Use of urban marine habitats by foraging wading birds

Wading birds (i.e, Ardeidae: herons, egrets, and bitterns) are a guild of waterbirds that forage in coastal habitats which in the US and Europe are often located in close proximity to urban centers. However, the use of urban marine habitats may have consequences for bird populations, as birds can be subject to stress from increased levels of passive and active human disturbance. We examined the effects of human disturbance, available foraging habitat, and prey abundance on wading bird density and species richness at 17 urban coastal sites in Narragansett Bay, Rhode Island USA. The sites represented a gradient of immediately adjacent residential and commercial land use (e.g., 0.0–67.7% urban land use within a 30.5 m buffer of the sites) within an urban matrix (i.e., all sites were located within a suburban center with a population of about 85,000 people). Wading bird density (0.62 ± 0.12 birds ha⁻¹) and species richness (average 4.49 ± 0.37 species across all sites) were not influenced by passive human disturbance as measured by the extent of urban land surrounding a site. However, wading bird density and species richness both decreased significantly as active disturbance (i.e., number of boats moored or docked upstream of the site) increased (r = −0.56, F = 6.85, p = 0.019 and r = −0.73, F = 16.6, p = 0.001, respectively). In addition, both density (r = 0.72, F = 16.2, p = 0.001) and species richness (r = 0.72, F = 16.2, p = 0.001) increased concomitantly with a prey index that combines the density of fish and invertebrates on which the birds feed with the amount of available shallow water foraging habitat at a site. Our results suggest that wading birds i) may not be negatively affected by urban land surrounding estuarine foraging areas in and of itself; and ii) may be utilizing urban areas in the absence of high levels of active disturbance to take advantage of potentially enhanced prey resources. In the case where the benefits of foraging at a site outweigh the costs related to human disturbance, urban marine habitats may need to be considered for restoration or protection from further increases in active human disturbance.     

The influence of anthropogenic resources on multi-scale habitat selection by raccoons

With the continuing spread of urban areas, gaining a greater understanding of the effect of human presence on wildlife species is essential for wildlife managers. We determined the influence of anthropogenic resources on home range size and habitat selection of raccoons (Procyon lotor) during summer (June–August) 1996–2000 for 120 raccoons at three sites exposed to varying levels of urbanization and anthropogenic resources, specifically food. Home range estimates were larger (P < 0.05) at the rural site than the suburban and urban sites for both genders. We used compositional analysis to examine raccoon habitat selection at the second-order home range, second-order core area, and third-order home range scales. Woodland was consistently a highly-selected habitat type for both sexes at every spatial scale. Relative to other habitat types, habitat associated with human-related food (human use areas) was selected most often at the urban site, intermediately at the suburban site, and not selected at the rural site. Spatial scale also affected habitat selection. Human use areas were preferentially selected at the second- and third-order level at the urban site, third-order level only at the suburban site, and at neither level at the rural site. Additionally, intersexual differences in habitat selection were reduced at the urban site, with both sexes preferentially selecting for human use areas as well as woodland habitat. Smaller home ranges in urbanized environments are often attributed to the abundant and concentrated anthropogenic resources associated with human activity, but with little empirical support. Our habitat selection analyses followed our predictions that raccoon foraging is strongly influenced by the artificial distribution and abundance of human-related food. Male and female raccoons in urban areas reduce their foraging patterns and focus their foraging activity on anthropogenic foods.     

Suburban wildlife: Lessons,challenges, and opportunities

The United States, as well as most developed and many developing nations worldwide, is becoming increasingly urban and suburban.Although urban, suburban, and commercial development account for less than one percent to just over 20% of land use among states, 50–90% of the residents of those states can be classified as urban or suburban dwellers. The population of the U.S. as a whole has risen from being > 95% rural in the 1790s to about 80% urban-suburban today. With these changes in land use and demographic patterns come changes in values and attitudes; many urbanites and suburbanites view wildlife and nature differently than rural residents. These are among the challenges faced by wildlife biologists and natural resource managers in a rapidly urbanizing world. In 2003, we convened a symposium to discuss issues related to suburban wildlife. The papers presented in this special issue of Urban Ecosystems address the lessons learned from the early and recently rapidly expanding literature, the challenges we face today, and the opportunities that can help deal with what is one of the biggest challenges to conservation in a modernizing world.     

