scholarly journals Can current farmland landscapes feed declining steppe birds? Evaluating arthropod abundance for the endangered little bustard ( Tetrax tetrax ) in cereal farmland during the chick‐rearing period: Variations between habitats and localities

2021 ◽  
Author(s):  
David González del Portillo ◽  
Beatriz Arroyo ◽  
Guillermo García Simón ◽  
Manuel B. Morales
Keyword(s):  
Tetrax Tetrax ◽  
Steppe Birds ◽  
Period Variations ◽  
Arthropod Abundance

Opposing population trajectories in two Bustard species: A long-term study in a protected area in Central Spain

2018 ◽  
Vol 29 (2) ◽  
pp. 308-320 ◽  
Author(s):  
FABIÁN CASAS ◽  
FRANÇOIS MOUGEOT ◽  
BEATRIZ ARROYO ◽  
MANUEL B. MORALES ◽  
ISRAEL HERVÁS ◽  
...  
Keyword(s):  
Protected Area ◽  
Bird Species ◽  
Population Monitoring ◽  
Population Trends ◽  
Central Spain ◽  
Great Bustard ◽  
Long Term Study ◽  
Tetrax Tetrax ◽  
Steppe Birds

SummaryIn conservation biology, population monitoring is a critical step, particularly for endangered groups, such as steppe birds in European agro-ecosystems. Long-term population monitoring allows for determination of species population trends and also provides insights into the relative roles that environmental variability and human activities have on priority species. Here, we compare the population trends of two sympatric, closely related farmland bird species, the Little Bustard Tetrax tetrax and Great Bustard Otis tarda, in a protected area of Central Spain, which is their main stronghold in Europe. Over 12 years of monitoring, the abundance of Little and Great Bustards shifted in opposite directions in our study area. Little Bustard abundance decreased significantly (both males [-56%], and harder-to-detect females [-55%]), while Great Bustard abundance increased significantly (1,800%). Future surveys should be more precise and frequent for Little Bustards to facilitate evaluation of their population status and trends. We recommend annual surveys in 2–3 important locations by region throughout the breeding range for Little Bustards, while for Great Bustard the current regional monitoring programmes would be sufficient.

On nearly-commensurable periods in the restricted problem of three bodies, with calculations of the long-period variations in the interior 2:1 case

1966 ◽  
Vol 25 ◽  
pp. 197-222 ◽  
Author(s):  
P. J. Message
Keyword(s):  
Periodic Solution ◽  
Periodic Solutions ◽  
Large Amplitude ◽  
Restricted Problem ◽  
Small Amplitude ◽  
Minor Planets ◽  
Long Period ◽  
Numerical Integrations ◽  
Period Variations ◽  
The Mean

An analytical discussion of that case of motion in the restricted problem, in which the mean motions of the infinitesimal, and smaller-massed, bodies about the larger one are nearly in the ratio of two small integers displays the existence of a series of periodic solutions which, for commensurabilities of the typep+ 1:p, includes solutions of Poincaré'sdeuxième sortewhen the commensurability is very close, and of thepremière sortewhen it is less close. A linear treatment of the long-period variations of the elements, valid for motions in which the elements remain close to a particular periodic solution of this type, shows the continuity of near-commensurable motion with other motion, and some of the properties of long-period librations of small amplitude.To extend the investigation to other types of motion near commensurability, numerical integrations of the equations for the long-period variations of the elements were carried out for the 2:1 interior case (of which the planet 108 “Hecuba” is an example) to survey those motions in which the eccentricity takes values less than 0·1. An investigation of the effect of the large amplitude perturbations near commensurability on a distribution of minor planets, which is originally uniform over mean motion, shows a “draining off” effect from the vicinity of exact commensurability of a magnitude large enough to account for the observed gap in the distribution at the 2:1 commensurability.

How to restore steppe birds’ habitat and recover its population?

