The role of churches in maintaining bird diversity: A case study from southern Poland

© 2018 Elsevier Ltd With the human population increasing there have been losses in biodiversity. A common feature of mankind is religious beliefs with various associated positive and negative consequences for biodiversity. Religion also has associated religious sites, many of which have a long history. The role of churches in benefitting biodiversity has not received attention. To examine the impact of churches we measured the taxonomic, phylogenetic and functional diversity of birds around Christian churches and compared this with matched farmsteads. We surveyed 101 churches and equal number of farmsteads in villages of southern Poland. We measured structural and compositional characteristics (e.g. number of trees, shrubs, number of buildings and height) at both churches and farmsteads. General additive models, ordination and rarefactions methods were used in data analysis. Species richness, abundance and phylogenetic diversity were each higher at churches than at farmsteads. The species composition differed between building types but functional diversity was similar at both types of buildings. Bird species richness and abundance were correlated with the church's age. Previous studies showed village farmsteads supported high species diversity, thus our current findings that churches are richer show they may increase bird diversity in studied villages. We suggest that the green surroundings and tall towers create strong environmental gradient that enhances species richness, functional and phylogenetic diversity. There are over ten thousand churches in Poland, and similar places of worship are present in many religions, thus this habitat may be important for sustaining local taxonomic, functional and phylogenetic biodiversity in different global areas

Numerical and behavioural response of Black-headed Gull Chroicocephalus ridibundus on population growth of the expansive Caspian Gull Larus cachinnans

Abstract We monitored population size from 1996 to 2003 and studied behavioural interactions (in 2001) between the native Black-headed Gull Chroicocephalus ridibundus and an expansive, opportunistic predator, the Caspian Gull Larus cachinnans, at water reservoirs in Poland. The expansive species caused a population decline in the native species and affected its choice of nest sites. The Black-headed Gulls perceived the risk of predation on the part of the larger Caspian Gulls. When both species occurred in close proximity, the native gull breeding pairs built nests where the vegetation was higher and its cover greater than at the sites chosen by pairs breeding far away from the expansive species. The native gulls in proximity to the expansive species spent more time guarding their nests. However, this was not compensatory, as egg losses were higher and breeding success much lower in pairs breeding near the Caspian Gulls than in those breeding far from the latter. Such a low breeding performance in the Blackheaded Gulls was probably caused either by predation on the part of Caspian Gulls or by aggressive interactions among Black-headed Gulls. In fact, the rate of intraspecific aggression in native gulls was higher in pairs breeding in proximity to the expansive species than in those breeding far away from it. These intraspecific fights, caused by the presence of the expansive species were, at least partially, responsible for egg and chick losses. We did not find the presence of native gulls to have any effect on the behaviour and breeding performance of the expansive gull. These results indicate that the expansive predatory Caspian Gull negatively affects local population size and alters the behaviour of the native Black-headed Gull, and may, both directly and indirectly, affect its reproductive performance. Keyword

Parasitism in early life: environmental conditions shape within-brood variation in responses to infection

Parasites play key ecological and evolutionary roles through the costs they impose on their host. In wild populations, the effect of parasitism is likely to vary considerably with environmental conditions, which may affect the availability of resources to hosts for defense. However, the interaction between parasitism and prevailing conditions is rarely quantified. In addition to environmental variation acting on hosts, individuals are likely to vary in their response to parasitism, and the combined effect of both may increase heterogeneity in host responses. Offspring hierarchies, established by parents in response to uncertain rearing conditions, may be an important source of variation between individuals. Here, we use experimental antiparasite treatment across 5 years of variable conditions to test how annual population productivity (a proxy for environmental conditions) and parasitism interact to affect growth and survival of different brood members in juvenile European shags (Phalacrocorax aristotelis). In control broods, last-hatched chicks had more plastic growth rates, growing faster in more productive years. Older siblings grew at a similar rate in all years. Treatment removed the effect of environment on last-hatched chicks, such that all siblings in treated broods grew at a similar rate across environmental conditions. There were no differences in nematode burden between years or siblings, suggesting that variation in responses arose from intrinsic differences between chicks. Whole-brood growth rate was not affected by treatment, indicating that within-brood differences were driven by a change in resource allocation between siblings rather than a change in overall parental provisioning. We show that gastrointestinal parasites can be a key component of offspring's developmental environment. Our results also demonstrate the value of considering prevailing conditions for our understanding of parasite effects on host life-history traits. Establishing how environmental conditions shape responses to parasitism is important as environmental variability is predicted to increase

Kin recognition and adjustment of reproductive effort in zebra finches

The differential allocation theory predicts that females should invest more in offspring produced with attractive partners, and a number of studies support this prediction in birds. Females have been shown to increase reproductive investment when mated to males showing elaborated sexual traits. However, mate attractiveness might also depend on the interaction between male and female genotypes. Accordingly, females should invest more in offspring sired by individuals that are genetically dissimilar or carry superior alleles. Here, we show in zebra finches (Taeniopygia guttata) that pairs of unfamiliar genetic brothers and sisters are less likely to reproduce in comparison with randomly mated pairs. Among the brother–sister pairs, those that attempted to breed laid smaller clutches and of lower total clutch mass. Our results provide the first experimental evidence that females adjust their reproductive effort in response to the genetic similarity of their partners. Importantly, these results imply a female ability to assess relatedness of a social mate without prior association