scholarly journals Trender i antal ringmärkta fåglar av fyrtio arter på Stora Fjäderäggs fågelstation, nordöstra Sverige, 1985–2014

Ornis Svecica ◽  
2015 ◽  
Vol 25 (3–4) ◽  
pp. 94-104
Author(s):  
Lars Edenius ◽  
Niklas Lindberg Alseryd ◽  
Sören Wulff

Very few data series are available on the long-term development of the bird fauna in northern Sweden. This kind of data is of great interest as there are recent signs that bird populations in northern Sweden are developing less favourable than in southern Sweden. We present trends in annual capture rates of 40 frequently ringed species at Stora Fjäderägg Bird Observatory, NE Sweden, autumns 1985–2014. Significant positive and negative trends were found in ten and eight species, respectively. Great tit, Chaffinch and Long-tailed Tit showed the strongest increases, whereas Northern Wheatear, Willow Tit and Bluethroat decreased the most. There was a significant negative trend in capture index for short-distance migrants and a positive trend for irruptive species/partial migrants. For many species, particularly those that were decreasing, the trends at Stora Fjäderägg are similar to population trends seen in Swedish and Finnish breeding bird surveys. For these species the trends at Stora Fjäderägg could be indicative of long-term population changes.

Author(s):  
Carmen Gache

Bird fauna long-term monitoring in the Romanian lower Prut river basin In the present paper, we give data on the bird' fauna's dynamic during the last 18 years in the Romanian Lower Prut River basin. This valley shelters a good level of the biodiversity being very well protected through the border status, but due the low level of the industrial development, too, despite an increasing of the human pressure in the last years. We recorded in this area some very rare breeding bird species for Romania - Platalea leucorodia, Plegadis falcinellus, Limosa limosa, Recurvirostra avosetta, Himantopus himantopus, Luscinia svecica, etc. but also some globally threatened species like Phalacrocorax pygmeus, Aythya nyroca or Crex crex. In this sector of the Prut River basin three Important Birds Areas (IBA) were delimited, all included in the "Romanian Nature 2000 Network".


Author(s):  
О. V. Matsyura ◽  
М. V. Matsyura ◽  
А. А. Zimaroyeva

<p>For the analysis of long-term observations data on dynamics of bird populations the most suitable methods could be the stochastic processes. Abundance (density) of birds is calculated on the integrated area of studied habitats. Using the method of autocorrelation the correlogram of changes in number of birds drawn during the study period in all the area. After that, the calculation of the autocorrelation coefficients and partial autocorrelation are performed. The most appropriate model is the mixed autoregressive moving average (ARIMA). Ecological significance of autoregressive parameters is to display the frequency of changes in the number of birds in the seasonal and long-term aspects. The sliding average is one of the simplest methods, which allows reject the random fluctuations of the empirical regression line. Validation of the model could be conducted on truncated data series (10 years). The forecast is calculated for the next two years and compared with empirical data. Calculation of correlation coefficients between the real data and the forecast is performed using non-parametric Spearman correlation coefficient. The residual rows of selected models are estimated by residual correlogram. The constructed model can be used to analyze and forecast the number of birds in breeding biotopes.</p> <p><em>Keywords: analysis, density, indirect methods, birds, Simply Tagging.</em></p> <p> </p>


Polar Record ◽  
2002 ◽  
Vol 38 (206) ◽  
pp. 203-210 ◽  
Author(s):  
E. J. Førland ◽  
I. Hanssen-Bauer ◽  
T. Jónsson ◽  
C. Kern-Hansen ◽  
P.Ø. Nordli ◽  
...  

AbstractIn a joint Nordic effort, a high-quality climate data set for the Nordic Arctic is established. The data set consists of monthly values from 20 stations in Greenland, Iceland, the Faeroes, and the Norwegian Arctic. The data set is made available on the web. Ten climate elements are included, and most of the series covers the period 1890–2000. The data series illustrate the large climatic contrasts in the Nordic Arctic, and demonstrate that parts of the region have experienced substantial climate variations during the last century. Despite increasing temperatures during recent decades, the present temperature level is still lower than in the 1930s and 1950s in large parts of the region. The pattern of long-term precipitation variations is more complicated, but in parts of the region the annual precipitation has increased substantially. At Svalbard Airport and Bjørnøya the annual precipitation has increased by more than 2.5% per decade during the twentieth century.Variations in atmospheric circulation can account for most of the long-term positive trend in precipitation in the Norwegian Arctic, and also for the positive temperature trend from the 1960s. The positive temperature trend before 1930 and the negative trend during the following decades, are, however, not accounted for by the circulation models.


