Search results for "bird"
showing 10 items of 420 documents
Climate-driven changes in winter abundance of a migratory waterbird in relation to EU protected areas
2015
AimSpecies are responding to climate change by changing their distributions, creating debate about the effectiveness of existing networks of protected areas. As a contribution to this debate, we assess whether regional winter abundances and distribution of the Smew Mergellus albellus, a migratory waterbird species listed on Annex I (EU Birds Directive) that overwinters exclusively in European wetlands, changed during 1990-2011, the role of global warming in driving distributional changes and the effectiveness of the network of Special Protection Areas (SPAs, EU Birds Directive) in the context of climate change. LocationEurope. MethodsWe used site-specific counts (6,883 sites) from 16 countr…
Competition for breeding sites and site-dependent population regulation in a highly colonial seabird, the common guillemot Uria aalge
2004
Summary 1. The hypothesis of site-dependent population regulation predicts that birds utilize available nesting sites in a pre-emptive (ideal despotic) manner, leading to density dependence in heterogeneous habitats as poorer sites are used at higher population densities. At small population sizes adaptive site choice protects populations against fluctuations (the buffer effect). 2. Common guillemots Uria aalge (Pontoppidan) breed at high density on sea-cliffs. The population breeding on the Isle of May, Scotland increased by 60% between 1981 and 2000. A good nest-site is a prerequisite for successful breeding and there is much competition for the best sites. Throughout this period, site us…
Continental-scale patterns of pathogen prevalence: a case study on the corncrake
2014
Pathogen infections can represent a substantial threat to wild populations, especially those already limited in size. To determine how much variation in the pathogens observed among fragmented populations is caused by ecological factors, one needs to examine systems where host genetic diversity is consistent among the populations, thus controlling for any potentially confounding genetic effects. Here, we report geographic variation in haemosporidian infection among European populations of corncrake. This species now occurs in fragmented populations, but there is little genetic structure and equally high levels of genetic diversity among these populations. We observed a longitudinal gradient…
Ecomorphological predictors of natal dispersal distances in birds.
2008
1. Dispersal is one of the key ecological parameters but it is very difficult to quantify directly. As a consequence, empirical studies often ignore dispersal or use indirect measures. 2. Ringing data have previously been used to estimate the natal dispersal distances of 47 British passerine bird species. This provides an excellent opportunity to examine the potential of various indirect measures to predict natal dispersal distances in British birds. 3. We use a phylogenetic comparative framework and single- and multipredictor models including ecomorphological, behavioural or ecological traits to predict natal dispersal distance. 4. A multipredictor model that includes Kipp's distance (a me…
THE ENVIRONMENTAL IMPACT OF POWER LINES ON BIRDS IN SICILY
2018
Electrocution is a serious conservation problem worldwide for a large number of bird species (BEVANGER, 1994, 1998; BIRDLIFE INTERNATIONAL, 2004; PRINSEN et al., 2011). Due to its wide extension, it is necessary to seek methods that optimize the identification of the most dangerous pylons (JANSS and FERRER, 2001; MANOSA, 2001), lines and the highest risk areas (TINTÓ et al., 2010; GUIL et al., 2011). Actually, the data on bird mortality caused by electrocution and collision in Sicily are deficient, however, a preliminary study suggests that the White Stork (Ciconia ciconia L., 1758) is one of the most threatened species inside two Special Protection Areas (SPA) (ZAFARANA and BARBERA, 2016).…
Biotic homogenization of forest bird communities under human influence
2018
Human actions impact biodiversity worldwide. Specialist species are particularly sensitive to environmental degradation whereas generalists may even benefit from habitat changes. As a consequence, specialists are declining while generalists are increasing and, therefore, communities become more similar. This phenomenon is known as biotic homogenization. In boreal forests logging and forest management is the most important factor changing the native habitat. In this thesis I studied if human actions are homogenizing boreal forest bird communities. I further studied if protected areas can maintain their diversity and, thus, prevent homogenization. Through the individual studies, biodiversity …
Does Arsenic Contamination Affect DNA Methylation Patterns in a Wild Bird Population? : An Experimental Approach
2021
Pollutants, such as toxic metals, negatively influence organismal health and performance, even leading to population collapses. Studies in model organisms have shown that epigenetic marks, such as DNA methylation, can be modulated by various environmental factors, including pollutants, influencing gene expression, and various organismal traits. Yet experimental data on the effects of pollution on DNA methylation from wild animal populations are largely lacking. We here experimentally investigated for the first time the effects of early-life exposure to environmentally relevant levels of a key pollutant, arsenic (As), on genome-wide DNA methylation in a wild bird population. We experimentall…
Reflections of Hope and Anxiety in Audience Responses to Three Environmental Films
2023
This article discusses the results of a reception study of three environmental films with a focus on emotional reactions and the films’ influence on the respondents’ environmental awareness. The short experimental film Valtakunnat/Realms (Finland, 2018) envisions post-human life, and the potential destruction that the planet is being driven towards. To Teach a Bird to Fly (Finland, 2020), a short documentary fiction film about a woman raising critically endangered birds, imagines a future where the effects of climate change have been reversed. The documentary film The Biggest Little Farm (USA, 2018) follows a couple who buy a barren farm with the aim of restoring its biodiversity. Through t…
Bottom-up control on macrobenthic communities in a guanotrophic coastal system.
2013
Soft bottom macrobenthic assemblage and sediment characteristics were studied from autumn 2008 to summer 2009 in three coastal ponds (Marinello ponds, Sicily, Italy) at increasing distances from a gull (Larus michahellis Naumann, 1840) colony to investigate the effect of seabird-induced eutrophication (i.e. guanotrophication) on macrobenthic communities. We hypothesized that enhanced nutrient concentration and organic load caused by guano input significantly alter the sedimentary condition of ponds, affecting benthic fauna through a bottom-up control. Polychaetes were the dominant taxon in the system, followed by amphipods, gastropods and bivalves. Macrobenthic patterns showed high variabil…
Maternal antibody transmission and breeding densities in the Black-headed Gull Larus ridibundus
2004
1. The offspring of avian species, especially those of colonial breeders, are exposed to a number of pathogens immediately after birth. The chick's immune system is, at that early stage still immature and inefficient. As a consequence, diseases can have a strong impact on chick survival.2. The ability of mothers to transmit passive immunity in terms of antibodies of their own acquired immunity to their chicks is probably an essential pathway to enhance the chick survival. Since the production of antibodies is costly, females are expected to adjust the transmission of passive immunity to the local disease environment.3. We found that in Black-headed Gulls (Larus ridibundus L.) yolk antibody …