Habitat preferences of two sparrow species are modified by abundances of other birds in an urban environment

Abstract

Every species has certain habitat requirements, which may be altered by interactions with other co-occurring species. These interactions are mostly ignored in predictive models trying to identify key habitat variables correlated with species population abundance/occurrence. We investigated how the structure of the urban landscape, food resources, potential competitors, predators, and interaction between these factors influence the abundance of house sparrow Passer domesticus and the tree sparrow P. montanus in sixty 25 ha plots distributed randomly across residential areas of the city of Poznań (Poland). The abundance of the house sparrow was positively correlated with the abundance of pigeons but negatively correlated with human-related food resources. There were significant interaction terms between abundances of other urban species and habitat variables in statistical models. For example, the abundance of house sparrow was negatively correlated with the abundance of corvids and tree sparrows but only when food resources were low. The abundance of tree sparrows positively correlated with density of streets and the distance from the city center. The abundance of this species positively correlated with the abundance of corvids when food resources were low but negatively correlated at low covers of green area. Our study indicates that associations between food resources, habitat covers, and the relative abundance of two sparrow species are altered by the abundance of other urban species. Competition, niche separation and social facilitation may be responsible for these interactive effects. Thus, biotic interactions should be included not only as an additive effect but also as an interaction term between abundance and habitat variables in statistical models predicting species abundance and occurrence.

Land snails benefit from human alterations in rural landscapes and habitats

“…, Skórka et al. ). Our results highlight the importance of human activity per se as a factor contributing to changes in predator–prey relationships.…”

“…Some recent theoretical and empirical models have shown that prey–predator relationships may be mediated by their interactions with species‐specific habitat preferences (Nakazawa and Huang , Skórka et al. ). Our results confirm these assumptions and indicate that some subtle factors like human activity at the local scale as well as human moderations at the landscape scale may alter prey–predator relationships.…”

Does Traditional Feeding of Outdoor Guard Dogs Provide a Food Resource for Wild Mammals and Birds?

“…Most recorded visits were by the house sparrow. This synanthropic species is declining in Europe [ 18 , 19 , 20 ] and is unable to survive in the European environment unless in coexistence with human settlements [ 19 , 21 ]. This strong dependence of house sparrow populations is mostly based on artificial food resources generated by humans.…”

“…Videos from camera traps allowed us also to investigate the behaviour of wild animals using the food of guard dogs. Due to limits of population size, we decided to conduct a fuller analysis of the house sparrow, Passer domesticus , which has declined throughout Europe, partly due to lack of food, [ 18 , 19 , 20 , 21 ]. Additionally, we analyzed the influence of dog behaviour on the probability of house sparrow foraging.…”

Congruence between the prioritisation of conservation problems at the local and national scale: an evaluation by environmental scientists in Poland

“…Interestingly, urbanisation appears to be one of the major issues at the local scale. Towns and cities are currently the most rapidly developing areas globally, having a profound effect on the environment and biodiversity (Marzluff et al 2001;Skórka et al 2006Skórka et al , 2016Evans et al 2010). Urbanisation is associated with many phenomena, including urban sprawl, road development, noise, increased human density, and pollution.…”