Body mass during the spring migration period of two long-lived seabirds varies with capture date, age, sex, and natal origin

AbstractThe continental scaup population (Lesser [Aythya affinis] and Greater [A. marila] combined) has declined markedly since 1978. One hypothesis for the population decline states that reproductive success has decreased because female scaup are arriving on breeding areas in poorer body condition than they did historically (i.e. spring condition hypothesis). We tested one aspect of that hypothesis by comparing body mass and nutrient reserves (lipid, protein, and mineral) of Lesser Scaup at four locations (Louisiana, Illinois, Minnesota, and Manitoba) between the 1980s and 2000s. We found that mean body mass and lipid and mineral reserves of females were 80.0, 52.5, and 3.0 g higher, respectively, in the 2000s than in the 1980s in Louisiana; similarly, body mass and lipid and mineral reserves of males were 108.8, 72.5, and 2.5 g higher, respectively. In Illinois, mean body mass and lipid reserves of females were 88.6 and 56.5 g higher, respectively, in the 2000s than in the 1980s; similarly, body mass and lipid and mineral reserves of males were 80.6, 76.0, and 2.7 g higher, respectively. Mean body mass of females were 58.5 and 58.9 g lower in the 2000s than in the 1980s in Minnesota and Manitoba, respectively; mean body mass of males, similarly, were 40.7 g lower in Minnesota. Mean lipid reserves of females in the 2000s were 28.8 and 27.8 g lower than those in the 1980s in Minnesota and Manitoba, respectively. Mean mineral reserves of females in the 2000s were 3.2 g lower than those in the 1980s in Manitoba. Consequently, females arriving to breed in Manitoba in the 2000s had accumulated lipid reserves for 4.1 fewer eggs and mineral reserves for 0.8 fewer eggs than those arriving to breed there in the 1980s. Accordingly, our results are consistent with the spring condition hypothesis and suggest that female body condition has declined, as reflected by decreases in body mass, lipids, and mineral reserves that could cause reductions in reproductive success and ultimately a population decline.

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Inability to regain normal body mass despite extensive refuelling in great reed warblers following the trans-Sahara crossing during spring migration

Journal of Avian Biology ◽

10.1111/jav.01250 ◽

2017 ◽

Vol 48 (1) ◽

pp. 58-65 ◽

Cited By ~ 2

Author(s):

Thord Fransson ◽

Måns Karlsson ◽

Cecilia Kullberg ◽

Robert Stach ◽

Christos Barboutis

Keyword(s):

Body Mass ◽

Spring Migration ◽

Normal Body

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Cross-seasonal dynamics in body mass of male Harlequin Ducks: a strategy for meeting costs of reproduction

Canadian Journal of Zoology ◽

10.1139/z09-135 ◽

2010 ◽

Vol 88 (2) ◽

pp. 224-230 ◽

Cited By ~ 1

Author(s):

Daniel Esler ◽

Jeanine C. Bond

Keyword(s):

Body Mass ◽

Spring Migration ◽

Feeding Time ◽

Energy Reserves ◽

Costs Of Reproduction ◽

Wintering Grounds ◽

Energy Stores ◽

Harlequin Ducks ◽

Breeding Grounds ◽

Wintering Areas

Considerations of acquisition of energy for reproduction by waterfowl have disproportionately focused on females, although males also require energy for reproduction. We quantified variation in body mass of male Harlequin Ducks ( Histrionicus histrionicus (L., 1758)) on coastal wintering areas prior to spring migration, as well as on breeding grounds, to determine when and where nutrients were acquired to meet costs of reproduction. Male mass on wintering grounds increased, on average, by 45 g (7%) in the weeks prior to migration. On breeding streams, we inferred that body mass of paired males decreased with the length of time on breeding grounds. Also, on average, male mass was considerably lower on breeding streams than when they departed coastal wintering sites. We conclude that males store nutrients on marine wintering grounds for subsequent use during the breeding season. Male Harlequin Ducks are highly vigilant while on breeding streams and the associated reduction in feeding time presumably requires energy stores. We suggest that males have evolved a strategy that is at least partially “capital” for meeting costs of reproduction, in which they acquire an optimal amount of energy reserves prior to spring migration and subsequently invest them in behaviours that can enhance reproductive success.

