scholarly journals РОЗВИТОК КОНЦЕПЦІЇ ЦІЛІСНИХ АРЕАЛІВ ПТАХІВ: АНАЛІЗ МІГРАЦІЙНИХ ШЛЯХІВ

Author(s):  
О. V. Matsyura ◽  
P. І. Gorlov ◽  
М. V. Matsyura

<p>Data on distribution and abundance of Ukraine migratory birds have nonsystematic character. Up to now there is no integrated evaluation of migratory bird populations’ status. The available information is of regional importance or it covers limited time period. Therefore, it is obvious to unite all the relevant information in order to establish monitoring program and work out the methodic on migratory birds abundance estimation concerning the Black-Mediterranean Sea Flyway.</p>

2015 ◽  
Vol 2 (12) ◽  
pp. 150347 ◽  
Author(s):  
Frank A. La Sorte ◽  
Wesley M. Hochachka ◽  
Andrew Farnsworth ◽  
Daniel Sheldon ◽  
Benjamin M. Van Doren ◽  
...  

Wind plays a significant role in the flight altitudes selected by nocturnally migrating birds. At mid-latitudes in the Northern Hemisphere, atmospheric conditions are dictated by the polar-front jet stream, whose amplitude increases in the autumn. One consequence for migratory birds is that the region’s prevailing westerly winds become progressively stronger at higher migration altitudes. We expect this seasonality in wind speed to result in migrants occupying progressively lower flight altitudes, which we test using density estimates of nocturnal migrants at 100 m altitudinal intervals from 12 weather surveillance radar stations located in the northeastern USA. Contrary to our expectations, median migration altitudes deviated little across the season, and the variance was lower during the middle of the season and higher during the beginning and especially the end of the season. Early-season migrants included small- to intermediate-sized long-distance migrants in the orders Charadriiformes and Passeriformes, and late-season migrants included large-bodied and intermediate-distance migrants in the order Anseriformes. Therefore, seasonality in the composition of migratory species, and related variation in migration strategies and behaviours, resulted in a convex–concave bounded distribution of migration altitudes. Our results provide a basis for assessing the implications for migratory bird populations of changes in mid-latitude atmospheric conditions probably occurring under global climate change.


2016 ◽  
Vol 8 (3) ◽  
Author(s):  
Azimah Abd Rahman

Climate changes especially temperature and rainfall effect the habitat selection of bird migration in mangrove area to get some food and temporary stopover. The increase and decrease of temperature and rainfall is varies between upstream to downstream. This research was done to prove that temperature and rainfall are uneven in some area even in same boundary that can give impact in habitat selection of migratory birds. This research was concern around Matang Mangrove Forest, Perak that already familiar as focal area for migratory birds. Remote Sensing application was used in this research through use of ERDAS Imagine 8.5 which is based on pixels. This application helps to model the relationship between climate, namely temperature and rainfall with distribution density of migratory birds around the study area. Climate modeling was conducted to predict the distribution of migratory bird populations in the future due to changes in temperature and rainfall over a period of 5 years and 20 years. The results of this study showed a decrease in the population of migratory birds by 6.4% for a period of 5 years and a decrease to 7.5% for the last 20 years.  Sungai Sepetang and Sungai Selinsing shown that migratory bird populations decreased continuously after 20 years. However the Sangga Besar, Teluk Kertang, Temerlok, Pulau Pasir Hitam dan Sungai Tinggi area showed an increase in the arrival of migratory birds after 20 years.  This information analysis help the related agencies in manage and maintain the area around the Matang Mangrove Forest identified potential habitat for migratory birds in the future. In addition, through this study migratory bird monitoring can be carried out systematically on a wider scope without ignoring areas that strives to be the alternative habitat for migratory birds in the future.


2001 ◽  
Vol 20 (1) ◽  
pp. 137-146 ◽  
Author(s):  
W. Robert Knechel ◽  
Jeff L. Payne

The process for providing accounting information to the public has not changed much in the last century even though the extent of disclosure has increased signifi-cantly. Sundem et al. (1996) suggest that the primary benefit of audited financial statements may not be decision usefulness but the discipline imposed by timely confirmation of previously available information. In general, the value of information from the audited financial statement will decline as the audit report lag (the time period between a company's fiscal year end and the date of the audit report) increases since competitively oriented users may obtain substitute sources of information. Furthermore, the literature on earnings quality and earnings management suggests that unexpected reporting delays may be associated with lower quality information. The purpose of this paper is to extend our understanding about the determinants of audit report lag using a proprietary database containing 226 audit engagements from an international public accounting firm. We examine three previously uninvestigated audit firm factors that potentially influence audit report lag and are controllable by the auditor: (1) incremental audit effort (e.g., hours), (2) the resource allocation of audit team effort measured by rank (partner, manager, or staff), and (3) the provision of nonaudit services (MAS and tax). The results indicate that incremental audit effort, the presence of contentious tax issues, and the use of less experienced audit staff are positively correlated with audit report lag. Further, audit report lag is decreased by the potential synergistic relationship between MAS and audit services.