Reproduction, juvenile survival and retention in an urban fox squirrel population

Fox squirrels in an urban environment had an average litter size of 2.83 (95% CI 2.5, 3.16) which was similar to rural populations. Nonetheless, the proportion of squirrels reproductively active during the summer/fall breeding season (0.73) and annually (spring + summer/fall) was higher (1.23) than previously recorded for non-manipulated rural populations. The average monthly survival rate () of urban juvenile fox squirrels during the first 14 weeks of life was higher than reported for adult populations in the area. High rates of reproduction and juvenile survival yielded high juvenile to adult ratios (juveniles/adults) averaging 0.44. Retention of juveniles after 6 months (15%) was significantly less (χ ² = 7.24, p = 0.0071) than adults/subadults (40%). Results suggest that the urban environment provides quality habitat for fox squirrels and fox squirrels in urban environments have the potential to be a source population for surrounding suburban and rural environments.     

Chemistry of growth medium and leachate from green roof systems in south-central Texas

Installation of intensive and extensive green roofs is becoming popular for reducing runoff from impervious surfaces in many cities around the world. Most studies on runoff quality from green roofs have been conducted in cooler northern climates. We examined the losses and gains of nutrients, cations and selected anions in planted and unplanted growth medium and compared these to initial growth medium (IGM) typically used for green roof modules in south-central Texas. Water extracts of growth medium and leachate from three replicates of unplanted growth medium and three planted species (Sedum kamtschaticum, Delosperma cooperi and Talinum calycinum) were examined. During the first 6 months after establishment we observed high losses of nitrate (25 to 44 mg kg⁻¹), dissolved organic carbon (DOC: 155 to 190 mg kg⁻¹) and nitrogen (DON: 9.0 to 11.2 mg kg⁻¹) and orthophosphate-P (1 to 2 mg kg⁻¹). Average leachate concentrations based on four rain events 6 months after establishment ranged from 0.3 to 6.6 mg L⁻¹ in planted modules and 6.3 mg L⁻¹ in unplanted modules for nitrate-N, 38 to 42 mg L⁻¹ in planted modules and 32 mg L⁻¹ in unplanted modules for DOC, 2.1 to 3.1 mg L⁻¹ in planted modules and 2.1 mg L⁻¹ in unplanted modules for DON and 0.27 to 0.37 mg L⁻¹ in planted modules and 0.40 mg L⁻¹ in unplanted modules for orthophosphate-P. We suggest that after the establishment of green roofs, leachate losses may contribute some runoff concentrations of nitrogen, carbon and phosphorous in urban areas.     

Towards a theory of the American rural residential land market

Since the late 1960s there has been a notable acceleration in America in the demand for rural residential land within commuting range of urban and suburban employment and service opportunities. American rural residential households do not seem to purchase acreage tracts primarily for their ‘productive’, or resource value, however. Instead, they purchase rural land for its ‘consumptive’ or residential value, as its value is primarily derived from the bundle of residential attributes associated with it. Over time, rural land within commuting range of metropolitan areas becomes underproductive and idled — a situation which precedes urban sprawl. Rural residential development has thus become a focus of debate on the effects and inefficiencies associated with urban sprawl. Yet, not enough is known about the nature of the rural residential land market. It is argued that American rural residential households are different from their suburban and urban counterparts for at least three reasons. First, they are distinguishable for their pursuit of self-sufficiency, self-expression, and the cultural status that a rural residential lifestyle offers. Second, they seek low cost rural jurisdictions in order to afford more housing and land than they could afford in higher cost urban and suburban locations. Third, they value distance from the city center colinearly with externalities such as pollution, crime, overcrowding, and noise associated with central city areas. In the latter sense, American rural residential households value land more highly the farther away it is from the city center, but discount land value the farther away it is from the boundary of urban development. In light of these considerations, this paper (a) reviews the literature describing the motivations of American rural residential households, (b) poses a theory of the American rural residential land market, (c) applies the theory to a case study, and (d) offers implications of the theory to planning efforts aimed at preserving resource land and containing urban sprawl.     

