نتایج جستجو برای: migratory birds

تعداد نتایج: 55279  

Journal: :The Journal of experimental biology 2008
Ian Henshaw Thord Fransson Sven Jakobsson Johan Lind Adrian Vallin Cecilia Kullberg

Recent studies have shown that migratory thrush nightingales (Luscinia luscinia) experimentally treated with multiple changes of the magnetic field simulating a journey to their target stopover area in northern Egypt, increased fuel deposition as expected in preparation to cross the Sahara desert. To investigate the significance of food intake on the body mass changes observed, in the work desc...

Journal: :The American naturalist 2016
Adam M Fudickar Timothy J Greives Jonathan W Atwell Craig A Stricker Ellen D Ketterson

Reproductive allochrony presents a potential barrier to gene flow and is common in seasonally sympatric migratory and sedentary birds. Mechanisms mediating reproductive allochrony can influence population divergence and the capacity of populations to respond to environmental change. We asked whether reproductive allochrony in seasonally sympatric birds results from a difference in response to s...

Journal: :The American naturalist 2007
W Alice Boyle Courtney J Conway

The question of why birds migrate is still poorly understood despite decades of debate. Previous studies have suggested that use of edge habitats and a frugivorous diet are precursors to the evolution of migration in Neotropical birds. However, these studies did not explore other ecological correlates of migration and did not control for phylogeny at the species level. We tested the evolutionar...

2014
Nele Lefeldt David Dreyer Nils-Lasse Schneider Friederike Steenken Henrik Mouritsen

Migratory birds are known to use the Earth’s magnetic field as an orientation cue on their 13 tremendous journeys between their breeding and overwintering grounds. The magnetic 14 compass of migratory birds relies on the magnetic field’s inclination, i.e. the angle between 15 the magnetic field lines and the Earth’s surface. As a consequence, vertical or horizontal field 16 lines corresponding ...

1996
FRANCISCO PULIDO PETER BERTHOLD

Most migratory bird populations are composed of individuals that migrate and individuals that remain resident. While the role of ecological factors in maintaining this behavioral dimorphism has received much attention, the importance of genetic constraints on the evolution of avian migration has not yet been considered. Drawing on the recorded migratory activities of 775 blackcaps (Sylvia atric...

Journal: :Ecology 2008
Sunshine A Van Bael Stacy M Philpott Russell Greenberg Peter Bichier Nicholas A Barber Kailen A Mooney Daniel S Gruner

Insectivorous birds reduce arthropod abundances and their damage to plants in some, but not all, studies where predation by birds has been assessed. The variation in bird effects may be due to characteristics such as plant productivity or quality, habitat complexity, and/or species diversity of predator and prey assemblages. Since agroforestry systems vary in such characteristics, these systems...

Journal: :The Journal of experimental biology 2015
Nele Lefeldt David Dreyer Nils-Lasse Schneider Friederike Steenken Henrik Mouritsen

Migratory birds are known to use the Earth's magnetic field as an orientation cue on their tremendous journeys between their breeding and overwintering grounds. The magnetic compass of migratory birds relies on the magnetic field's inclination, i.e. the angle between the magnetic field lines and the Earth's surface. As a consequence, vertical or horizontal field lines corresponding to 0 or 90 d...

Journal: :Proceedings of the National Academy of Sciences 2009

Journal: :persian journal of acarology 0
ehsan mohammadi ghalehjoughi department of pathobiology, faculty of veterinary medicine, urmia university, urmia, iran mousa tavassoli department of pathobiology, faculty of veterinary medicine, urmia university, urmia, iran soraya naem department of pathobiology, faculty of veterinary medicine, urmia university, urmia, iran

migratory birds are most often responsible for the distribution of avian diseases in different areas and serve as hosts for most parasites, including ectoparasites. the aim of the present study was to record the distribution range of a mesostigmatic mite species, dermanyssus gallinae in barn swallow nests in urmia suburb, north west of iran. the samples were collected from 161 bird nests in 44 ...

2008
Colin E. Studds Peter P. Marra

Research on long-distance migratory birds has yielded some of the strongest evidence that shifts in climate are changing ecosystem processes. Much of this work has focused on understanding whether rising temperatures on temperate breeding grounds are advancing migration phenology and limiting reproductive success. However, conditions on tropical nonbreeding quarters can also shape these process...

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