scholarly journals Patterns of spatial distribution and migration phenology of common pochards Aythya ferina in the Western Palearctic: a ring-recoveries analysis

2018 ◽  
Vol 2018 (1) ◽  
Author(s):  
Benjamin Folliot ◽  
Matthieu Guillemain ◽  
Jocelyn Champagnon ◽  
Alain Caizergues
2010 ◽  
Vol 62 (1) ◽  
pp. 107-114 ◽  
Author(s):  
B. Mickovic ◽  
M. Nikcevic ◽  
A. Hegedis ◽  
S. Regner ◽  
Z. Gacic ◽  
...  

Three localities, representing three distinct coastal areas, were investigated: 1. the mouth of the Sutorina River; 2. the mouth of the Jaska River; 3. the mouth of the Bojana River (right branch). Regarding the composition of young mullet assemblages, Lisa saliens, Lisa ramada and Lisa aurata were dominant at the first locality; L. aurata and Chelon labrosus at the second; and at the third L. ramada was clearly dominant, Mugil cephalus occupied the subdominant position, while L. aurata was absent. The seasons of the first appearance of migratory fry were October, April, November, October and July, for M. cephalus, C. labrosus, L. ramada, L. aurata and L. saliens, respectively. Migratory periods varied from 2 (C. labrosus) to 7 (L. ramada) months.


Ibis ◽  
2019 ◽  
Vol 162 (2) ◽  
pp. 373-380 ◽  
Author(s):  
Chris P. F. Redfern ◽  
Richard M. Bevan

Parasitology ◽  
1991 ◽  
Vol 103 (1) ◽  
pp. 77-83 ◽  
Author(s):  
M. Y. Xia ◽  
J. Jourdane

The routes of penetration and the strategies of invasion of Schistosoma japonicum miracidia in the snail vector Oncomelania hupensis were observed in a histological study. In all species of the genus Schistosoma, it is usually assumed that the miracidia achieve penetration through the tegument. Our results showed that at least 57% of S. japonicum miracidia penetrated the snail by natural openings (branchial cavity, mouth and rectum). Throughout the invasion phase, the larvae were observed in all the tissues and organs with the exception of the genital gland. The spatial distribution of parasites in the snail revealed that the migration towards the visceral organs such as the kidney, heart and sinuses (which are the most usual microhabitats of the mother sporocysts of S. japonicum) appeared to take place via the circulatory system. Using natural openings as routes for penetration probably provides a selective advantage in a host–parasite system in which the target mollusc is amphibious: we presume that the miracidia inside these natural openings are protected against desiccation when the snail leaves the water, and that they can subsequently invade the tissues.


Geophysics ◽  
1998 ◽  
Vol 63 (4) ◽  
pp. 1177-1183 ◽  
Author(s):  
Anat Canning ◽  
Gerald H. F. Gardner

The acquisition patterns of 3-D surveys often have a significant effect on the results of dip moveout (DMO) or prestack migration. When the spatial distribution of input traces is irregular, results from DMO and migration are contaminated by artifacts. In many cases, the footprint of the acquisition patterns can be seen on the migrated section and may result in incorrect interpretation. This phenomena also has a very significant effect on the feasibility of conducting amplitude variation with offset (AVO) analysis after 3-D prestack migration or after 3-D DMO, and also may affect velocity analysis. We propose a simple enhancement to migration and DMO programs that acts to minimize acquisition artifacts.


Author(s):  
Clarissa O. Santos ◽  
Jonathan M. Branco ◽  
Maria C. T. D. Belotti ◽  
Pedro Abilleira ◽  
Joe Siegrist ◽  
...  

2019 ◽  
Vol 47 (2) ◽  
pp. 131-139
Author(s):  
O. V. Maltseva

This study explores the socio-tribal organization of the Nanai living near Lake Bolon, with reference to environment and migration, using published and unpublished sources, S.K. Patkanov’s statistical materials, and our field data. We employ D.N. Anuchin’s spatial distribution and variation method for reconstructing the settlement pattern and assessing the socio-tribal structure with regard to the contacts between sedentary and nomadic populations. The Lake Bolon area is a transit territory traversed by reindeer herders and hunters on their way to the Pacifi c coast, and the place from whence the Amur natives migrated in various directions. This is where the herding, hunting, and fi shing traditions merged. The Nanai settlers selected places that matched their economic specialization, and these places eventually acquired symbolic functions. Small populations merged, adapted, and borrowed the names of large territorial groups. Marital contacts and kinship ties are analyzed in detail. Social relationships were regulated by the Dokha institute: clans concluded alliances based on mutual aid. Intermarriage was allowed only after several generations. The analysis of exogamous clans such as Hodzher, Odzyal, Kileh, and Beldy, which had settled near the lake, and the interviewing of the natives suggest that along with the Tungus patrilineal kinship, the matrilineal system predating the Tungus expansion was still practiced.


2015 ◽  
Vol 39 (3) ◽  
pp. 553-563 ◽  
Author(s):  
David S. Jachowski ◽  
Todd Katzner ◽  
Jane L. Rodrigue ◽  
W. Mark Ford

2020 ◽  
Vol 12 (16) ◽  
pp. 6645
Author(s):  
Qianqian Liu ◽  
Gulimire Hanati ◽  
Sulitan Danierhan ◽  
Guangming Liu ◽  
Yin Zhang ◽  
...  

Soil salinity is an active and complex part of soil property in arid and semiarid irrigation areas that restricts the sustainability of agriculture production. Knowledge of seasonal distributions and migration of soil salinity is important for the management of agriculture. In this study, three-dimensional (3-D) geostatistical methods were used to construct seasonal 3-D spatial distribution maps of soil salinity, and then the quantitative analysis methods were used to study the seasonal accumulation patterns of soil salinity for the 0–150 cm soil depth in cold and semiarid irrigated rice fields. The results revealed that there were different spatial distribution and migration patterns of soil salinity in autumn 2015, spring 2016, autumn 2016, and spring 2017. The migration of soil salinity had a dispersion trend from autumn to spring, and the area of non-saline soil increased. Whereas there was an accumulation trend from spring to autumn, and the area of non-saline soil decreased. There were about 10–20% of the study area had experienced transitional changes of different soil salinity levels in different seasons. The correlation coefficient showed that there were significant positive correlations among the five depth increments (30 cm) in different seasons, and the correlations of soil salinity were higher in adjacent layers than in nonadjacent layers. The ECe values were higher in the topsoil (0–30 cm) and deeper subsoil (120–150 cm), indicating that soil soluble salts accumulated in the soil surface due to evaporation and accumulated in the bottom due to leaching and drainage. Microtopography was the major factor influencing spatial distribution of soil salinity in different seasons. The ECe values were generally higher in the swales or in areas with rather poor drainage, whereas the values were lower in relatively higher-lying slopes or that were well-drained. The results provide theoretical basis and reference for studying the variation of seasonal soil salinity in irrigated fields.


2017 ◽  
Vol 90 (6) ◽  
pp. 2375-2393 ◽  
Author(s):  
G. Bal ◽  
L. Montorio ◽  
E. Rivot ◽  
E. Prévost ◽  
J.-L. Baglinière ◽  
...  

2020 ◽  
Vol 22 (5) ◽  
pp. 1256-1265 ◽  
Author(s):  
Dong Peng ◽  
Ziyu Liu ◽  
Xinyue Su ◽  
Yaqian Xiao ◽  
Yuechen Wang ◽  
...  

The protection of Dongting Lake is important because it is an overwintering and migration route for many rare and endangered birds of East Asia and Australasia, but an assessment of heavy metal contamination in West Dongting Lake is lacking.


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