scholarly journals Males migrate farther than females in a differential migrant: an examination of the fasting endurance hypothesis

2014 ◽  
Vol 1 (4) ◽  
pp. 140346 ◽  
Author(s):  
Elizabeth A. Gow ◽  
Karen L. Wiebe
Keyword(s):  
Parental Care ◽  
Intraspecific Variation ◽  
Experimental Studies ◽  
Light Level ◽  
Migration Distance ◽  
Individual Fitness ◽  
The North ◽  
Breeding Populations ◽  
Migration Strategies ◽  
And Migration

Patterns of migration including connectivity between breeding and non-breeding populations and intraspecific variation in the distance travelled are important to study because they can affect individual fitness and population dynamics. Using data from 182 band recoveries across North America and 17 light-level geolocators, we examined the migration patterns of the northern flicker ( Colaptes auratus ), a migratory woodpecker. This species is unusual among birds because males invest more in parental care than females. Breeding latitude was positively correlated to migration distance because populations in the north appeared to travel farther distances than southern populations to find wintering locations with little snow cover. Connectivity was strong for populations west and east of the Continental Divide. Contrary to the three main hypotheses for intraspecific variation in migration distance, females wintered, on average, farther north than males, although there was overlap throughout their non-breeding range. This pattern contradicts those of other species found to date and is most consistent with the fasting endurance hypothesis if investment in parental care depletes the energy reserves of male flickers more than females. We thus propose a new factor, parental effort, which may influence optimal wintering areas and migration strategies within birds, and encourage future experimental studies to test the relationship between parental care roles and migration strategies of the sexes.

The relationship between annual survival rate and migration distance in mallards: an examination of the time-allocation hypothesis for the evolution of migration

1992 ◽  
Vol 70 (10) ◽  
pp. 2021-2027 ◽  
Author(s):  
Jay B. Hestbeck ◽  
James D. Nichols ◽  
James E. Hines
Keyword(s):  
Survival Rate ◽  
Production Rate ◽  
Time Allocation ◽  
Negative Relationship ◽  
Analysis Of Covariance ◽  
Migration Distance ◽  
Breeding Populations ◽  
Wintering Areas ◽  
Migration Chronology ◽  
And Migration

Predictions of the time-allocation hypothesis were tested with several a posteriori analyses of banding data for the mallard (Anas platyrhynchos). The time-allocation hypothesis states that the critical difference between resident and migrant birds is their allocation of time to reproduction on the breeding grounds and survival on the nonbreeding grounds. Residents have higher reproduction and migrants have higher survival. Survival and recovery rates were estimated by standard band-recovery methods for banding reference areas in the central United States and central Canada. A production-rate index was computed for each reference area with data from the U.S. Fish and Wildlife Service May Breeding Population Survey and July Production Survey. An analysis of covariance was used to test for the effects of migration distance and time period (decade) on survival, recovery, and production rates. Differences in migration chronology were tested by comparing direct-recovery distributions for different populations during the fall migration. Differences in winter locations were tested by comparing distributions of direct recoveries reported during December and January. A strong positive relationship was found between survival rate and migration distance for 3 of the 4 age and sex classes. A weak negative relationship was found between recovery rate and migration distance. No relationship was found between production rate and migration distance. During the fall migration, birds from the northern breeding populations were located north of birds from the southern breeding populations. No pattern could be found in the relative locations of breeding and wintering areas. Although our finding that survival rate increased with migration distance was consistent with the time-allocation hypothesis, our results on migration chronology and location of wintering areas were not consistent with the mechanism underlying the time-allocation hypothesis. Neither this analysis nor other recent studies of life-history characteristics of migratory and resident birds supported the time-allocation hypothesis.

scholarly journals Population specific annual cycles and migration strategies in a leap-frog migrant

2021 ◽  
Vol 76 (1) ◽  
Author(s):  
Linus Hedh ◽  
Juliana Dänhardt ◽  
Anders Hedenström
Keyword(s):  
Annual Cycle ◽  
Light Level ◽  
Complex Interaction ◽  
Breeding Area ◽  
Annual Cycles ◽  
Breeding Populations ◽  
Migration Strategies ◽  
Migratory Population ◽  
Migratory Strategies ◽  
Specific Timing

