Differential Long-Term Population Responses of Two Closely Related Human-Associated Sparrow Species with Respect to Urbanization

Urban planning and management need long-term population level studies for evaluating how urbanization influences biodiversity. Firstly, we reviewed the current trends of House Sparrow (Passer domesticus) Eurasian Tree montanus) in Europe, evaluated usefulness citizens’ science projects to monitor these species Finland. Secondly, conducted a (1991–2020) winter field study 31 urban settlements along 950 km north–south extent Finland latitude, weather influence on sparrow’s growth rates. The is declining 15 countries, increasing 5, whereas 12 9 European countries. trend was significantly negative continental Europe. However, not significant. Both have declined simultaneously six four their are opposite. Citizen-based, (2006–2020) season project data indicated that has decreased, increased short-term (2013–2020) breeding citizen-based did indicate significant changes occupation rate sparrows. Our wintering populations Sparrows both expanded range size. Based our count data, latitude rates When human within plot, vice versa. There also decreasing number feeding sites decreased numbers. Urban-related factors Sparrow. results colonization new, even closely related does negatively earlier urbanized species. It probable niches sparrow different enough allowing them co-occur. mainly nests buildings, can easily accept, e.g., nest boxes. should take care food availability