Artur Goławski

Conservation of farmland birds faces different challenges in Western and Central-Eastern Europe

Abstract. Birds are commonly used as an example of the strongly declining farmland biodiversity in Europe. The populations of many species have been shown to suffer from intensification of management, reduction of landscape heterogeneity, and habitat loss and fragmentation. These conditions particularly dominate farmland in the economically well developed countries of Western Europe. Currently, the farmland environment in Central-Eastern Europe is generally more extensive than in Western Europe and a larger proportion of people still live in rural areas; thus generating different conditions for birds living in agricultural areas. Furthermore, the quasi-subsistence farming in much of Central-Eastern Europe has resulted in agricultural landscapes that are generally more complex than those in Western Europe. To protect declining bird populations living in farmland, detailed knowledge on both species and communities is necessary. However, due to scientific tradition and availability of funding, the majority of studies have been carried out in Western Europe. In consequence this provokes a question: are findings obtained in western conditions useful to identify the fate of farmland bird biodiversity in Central-Eastern Europe? Therefore, the major goal of this paper is to highlight some local and regional differences in biodiversity patterns within EU farmland by comparing intensive agricultural landscapes with more extensive ones. More specifically, we aim to outline differences in agricultural landscapes and land use history in the two regions, use farmland birds to provide examples of the differences in species dynamics and species-habitat interactions between the two regions, and discuss possible social and ecological drivers of the differences in the context of biodiversity conservation. Factors governing spatio-temporal dynamics of farmland bird populations may differ in intensive and extensive landscapes as illustrated here using the Grey Partridge Perdix perdix and the Red-backed Shrike Lanius collurio as examples. The unevenness of farmland bird studies distribution across Europe was also presented. We call for more emphasis on pluralism in furthering both pan-European research on farmland bird ecology and conservation strategies. We also highlight some features specific to Central-Eastern Europe that merit consideration for the more efficient conservation of farmland birds and farmland biodiversity across Europe.

Sex differences in nest defence by the red-backed shrike Lanius collurio: effects of offspring age, brood size, and stage of breeding season

The red-backed shrike Lanius collurio is an open-cup nesting passerine bird, which protects its nest aggressively attacking predators near the nest. The response of parents to a human observer was investigated during the nesting period 1999–2001 in Poland. The intensity of nest defence increased as the breeding cycle progressed in accordance to the offspring value hypothesis. However, we did not find an increase in the level of aggression according to the number of offspring and the time of season. Contrary to previous predictions, we did not find gender differences in nest defence. More aggressive parents, both females and males, have significantly better breeding success than quieter individuals.

Urbanization affects neophilia and risk-taking at bird-feeders

Urban environments cover vast areas with a high density of humans and their dogs and cats causing problems for exploitation of new resources by wild animals. Such resources facilitate colonization by individuals with a high level of neophilia predicting that urban animals should show more neophilia than rural conspecifics. We provided bird-feeders across urban environments in 14 Polish cities and matched nearby rural habitats, testing whether the presence of a novel item (a brightly coloured green object made out of gum with a tuft of hair) differentially delayed arrival at feeders in rural compared to urban habitats. The presence of a novel object reduced the number of great tits Parus major, but also the total number of all species of birds although differentially so in urban compared to rural areas. That was the case independent of the potentially confounding effects of temperature, population density of birds, and the abundance of cats, dogs and pedestrians. The number of great tits and the total number of birds attending feeders increased in urban compared to rural areas independent of local population density of birds. This implies that urban birds have high levels of neophilia allowing them to readily exploit unpredictable resources in urban environments.

Disperse or Stay? Exceptionally High Breeding-Site Infidelity in the Red-Backed Shrike Lanius collurio

Nesting in the same breeding area in successive years provides information to help understand the cues used by birds in habitat selection. Moreover, such information may also be an important tool for the conservation and management of endangered species. Based on the ringing results of 122 adult and 1245 nestling Red-backed Shrike Lanius collurio in the years 1996–2005, we studied philopatry of the species in two different populations: in western and in eastern Poland. Moreover we analysed all Polish Red-backed Shrike ring recoveries since 1996 (n = 3102 ringed birds). We noted that both natal and breeding philopatry in the populations were almost entirely absent. This is surprising in comparison with other studies, especially those including shrikes. Comparisons with other populations suggest that the lack of philopatry is not related to the breeding success of local birds and/or the size of the study area. In contrast, we suggest that low philopatry is an effect of and/or an adaptation to a relatively high population density at the land-scape scale, where many breeding areas and potential nesting sites still remain vacant.

Who started first? Bird species visiting novel birdfeeders.

Adapting to exploit new food sources may be essential, particularly in winter, when the impact of food limitation on survival of individuals is critical. One of the most important additional sources of food for birds in human settlements is birdfeeders. At a large spatial scale, we experimentally provided birdfeeders with four different kinds of food to analyze exploitation and use of a novel food supply provided by humans. Nine species started foraging at the new birdfeeders. The species that exploited the new feeders the fastest was the great tit. Use of novel food sources was faster in urban habitats and the presence of other feeders reduced the time until a new feeder was located. Urbanization may be associated with behavioural skills, technical innovations and neophilia resulting in faster discovery of new food sources. This process is accelerated by the experience of feeder use in the vicinity, with a strong modifying effect of the number of domestic cats.

