Nature Ramblings: Bird Migrations

1952 ◽  
Vol 62 (17) ◽  
pp. 272
Keyword(s):  
Bird Migrations

scholarly journals Disentangling the role of Africa in the global spread of H5 highly pathogenic avian influenza

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Alice Fusaro ◽  
Bianca Zecchin ◽  
Bram Vrancken ◽  
Celia Abolnik ◽  
Rose Ademun ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Highly Pathogenic Avian Influenza ◽  
Joint Analysis ◽  
Avian Host ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
Global Spread ◽  
Bird Migrations ◽  
Virus Spreading

AbstractThe role of Africa in the dynamics of the global spread of a zoonotic and economically-important virus, such as the highly pathogenic avian influenza (HPAI) H5Nx of the Gs/GD lineage, remains unexplored. Here we characterise the spatiotemporal patterns of virus diffusion during three HPAI H5Nx intercontinental epidemic waves and demonstrate that Africa mainly acted as an ecological sink of the HPAI H5Nx viruses. A joint analysis of host dynamics and continuous spatial diffusion indicates that poultry trade as well as wild bird migrations have contributed to the virus spreading into Africa, with West Africa acting as a crucial hotspot for virus introduction and dissemination into the continent. We demonstrate varying paths of avian influenza incursions into Africa as well as virus spread within Africa over time, which reveal that virus expansion is a complex phenomenon, shaped by an intricate interplay between avian host ecology, virus characteristics and environmental variables.

scholarly journals Characteristics of bird's visible migrations at the Dniester Delta in 1974-1976

2020 ◽  
Vol 2020 (23) ◽  
pp. 60-91
Author(s):  
I. I. Chernichko ◽  
Keyword(s):  
Bird Species ◽  
Passerine Bird ◽  
Similarity Coefficient ◽  
Jaccard Index ◽  
Frequency Of Occurrence ◽  
Jaccard Similarity ◽  
Observation Site ◽  
Migration Flow ◽  
Anthropogenic Transformation ◽  
Bird Migrations

The article deals with the results of observations of diurnal bird migrations and counts on a fixed route in the spring and autumn of 1974-1976, in the Dniester Delta. The total number of observation days was 82 (32 in spring and 50 in autumn, respectively). For this period, during observations and counts on the route, 135 bird species from 11 orders were registered, the total number of which exceeded 600 000 individuals. The study of migrations was carried out according to the E. Kumari method (1955). At the observation site, 80 species were counted, including 52 in spring and 60 in autumn. The Jaccard similarity coefficient (Jaccard index) was quite low between seasons and amounted to only 0.59. The frequency of occurrence of the majority of registered species was low. This may have been due to the area of the floodplains themselves, as well as to the weak extent of their anthropogenic transformation observed in the late 70s of the 20th century, which contributed to the bird migrations over the Delta in a wide front. The density of the spring migration flow was maximum in March and averaged 1077.4 ind. (n=32) per a daylight, while the autumn migration flow was 1926.2 ind. (n=50). There were interannual differences in the density of migrations in March. In the spring of 1975, the flight density was 900.3 ind. (n=15), and in 1976 it was almost twice more and amounted to 2094.7 ind. (n=11). There were no interannual differences in the intensity of autumn migrations. The maximum migration density was 2585.2 ind. (n=23) in October. The majority of non-passerine bird species flew in the morning: in spring up to 43.8%, in autumn - 64.1%. The diurnal activity of Passeriformes varied by season: in spring, morning migrations prevailed (56.1%), and in autumn, with the same ratio in the evening (56.1%). The vast majority of flocks (87 - 90%) amounted from 1 to 50 individuals. At altitudes up to 50 m, 37.0% flew, 51-150 m – 24.9% and above 150 m – 38.1% of birds. For a number of species, it was proved that the height of their flights in the general for the season migration sector of directions was higher than in the reverse directions.127 bird species were registered on all routes, of which 106 were registered on a permanent (fixed) route. Maximum species diversity was observed in March – 85, in April − 65, in September − 60, in October − 61 and in November – 40 species. The dynamics of the species composition of birds on a fixed route can be used as an additional characteristic of day transit migrations.

scholarly journals Bird Migrations and Nesting

Blue Jay ◽  
1951 ◽  
Vol 9 (3) ◽  
Author(s):  
W. Yanchinski
Keyword(s):  
Bird Migrations

scholarly journals Fruit and berry plants of forest belts as a factor of species diversity of ornithofauna during the breeding season and autumn migration period

2020 ◽  
Vol 28 (3) ◽  
pp. 290-297
Author(s):  
V. V. Pesotskaya ◽  
A. B. Chaplygina ◽  
T. V. Shupova ◽  
R. I. Kratenko
Keyword(s):  
Migratory Birds ◽  
Food Resource ◽  
Bird Species ◽  
Migration Routes ◽  
Rosa Canina ◽  
Α Diversity ◽  
Crataegus Laevigata ◽  
Forest Belts ◽  
Bird Migrations ◽  
The Relationship

