scholarly journals Long-distance migrating species of birds travel in larger groups

2011 ◽  
Vol 7 (5) ◽  
pp. 692-694 ◽  
Author(s):  
Guy Beauchamp
Keyword(s):  
Body Mass ◽  
Breeding Season ◽  
Group Size ◽  
Short Distance ◽  
Selection Pressure ◽  
Group Foraging ◽  
Long Distance ◽  
Migration Distance ◽  
Evolutionary Transitions ◽  
Scant Attention

How individuals migrate over long distances is an enduring mystery of animal migration. Strong selection pressure for travelling in groups has been suggested in long-distance migrating species. Travelling in groups can reduce the energetic demands of long migration, increase navigational accuracy and favour group foraging at migratory halts. Nevertheless, this hypothesis has received scant attention. I examined evolutionary transitions in migration distance in all North American breeding species of birds. I documented 72 evolutionary shifts in migration distance in the pool of 409 species. In contrasting clades, long-distance migration, as opposed to short-distance migration, was associated with a larger travelling group size. No other transitions occurred alongside in other traits such as group size in the non-breeding season or body mass. The results suggest that larger group sizes have been beneficial in the evolution of long-distance migration in a large clade of birds.

scholarly journals Group-foraging is not associated with longevity in North American birds

2009 ◽  
Vol 6 (1) ◽  
pp. 42-44 ◽  
Author(s):  
Guy Beauchamp
Keyword(s):  
Body Mass ◽  
Group Size ◽  
North American ◽  
Life History Theory ◽  
Foraging Efficiency ◽  
Passerine Birds ◽  
Group Foraging ◽  
Evolutionary Transitions ◽  
Age At First Reproduction ◽  
First Reproduction

Group-foraging is common in many animal taxa and is thought to offer protection against predators and greater foraging efficiency. Such benefits may have driven evolutionary transitions from solitary to group-foraging. Greater protection against predators and greater access to resources should reduce extrinsic sources of mortality and thus select for higher longevity according to life-history theory. I assessed the association between group-foraging and longevity in a sample of 421 North American birds. Taking into account known correlates of longevity, such as age at first reproduction and body mass, foraging group size was not correlated with maximum longevity, with and without phylogenetic correction. However, longevity increased with body mass in non-passerine birds. The results suggest that the hypothesized changes in predation risk with group size may not correlate with mortality rate in foraging birds.

scholarly journals K → μ+μ− as a clean probe of short-distance physics

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Avital Dery ◽  
Mitrajyoti Ghosh ◽  
Yuval Grossman ◽  
Stefan Schacht
Keyword(s):  
Matrix Element ◽  
Standard Model ◽  
Short Distance ◽  
Time Dependent ◽  
Final States ◽  
Interference Effects ◽  
Fundamental Theory ◽  
Long Distance ◽  
Ckm Matrix ◽  
The Standard Model

Abstract The K → μ+μ− decay is often considered to be uninformative of fundamental theory parameters since the decay is polluted by long-distance hadronic effects. We demonstrate that, using very mild assumptions and utilizing time-dependent interference effects, ℬ(KS → μ+μ−)ℓ=0 can be experimentally determined without the need to separate the ℓ = 0 and ℓ = 1 final states. This quantity is very clean theoretically and can be used to test the Standard Model. In particular, it can be used to extract the CKM matrix element combination $$ \mid {V}_{ts}{V}_{td}\sin \left(\beta +{\beta}_s\right)\mid \approx \mid {A}^2{\lambda}^5\overline{\eta}\mid $$ ∣ V ts V td sin β + β s ∣ ≈ ∣ A 2 λ 5 η ¯ ∣ with hadronic uncertainties below 1%.

scholarly journals Limited Access to Food and Physiological Trade‐Offs in a Long‐Distance Migrant Shorebird. I. Energy Metabolism, Behavior, and Body‐Mass Regulation

2009 ◽  
Vol 82 (5) ◽  
pp. 549-560 ◽  
Author(s):  
François Vézina ◽  
Magali Petit ◽  
Deborah M. Buehler ◽  
Anne Dekinga ◽  
Theunis Piersma
Keyword(s):  
Energy Metabolism ◽  
Body Mass ◽  
Long Distance ◽  
Limited Access ◽  
Body Mass Regulation ◽  
Trade Offs ◽  
Access To Food

scholarly journals The impact of some morphological and motor characteristics in short distance running

2021 ◽  
Vol 11 (6) ◽  
pp. 109-119
Author(s):  
Q. Ramabaja ◽  
N. Rashiti ◽  
M. Shkodra ◽  
L. Ramadani
Keyword(s):  
Physical Education ◽  
Motor Skills ◽  
Short Distance ◽  
Morphological Development ◽  
Strong Impact ◽  
Distance Running ◽  
Anthropometric Parameters ◽  
Long Distance ◽  
Anthropometric Characteristics ◽  
The Impact

