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Intraspecific variation in avian pectoral muscle mass: constraints on maintaining manoeuvrability with increasing body mass

Dietz, Maurine; Piersma, Theunis; Hedenström, Anders LU and Brugge, Maarten (2007) In Functional Ecology 21(2). p.317-326
Abstract
1. Within a single year, long-distance migrants undergo a minimum of four cycles of fuel storage and depletion because their migrations have at least one stopover. Each cycle includes an almost twofold change in body mass (m(b)). Pervasive predation threats beg the question whether escape flight abilities keep up with such large changes in m(b). 2. We derive aerodynamic predictions how pectoral muscle mass (m(pm)) should change with m(b) to maintain constant relative flight power. 3. We tested these predictions with data on red knot Calidris canutus, a long-distance migrating wader that breeds in arctic tundra and winters in temperate and tropical coastal areas. We focused on the subspecies C. c. islandica. 4. m(pm) varied with m(b) in a... (More)
1. Within a single year, long-distance migrants undergo a minimum of four cycles of fuel storage and depletion because their migrations have at least one stopover. Each cycle includes an almost twofold change in body mass (m(b)). Pervasive predation threats beg the question whether escape flight abilities keep up with such large changes in m(b). 2. We derive aerodynamic predictions how pectoral muscle mass (m(pm)) should change with m(b) to maintain constant relative flight power. 3. We tested these predictions with data on red knot Calidris canutus, a long-distance migrating wader that breeds in arctic tundra and winters in temperate and tropical coastal areas. We focused on the subspecies C. c. islandica. 4. m(pm) varied with m(b) in a piecewise manner. In islandica knots with m(b) <= 148 g, the slope (1.06) was indistinguishable from the prediction (1.25). In heavy knots (m(b) > 148 g) the slope was significantly lower (0.63), yielding a m(pm) 0.81 times lower than predicted at pre-departure weights (210 g). 5. Manoeuvrability tests showed that above 160 g, knots were increasingly unable to make a 90 degrees angle turn. This is consistent with m(pm) being increasingly smaller than predicted. 6. Relatively low m(pm) enables savings on mass and hence flight costs, and savings on overall energy expenditure. We predict that reduced escape flight ability at high m(b) will be compensated by behavioural strategies to minimize predation risk. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
shorebird, predation, phenotypic flexibility, flight, migration
in
Functional Ecology
volume
21
issue
2
pages
317 - 326
publisher
Wiley-Blackwell
external identifiers
  • wos:000244943000016
  • scopus:33947207474
ISSN
1365-2435
DOI
10.1111/j.1365-2435.2006.01234.x
language
English
LU publication?
yes
id
766428e7-9176-48da-b825-a0211f660729 (old id 670135)
date added to LUP
2007-12-11 19:28:13
date last changed
2017-08-20 03:27:39
@article{766428e7-9176-48da-b825-a0211f660729,
  abstract     = {1. Within a single year, long-distance migrants undergo a minimum of four cycles of fuel storage and depletion because their migrations have at least one stopover. Each cycle includes an almost twofold change in body mass (m(b)). Pervasive predation threats beg the question whether escape flight abilities keep up with such large changes in m(b). 2. We derive aerodynamic predictions how pectoral muscle mass (m(pm)) should change with m(b) to maintain constant relative flight power. 3. We tested these predictions with data on red knot Calidris canutus, a long-distance migrating wader that breeds in arctic tundra and winters in temperate and tropical coastal areas. We focused on the subspecies C. c. islandica. 4. m(pm) varied with m(b) in a piecewise manner. In islandica knots with m(b) &lt;= 148 g, the slope (1.06) was indistinguishable from the prediction (1.25). In heavy knots (m(b) &gt; 148 g) the slope was significantly lower (0.63), yielding a m(pm) 0.81 times lower than predicted at pre-departure weights (210 g). 5. Manoeuvrability tests showed that above 160 g, knots were increasingly unable to make a 90 degrees angle turn. This is consistent with m(pm) being increasingly smaller than predicted. 6. Relatively low m(pm) enables savings on mass and hence flight costs, and savings on overall energy expenditure. We predict that reduced escape flight ability at high m(b) will be compensated by behavioural strategies to minimize predation risk.},
  author       = {Dietz, Maurine and Piersma, Theunis and Hedenström, Anders and Brugge, Maarten},
  issn         = {1365-2435},
  keyword      = {shorebird,predation,phenotypic flexibility,flight,migration},
  language     = {eng},
  number       = {2},
  pages        = {317--326},
  publisher    = {Wiley-Blackwell},
  series       = {Functional Ecology},
  title        = {Intraspecific variation in avian pectoral muscle mass: constraints on maintaining manoeuvrability with increasing body mass},
  url          = {http://dx.doi.org/10.1111/j.1365-2435.2006.01234.x},
  volume       = {21},
  year         = {2007},
}