Browsing by Subject "urbanization"

Flight collisions with buildings contribute to a significant proportion of human-related bird mortalities globally. However, the global scope of this phenomenon remains poorly studied and little is known about the vulnerability of European bird populations to glass collisions. Here I investigate the impact of bird-window collisions (BWCs) on bird populations in Finland by analyzing long-term ringed-bird data and complementing it with empirical findings from an on-site survey in an urban area. Specifically, I aimed to discern spatiotemporal and ecological patterns in collisions over the past 50 years at both national and local scales. I found that based on ringing recoveries, the probability of detecting collisions has decreased over time and there are distinct seasonal patterns, with collisions peaking during the spring and fall seasons. Most collisions have occurred in urban areas, with collision densities decreasing with degrees of urbanization. Notably, the White-backed Woodpecker (Dendrocopos leucotos), an endangered species in Finland, emerged as the most vulnerable species. Moreover, young, first-year birds collide at higher rates than adults, and habitat preference and foraging strata significantly influence species-specific collision risks. Specifically, species with open and aquatic habitat preferences collide at lower rates than species favoring urban and forested areas, while water-foraging birds collide less than species foraging at low and high levels. In my case study in Helsinki, I found 42 collisions over 21 days, with the House Sparrow (Passer domesticus), another endangered species in Finland, being the most common collider. A positive correlation was identified between site-specific collision rates and glass area, while vegetation cover had no significant effect on collisions. These findings shed light on critical species, temporal variations, and urban factors influencing BWCs at a national level, representing a crucial step in understanding and monitoring the threat posed by glass to Finland’s bird population. I propose a standardized survey procedure to further understand the extent of this issue in Finland, which will be essential in developing efforts to mitigate the adverse impact of human activities on wildlife.

Microbial diversity can be found everywhere around us. The diversity is however declining globally and the diversity loss is most visible in highly urbanized areas. The lack of microbial biodiversity has been linked to increased risk of certain im-mune mediated diseases most prevalent within urban population. Understanding how diversity differs between urban and rural areas can help us to figure out mechanisms behind biodiversity loss and higher frequency of immune-mediated dis-eases and develop prevention methods for the latter. The aim of the thesis is to study how bacterial communities differ between urban and rural areas using indicator species as proxy. The aim is also to find out if the results support the biodiversity hypothesis. The results of the thesis found out significant differences in diversity indexes between bacterial communities in urban and rural areas, which supports the biodiversity hypothesis. The study also found differences in Proteobacteria diversity index-es, which have been linked to some immune mediated diseases in previous studies.