The knowledge of morphological development and their impact on motor skills in short-distance athletes should be one of the main concerns of athletics coaches, because any scientific research in the field of physical culture and sports is about proving the development and evaluation of anthropological characteristics which are responsible for achieving success in athletics. The purpose of this paper is to confirm the impact of some anthropometric characteristics in the execution of running speeds on short distances, specifically in running at 100, 200 and 400 meters to students aged 18 ± 6 years of the Faculty of Physical Education and Sports in Prishtina. The sample of this research has included a total of 60 students aged 18 years of the Faculty of Physical Education and Sports in Prishtina. The measurements were executed during September in the hall of the Faculty, while the 100, 200, and 400 meter runs in the stadium "Fadil Vokrri" Prishtina. The only condition that was used during the determination of the sample was: that the students are involved in regular physical education classes (and on the day of the measurement be healthy, without the flu, cold or other symptoms). The variables which are applied in this research have been 8 anthropometric variables and 3 motor-specific variables. The results obtained after their processing indicate that the impact of anthropometric variables is higher in running at 100, 200 and 400 meters. Short distance running and long distance running reduces the impact of anthropometric parameters whereas the influence of metabolic factors of energy production is increased.  These results were also confirmed using regression analysis, so that groups of predictors of anthropometric characteristics, specific motor skills that statistically significantly influenced each variable of individual criteria. The world records below the 10-second limit, in the 100 m, near the 9-meter limit, show not only the high level of sports, but also the strong impact on the growth, especially of strength indicators, speed-strength, explosive force, as main and applied motor skills in sports and athlete’s everyday life.

scholarly journals Brain regions associated with visual cues are important for bird migration

2015 ◽  
Vol 11 (11) ◽  
pp. 20150678 ◽  
Author(s):  
Orsolya Vincze ◽  
Csongor I. Vágási ◽  
Péter L. Pap ◽  
Gergely Osváth ◽  
Anders Pape Møller
Keyword(s):  
Visual Cues ◽  
Optic Lobe ◽  
Brain Size ◽  
Relative Size ◽  
Bird Species ◽  
Interspecific Variation ◽  
Brain Regions ◽  
Long Distance ◽  
Migration Distance ◽  
Whole Brain

Long-distance migratory birds have relatively smaller brains than short-distance migrants or residents. Here, we test whether reduction in brain size with migration distance can be generalized across the different brain regions suggested to play key roles in orientation during migration. Based on 152 bird species, belonging to 61 avian families from six continents, we show that the sizes of both the telencephalon and the whole brain decrease, and the relative size of the optic lobe increases, while cerebellum size does not change with increasing migration distance. Body mass, whole brain size, optic lobe size and wing aspect ratio together account for a remarkable 46% of interspecific variation in average migration distance across bird species. These results indicate that visual acuity might be a primary neural adaptation to the ecological challenge of migration.

scholarly journals Job Accessibility from a Multiple Commuting Circles Perspective Using Baidu Location Data: A Case Study of Wuhan, China

2019 ◽  
Vol 11 (23) ◽  
pp. 6696 ◽  
Author(s):  
Cai ◽  
Liu ◽  
Luo ◽  
Xing ◽  
Liu
Keyword(s):  
Urban Areas ◽  
Short Distance ◽  
Long Distance ◽  
Job Accessibility ◽  
Location Data ◽  
Job Opportunities ◽  
Transit Services ◽  
Service Jobs ◽  
Wuhan Metropolitan Area

Jobs–housing imbalance is a hot topic in urban study and has obtained many results. However, little research has overcome the limits of administrative boundaries in job accessibility measurement and considered differences in job accessibility within multiple commuting circles. Using Baidu location data, this research proposes a new method to measure job accessibility within multiple commuting circles at the grids’ level. Taking the Wuhan metropolitan area as a case study, the results are as follows: (1) Housing and service jobs are concentrated in the central urban areas along the Yangtze River, whereas industrial jobs are scattered throughout suburbs with double centers. The potential competition for job opportunities is fiercer in the city center than in the suburbs. (2) Job accessibility with different levels shows significant circle-like distribution. People with long- or short-distance potential commutes demand to live close to the groups with the same demand. Residents with long-distance commutes demand to live outside of where those with short-distance commutes demand to reside, regardless of whether their commuting demand is for service or industrial jobs. (3) There are three optimization patterns for transit services to increase job accessibility in various areas. These patterns involve areas with inadequate job opportunities, poor transit services to service jobs, and poor transit services to industrial jobs. Developing current transit facilities or new transit alternatives as well as adding extra jobs near housing could improve jobs–housing imbalance in these areas. Findings from this study could guide the allocation of jobs and housing as well as the development of transport to reduce residents’ commuting burdens and promote transportation equity. The method used in this study can be applied to evaluate jobs–housing imbalance from the perspective of the supply in other metropolises.

scholarly journals Increased EEG coherence in long‐distance and short‐distance connectivity in children with autism spectrum disorders

2020 ◽  
Vol 10 (10) ◽  
Author(s):  
Jia Wang ◽  
Xiaomin Wang ◽  
Xuelai Wang ◽  
Huiying Zhang ◽  
Yong Zhou ◽  
...  
Keyword(s):  
Autism Spectrum Disorders ◽  
Short Distance ◽  
Children With Autism ◽  
Autism Spectrum ◽  
Eeg Coherence ◽  
Long Distance ◽  
Spectrum Disorders
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