| 1. |
- Altewischer, Andrea, et al.
(author)
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Habitat preferences of male Corn Buntings Emberiza calandra in north-eastern Germany
- 2015
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In: Acta Ornithologica. - 0001-6454 .- 1734-8471. ; 50:1, s. 1-10
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Journal article (peer-reviewed)abstract
- Agricultural ecosystems have faced dramatic changes during past decades, resulting in a dramatic loss of farmland biodiversity. The Corn Bunting Emberiza calandra is considered a suitable indicator for the conservation value of farmland habitats, and has recently suffered strong declines throughout much of its European range. As a basis for targeted conservation measures, we investigated the habitat preferences of this species in north-eastern Germany by comparing the composition of male territories with randomly chosen control sites. A territory was defined as the area within a radius of 150 meters around the assumed centre of the territory, as the majority of nests is found within this radius. To assess food availability for nestlings, arthropod abundance within the most abundant land use types i.e. crop fields, fallows, grassland as well as within unploughed strips was investigated. In total we found 102 male Corn Bunting territories, which were mainly composed of crop fields (50%), grassland (28%), and fallows (12%). Territories compared with control sites were characterized by a lower proportion of crop fields, a higher proportion of fallows, more diverse land use types, more abundant field boundaries, unploughed strips, and tracks, and a higher availability of song posts. However, neither the number of larger (≥ 1 cm), smaller (< 1 cm) or all arthropods differed significantly among analysed land use types i.e. crop fields, fallows, grassland, unploughed strips. Our study confirms the significance of habitat heterogeneity and especially of sites with sparse vegetation (fallows > 10%) and song posts (> 70 m ‘linear song posts’ or > 1 solitary post per ha) for the habitat selection of male Corn Buntings. We conclude that measures to halt population declines of Corn Buntings seem to be relatively easy to implement, provided that farmers are granted a fair compensation.
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| 2. |
- Djerdali, Sofia, et al.
(author)
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Food supply and external cues limit the clutch size and hatchability in the White Stork Ciconia ciconia
- 2008
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In: Acta Ornithologica. - 0001-6454 .- 1734-8471. ; 43:2, s. 145-150
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Journal article (peer-reviewed)abstract
- Clutch size is an important life history trait and factors such as nest predation and food availability can both be of crucial importance for its variation in nature. The aim of the present study was to evaluate the effects of extra food on clutch size, laying date and hatching success in the White stork Ciconia ciconia. Three different colonies of White stork were studied over a three-year period where there was difference in both food availability and precipitation. This study demonstrated that an extra food supply during the pre-laying period had a positive effect on clutch size - nests with extra food had a larger clutch size. There was also an advance in laying date and a higher hatching success in nests with access to extra food. In addition to food supply, clutch size was independently affected by rainfall, which suggests that parents additionally also were sensitive to other external cues than to the extra food. Furthermore, this study also suggests that an extra food during the incubation period could probably help the parents to solve the conflict between incubation behaviour and minimizing the time off the nest, i.e. increasing nest attentiveness in nests with extra food.
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| 3. |
- Lambrechts, Marcel M., et al.
(author)
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The design of artificial nestboxes for the study of secondary hole-nesting birds: a review of methodological inconsistencies and potential biases
- 2010
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In: Acta Ornithologica. - 0001-6454 .- 1734-8471. ; 45:1, s. 1-26
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Journal article (peer-reviewed)abstract
- The widespread use of artificial nestboxes has led to significant advances in our knowledge of the ecology, behaviour and physiology of cavity nesting birds, especially small passerines Nestboxes have made it easier to perform routine monitoring and experimental manipulation of eggs or nestlings, and also repeatedly to capture, identify and manipulate the parents However, when comparing results across study sites the use of nestboxes may also Introduce a potentially significant confounding variable in the form of differences in nestbox design amongst studies, such as their physical dimensions, placement height, and the way in which they are constructed and maintained However, the use of nestboxes may also introduce an unconsidered and potentially significant confounding variable clue to differences in nestbox design amongst studies, such as their physical dimensions, placement height, and the way in which they are constructed and maintained Here we review to what extent the characteristics of artificial nestboxes (e g size, shape, construction material, colour) are documented in the 'methods' sections of publications involving hole-nesting passerine birds using natural or excavated cavities or artificial nestboxes for reproduction and roosting Despite explicit previous recommendations that authors describe in detail the characteristics of the nestboxes used, we found that the description of nestbox characteristics in most recent publications remains poor and insufficient We therefore list the types of descriptive data that should be included in the methods sections of relevant manuscripts and justify this by discussing how variation in nestbox characteristics can affect or confound conclusions from nestbox studies We also propose several recommendations to improve the reliability and usefulness of research based on long-term studies of any secondary hole-nesting species using artificial nestboxes for breeding or roosting.
