AGE-RELATED DIFFERENCES IN FORAGING EFFICIENCY, MOLT, AND FAT DEPOSITION OF GRAY CATBIRDS PRIOR TO AUTUMN MIGRATION

The Condor ◽  
10.1650/7183 ◽  
2003 ◽  
Vol 105 (3) ◽  
pp. 496 ◽  
Author(s):  
Colleen Dwyer Heise ◽  
Frank R. Moore
Keyword(s):  
Fat Deposition ◽  
Autumn Migration ◽  
Foraging Efficiency ◽  
Age Related

scholarly journals Age-Related Differences in Foraging Efficiency, Molt, and Fat Deposition of Gray Catbirds Prior to Autumn Migration

The Condor ◽  
2003 ◽  
Vol 105 (3) ◽  
pp. 496-504 ◽  
Author(s):  
Colleen Dwyer Heise ◽  
Frank R. Moore
Keyword(s):  
Annual Cycle ◽  
Fat Deposition ◽  
Energy Requirements ◽  
Autumn Migration ◽  
Foraging Efficiency ◽  
Age Related ◽  
Age Dependent ◽  
Dumetella Carolinensis ◽  
Para Determinar

AbstractThe ability to satisfy the energy requirements of migration and to cope with problems that arise en route is likely to be age dependent. We studied hatch-year (HY) and after-hatch-year (AHY) Gray Catbirds (Dumetella carolinensis) to determine if differences in foraging efficiency and molt affected fat deposition prior to autumn migration. Hatch-year catbirds were less efficient foragers than AHY catbirds; however, efficiency improved with age to the extent that many HY catbirds are probably as efficient as AHY birds by the time they commence migration. We discovered age-dependent patterns of fat deposition, which probably resulted from differences in foraging efficiency and molt timing. Hatch-year catbirds began to deposit fat sooner than AHY catbirds but did so more slowly throughout the postbreeding and premigratory phases of the annual cycle. Adult catbirds did not become hyperphagic until they neared the completion of their molt, then deposited fat rapidly.Diferencias Relacionadas con la Edad en la Eficiencia de Forrajeo, Muda y Almacenamiento de Grasas en Dumetella carolinensis antes de la Migración OtoñalResumen. Es probable que la habilidad de satisfacer los requerimientos energéticos de la migración y de sobrellevar problemas surgidos durante ésta, esté relacionada con la edad. Estudiamos individuos de la especie Dumetella carolinensis en su año de eclosión (AE) y de más de un año post-eclosión (PAE) para determinar si las diferencias en la eficiencia de forrajeo y en muda afectan el almacenamiento de grasas antes de la migración otoñal. Las aves AE forrajearon menos eficientemente que las PAE, pero la eficiencia aumentó con la edad de manera que muchas aves AE eran probablemente tan eficientes como las PAE en el momento en que iniciaron la migración. Descubrimos patrones dependientes de la edad en el almacenamiento de grasas, que probablemente fueron el resultado de las diferencias en la eficiencia de forrajeo y el momento de la muda. Los individuos AE comenzaron a almacenar grasas antes que los PAE, pero lo hicieron a una tasa menor a lo largo de las fases postreproductiva y premigratoria del ciclo anual. En cambio, las aves adultas no se volvieron hiperfágicas hasta que estaban cerca de completar la muda; luego, almacenaron grasas rápidamente.

scholarly journals Age-Related Changes in Molecular and Whole Muscle Function: Role of Fat Content?

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 141-141
Author(s):  
Joseph Gordon III ◽  
Nicholas Remillard ◽  
Chad Straight ◽  
Rajakumar Nagarajan ◽  
Bruce Damon ◽  
...  
Keyword(s):  
Older Adults ◽  
Molecular Mechanisms ◽  
Fat Content ◽  
Fat Deposition ◽  
Muscle Size ◽  
Type I ◽  
Contraction Velocity ◽  
Age Related ◽  
Whole Muscle ◽  
Age Related Changes