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Diet and Preparation for Spring Migration in Captive Hermit Thrushes (Catharus Guttatus)

The Auk ◽

10.1093/auk/120.2.323 ◽

2003 ◽

Vol 120 (2) ◽

pp. 323-330

Author(s):

Jennifer A. Long ◽

Philip C. Stouffer

Keyword(s):

Body Mass ◽

Food Choice ◽

Migratory Birds ◽

Subcutaneous Fat ◽

Spring Migration ◽

Migratory Activity ◽

Fat Reserves ◽

Significant Difference ◽

Catharus Guttatus ◽

Fat Score

Abstract Seasonal changes in food choice by migratory birds often reflect changes in relative food abundance and increased energetic demand. Hermit Thrushes (Catharus guttatus) in southeastern Louisiana are highly frugivorous during winter but forage exclusively on arthropods just prior to spring migration. We hypothesized that this switch to an exclusively arthropod diet would lead to an increase in fat reserves compared to a frugivorous diet, and that fat birds would initiate migration sooner and display more migratory activity than lean birds. We tested these hypotheses on captive Hermit Thrushes maintained on either an arthropod only diet or a mixed fruit and arthropod diet and measured changes in fat score, body mass, and nocturnal migratory activity (Zugunruhe) from February to April 2000. We found that the arthropod-only treatment led to greater body mass and greater amounts of subcutaneous fat than the mixed fruit and arthropod treatment by the third week of the experiment. Despite those differences, body mass was not correlated with intensity of Zugunruhe. We also did not find a significant difference in intensity or onset of Zugunruhe between treatments. We concluded that because Hermit Thrushes are short-distance migrants, large fat reserves are not crucial for their migration. Consequently, fruit and arthropods appear to be equivalent with respect to migratory behavior.

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The familiar area hypothesis and movement patterns of wild forest reindeer in Karelia, Northern Europe

Rangifer ◽

10.7557/2.6.2.652 ◽

1986 ◽

Vol 6 (2) ◽

pp. 235 ◽

Cited By ~ 2

Author(s):

E. Pulliainen ◽

P. I. Danilov ◽

K. Heikura ◽

E. Erkinaro ◽

S. Sulkava ◽

...

Keyword(s):

Small Groups ◽

Rangifer Tarandus ◽

Movement Patterns ◽

Spring Migration ◽

Exploratory Behaviour ◽

Autumn Migration ◽

Northern Europe ◽

Migration Routes ◽

Migration Period ◽

Restricted Area

The relevance of the familiar area hypothesis to the behaviour of the wild forest reindeer (Rangifer tarandus fennicus Lönnb.) was studied in a Fenno-Soviet project by radio and field tracking of these ungulates in Karelia, Northern Europe, in 1978 - 1985. This subpopulation (500 - 600 exx.) has a tradition of overwintering in a restricted area around Lake Lentua (ca. 1000 km2). The spring migration period is shorter in length than the autumn migration. The migration routes are generally the same in autumn and spring, although exceptions occur, indicating exploratory behaviour. The large winter herds disband into small groups or lone individuals for the summertime, when this subpopulation is spread over a much wider area (ca. 5400 km2). It is concluded that the observations made support the familiar area hypothesis in all essential points.

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Effect of the Social Environment on Spring Migration Timing of a Songbird

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.715418 ◽

2021 ◽

Vol 9 ◽

Author(s):

Jessica E. Deakin ◽

Christopher G. Guglielmo ◽

Yolanda E. Morbey

Keyword(s):