Winter Bird Assemblages in Rural and Urban Environments: A National Survey

Urban development has a marked effect on the ecological and behavioural traits of many living organisms, including birds. In this paper, we analysed differences in the numbers of wintering birds between rural and urban areas in Poland. We also analysed species richness and abundance in relation to longitude, latitude, human population size, and landscape structure. All these parameters were analysed using modern statistical techniques incorporating species detectability. We counted birds in 156 squares (0.25 km2 each) in December 2012 and again in January 2013 in locations in and around 26 urban areas across Poland (in each urban area we surveyed 3 squares and 3 squares in nearby rural areas). The influence of twelve potential environmental variables on species abundance and richness was assessed with Generalized Linear Mixed Models, Principal Components and Detrended Correspondence Analyses. Totals of 72 bird species and 89,710 individual birds were recorded in this study. On average (±SE) 13.3 ± 0.3 species and 288 ± 14 individuals were recorded in each square in each survey. A formal comparison of rural and urban areas revealed that 27 species had a significant preference; 17 to rural areas and 10 to urban areas. Moreover, overall abundance in urban areas was more than double that of rural areas. There was almost a complete separation of rural and urban bird communities. Significantly more birds and more bird species were recorded in January compared to December. We conclude that differences between rural and urban areas in terms of winter conditions and the availability of resources are reflected in different bird communities in the two environments.

Costly replacement: how do different stages of nest failure affect clutch replacement in the red- backed shrikes Lanius collurio?

Re-nesting is costly and strongly stage- and time-related in the redbacked shrike. We tested whether failure which occurred at more costly developmental stages of the first clutches influenced the characteristics of replacement clutches in red-backed shrike Lanius collurio. Field work was conducted in the breeding seasons 1999–2006 at three study plots in Poland. During nest visits, standard data on breeding biology were collected, including clutch size, eggs measurements, laying date, and number of nestlings. We found significant differences in the clutch size of replaced clutches according to the failure phase of first clutches. Pairs which experienced brood failure at the nestling phase produced smaller replacement clutches than pairs whose nest was destroyed at the egg laying stage. There were no differences in the nesting success of replaced cluches relative to the stage where the first clutch was lost. However, pairs which failed during the nestling phase of the first clutch significantly more often skipped further reproduction in that season than those which failed during other phases. For breeding red-backed shrikes the best strategy is to initiate clutches as early as possible because it gives a more time for possible re-nesting.

The effects of weather conditions on the numbers of wintering birds and the diversity of their assemblages in villages and crop fields in east-central Poland

Abstract Winter in northern and central Europe can be a harsh time, especially for farmland birds. When fields are covered by snow, birds must search for food elsewhere, moving away to areas with more favourable weather or to habitats where food is more readily available. This study examines the changes in the numbers of wintering birds and the diversity of their assemblages in the farmlands and rural settlements of eastern Poland as a response to weather conditions. Deeper snow and low ambient temperatures caused the numbers of birds to increase in settlements but decrease in farmland. The numbers of species in both habitats were independent of the weather conditions, however. Among the species more frequently found in both habitats, only yellowhammer and tree sparrow showed a negative correlation between their numbers in settlements and in the surrounding farmland. This strongly suggests that these two species move back and forth between the two habitats, depending on the weather.

Habitat preferences of granivorous passerine birds wintering on farmland in eastern Poland

Capsule Fallow land, manure heaps and stubble were the most important habitats for birds wintering in low-intensity farmland in eastern Poland. Aims To describe habitat types and to determine the preferences of granivorous passerines in open farmland in eastern Poland. Methods Small passerines were counted along ten 1-km-long transects in three seasons from 2003 to 2006 in open, strongly fragmented farmland in eastern Poland. Results Birds were recorded in eight habitat types of different significance for particular species. More than 50% of individuals and the highest number of species were recorded on stubble and fallow land. The glm model showed the influence of fallow areas and the presence of the other habitats on bird species numbers. The preference index was significantly higher for manure heaps than for other habitats. Conclusion The open agricultural landscape in eastern Poland provides attractive habitats for wintering granivorous birds, such as stubble and fallow land. These birds also use the manure heaps that are a feature of traditional, low-intensity farmland.

Entomotoxic action of jackbean lectin (Con A) in bird cherry-oat aphid through the effect on insect enzymes

The mechanism of the toxicity of plant lectins is not clearly understood. The insecticidal activity of plant lectins results from effects on insect metabolism by interfering with gut enzymatic function. Thus, a greater understanding of the mechanisms of plant lectin toxicity in insects is required. This study reports the effects of dietary ingestion of the glucose-mannose binding lectin Concanavaline A (Con A) on bird cherry-oat aphid (Rhopalosiphum padi L.) enzymes involved in protein digestion [aminopeptidase N and cathepsin L (CatL)], sugar (α- and β-glucosidases), and phosphorus (alkaline and acid phosphatase) metabolism. An aphid bioassay test using artificial diets containing Con A is also presented. An increase in the concentration of Con A generally suppressed the activity of glucosidases and phosphatases, and increased the activity of CatL in apterae morphs. Bird cherry-oat aphid performance was affected by the presence of Con A in artificial diets. The lectin added to the liquid diet increased the pre-reproductive period, mortality, and the average time of generation development (T) and decreased fecundity and the intrinsic rate of natural increase (rm). Aphicidal activity of Con A might be linked to its interference in the activity of digestive enzymes.