Abstract Decreases in muscle size and function are a general consequence of old age; the precise mechanisms of these changes remain unclear. Recent studies suggest that fat deposition in muscle may also contribute to dysfunction in older adults. Fat content was quantified in the quadriceps, and its effects on function in healthy young (21-45 y) and older (65-75 y) men and women (n=44) of comparable physical activity were compared. A subset of the young matched with the older group for muscle fat content were also examined. Peak fat-free whole muscle cross-sectional area (mCSA; cm2), volume (MV; cm3), fat content (fat fraction, FF; %), specific torque (Nm/mCSA) and peak contraction velocity (Nm∙s-1) were determined using fat-water magnetic resonance imaging and dynamometry (0-300□∙s-1). To examine potential molecular mechanisms of muscle weakness, vastus lateralis biopsies were obtained (n=31) and cross-bridge kinetics of type I and II fibers were determined. FF was higher in older adults than young (8.4±1.2% (SE), 7.6±1.4; p=0.03), while mCSA (48.9±10.4 vs. 64.2±17.3), MV (1536±532 vs. 2112±708), specific torque (2.6±0.4 vs. 3.2±0.4), and peak voluntary contraction velocity (422±20 vs. 441±23) were lower in older than young (p<0.01). Type II fiber myosin attachment rate was slower and attachment time longer in older muscle (p<0.017), providing a potential mechanism for the slowing of peak contraction velocity with age. Notably, differences at the whole muscle and molecular levels remained for the subset of young and older groups matched for FF, suggesting that fat deposition in muscle does not exacerbate age-related changes in function.

Malaria infection status of European Robins seems to associate with timing of autumn migration but not with actual condition

Parasitology ◽  
2019 ◽  
Vol 146 (6) ◽  
pp. 814-820
Author(s):  
Nóra Ágh ◽  
Imre Sándor Piross ◽  
Gábor Majoros ◽  
Tibor Csörgő ◽  
Eszter Szöllősi
Keyword(s):  
Avian Malaria ◽  
Arrival Time ◽  
Parasite Prevalence ◽  
Malaria Prevalence ◽  
Blood Parasites ◽  
Autumn Migration ◽  
Actual Condition ◽  
Infection Status ◽  
Stopover Site ◽  
Age Related

AbstractAvian malaria parasites can negatively affect many aspects of the life of the passerines. Though these parasites may strongly affect the health and thus migration patterns of the birds also during autumn, previous studies on avian malaria focused mainly on the spring migration and the breeding periods of the birds. We investigated whether the prevalence of blood parasites varies in relation to biometrical traits, body condition and arrival time in the European Robin (Erithacus rubecula) during autumn migration. We found no sex or age related differences in avian malaria prevalence and no relationship between infection status and body size or actual condition of the birds was found either. However, the timing of autumn migration differed marginally between infected and non-infected juveniles, so that parasitized individuals arrived later at the Hungarian stopover site. This is either because avian malaria infections adversely affect the migration timing or migration speed of the birds, or because later arriving individuals come from more distant populations with possibly higher blood parasite prevalence. The possible delay that parasites cause in the arrival time of the birds during autumn migration could affect the whole migratory strategy and the breeding success of the birds in the next season.

scholarly journals Fat-Deposition Strategies Among High-Latitude Passerine Migrants

The Auk ◽  
2005 ◽  
Vol 122 (2) ◽  
pp. 544-557
Author(s):  
Anna-Marie Benson ◽  
Kevin Winker
Keyword(s):  
Body Condition ◽  
High Latitude ◽  
Subcutaneous Fat ◽  
Time Of Day ◽  
Fat Deposition ◽  
Day Length ◽  
Long Distance ◽  
Age Related ◽  
Fat Stores ◽  
Condition Indices

Abstract We studied fat stores in passerine migrants at a high-latitude site in Fairbanks, Alaska (64°50'N, 147°50'W). We examined fat-deposition strategies during the final (spring) and initial (autumn) stages of long-distance migration, 1992–1998, to (1) improve understanding of geographic fat-deposition patterns by adding a high-latitude perspective; (2) determine whether there are age-related differences in fat-deposition strategies in autumn; and (3) test the “spring fatter” hypothesis of seasonal fat-deposition, which suggests that migrants should carry more fat in spring when they near their breeding areas than in autumn when they depart. Our analyses examined factors affecting daily fat scores during migration and compared between-season differences in fat stores among a total of 18,685 individuals of 16 migrant species. In autumn, adults had higher visible subcutaneous fat scores than immatures in 11 of 16 species. However, in all but two species, those differences were attributable to the effects of overnight low temperature, day length, and time of day, rather than age, probably because of later departures by adults. Fat scores were higher in autumn than in spring in 6 of 16 species, and body-condition indices were higher in autumn in 5 of 16 species. Only one species showed higher fat scores in spring, but that difference was not reflected in a seasonal comparison of body- condition indices. No species arrived with high fat loads in spring, and generally low fat levels in autumn suggest that high-latitude passerine migrants in North America are paying most of the energetic costs of long-distance migration with resources obtained en route to their wintering grounds. Among passerine migrants near these high-latitude breeding grounds, seasonal fat-deposition strategies appear to be responding to energetic needs at the level of daily maintenance, rather than to hypothesized insurance needs in spring or to the forthcoming needs of a long- distance migration in autumn.

