Changes in body mass and organ size during wing moult in non-breeding greylag geeseAnser anser

A method was developed for indexing moulting costs in waterfowl based on intensity of moult and proportional mass of feathers in seven feather regions (ADJMOLT). This method was then applied to an examination of relations between moulting costs and size-adjusted body mass and composition of postbreeding male and female ruddy ducks (Oxyura jamaicensis) collected in southwestern Manitoba, 30 July – 24 August 1985. Moderate to heavy moult (25 to > 50% of moulting feathers) was recorded in all feather regions. The intensity of down moult was greater in males than in females, but no differences between sexes in moult score by contour feather region, overall mean moult score, or ADJMOLT were detected. Relations between ADJMOLT and body fat (FAT), liver protein (LIVER), and size-adjusted body mass (ADJMASS), body protein (ADJPROT), and leg and breast muscle protein (ADJLEG and ADJBR, respectively) were not influenced by sex, but there was a sex effect on the relation of ADJMOLT to gizzard mass (GIZZWT). ADJPROT and ADJBR were negatively associated with ADJMOLT, whereas female GIZZWT was positively related to ADJMOLT. ADJMASS, ADJLEG, FAT, and LIVER were unrelated to ADJMOLT. Female ruddy ducks were structurally smaller and had less ADJMASS, ADJPROT, ADJLEG, and FAT than males, but there were no sex-related differences in ADJBR. I found no evidence of nutritional stress in post-breeding ruddy ducks, but argue that stress associated with moult in waterfowl is most likely to occur in females, especially small-bodied species that are primarily herbivorous.

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Non‐breeding Cackling, Ross's and Snow Geese on Baffin Island show no loss of body mass during wing moult

Ibis ◽

10.1111/ibi.12392 ◽

2016 ◽

Vol 158 (4) ◽

pp. 876-880 ◽

Cited By ~ 1

Author(s):

Anthony D. Fox ◽

James O. Leafloor ◽

Thorsten J. S. Balsby ◽

Kathryn M. Dickson ◽

Michael A. Johnson ◽

...

Keyword(s):

Body Mass ◽

Baffin Island ◽

Snow Geese ◽

Wing Moult

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Annual changes in body mass and resting metabolism in captive barnacle geese (Branta leucopsis): the importance of wing moult

Journal of Experimental Biology ◽

10.1242/jeb.004598 ◽

2007 ◽

Vol 210 (8) ◽

pp. 1391-1397 ◽

Cited By ~ 66

Author(s):

S. J. Portugal ◽

J. A. Green ◽

P. J. Butler

Keyword(s):

Body Mass ◽

Resting Metabolism ◽

Barnacle Geese ◽

Branta Leucopsis ◽

Annual Changes ◽

Wing Moult

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The diet of the coffin ray, Hypnos monopterygius (Shaw, 1795), and predation mode inferred from jaw, dentition and electric organ morphology

Marine and Freshwater Research ◽

10.1071/mf16200 ◽

2017 ◽

Vol 68 (6) ◽

pp. 1193 ◽

Cited By ~ 1

Author(s):

A.-M. Frost ◽

I. P. Jacobsen ◽

M. B. Bennett

Keyword(s):

Body Mass ◽

Electric Organ Discharge ◽

Electric Organ ◽

Stomach Contents ◽

Organ Size ◽

Teleost Fishes ◽

Marked Contrast ◽

Organ Mass ◽

Electric Organs ◽

Stomach Contents Analysis

The diet of the coffin ray, Hypnos monopterygius (Family Hypnidae), an electric ray endemic to Australia, was described on the basis of stomach contents analysis. Benthos-associated teleost fishes and cephalopod molluscs, predominantly Octopus, dominated the diet. The large, paired electric organs of this species scaled close to isometrically in relation to body mass for electric-organ area and electric-organ mass. The number of electrocyte columns that comprise each electric organ (mean=435 columns) was independent of body mass. Jaws were long and slender, and supported small tricuspidate teeth only on the central 55% of their length. Diet, electric-organ size and jaw morphology in Hypnos and the torpedoes (Family Torpedinidae) are similar, but in marked contrast to members of the numbfishes (Family Narcinidae). The differences are interpreted in relation to the use of electric-organ discharge while foraging in the former families.