Sex Ratio ◽

Social Environment ◽

Body Mass ◽

Annual Cycle ◽

Spring Migration ◽

Migratory Restlessness ◽

Migration Timing ◽

The Social ◽

Radio Transmitters ◽

Biased Sex Ratio

The influence of the social environment on the timing of the annual cycle is poorly understood. Seasonally migratory birds are under pressure to accurately time their spring migration, and throughout the annual cycle, they may experience variability of the local sex-ratio. A population-level male-biased sex ratio is predicted to advance spring migration timing in males and is attributed to the increased intra-specific competition for access to females and/or breeding territories. The present study had two goals. First, to develop a method that utilizes digitally coded radio-transmitters to quantify the activity of flocked individuals in captivity. Second, to use this method to test the hypothesis that the social environment influences the spring migration traits of male yellow-rumped warblers (Setophaga coronata coronata). To accomplish this, birds were captured in the fall in Long Point, Ontario, and transferred to the Advanced Facility for Avian Research, London, Ontario. In the winter, they were assigned to a slightly male- or female-biased treatment and housed in flocks in large free-flight rooms. Throughout the experimental period, we took body mass measurements and standardized photos to monitor body condition and molt progression. To measure locomotor activity, the birds were outfitted with digitally coded radio-transmitters in April and photo-triggered to enter a migratory phenotype. The tagged birds were released at their capture site in May and the Motus Wildlife Tracking System was used to determine stopover departure timing and migratory movements. Sex ratio did not influence body mass or molt progression. However, males from the male-biased treatment had significantly less locomotor movement than those from the female-biased treatment. Additionally, a lower proportion of males from the male-biased treatment initiated migratory restlessness, an indicator of the urge to migrate. Overall, these findings suggest that the social environment can influence behavior of songbirds, but do not support the hypothesis that a male-biased sex ratio accelerates migration.

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Body Condition and Fat Score in Local and Passage Populations of the Great Reed Warbler (Acrocephalus arundinaceus) During the Spring Migration in NE Bulgaria

Ring ◽

10.2478/v10050-008-0025-y ◽

2005 ◽

Vol 27 (2) ◽

pp. 137-143 ◽

Cited By ~ 1

Author(s):

Pavel Zehtindjiev

Keyword(s):

Body Mass ◽

Body Condition ◽

Spring Migration ◽

The Body ◽

Great Reed Warbler ◽

Acrocephalus Arundinaceus ◽

Reed Warbler ◽

Field Methods ◽

Field Station ◽

Fat Score

Body Condition and Fat Score in Local and Passage Populations of the Great Reed Warbler (Acrocephalus arundinaceus) During the Spring Migration in NE Bulgaria The fat level and the body mass of local Great Reed Warblers in the Kalimok Field Station, NE Bulgaria (41°00'N, 26°26'E) were compared with those of passing birds. During the springs of 1998-2004, 591 individuals of this species were mist-netted and handled according to the guidelines in the Manual of Field Methods (ESF project) and to the South-East European Bird Migration Network (SEEN) standards. As local birds we identified 60 individuals caught at least twice in different seasons. The means of the fat score and the body mass calculated for the local birds and for the passing Great Reed Warblers were similar. Also, the time of the local birds arrival and the passage of the species in the region studied coincided. Therefore, we suggest that the southern and northern populations have equal potentials for realization of their migratory state and birds from southern populations could spread in spring to the north, being an important interregional gene flow in Great Reed Warblers.

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Difference in Migration Pattern Between Adult and Immature Birds Using Satellites

The Auk ◽

10.1093/auk/119.3.832 ◽

2002 ◽

Vol 119 (3) ◽

pp. 832-835

Author(s):

Mutsuyuki Ueta ◽

Hiroyoshi Higuchi

Keyword(s):

Spring Migration ◽

Migration Pattern ◽

Migration Routes ◽

Migration Distance ◽

Migration Period ◽

Stopover Sites ◽

Fat Stores ◽

Resting Period ◽

Total Migration

Abstract We satellite-tracked Steller's Sea Eagles (Haliaeetus pelagicus), Black-faced Spoonbills (Platalea minor), and White-naped Cranes (Grus vipio) to determine migration routes and stopover tactics of adult and immature birds. During spring migration, there were no significant differences between adult and immature birds in total migration distance and distance between stopover sites, but the migration period and resting period at stopover sites were significantly longer in immature individuals. There are two possible tactics for migrating without expending fat stores: longer rests or shorter migration distances between stopover sites. Our results suggest that immature birds try to increase fat stores by increasing time available for foraging at stopover sites.

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