2006 ◽  
Vol 2 (2) ◽  
pp. 213-216 ◽  
Author(s):  
Sylvia M Fallon ◽  
Robert C Fleischer ◽  
Gary R Graves

We tested the hypothesis that malarial parasites ( Plasmodium and Haemoproteus ) of black-throated blue warblers ( Dendroica caerulescens ) provide sufficient geographical signal to track population movements between the warbler's breeding and wintering habitats in North America. Our results from 1083 warblers sampled across the species' breeding range indicate that parasite lineages are geographically widespread and do not provide site-specific information. The wide distribution of malarial parasites probably reflects postnatal dispersal of their hosts as well as mixing of breeding populations on the wintering range. When compared to geographically structured parasites of sedentary Caribbean songbirds, patterns of malarial infections in black-throated blue warblers suggest that host–malaria dynamics of migratory and sedentary bird populations may be subject to contrasting selection pressures.


Birds ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 261-274
Author(s):  
Heather L. Bateman ◽  
Sidney B. Riddle ◽  
Erin S. Cubley

Passive acoustic recorders have been used successfully as automated survey tools to detect terrestrial wildlife. However, few studies have monitored Neotropical migratory bird use of riparian forest habitat using this technology. Within dryland ecosystems, the forests along rivers support high bird diversity. Many bird species of conservation concern require these floodplain forest habitats for foraging, migration stop-overs, and breeding. Few studies have explored the use of acoustic records in riverine systems designated for conservation for their natural resource value via the Wild and Scenic Rivers Act in the USA. Using acoustic recorders, we document vocal activity of four riparian-obligate species (Bell’s Vireo, Vireo bellii; Summer Tanager, Piranga rubra; Yellow Warbler, Setophaga petechial; and Yellow-billed Cuckoo, Coccyzus americanus) to determine species occurrence along a Wild and Scenic River. We established three study reaches along the perennial Lower Verde River, in the Sonoran Desert of central Arizona, USA. Nine acoustic recorders were used over the period of 80–120 days during the summer of 2018. We measured vegetation composition and structure in 100 m2 plots paired with acoustic recorders. Visualizing vocal activity showed that three species were calling and singing at each reach; whereas, one species, the cuckoo, had fewer recordings and occurred later in the summer. We demonstrate the utility of acoustic monitoring even when applied to rare birds in complex riparian habitats. This information is important for land management and conservation efforts concerning these species of interest and identifying important habitat features in Southwestern US riparian woodlands.


2015 ◽  
Vol 26 (1) ◽  
pp. 39-51 ◽  
Author(s):  
PERRI EASON ◽  
BASEM RABIA ◽  
OMAR ATTUM

SummaryDuring autumn migration, people set trammel nets along most of the Mediterranean coast of Egypt, with migrating Common Quail Coturnix coturnix as their primary target. These nets capture large numbers of quail, but also illegally capture other birds, which are then killed. We present the results of surveys from 2008 to 2012 along these lines of nets on the coast of North Sinai, Egypt. In desert scrub, which covers most of the Sinai coast, the mean number of quail killed reached a high of 357.1 per km per day in 2012, with a grand mean over the study period of 191.9 per km per day. Trammel nets also captured 54 other bird species in 28 families. Species captured at the highest rates in desert scrub included Corncrake Crex crex, Isabelline Wheatear Oenanthe isabellina and Greater Short-toed Lark Calandrella brachydactyla. Based on mean rates of capture from 2008 to 2012 in desert scrub and sand bar habitats, we estimate 2.0 million quail and 0.5 million birds of other species are killed annually in North Sinai during the 45 days of peak migration. In 2012, however, after the use of MP3 players to attract quail became widespread, we estimate that 3.3 million quail and 0.5 million other birds were captured. Hunters near the coast have recently begun covering shrubs and trees with mist nets to catch passerines. From 2010 to 2012, mist nets along our survey routes caught birds of 17 species in three families, with seven of these species caught only in this type of net. Hunting is likely to be a contributing factor to population declines for some species that migrate across Egypt and further studies of migratory bird hunting along the southern Mediterranean shore are badly needed.