Author(s):  
Martin Cody ◽  
Stephen Cain

In summer 1997 our NPS-funded project # CA-1460-5-0010, covering a 3-y period from summer 1995 through summer 1997, was completed. The immediate goals of the project were to instigate a system for monitoring the densities of breeding bird species, by establishment of flxed sites as a basis for a long term monitoring plan and of census protocols that can detect changes of breeding species and their densities over successive years. The monitoring scheme is conducted largely within Grand Teton National Park (GTNP), but covers habitats and an avifauna representative of the Greater Yellowstone Ecosystem (GYE) and the central-northern Rocky Mountains in general. The project emphasizes the need for long­term and on-going studies on breeding bird species and densities and their importance as a tool for evaluating the impact of both local and distant influences on breeding bird populations. For residents, species that remain all year in or near the breeding habitat, local effects include those operating on-site during the non-breeding season as well as during the breeding season. For migrant species, those that breed on-site but leave to spend the non-breeding season in other locations, often distant and usually of quite different habitat composition, there are both on-site influences on breeding population densities, such as inter-year changes in vegetation structure and productivity, and off-site or distant influences, including factors that affect over-wintering success in the non­breeding habitat and others that influence a successful transit between wintering and breeding grounds. The assessment of long-term trends in bird densities may be used as a form of bioassay of the state of the local environments. Information from such studies can provide region-wide indicators that, given a sufficiently comprehensive data base, can segregate local from distant influences on populations. Such indicators can be incorporated into management strategies to aid in determining which local strategies may be necessary (and feasible) to help maintain the biota.


Author(s):  
Gregory Schrott

This project examined the bird species breeding in the morainal forests on the valley floor in Grand Teton National Park. These forests are very patchily distributed and range in size from less than 1 hectare to over 700 hectares, allowing for a unique opportunity to study the responses of the local bird species to a forest system that has been fragmented for centuries through natural processes. This information can be useful for predicting the potential long-term impacts of human-caused forest fragmentation on bird populations in western North America. Until quite recently very little was known of the tolerances of western forest bird species to habitat fragmentation and this project could represent an important step towards understanding their needs in this regard.


1988 ◽  
Vol 46 (2) ◽  
pp. 145-157 ◽  
Author(s):  
Charles F. Leck ◽  
Bertram G. Murray ◽  
Jeff Swinebroad

2018 ◽  
Vol 36 (1) ◽  
pp. 76-85 ◽  
Author(s):  
Kristen E. Dybala ◽  
Andrew Engilis ◽  
John A. Trochet ◽  
Irene E. Engilis ◽  
Melanie L. Truan

2017 ◽  
Vol 168 (2) ◽  
pp. 59-66
Author(s):  
Pierre Mollet ◽  
René Hardegger ◽  
Res Altwegg ◽  
Pius Korner ◽  
Simon Birrer

Breeding bird fauna in a coniferous forest in the northern Prealps after storm Lothar In a 70-hectare large coniferous forest located on the northern edge of the Alps in central Switzerland, Canton of Obwalden, at an altitude of 1260 to 1550 metres above sea level, we surveyed the local breeding bird fauna in 2002 and 2013 by means of point counts as well as additional area searches for rare species. In December 1999, hurricane Lothar caused two large windthrow areas and several smaller areas with scattered throws in the survey range. We found a total of 48 breeding bird species, which is a very diverse species composition for a mountain forest. In the eleven years between surveys, a decline in distribution or abundance was recorded for four species, while seven species showed an increase; a further four species showed no change. For the remaining species, the data sets were too small to reliably estimate changes. A comparison with forest structure data provided by the Swiss Federal Institute of Forest, Snow and Landscape Research WSL revealed that for five bird species, the changes in distribution or abundance could be explained at least partially by forest succession. In order to obtain realistic distribution and abundance values in this kind of breeding bird survey, it is essential to collect large enough samples and to consider the detection probability of each individual species using appropriate statistical methods.


Bird Study ◽  
2021 ◽  
pp. 1-13
Author(s):  
Esther F. Kettel ◽  
Ivan Lakin ◽  
Matthew J. Heydon ◽  
Gavin M. Siriwardena

Sign in / Sign up

Export Citation Format

Share Document