Evaluating the distribution of invasive woody vegetation around riparian corridors in relation to land use

Invasive species have been causing important and irreversible impacts to native species and communities of ecosystems. They distort ecosystem functions by degrading forest lands, wetlands, and agricultural habitats and replace the native vegetation and reduce biodiversity, forest productivity, and suitable wildlife habitat. To address disturbances caused by invasive species occurrence, further information is needed regarding the occurrence, extent, and dispersal of invasive species and how land use may increase the spread of these species. The objective of this study was to find the frequency and dominance of three invasive species common to riparian areas of east Alabama: Ligustrum sinense (Chinese privet), Elaeagnus pungens (silverthorn), and Triadica sebifera (Chinese tallow tree). Surveys of these species in riparian forests in and around Auburn, Alabama were conducted to show the relative extent of these shrubs and their relation to urban land use. It was expected to see the highest levels of invasive species in the city center with decreasing levels radiating outward into rural areas. Another objective was how urban land use may affect the presence-absence and prevalence of these non-native plant species within study sites. The results showed that around the city center and suburban lands, cover of both Chinese privet and silverthorn tended to increase. In contrast, Chinese tallow tree density percent cover showed an opposite trend with landscapes close to city center often having slightly less cover. This study shows that urban land use may be an important association with distribution of invasive plant species.     

Vascular plants along an urban-rural gradient in the city of Tampere,Finland

The aim of this study was to analyse the spatial distribution of vascular plants along a 21-kilometre rural–urban–rural transect in the city of Tampere, Finland. The study emphasised the distribution of native and non-native species, both in absolute numbers and proportionally. The observed differences are explained by the share of forest land, the number of detached houses, distance from the city centre, and human population. Non-natives showed the highest values in suburban areas. Still, the difference in number of non-natives between suburban and central areas was quite small. In the city of Tampere, there are not continuous large areas devoid of vegetation. The number of native species remained high until the urban core and natives dominated in the rural-type areas of the city. However, there was not a great difference in the number of native species between rural and suburban areas. In the suburban areas, the detached houses and block-of-flats have little effect on the general vegetation. Proportionally, the share of natives decreases in line with the urban traits of the city. Urbanisation therefore affects native species in Finland. Overall, the characteristic features of a Finnish city, such as dispersed urban structure, small population, late urbanisation, abundant natural vegetation (forest) and the qualities of Finnish forests, guarantee the continuing diversity of urban vascular plants.     

Soil-atmosphere exchange of carbon dioxide,methane and nitrous oxide in urban garden systems: impact of irrigation,fertiliser and mulch