Abstract A common migratory pattern in birds is that northerly breeding populations migrate to more southerly non-breeding sites compared to southerly breeding populations (leap-frog migration). Not only do populations experience differences in migration distances, but also different environmental conditions, which may vary spatiotemporally within their annual cycles, creating distinctive selective pressures and migratory strategies. Information about such adaptations is important to understand migratory drivers and evolution of migration patterns. We use light-level geolocators and citizen science data on regional spring arrivals to compare two populations of common ringed plover Charadrius hiaticula breeding at different latitudes. We (1) describe and characterize the annual cycles and (2) test predictions regarding speed and timing of migration. The northern breeding population (NBP) wintered in Africa and the southern (SBP) mainly in Europe. The annual cycles were shifted temporally so that the NBP was always later in all stages. The SBP spent more than twice as long time in the breeding area, but there was no difference in winter. The NBP spent more time on migration in general. Spring migration speed was lower in the SBP compared to autumn speed of both populations, and there was no difference in autumn and spring speed in the NBP. We also found a larger variation in spring arrival times across years in the SBP. This suggests that a complex interaction of population specific timing and variation of breeding onset, length of breeding season, and proximity to the breeding area shape the annual cycle and migratory strategies. Significance statement Migration distance, climate, and the resulting composition of the annual cycle are expected to influence migration strategies and timing in birds. Testing theories regarding migration behaviours are challenging, and intraspecific comparisons over the full annual cycle are still rare. Here we compare the spatiotemporal distributions of two latitudinally separated populations of common ringed plovers using light-level geolocators. We found that there was a larger long-term variation in first arrival dates and that migration speed was slower only in spring in a temperate, short-distance migratory population, compared to an Arctic, long-distance migratory population. This suggests that a complex interaction of population specific timing and variation of breeding onset, length of breeding season and proximity to the breeding area shape the annual cycle and migratory behaviours.

DIET QUALITY OF MOROCCAN ADOLESCENTS LIVING IN MOROCCO AND IN SPAIN

2016 ◽  
Vol 49 (2) ◽  
pp. 173-186 ◽  
Author(s):  
M. Del Pilar Montero ◽  
Ana Isabel Mora-Urda ◽  
Karim Anzid ◽  
Mohamed Cherkaoui ◽  
M. Dolores Marrodan
Keyword(s):  
Diet Quality ◽  
Eating Habits ◽  
Meat Consumption ◽  
Negative Consequences ◽  
The North ◽  
Socioeconomic Changes ◽  
Cholesterol Intake ◽  
Growth Development ◽  
And Migration

SummaryIntra-population socioeconomic changes and migration are powerful factors in changing eating habits. Changes in eating habits could affect the nutritional status, growth, development and health of adolescents. The aim of this study was to compare the diet of adolescents of Moroccan origin living in Spain with that of adolescents living in Morocco. The sample comprised 428 Moroccan adolescents aged from 12 to 19 recruited in high schools: 327 living in Ouarzazate (Morocco) and 101 living in Madrid (Spain). The variables studied were energy intake (kcal/day), diet quality indicators (adherence to the Mediterranean Adequacy Index (MAI); cholesterol intake (mg/day); fibre intake (g/day) and energy profile)); and indicators of keeping traditional customs (halalmeat consumption, bread made at home). Teenagers from Morocco living in Madrid consumed more calories, proteins, saturated fats and simple sugars (p<0.001) than those living in Morocco. Their diet was of lower quality than that of their peers in Morocco. This difference was more marked in boys than in girls. Changes in eating habits associated with migration from the south to the north Mediterranean basin can benefit young migrants in an immediate way (through greater availability of energy and nutrients), but later in life it could have negative consequences for their health, increasing the risk of overweight, obesity and cardiovascular and metabolic problems.

Influence of electric field intensity, ionic strength, and migration distance on the mobility and diffusion in DNA surface electrophoresis

2006 ◽  
Vol 27 (7) ◽  
pp. 1312-1321 ◽  
Author(s):  
Bingquan Li ◽  
Xiaohua Fang ◽  
Haobin Luo ◽  
Eric Petersen ◽  
Young-Soo Seo ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Electric Field ◽  
Field Intensity ◽  
Electric Field Intensity ◽  
Migration Distance ◽  
And Migration ◽  
And Diffusion

Microhabitat use and migration distance of an endangered grassland amphibian

2013 ◽  
Vol 158 ◽  
pp. 80-87 ◽  
Author(s):  
Christopher A. Searcy ◽  
Emilio Gabbai-Saldate ◽  
H. Bradley Shaffer
Keyword(s):  
Microhabitat Use ◽  
Migration Distance ◽  
And Migration

A Taxonomic Revision of the Genus Megetra (Coleoptera: Meloidae) with Ecological and Behavioral Notes

