Michela Corsini

While there are increasing examples of phenotypic and genotypic differences between urban and non-urban populations of plants and animals, few studies identified the mechanisms explaining those dissimilarities. The characterization of the urban landscape, which can only be achieved by measuring variability in relevant environmental factors within and between cities, is a keystone prerequisite to understand the effects of urbanization on wildlife. Here, we measured variation in bird exposure to metal pollution within 8 replicated urbanization gradients and within 2 flagship bird species in urban evolutionary ecology: the blue tit (Cyanistes caeruleus) and the great tit (Parus major). We report on a highly significant, positive linear relationship between the magnitude of urbanization – inferred as either tree cover, impervious surface cover, or an urbanization score computed from several environmental variables, and copper, zinc and lead concentrations in bird feathers. The reverse r...

Urbanisation is a major anthropogenic perturbation that progressively alters multiple environmental parameters, thereby presenting novel evolutionary challenges to wild populations. Symbiotic microorganisms residing in the gastrointestinal tracts (gut) of vertebrates have well-established mutual connections with the physiology of their hosts and respond quickly to environmental alterations. However, the impacts of anthropogenic changes and urbanisation on gut microbiota remain poorly understood, especially in early development. To address this knowledge gap, we investigated the gut microbiota in juvenile great tits (Parus major) in an urban mosaic. First, we compared the microbiota of nestlings reared in artificial nest boxes or natural cavities. Next, we analysed microbiota variations employing two distinct urbanisation frameworks, (i) the classical urban/rural dichotomy and (ii) gradual changes in the amount of impervious surface area (ISA) in the urban space and identified the en...

Environmental variation was quantified at nestboxes monitored as part of a prospectively long-term project on the ecology and evolution of great tits Parus major and blue tits Cyanistes caeruleus in Warsaw, Poland. Nine axes of environmental variation were investigated across 9 different urban sites, for a total of 565 specific locations (here: nestboxes). Data was collected on the ground, with the use of GIS and remote sensing using the following methodology:...

Rapid environmental change driven by urbanization offers a unique insight into the adaptive potential of urban‐dwelling organisms. Urban‐driven phenotypic differentiation is increasingly often demonstrated, but the impact of urbanization (here modelled as the percentage of impervious surface (ISA) around each nestbox) on offspring developmental rates and subsequent survival remains poorly understood. Furthermore, the role of selection on urban‐driven phenotypic divergence was rarely investigated to date.

Where introduced, the European rabbit Oryctolagus cuniculus is considered among the most destructive and invasive species. To date, research focused mostly on populations of wild rabbit, whereas little is known on feral domestic rabbit populations. In this work, we reported the establishment of two self-sustaining populations of feral rabbits in Italy. Direct observations were conducted to assess rabbit range expansion and population increase over time. We also evaluated prey-predator interactions between rabbits and native red foxes Vulpes vulpes , by means of camera trapping and the analysis of fox scats. Moreover, we also assessed the social perception towards feral rabbits and the acceptability of various management options through the administration of a structured questionnaire to park visitors. Rabbit populations increased between 2018 and 2019, as well as the size of the invaded range. Rabbits are predated by foxes, but they seem to have adapted their activity rhythms to min...

Humans are transforming natural habitats into managed urban green areas and impervious surfaces with unprecedented pace. Yet the effects of human presence per se on animal life-history traits are rarely tested. This is particularly true in cities, where human presence is often indissociable from urbanisation itself. The onset of the SARS-CoV-2 outbreak, along with the resulting lockdown restrictions, offered a unique, “natural experiment” context to investigate wildlife responses to a sudden reduction of human activities. We analysed four years of avian breeding data collected in a European capital city to test whether lockdown measures altered nestbox occupancy and life-history traits in two urban adapters: great tits (Parus major) and blue tits (Cyanistes caeruleus). Lockdown measures, which modulated human presence, did not influence any of the life-history traits inferred. In contrast, tree cover, a distinct ecological attribute of the urban space, positively influenced clutch s...