Urban green spaces provide important ecosystem services, such as amenity, biodiversity, productivity, climate amelioration, hydrological and biogeochemical cycling. Intensively managed urban gardens can sequester carbon through vegetation growth and soil C increase, but may experience nitrous oxide (N₂O) emissions and reduced soil methane (CH₄) uptake from irrigation and fertiliser use. Soil atmosphere exchange of N₂O, CH₄ and carbon dioxide (CO₂) was measured in lawn and wood chip mulched garden areas in Melbourne, Australia in winter, spring and summer under various water and fertiliser regimes. Gas exchange before and after lawn fertiliser application was measured continuously for three weeks using an automated chamber system. Applying fertiliser led to a peak N₂O emission of >60 μg N m⁻² h⁻¹, but overall only weekly irrigation (10 mm) significantly increased mean soil N₂O emissions above that in other treatments. Under mulch, mean soil N₂O emissions (14.0 μg N m⁻² h⁻¹) were significantly smaller than from irrigated lawn (27.9 μg N m⁻² h⁻¹), whereas mean soil CH₄ uptake under mulch (−30.7 μg C m⁻² h⁻¹) was significantly greater (p < 0.01) than in any lawn treatment. Lawns were either a weak CH₄ sink or source. Soil C density (0–25 cm) under mulch (12.5 kg C m⁻²) was greater that under lawn (8.0 kg C m⁻²). On a carbon dioxide equivalent (CO₂-e) basis, soil N₂O emissions offset the benefits of soil CH₄ uptake. Mulched garden areas provide greatest C sequestration potential in soil and vegetation and the smallest non-CO₂ emissions, as soil CH₄ uptake offsets a large fraction of soil N₂O emissions. Results of this study suggest that reducing the irrigation and fertiliser application to lawns can help mitigate GHG emissions from urban garden systems, and increasing the area of mulched perennial garden beds can also provide net GHG benefits; however, this needs to be tested in other garden systems with different soil types and environmental conditions.     

Short- and long-term effects of site factors on net N-mineralization and nitrification rates along an urban-rural gradient

Long- and short-term effects of urban site factors on net N-mineralization and nitrification rates were investigated in oak stands along an urban-rural land-use transect in the New York City metropolitan area. We used reciprocal transplants of undisturbed soil cores between urban and rural forests to determine the relative importance of long-term effects (mor vs. mull soils, quality of soil organic matter, and deposition of N) vs. short-term effects (soil temperature) of urban factors in controlling field N-transformation rates along the gradient. In addition, undisturbed soil cores from surface (A, Oe horizons) and subsurface (B horizon) soil were collected from urban, suburban, and rural stands and allowed to incubate in these respective sites to compare the net effect of all urban factors with transplanted-core results. The transplant experiment revealed that soil type (long-term) affected net N-mineralization and nitrification rates. Urban soils nitrified nearly 6.3 and 5.4 times more than rural soils incubating in urban and rural stands, respectively (p = 0.003 and p = 0.002, respectively). Similarly, in rural stands total accumulation of inorganic N was 87% higher in urban than in rural soils, whereas in urban stands, urban soils mineralized 83% more N than rural soils (p = 0.043 and 0.08, respectively). Comparing soils incubating in their native locations, urban soils incubating in urban stands mineralized more than 2.5 times the amount of N than rural soils incubating in the rural stands (p = 0.019). By contrast, urban soils incubating in urban stands exhibited a 8-fold increase in nitrification over rural soils incubating in rural stands (p = 0.008). As with the transplanted cores, the urban and suburban environments had a positive effect on net rates of N-mineralization and nitrification in both surface and subsurface layers of soil. The surface layer of suburban and urban stands had a 3- and 2.3-fold higher accumulation of net inorganic N than rural stands (ANOVA, p = 0.05). Similarly, in the subsurface layer both urban and suburban stands had 2.6-fold higher net N-mineralization rate than rural stands (ANOVA, p = 0.01). Along this urban-rural gradient, soils in oak stands exhibit higher net nitrification and, to a lesser extent, net N-mineralization rates in urban and suburban stands than in rural stands. Results from the transplant experiment and in situ measurements of surface and subsurface soil indicate that long-term effects (mor vs. mull soils, N deposition) contribute to the higher N-transformation rates in urban and suburban stands. As a result of these effects, urban and suburban stands have the potential for higher losses of N than rural stands.     

Urbanicity Moderates Associations between Family Income and Adolescent Academic Achievement

Research has shown that family income's relations to early childhood achievement is stronger in large inner cities and weaker in less urbanized areas. Research has not yet considered whether links between family income and achievement in adolescence differ across the urban to rural landscape. Using nationally representative data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998–1999 (N ≈ 9,350), this study examines differences in family income's links with eighth‐grade achievement across large urban, small urban, suburban, and rural communities. The point at which income‐achievement links plateau occurs later in the income distribution in less urbanized areas. The magnitude of the association between family income and reading and science skills also differs across the urban‐rural continuum, such that family income has stronger relations to reading and science achievement in urban cities and weaker links in suburban and rural communities.     