2014 ◽  
Vol 2 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Phillip G. Post ◽  
Jeffrey T. Fairbrother ◽  
Joao A. C. Barros ◽  
J. D. Kulpa

Allowing self-control over various modes of instructional support has been shown to facilitate motor learning. Most research has examined factors that directly altered task-relevant information on a trial-to-trial basis (e.g., feedback). Recent research suggests that self-control (SC) effects extend to the manipulation of other types of factors (e.g., total number of practice trials completed). This research also illustrated that learners sometimes select a very small amount of practice when given latitude to do so. The purpose of the current study was to examine the effects of SC practice within a fixed time period on the learning of a basketball set shot. SC participants chose when to attempt each shot within two 15-min practice sessions, thereby controlling both the total number of shots taken and the spacing of shots. Yoked participants completed the same number of shots as their SC counterparts. Spacing of shots was also matched across groups. The SC group was more accurate and had higher form scores and longer preshot times during retention. These findings provided additional support for the generalizability of SC effects and extended prior research, showing that autonomy over total practice duration was not a prerequisite for the observed effects.


2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Rainer Baule ◽  
Hannes Wilke

This paper bridges two recent studies on the role of analysts to provide new and relevant information to investors. On the one hand, the contribution of analysts to long-term price discovery on the US market is rather low. Considering earnings per share forecasts as the main output of analysts’ reports, their information share amounts to only 4.6% on average. On the other hand, trading strategies set up on these EPS forecasts are quite profitable. Self-financing portfolios yield excess returns of more than 5% over the S&P 100 index for a time period of 36 years, which is persistent after controlling for the well-known risk factors. In this paper, we discuss the link between the low information shares and the high abnormal returns. We argue that information shares of analysts cannot be higher, because otherwise their forecasts would lead to excessively profitable trading strategies which are very unlikely to persist over such a long period of time.


2011 ◽  
Vol 278 (1723) ◽  
pp. 3437-3443 ◽  
Author(s):  
Colin E. Studds ◽  
Peter P. Marra

Climatic warming has intensified selection for earlier reproduction in many organisms, but potential constraints imposed by climate change outside the breeding period have received little attention. Migratory birds provide an ideal model for exploring such constraints because they face warming temperatures on temperate breeding grounds and declining rainfall on many tropical non-breeding areas. Here, we use longitudinal data on spring departure dates of American redstarts ( Setophaga ruticilla ) to show that annual variation in tropical rainfall and food resources are associated with marked change in the timing of spring departure of the same individuals among years. This finding challenges the idea that photoperiod alone regulates the onset of migration, providing evidence that intensifying drought in the tropical winter could hinder adaptive responses to climatic warming in the temperate zone.


2020 ◽  
Vol 117 (43) ◽  
pp. 26833-26841 ◽  
Author(s):  
David W. Steadman ◽  
Janet Franklin

Comparing distributional information derived from fossils with the modern distribution of species, we summarize the changing bird communities of the Bahamian Archipelago across deep ecological time. While our entire dataset consists of 7,600+ identified fossils from 32 sites on 15 islands (recording 137 species of resident and migratory birds), we focus on the landbirds from four islands with the best fossil records, three from the Late Pleistocene (∼25 to 10 ka [1,000 y ago]) and one from the Holocene (∼10 to 0 ka). The Late Pleistocene sites feature 51 resident species that have lost one or more Bahamian populations; 29 of these species do not occur in any of the younger Holocene sites (or in the Bahamas today). Of these 29 species, 17 have their closest affinities to species now or formerly living in Cuba and/or North America. A set of 27 species of landbirds, most of them extant somewhere today, was more widespread in the Bahamas in the prehistoric Holocene (∼10 to 0.5 ka) than they are today; 16 of these 27 species were recorded as Pleistocene fossils as well. No single site adequately captures the entire landbird fauna of the combined focal islands. Information from all sites is required to assess changes in Bahamian biodiversity (including endemism) since the Late Pleistocene. The Bahamian islands are smaller, flatter, lower, and more biotically depauperate than the Greater Antilles, resulting in more vulnerable bird communities.


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