1965 ◽  
Vol 97 (6) ◽  
pp. 561-580 ◽  
Author(s):  
Richard B. Selander
Keyword(s):  
New Species ◽  
New Mexico ◽  
Intraspecific Variation ◽  
North American ◽  
Taxonomic Revision ◽  
Seasonal Distribution ◽  
The State ◽  
Northern Arizona ◽  
The North ◽  
And Behavior

Abstract>Three species are recognized in the North American genus Megetra LeConte. The most distinctive of these anatomically and ecologically is M. cancellata (Brandt and Erichson), which ranges discontinuously from Arizona and New Mexico to the state of Hidalgo in México and occurs in limited sympatry with both of its congeners. Megetra vittata (LeConte) ranges from northern Arizona to western Texas. It appears to be strictly allopatric with, and similar ecologically to, M. punctata, new species, which ranges from southern Arizona and New Mexico to Durango, México. Specific diagnoses are made on the basis of characters of adult and, for M. cancellata and M. punctata, larval anatomy. Intraspecific variation in several adult characters is analyzed. Notes on the seasonal distribution, habitat, and behavior of the adult beetles are included.

Dynamic multi-objective optimized replica placement and migration strategies for SaaS applications in edge cloud

2019 ◽  
Vol 100 ◽  
pp. 921-937 ◽  
Author(s):  
Chunlin Li ◽  
YaPing Wang ◽  
Hengliang Tang ◽  
Youlong Luo
Keyword(s):  
Replica Placement ◽  
Multi Objective ◽  
Migration Strategies ◽  
And Migration

scholarly journals Brazilian norms for the International Affective Picture System (IAPS): comparison of the affective ratings for new stimuli between Brazilian and North-American subjects

2008 ◽  
Vol 57 (4) ◽  
pp. 270-275 ◽  
Author(s):  
Cristina Lasaitis ◽  
Rafaela Larsen Ribeiro ◽  
Orlando Francisco Amodeo Bueno
Keyword(s):  
North American ◽  
Experimental Studies ◽  
International Affective Picture System ◽  
The Self ◽  
Self Assessment ◽  
North Americans ◽  
The North ◽  
Reliable Instrument ◽  
Student’S T ◽  
Normative Ratings

OBJECTIVE: The study presents the Brazilian norms for 240 new stimuli from International Affective Picture System (IAPS), a database of affective images widely used in research, compared to the North-American normative ratings. METHODS: The participants were 448 Brazilian university students from several courses (269 women and 179 men) with mean age of 24.2 (SD = 7.8), that evaluated the IAPS pictures in the valence, arousal and dominance dimensions by the Self-Assessment Manikin (SAM) scales. Data were compared across the populations by Pearson linear correlation and Student's t-tests. RESULTS: Correlations were highly significant for all dimensions; however, Brazilians' averages for arousal were higher than North-Americans'. CONCLUSIONS: The results show stability in relation to the first part of the Brazilian standardization and they are also consistent with the North-American standards, despite minor differences relating to interpretation of the arousal dimension, demonstrating that IAPS is a reliable instrument for experimental studies in the Brazilian population.

scholarly journals Fluid–rock interactions along detachment faults during continental rifting and mantle exhumation: the case of the Urdach lherzolite body (North Pyrenees)

2020 ◽  
pp. jgs2020-116
Author(s):  
Jehiel Nteme Mukonzo ◽  
Marie-Christine Boiron ◽  
Yves Lagabrielle ◽  
Michel Cathelineau ◽  
Benoit Quesnel
Keyword(s):  
Fluid Flow ◽  
Continental Crust ◽  
Continental Rifting ◽  
Detachment Faults ◽  
The North ◽  
And Migration ◽  
Mantle Exhumation ◽  
Crucial Part

The North Pyrenean Zone corresponds to the palaeopassive margin of the North Iberia plate, at the foot of which subcontinental mantle was exhumed during Albian times. Rare bodies of exhumed mantle rocks associated with strongly sheared lenses of continental crust are scattered among the North Pyrenean Zone metasediments. Significant fluid flow occurred along a major décollement at the basement–Trias interface in the Urdach massif (Chaînons Béarnais). Fluids with a broad range of salinity (10–38 wt.% NaCl equiv.), indicative of mixing between brines and more dilute waters, produced strong silicification of breccias. The brines circulated at c. 240–280°C under lithostatic pressures at c. 6 ± 1 km depth. The fluids became increasingly saline towards the final stages. The syndeposition of Cenomano-Turonian flysch layers then progressively isolated the lower aquifers close to the décollement where Triassic brines were predominant. The release and migration of significant volumes of brines during stretching and squeezing of the Triassic evaporites played a crucial part in the mineralogical and rheological transformations that occurred during the Pyrenean Cretaceous rifting event.

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