Spatial distribution and the value of green spaces for urban red-tailed hawks

Raptors increasingly live and nest successfully in urban areas. In the urban landscape of Hartford, CT, red-tailed hawks established home ranges in large green spaces such as parks, golf courses, and cemeteries but also nested successfully in the commercial district of downtown and in densely built urban and suburban neighborhoods. Data collected from 11 radio-tagged breeding adult hawks indicated that year-round home ranges averaged 107.7 ha, much smaller than home ranges reported for hawks inhabiting rural areas. Most hawk home ranges had multiple core areas that were usually associated with favored perches or larger patches of ‘usable’ green space, defined as patches ≥0.25 ha in size, and home range size was positively associated with larger usable green space patches in core areas. Most nests were located in the largest core area and were within a larger patch of green space within the largest core area. Rather than just the amount or size of green space patches, the value of urban green spaces for these hawks likely also varies with the number and proximity of suitable perches such as buildings or tall trees, types and density of prey, and amount of human activity in and adjacent to these spaces. Territoriality and intraspecific competition may also influence home range size and dispersion of red-tailed hawks nesting in Hartford. In this urban area, mortality due to ingestion of rodenticides and collisions with vehicles affected hawk reproductive success.

     

Effect of urbanization on surface water chemistry in south-central Texas

The use of state factors can adequately describe the biogeochemistry and geochemistry of relatively undisturbed surface waters. Watersheds with increasing proportions of urban and suburban land use, particularly in sub-tropical, semi-arid and arid urban areas, that utilize irrigation for turfgrass and landscaping may have a low flow urban signature that relates to the source water used by municipal water suppliers. We examined thirteen watersheds; four with waste water treatment plants (24–67% urbanization), four rural (< 30% urbanization) and five urban (> 30% urbanization) in a humid sub-tropical oak savannah in south-central Texas. Three of our urban and one of our rural watersheds displayed the signature of municipal tap water. Three out of four watersheds with waste water treatment plants displayed the signature of treated sewage effluent. We suggest as a result of this study that the chemistry of municipal tap water particularly that with high sodium and bicarbonate, used in urban watersheds for irrigating turfgrass and landscapes may have detrimental effects on base flow stream water quality after it has interacted with watershed soils.     

Salinization alters ecosystem structure in urban stormwater detention ponds

Stormwater ponds now comprise a significant portion of standing water in urban areas. These ponds act to sequester excess run-off and pollutants, such as road salt deicers. While these man-made ponds are not intended to serve as freshwater ecosystems, it is becoming clear that they do provide habitat for many organisms, but we know little of their ecosystem structure, function and interactions with pollutants. From April through June 2009, we surveyed 8 stormwater ponds in the Red Run Watershed, Baltimore County, Maryland, USA to describe patterns in aquatic food webs associated with a gradient in road salt inputs. Periphyton, phytoplankton and zooplankton samples were collected from each pond every 4–6 weeks. Specific conductance, a measure of chloride salt loading, among the 8 ponds varied widely throughout the survey, ranging from 99 μS cm⁻¹ to 19,320 μS cm⁻¹. Low (average = 404 +/− 82.6 (SE) μS cm⁻¹) and medium (average = 1749 +/− 267 (SE) μS cm⁻¹) conductance ponds had lower algal biomass and higher densities of zooplankton taxa relative to high (average = 7231 +/− 2143 (SE) μS cm⁻¹) conductance ponds, which were largely devoid of all zooplankton through the end of May. The observed decline in zooplankton density along an increasing chloride gradient is consistent with experimental results of road deicer effects, suggesting algal resources are possibly freed from grazing pressure as zooplankton consumers are negatively impacted by road salt exposure. Our results highlight the potential for both direct and indirect effects of road deicers on freshwater communities.     