During migration, the availability of food that affects the success of bird movements, the nature and timing of their movements, is critical for many bird species. The relationship between migration routes and the ripening of fruit and berry plants along the route is important. Four types of forest belts were studied: wind-blown maple-ash, latticed maple-linden, dense oak-maple-linden, wind-blown oak-maple-poplar. During the study 43 bird species were identified consuming 9 major fruit and berry plant species: Sambucus nigra, Prunus spinosa, Crataegus laevigata, Rosa canina, Prunus padus, Sorbus aucuparia, Rhamnus cathartica, Morus nigra, Prunus cerasus. The highest average number of birds feeding in forest belts (4.14 ind./km) was registered in oak-maple-linden dense forest belts, while the lowest number (1.48 ind./km) was recorded in wind-blown maple-ash ones. Maple-linden latticed forest belts characterize the best index data of α-diversity of birds. In the summer-autumn diet, succulent fruit are the most important: Starling (Sturnus vulgaris) – 11.8% of the total number of birds observed to feed on this food resource, Greenfinch (Chloris chloris) – 11.3%, Chaffinch (Fringilla coelebs) – 9.3%, Song thrush (Turdus philomelos) – 7.3%, Hawfinch (Coccothraustes coccothraustes) – 7.1%, Blackbird (Turdus merula) – 5.4%. 42 species of birds were observed to feed on black elderberry. More than half (51.2%) of the species composition of birds feeding on fruit and berry plants were migratory birds. Consequently, juicy berries are an important food during bird migrations.

scholarly journals Reconstructing the geographic and climatic origins of long‐distance bird migrations

2019 ◽  
Vol 47 (1) ◽  
pp. 155-166 ◽  
Author(s):  
Paul Dufour ◽  
Sébastien Descamps ◽  
Stéphane Chantepie ◽  
Julien Renaud ◽  
Maya Guéguen ◽  
...  
Keyword(s):  
Long Distance ◽  
Bird Migrations

scholarly journals Spring Bird Migrations of 1903

The Auk ◽  
1904 ◽  
Vol 21 (3) ◽  
pp. 341-345 ◽  
Author(s):  
Elon Howard Eaton
Keyword(s):  
Bird Migrations

Ecology and conservation of the Milos viper, Macrovipera schweizeri (Werner, 1935)

1999 ◽  
Vol 20 (4) ◽  
pp. 355-375 ◽  
Author(s):  
Claes Andrén ◽  
Yiannis Ioannidis ◽  
Maria Dimaki ◽  
Göran Nilson
Keyword(s):  
Home Range ◽  
Total Population ◽  
Early Summer ◽  
Home Ranges ◽  
Night Time ◽  
Mating Period ◽  
Small Change ◽  
Typical Habitat ◽  
Bird Migrations ◽  
Reproductive Activities

AbstractThe Milos viper (Macrovipera schweizeri) is nocturnal from early summer until mid-September. The typical habitat was maquis terrain with small and large bushes on gravel or rocky ground. Telemetric studies showed that cryptic basking behaviour was used during 23.5% of the localisations, and a preference for large bushes (77.7%). The mean distance moved between two succeeding days was 28.5 m (with s_x, of 47.9), and in general, the male home range covered an area of 10 to 20 ha, while the female home range was smaller. Hibernacula were south facing and situated in the middle of the home ranges. Population density was 50 adult vipers per km2 in the optimal habitats. The total population for western Milos was estimated to be around 2,500 adult vipers during the study period (1993-98). The present total population on Milos seems to be below 3,000 adult animals. The species has been isolated since the Pliocene, and adapted to a diet of passerine birds. A pattern of twice-a-year foraging during spring and autumn bird migrations was highlighted. During spring, the vipers tend to be concentrated around water pools; in the dry autumn nights they climb up trees for resting birds. In years with a cold spring or autumn, critical situations may occur with starvation, resulting in cyclic population patterns. Mid-May is the mating period. The female reproductive cycle is biennial. The sex ratio is nearly equal. Around 600 specimens reach adulthood and participate in the reproductive activities each year. Mining and fires destroy habitat. The yearly estimated removal by man and road killing of vipers is up to 500-600 adult specimens. Thus, the input and out-take of adult specimens is of the same magnitude, and equal to a yearly 25% turnover. This indicates a very delicate balance, and even a small change that increases the removed number can lead towards a rapid extinction. A conservation program is urgently needed and should include the establishment of protected areas, the closing of roads for night-time driving, and prohibition of increased mining activities.

scholarly journals Seasonal Spatial Dynamics of Butterfly Migration

2020 ◽  
Author(s):  
Shawan Chowdhury ◽  
Myron Zalucki ◽  
Tatsuya Amano ◽  
Bradley Woodworth ◽  
Ruben Venegas-Li ◽  
...  
Keyword(s):  
Habitat Suitability ◽  
Extinction Risk ◽  
Spatial Dynamics ◽  
Butterfly Species ◽  
Migratory Species ◽  
Ecological Processes ◽  
Seasonal Movement ◽  
Bird Migrations ◽  
The Tropics ◽  
Conservation Interventions

Understanding the seasonal movements of migratory species underpins ecological studies. Nearly 600 butterfly species show migratory behaviour, yet the spatial pattern of these migrations is poorly understood. We developed climatic niche models for 405 migratory butterfly species globally to estimate patterns of seasonal movement and the distribution of seasonal habitat suitability. We discover strong seasonal variation in habitat suitability for most of the migratory butterflies with >75% of pixels showing seasonal change in predicted occupancy for 85% of species. In contrast to bird migrations, the greatest rate of seasonal switching occurs in the tropics. Several species showed extreme range fluctuations, exceeding 10-fold for 53 species (13%) and more than 100-fold for nine species (2%); such species may be at elevated extinction risk. Our results can be used to search for the ecological processes that underpin migration in insects, as well as to design conservation interventions for declining migratory insects.

Bird Migrations

2017 ◽  
pp. 1-12
Author(s):  
David V. Gesicki ◽  
Verner P. Bingman
Keyword(s):  
Bird Migrations
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