The skylight polarization patterns at dusk affect the orientation behavior of blackcaps,Sylvia atricapilla

1989 ◽  
Vol 76 (5) ◽  
pp. 227-229 ◽  
Author(s):  
A. J. Helbig ◽  
W. Wiltschko
Keyword(s):  
Orientation Behavior ◽  
Sylvia Atricapilla ◽  
Skylight Polarization

scholarly journals Sex and age-specific differences in wing pointedness and wing length in blackcaps Sylvia atricapilla migrating through the southern Baltic coast

2020 ◽  
Author(s):  
Agnieszka Ożarowska ◽  
Grzegorz Zaniewicz ◽  
Włodzimierz Meissner
Keyword(s):  
Wing Length ◽  
Sub Saharan Africa ◽  
Migration Route ◽  
Sylvia Atricapilla ◽  
Climatic Effects ◽  
Migration Distance ◽  
Baltic Coast ◽  
Southern Baltic ◽  
Sub Saharan ◽  
Migrating Birds

Abstract The blackcap Sylvia atricapilla shows a complex migratory pattern and is a suitable species for the studies of morphological migratory syndrome, including adaptations of wing shape to different migratory performance. Obligate migrants of this species that breed in northern, central, and Eastern Europe differ by migration distance and some cover shorter distance to the wintering grounds in the southern part of Europe/North Africa or the British Isles, although others migrate to sub-Saharan Africa. Based on ˃40 years of ringing data on blackcaps captured during autumn migration in the Southern Baltic region, we studied age- and sex-related correlations in wing pointedness and wing length of obligate blackcap migrants to understand the differences in migratory behavior of this species. Even though the recoveries of blackcaps were scarce, we reported some evidence that individuals which differ in migration distance differed also in wing length. We found that wing pointedness significantly increased with an increasing wing length of migrating birds, and adults had longer and more pointed wings than juvenile birds. This indicates stronger antipredator adaptation in juvenile blackcaps than selection on flight efficiency, which is particularly important during migration. Moreover, we documented more pronounced differences in wing length between adult and juvenile males and females. Such differences in wing length may enhance a faster speed of adult male blackcaps along the spring migration route and may be adaptive when taking into account climatic effects, which favor earlier arrival from migration to the breeding grounds.

Measurements of skylight polarization: a case study in urban region with high-loading aerosol

2015 ◽  
Vol 54 (4) ◽  
pp. B256 ◽  
Author(s):  
Lianghai Wu ◽  
Jun Gao ◽  
Zhiguo Fan ◽  
Jun Zhang
Keyword(s):  
High Loading ◽  
Urban Region ◽  
Skylight Polarization

Song rate as a signal for nest site quality in blackcaps (Sylvia atricapilla)

1995 ◽  
Vol 37 (6) ◽  
pp. 399-405 ◽  
Author(s):  
M. Hoi-Leitner ◽  
H. Nechtelberger ◽  
H. Hoi
Keyword(s):  
Nest Site ◽  
Site Quality ◽  
Sylvia Atricapilla ◽  
Song Rate

scholarly journals Circuit Motifs for Spatial Orientation Behaviors Identified by Neural Network Optimization

2007 ◽  
Vol 98 (2) ◽  
pp. 888-897 ◽  
Author(s):  
N. A. Dunn ◽  
J. S. Conery ◽  
S. R. Lockery
Keyword(s):  
Spatial Orientation ◽  
Network Optimization ◽  
Hill Climbing ◽  
Spatial Gradient ◽  
Orientation Behavior ◽  
Neuronal Connectivity ◽  
Neural Network Optimization ◽  
Intermediate Point ◽  
Type Of Behavior ◽  
Acting In Concert

Spatial orientation behavior is universal among animals, but its neuronal basis is poorly understood. The main objective of the present study was to identify candidate patterns of neuronal connectivity (motifs) for two widely recognized classes of spatial orientation behaviors: hill climbing, in which the organism seeks the highest point in a spatial gradient, and goal seeking, in which the organism seeks an intermediate point in the gradient. Focusing on simple networks of graded processing neurons characteristic of Caenorhabditis elegans and other nematodes, we used an unbiased optimization algorithm to seek values of neuronal time constants, resting potentials, and synaptic strengths sufficient for each type of behavior. We found many different hill-climbing and goal-seeking networks that performed equally well in the two tasks. Surprisingly, however, each hill-climbing network represented one of just three fundamental circuit motifs, and each goal-seeking network comprised two of these motifs acting in concert. These motifs are likely to inform the search for the real circuits that underlie these behaviors in nematodes and other organisms.

Nocturnal activity and orientation behavior during spring migration and early summer in the indigo bunting,Passerina cyanea

1980 ◽  
Vol 137 (1) ◽  
pp. 47-49 ◽  
Author(s):  
Wolfgang Wiltschko ◽  
Roswitha Wiltschko ◽  
Stephan T. Emlen ◽  
Natalie J. Demong
Keyword(s):  
Early Summer ◽  
Spring Migration ◽  
Orientation Behavior ◽  
Nocturnal Activity ◽  
Passerina Cyanea
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