be inevitable to end the assimilation of FFA inside the SAT. In a first step,<br />we have reproduced the conditions of a resting night at sea and events of rewarming skin<br />temperature, using a sea water tank in which king penguins equipped with internal temperature<br />loggers were maintained several days. In a second step, we have tested a generalisation of our<br />hypothesis studying body temperature variations on penguins fast and feed. Finally, we have<br />measured the cost to maintain normothermia in cold water with respirometry measures and<br />investigated peripheral vasodilation with body temperature variations and infrared thermography.<br />Key words: Thermoregulation – Normothermia – Seabirds – Vasodilation – Energetic
L1  - http://publi.ipev.fr/polar_references/files/yes
N1  - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=7344), last updated on Tue, 30 Nov 1999 00:00:00 +0100
ID  - AgnesLewden2017
U1  - Ph.D. thesis
ER  -