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Pre-winter fattening and fat loss during wing moult: the annual cycle of fat deposition in captive barnacle geese (branta leucopsis)

10.1101/2020.04.26.062364 ◽

2020 ◽

Author(s):

Steven J. Portugal ◽

Rona A. McGill ◽

Jonathan A. Green ◽

Patrick J. Butler

Keyword(s):

Body Mass ◽

Body Fat ◽

Annual Cycle ◽

Deuterium Oxide ◽

Fat Deposition ◽

Fat Loss ◽

Barnacle Geese ◽

Branta Leucopsis ◽

Wing Moult ◽

Winter Fattening

AbstractMany different physiological changes have been observed in wild waterfowl during the flightless stage of wing moult, including a loss of body mass. Previously we established that captive barnacle geese (Branta leucopsis) underwent this characteristic decrease in body mass during their wing moult, even though they had unlimited and unrestricted access to food. In the present study we aimed to determine if this body mass loss during moult comprised mainly a reduction in fat stores, and to ascertain if the captive geese undergo pre-migratory and pre-winter fattening over a similar temporal scale to their wild conspecifics. The non-destructive technique of deuterium oxide isotope dilution was employed to provide repeated measurements of estimated fat deposition from a captive flock of fourteen barnacle geese. Birds were injected with deuterium oxide at 7 distinct intervals for one annual cycle. During the flightless period of the moult, body fat decreased by approximately 40% from the pre-moult value. During late-September and early October, body fat reached its highest point in the annual cycle, both as an absolute value and as a percentage of total body mass. We propose that while the energetic cost of wing moult is not the ultimate cause of fat loss in moulting barnacle geese, the approximate 212 g of fat catabolised during moult would provide sufficient energy to cover the cost of the replacement of the flight feathers, estimated to be 6384 kJ, over an approximate 42 day period. We conclude that the previously recorded increase in metabolism during moult in the geese, led to the use of endogenous fat reserves because the birds reduced rather than increased their food intake rates owing to the increased risk of predation when flightless. We also conclude that captive barnacle geese do undergo pre-winter and pre-migratory fattening, providing further evidence of the innate nature of these fat deposition cycles.

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Time course and reversibility of changes in the gizzards of red knots alternately eating hard and soft food

Journal of Experimental Biology ◽

10.1242/jeb.204.12.2167 ◽

2001 ◽

Vol 204 (12) ◽

pp. 2167-2173 ◽

Cited By ~ 8

Author(s):

Anne Dekinga ◽

Maurine W. Dietz ◽

Anita Koolhaas ◽

Theunis Piersma

Keyword(s):

Body Mass ◽

Time Course ◽

Organ Size ◽

Digestive Organ ◽

Food Type ◽

Calidris Canutus ◽

Non Invasive

SUMMARYThe ability to change organ size reversibly can be advantageous to birds that perform long migrations. During winter, red knots (Calidris canutus) feed on shellfish and carry a muscular gizzard that weighs 10% of their body mass. Gizzard size decreases when these birds eat soft foods, e.g. while breeding in the tundra. We studied the reversibility and time course of such changes using ultrasonography. Two groups of shellfish-adapted knots (N=9 and N=10) were fed alternately a hard and a soft food type. Diet switches elicited rapid reversible changes. Switches from hard to soft food induced decreases to 60% of initial gizzard mass within 8.5 days, while switches to hard food induced increases in gizzard mass to 147% within 6.2 days. A third group of knots (N=11), adapted to soft food for more than 1 year, initially had very small gizzards (25% of the mass of shellfish-adapted gizzards), but showed a similar capacity to increase gizzard size when fed shellfish. This is the first non-invasive study showing rapid digestive organ adjustments in non-domesticated birds.

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