Research in urban evolution requires that the features of cities are accurately captured for input into evolutionary models. Until recently, the evolutionary effects of cities have often been addressed using single sites, dichotomous urban–rural contrasts or, to a lesser extent, using urban gradients. However, urbanization does not produce a homogenous spatial continuum: cities are highly heterogeneous environments, with sharp and often non-linear environmental changes related to the amount of impervious surface, green vegetation, air pollution, light, noise, or contrasted temperature profiles. The comprehensive quantification of urban heterogeneity in space and time is essential for exploring the origins of organismal variation and adaptation in cities, and to best identify the strength and directionality of selective pressures and neutral processes occurring in populations of urban organisms. This chapter reviews frameworks that can be used to describe and quantify urbanization—th...

While there are increasing examples of phenotypic and genotypic differences between urban and non-urban populations of plants and animals, few studies identified the mechanisms explaining those dissimilarities. The characterization of the urban landscape, which can only be achieved by measuring variability in relevant environmental factors within and between cities, is a keystone prerequisite to understand the effects of urbanization on wildlife. Here, we measured variation in bird exposure to metal pollution within 8 replicated urbanization gradients and within 2 flagship bird species in urban evolutionary ecology: the blue tit (Cyanistes caeruleus) and the great tit (Parus major). We report on a highly significant, positive linear relationship between the magnitude of urbanization—inferred as either tree cover, impervious surface cover, or an urbanization score computed from several environmental variables, and copper, zinc and lead concentrations in bird feathers. The reverse rel...

Abstract
Introduction: Rapid environmental change driven by urbanization offers a unique
insight into the adaptive potential of urban-dwelling organisms. Urban-driven phenotypic
differentiation is increasingly often demonstrated, but the impact of urbanization
(here modelled as the percentage of impervious surface (ISA) around each
nestbox) on offspring developmental rates and subsequent survival remains poorly
understood. Furthermore, the role of selection on urban-driven phenotypic divergence
was rarely investigated to date.
Methods and Results: Data on nestling development and body mass were analysed
in a gradient of urbanization set in Warsaw, Poland, in two passerine species: great
tits (Parus major) and blue tits (Cyanistes caeruleus). Increasing levels of impervious
surface area (ISA) delayed the age of fastest growth in blue tits. Nestling body mass
was also negatively affected by increasing ISA 5 and 10 days after hatching in great
tits, and 10 and 15 days in blue tits, respectively. High levels of ISA also increased
nestling mortality 5 and 10 days after hatching in both species. An analysis of selection
differentials performed for two levels of urbanization (low and high ISA) revealed
a positive association between mass at day 2 and survival at fledging.
Discussion: This study confirms the considerable negative impact of imperviousness—
a proxy for urbanization level—on offspring development, body mass and
survival, and highlights increased selection on avian mass at hatching in a high ISA
environment.

Environmental conditions are key drivers of life-history evolution, and the urban environment is an extreme form of land-use readily inhabited by avian wildlife, whose life-history variation in such altered environment is still poorly understood. Recently, the study of environmental variables associated with urban living—which include shifts in temperature, light, noise or food availability—has attracted increased attention. Another environmental axis that sets the urban space at odds relative to natural habitats is high human abundance, yet very little is known about its effect on avian fitness. We developed a protocol to quantify human presence by performing repeated counts of humans on the ground within a 15 m radius of nestboxes monitored in two centrally-located study areas of a European capital city. In parallel, a GIS-based approach was used to infer nestbox distance to the nearest path and road. Multiple counts of human presence around each nestbox yielded moderate to high repeatabilities (0.6 ≤ r ≤ 0.8) while requiring considerable resources time-and people-wise. In contrast, GIS-based estimates of nestbox distance to paths and roads were time efficient and generated highly repeatable results. The effects of (i) human presence around each nestbox, (ii) nestbox distance to the nearest path and (iii) nestbox distance to the nearest road were tested on reproductive traits of blue tits Cyanistes caeruleus and great tits Parus major breeding in two urban sites. Human presence did not influence blue tit or great tit life-history traits and reproductive success, suggesting reproductive habituation to humans in an urban landscape. In contrast, nestbox distance to roads shortened incubation time in great tits while nestbox distance to paths increased incubation time in blue tits. Moreover, blue tit offspring 2 weeks after hatching were lighter closer to roads. Our study confirms the reliability of a field protocol capturing human presence around multiple fixed locations that can be easily implemented in either urban or rural landscapes. At the same time, it appears that when applied to two urban sites where habituation to humans might have occurred, it is infrastructural networks rather than human presence per se that played a greater role in tit reproductive trait variation.