2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Ernesto Aguirre–Ruiz ◽  
Martínez–Chana Luis ◽  
ópez–Onieva María ◽  
Jiménez–Valdés Alejandro ◽  
Pontes–Pazo Ángeles ◽  
...  
Keyword(s):  
Steppe Birds

An importance of soil humidification in forming of avifauna of arboreal plantation in the Biosphere reserve «Askania Nova» (un-reproductive period)

2016 ◽  
Vol 27 (3-4) ◽  
pp. 55-69
Author(s):  
M. A. Listopadsky
Keyword(s):  
Soil Moisture ◽  
Influence Factors ◽  
Data Communication ◽  
Biosphere Reserve ◽  
Reproductive Period ◽  
Defined Contribution ◽  
Separate Species ◽  
Steppe Birds ◽  
Reserve Forest ◽  
Autumn And Winter

With gradient analysis investigated the role of soil moisture in the formation of the modern population of birds in the reserve forest plantations. Soil moisture was divided into seven grades. For this purpose used grass cover and the coefficient of local moistening. His proposed PhD L. P. Travleev. This method allows knowing the degree of influence of soil moisture at the birds. We analyzed birds species composition, population, placement in space and power of influence factors (soil moisture). Investigations were carried out on the territory of the Biosphere Reserve «Askania Nova». We studied the birds which live in the reserve at the end of the summer, autumn and winter. This happened from 2006 to 2013 years. Specially was studied as permanently specific form of birds is found in a particular humidity. The degree of coupling was studied using the amount of information that transmits to the local bird humidification. For 68 species of birds are the options of the population density, coefficient koligatsii and data communication with the seven variants of soil moisture. For all kinds of set information «price» of each option dampening that contributes to the formation of a particular community of birds. Thus, the defined contribution to the formation of soil moisture forest bird communities. Species representation and density gradient within the test moisture is not in direct linear relationship from moisture and ranges from 11 (very coldly) to 50 species (moist soil). The density of the community varies from 0,5 birds / hectare (very dry) to 269 birds / hectare (fresh soil). The strongest link between the information and the formation of moisture gradient structure avifauna is typical in a fresh soil – bird on the edge, and wet – forest representatives. These types of humidification function is performed starting in the formation of two major blocks dendrophilous community. The steppe birds give way to forest representatives when the soil slightly moist. The main conclusion of our study includes the following: than wetter the soil the more species of birds lives in the forest; some graduation humidity are the most important for separate species of birds; it is very important for birds, there are places where one can drink water. Further invasive alien species can occur where the soil is moist. Forest with dry soil is already fully occupied by birds.

On the Long-Period Variations in the F2Region of the Ionosphere

1938 ◽  
Vol 26 (11) ◽  
pp. 1340-1346 ◽  
Author(s):  
Keikitiro Tani ◽  
Y. Ito ◽  
H. Sinkawa
Keyword(s):  
Long Period ◽  
Period Variations

scholarly journals Fate of unproductive and unattractive habitats: recent changes in Iberian steppes and their effects on endangered avifauna

2006 ◽  
Vol 33 (3) ◽  
pp. 223-232 ◽  
Author(s):  
PAOLA LAIOLO ◽  
JOSÉ L. TELLA
Keyword(s):  
Primary Productivity ◽  
Western Europe ◽  
Agricultural Development ◽  
Public Awareness ◽  
Species Dispersal ◽  
Ecological Value ◽  
Shrub Steppe ◽  
Steppe Birds ◽  
Dupont’S Lark ◽  
The Impact