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| 4. |
- Marklund, Susanna, et al.
(author)
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Risk factors associated with incidence and persistence of frequent headaches
- 2014
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In: Acta Odontologica Scandinavica. - : Taylor & Francis. - 0001-6357 .- 1502-3850. ; 72:8, s. 788-794
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Headaches represent a significant public health problem, but the knowledge of factors specifically related to incidence and persistence of headaches is still limited. The aim of this study was to evaluate whether gender, self-reported bruxism and variations in the dental occlusion contribute to onset and persistence of frequent headaches. MATERIALS AND METHODS: The study population comprised 280 dental students, examined annually in a 2-year prospective study with a questionnaire and a clinical examination of the jaw function. In the analysis subjects were dichotomized into cases with frequent (once a week or more) or without frequent headaches (controls). The 2-year cumulative incidence was based on subjects without frequent headaches at baseline. Cases with 2-year persistent headaches reported such symptoms at all three examinations. Self-reported bruxism and factors in the dental occlusion at baseline were used as independent variables in logistic regression analyses. RESULTS: The 2-year cumulative incidence of frequent headaches was 21%. Female gender (OR = 2.6; CI = 1.3-5.4), self-reported bruxism (OR = 2.3; CI = 1.2-4.4) and mandibular instability in intercuspal position (OR = 3.2; CI = 1.4-7.5) were associated with incidence of frequent headaches. Persistent headaches during the observation period were present in 12 individuals (4%) and significantly related to mandibular instability in intercuspal position (OR = 6.1; CI = 1.6-22.6). CONCLUSIONS: The results indicate that female gender, self-reported bruxism and mandibular instability in intercuspal position are of importance in the development of frequent headaches. In management of these patients a multidisciplinary approach including dentists may be important and, thus, advocated.
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| 5. |
- Zmihorski, Michal, et al.
(author)
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Spatial variation in long-term trends in a metapopulation of the globally threatened Aquatic Warbler Acrocephalus paludicola in Poland
- 2016
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In: Acta Ornithologica. - 0001-6454. ; 51, s. 245–256-
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Journal article (peer-reviewed)abstract
- The Polish breeding population (3,200-3,250 males) of the globally threatened Aquatic Warbler Acrocephalus paludicola represents almost 25% of the global population. Except for the relatively stable large population in the Biebrza valley in north-east Poland less is known about population trends of peripheral populations in western, central and south-eastern regions of the country and whether trends differ depending on region. We investigated the long-term population dynamics in 38 small populations between 1969-2013 in the four Polish regions. Summarizing the trends of all small populations of Aquatic Warblers showed a significant decline in total number of individuals and declining number of populations over time. However, population trends were distinctly different in the different regions, with stable dynamics in south-east, moderate decline in north-east and sharp decline in the central and western regions. During the study period 19 out of 38 populations became extinct (11 populations in the western region, two in central region, four in north-east region and none in the south-east region). Five of these populations were later recolonised thus Suggesting a pattern of metapopulation dynamics. To mitigate the negative trends and increased risk of local and regional extinction in the western and central parts of Poland effort should be put to increasing dispersal among populations by increasing the number of stepping stone patches between the viable large eastern populations and the smaller central and western ones.
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