Seasonal hypothermia in a large migrating bird: saving energy for fat deposition?

2001 ◽  
Vol 204 (7) ◽  
pp. 1361-1367 ◽  
Author(s):  
P.J. Butler ◽  
A.J. Woakes
Keyword(s):  
Intestinal Tract ◽  
Migratory Bird ◽  
Fat Deposition ◽  
Autumn Migration ◽  
Data Logger ◽  
Daily Cycle ◽  
Barnacle Goose ◽  
Rapid Replacement ◽  
Gastro Intestinal Tract ◽  
The Relationship

We have tested the hypothesis that a large (2 kg) migratory bird, such as the barnacle goose Branta leucopsis, becomes hypothermic before its autumn migration, when food is not scarce, but when it is necessary to conserve and/or store energy in the form of fat. Abdominal temperature (T(ab)) was measured in wild geese using an implanted data logger. Commencing a few days before and continuing until approximately 20 days after the start of their autumn migration, mean daily T(ab) fell progressively by 4.4 degrees C. Thus, it is suggested that, rather than increasing the rate of pre-migratory fattening, the energy saved as a result of this hypothermia reduces the rate at which fat is used and thus enables its more rapid replacement following and, possibly during, migration. The energy saved may also be used for the replacement of non-fat tissues such as the locomotory muscles and gastro-intestinal tract. These observations are the first of their kind from birds in their natural environment and, together with other data, demonstrate that hypothermia in endotherms is not necessarily related to extremely low environmental temperature, to shortage of food or to the resting phase of the daily cycle. The data also highlight the relationship between hypothermia and fat deposition over extended periods in relatively large, endothermic animals and may have some relevance to obesity in humans.

Age-related fat deposition in multifidus muscle could be a marker for nonalcoholic fatty liver disease

2009 ◽  
Vol 45 (2) ◽  
pp. 218-224 ◽  
Author(s):  
Yoichiro Kitajima ◽  
Yuichiro Eguchi ◽  
Eriko Ishibashi ◽  
Shunya Nakashita ◽  
Shigehisa Aoki ◽  
...  
Keyword(s):  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
Fat Deposition ◽  
Multifidus Muscle ◽  
Nonalcoholic Fatty Liver ◽  
Age Related

Within-season and age-related patterns of reproductive performance in female tree swallows (Tachycineta bicolor)

1988 ◽  
Vol 66 (4) ◽  
pp. 827-834 ◽  
Author(s):  
Bridget J. Stutchbury ◽  
Raleigh J. Robertson
Keyword(s):  
Clutch Size ◽  
Breeding Season ◽  
Reproductive Performance ◽  
Tachycineta Bicolor ◽  
Foraging Efficiency ◽  
Tree Swallows ◽  
Age Classes ◽  
Age Related ◽  
Female Tree ◽  
Second Year

In many species of birds, clutch size decreases as the season progresses, but this is confounded by the fact that young birds not only often have smaller clutches but also breed later than older females. We examined the effect of time of season on clutch size, hatching success, and fledging success of female tree swallows (Tachycineta bicolor) in their second year (SY) and after their second year (ASY), and compared their reproductive performance while controlling for time of season. For both SY and ASY females, clutch size decreased significantly with later first egg dates, which caused number hatched and number fledged per brood to also decline as the season progressed. However, neither the proportion of eggs hatched nor the proportion of young fledged was correlated with first egg date. The within-season decline in clutch size was not due simply to replacement clutches or female age, and we argue that it is also not due to a decrease in food abundance over the breeding season. Age-related differences in reproductive success depended on the time of season. Early in the breeding season, ASY females were superior to SY females in every measure of reproductive performance; however, there were no significant differences between age-classes late in the season. ASY females were more successful than SY females in raising clutches of five or six eggs, which were most common early in the season, but there was no difference between age-classes in raising clutches of four eggs. We suggest that an age-related difference in foraging efficiency and within-season changes in the cost of competition could explain this pattern.

Does the first pregnancy precipitate age-related fat deposition?

2002 ◽  
Vol 26 (9) ◽  
pp. 1274-1276 ◽  
Author(s):  
H Friis ◽  
E Gomo ◽  
P Kæstel ◽  
N Nyazema ◽  
P Ndhlovu ◽  
...  
Keyword(s):  
Fat Deposition ◽  
Age Related
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