Steppe ecosystems worldwide are affected by agricultural development and generally unprotected. Spanish shrub-steppes contain endangered avifauna, and this paper analyses their state of habitat conservation, the changes that have occurred in the last decade, primary productivity and its relationship with land exploitation and the richness of threatened birds, and avifauna responses to habitat loss. Fifty steppe remnants distributed throughout Spain and inhabited by Dupont's lark Chersophilus duponti, an endangered passerine representative of shrub steppe-like habitat, were studied. The study fragments were generally affected by agriculture exploitation, and steppe cover had significantly decreased in several isolated patches during the period 1991–1999. Steppe habitat recovered slightly in areas with low plant productivity indices, and decreased in extent in the most productive areas, in line with EU (European Union) agricultural policy recommendations to abandon marginal land of low productivity. The low overall primary productivity of Iberian steppes opened the way to industrial activities (mining, waste collection and wind-farming), which in the study areas occurred more frequently in steppe than in other habitat types that are more attractive to the public (woodland) or more productive (farmland). The emerging wind industry little affected the study plots, but the presence of anemometers suggests that the impact is likely to increase in the near future, especially in the largest steppelands. Dupont's lark was sensitive to the fragmentation of its habitat; crowding occurred in isolated and small fragments, possibly as a consequence of habitat constraints and species dispersal dynamics. Fragments inhabited by Dupont's lark also hosted other steppe birds with a high conservation value; the community of endangered birds, mostly adapted to arid conditions, was richest in the less productive sites. Only four shrub-steppe fragments are given some kind of protection throughout Spain, testifying to the limited public awareness about the value of this habitat. Urgent action is required to restore this habitat through abandonment of less productive farmland, and to create a network of protected and connected steppelands, in order to assure the long-term viability of steppe specialists and the preservation of a habitat that is unique in Western Europe. This should be coupled to an effort to increase social consciousness of the ecological value of steppes and arid landscapes in general.

scholarly journals Survey of period variations of superhumps in SU UMa-type dwarf novae. IX. The ninth year (2016–2017)

2017 ◽  
Vol 69 (5) ◽  
Author(s):  
Taichi Kato ◽  
Keisuke Isogai ◽  
Franz-Josef Hambsch ◽  
Tonny Vanmunster ◽  
Hiroshi Itoh ◽  
...  
Keyword(s):  
Dwarf Novae ◽  
Period Variations

Long-period variations in the magnetic field of small-scale solar structures

2016 ◽  
Vol 56 (8) ◽  
pp. 1052-1059 ◽  
Author(s):  
P. V. Strekalova ◽  
Yu. A. Nagovitsyn ◽  
A. Riehokainen ◽  
V. V. Smirnova
Keyword(s):  
Magnetic Field ◽  
Small Scale ◽  
Long Period ◽  
Period Variations ◽  
The Magnetic Field

Little Bustard (Tetrax tetrax Linnaeus, 1758) Number Observation on the Rostov Nature Reserve Grounds the Middle of 20th Century to 2020

2021 ◽  
pp. 113-121
Author(s):  
Victor A. Minoranskiy ◽  
Yulia V. Malinovskaya ◽  
Vasily I. Dankov ◽  
Sergey I. Kolesnikov
Keyword(s):  
Twentieth Century ◽  
Economic Activity ◽  
Nature Reserve ◽  
Positive Impact ◽  
Steppe Zone ◽  
Eastern European ◽  
Steppe Species ◽  
Animal Tracking ◽  
Number Of Factors ◽  
Tetrax Tetrax

The purpose of the work. Elucidation of changes in the number and distribution of little bustard (Tetrax tetrax Linnaeus, 1758) on the territory of the Rostov Nature Reserve in the 20th-21st centuries and the reasons for their transformation. Place and methods of work. The reserve is located in the arid Eastern European steppes. The authors used their own observations from 1959 and publications on Tetrax tetrax L. The materials are collected using regular route methods and animal tracking at individual sites, as well as analysis of published information. Results. The little bustard is a characteristic steppe species that historically lived on the Don land. Since the mid-twentieth century, the steppes have experienced deep anthropogenic changes, which have had a great impact on this species. Currently, the little bustard in the steppe zone is a rare species. The creation of the reserve has had a positive impact on this species. In it, the little bustard is a small breeding species, and its number is constrained by a number of factors. The intensification of economic activity in the region and the aridization of the climate make it necessary to improve environmental protection work.

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