Thermogenic side effects to migratory predisposition in shorebirds.
Details
Serval ID
serval:BIB_602B52507751
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Thermogenic side effects to migratory predisposition in shorebirds.
Journal
American journal of physiology. Regulatory, integrative and comparative physiology
ISSN
0363-6119 (Print)
ISSN-L
0363-6119
Publication state
Published
Issued date
03/2007
Peer-reviewed
Oui
Volume
292
Number
3
Pages
R1287-97
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Publication Status: ppublish
Abstract
In the calidrine sandpiper red knot (Calidris canutus), the weeks preceding takeoff for long-distance migration are characterized by a rapid increase in body mass, largely made up of fat but also including a significant proportion of lean tissue. Before takeoff, the pectoral muscles are known to hypertrophy in preparation for endurance flight without any specific training. Because birds facing cold environments counterbalance heat loss through shivering thermogenesis, and since pectoral muscles represent a large proportion of avian body mass, we asked the question whether muscle hypertrophy in preparation for long-distance endurance flight would induce improvements in thermogenic capacity. We acclimated red knots to different controlled thermal environments: 26 degrees C, 5 degrees C, and variable conditions tracking outdoor temperatures. We then studied within-individual variations in body mass, pectoral muscle size (measured by ultrasound), and metabolic parameters [basal metabolic rate (BMR) and summit metabolic rate (M(sum))] throughout a 3-mo period enclosing the migratory gain and loss of mass. The gain in body mass during the fattening period was associated with increases in pectoral muscle thickness and thermogenic capacity independent of thermal acclimation. Regardless of their thermal treatment, birds showing the largest increases in body mass also exhibited the largest increases in M(sum). We conclude that migratory fattening is accompanied by thermoregulatory side effects. The gain of body mass and muscle hypertrophy improve thermogenic capacity independent of thermal acclimation in this species. Whether this represents an ecological advantage depends on the ambient temperature at the time of fattening.
Keywords
Acclimatization, Animal Migration/physiology, Animals, Basal Metabolism, Body Mass Index, Charadriiformes/anatomy & histology, Charadriiformes/metabolism, Charadriiformes/physiology, Pectoralis Muscles/anatomy & histology, Pectoralis Muscles/diagnostic imaging, Seasons, Temperature, Thermogenesis/physiology, Ultrasonography
Pubmed
Web of science
Create date
08/10/2015 19:15
Last modification date
23/02/2024 15:04