A microcosm study of the common night crawler earthworm (<Emphasis Type="Italic">Lumbricus terrestris</Emphasis>) and physical,chemical and biological properties of a designed urban soil

Designed soils are used in specialized urban areas, such as under sidewalks or on roof-tops. These substrates have coarse light-weight aggregates to meet load-bearing specifications with soil in voids for rooting medium. A full-factorial microcosm approach was used to study Lumbricus terrrestris (two adult worms added and no-worms added), compaction (bulk density of 1.95 and 1.48 g cm⁻³), and litter (litter and no-litter additions) in a designed soil. Earthworm biomass, soil physical, chemical, and biological properties, anion leaching and surface C efflux was measured on days 0, 7, 14, 21, 28, 72, 112, and 140. Earthworms decreased bulk density in compacted soil, but did not impact density of un-compacted soil. Earthworm biomass increased days 7 to 14, but declined from days 28 to 140, likely as result of the abrasiveness of the aggregate component and relatively shallow depth of the soil (25 cm). During the period of increasing earthworm biomass, surface C efflux, microbial biomass N, soil Ca²⁺ and NH₄⁺ increased with earthworms. During the period of declining earthworm biomass, surface C efflux, microbial biomass N, soil Ca²⁺ and NO₃⁻, and leachate NO₃⁻ increased, and soil pH decreased with earthworms. While alive and dying, Lumbricus terrestris stimulated microbial activity and biomass and nutrient availability, but an apparent shift to nitrification was observed as earthworm biomass declined. The results show Lumbricus terrestris to improve designed soil properties for plants, but the improvements may be short-lived due to the inability of these earthworms to survive in the designed soil.     

Establishing turf grass increases soil greenhouse gas emissions in peri-urban environments

Urbanization is becoming increasingly important in terms of climate change and ecosystem functionality worldwide. We are only beginning to understand how the processes of urbanization influence ecosystem dynamics and how peri-urban environments contribute to climate change. Brisbane in South East Queensland (SEQ) currently has the most extensive urban sprawl of all Australian cities. This leads to substantial land use changes in urban and peri-urban environments and the subsequent gaseous emissions from soils are to date neglected for IPCC climate change estimations. This research examines how land use change effects methane (CH₄) and nitrous oxide (N₂O) fluxes from peri-urban soils and consequently influences the Global Warming Potential (GWP) of rural ecosystems in agricultural use undergoing urbanization. Therefore, manual and fully automated static chamber measurements determined soil gas fluxes over a full year and an intensive sampling campaign of 80 days after land use change. Turf grass, as the major peri-urban land cover, increased the GWP by 415 kg CO₂-e ha^?1 over the first 80 days after conversion from a well-established pasture. This results principally from increased daily average N₂O emissions of 0.5 g N₂O ha^?1 d^?1 from the pasture to 18.3 g N₂O ha^?1 d^?1 from the turf grass due to fertilizer application during conversion. Compared to the native dry sclerophyll eucalypt forest, turf grass establishment increases the GWP by another 30 kg CO₂-e ha^?1. The results presented in this study clearly indicate the substantial impact of urbanization on soil-atmosphere gas exchange in form of non-CO₂ greenhouse gas emissions particularly after turf grass establishment.     

Determining the effect of urbanization on generalist butterfly species diversity in butterfly gardens

This study investigates the effects of urbanization on local butterfly populations and the role of butterfly gardens in preserving regional butterfly diversity. Data are from 135 butterfly gardens of varying size, location, and number of blooming plants in the Washington DC metropolitan area observed during 2001 and 2002. We investigated the species diversity for comparable gardens in rural, suburban, and urban locations to determine whether the landscape matrix surrounding otherwise suitable habitat affects the diversity found in the habitat. We hypothesized that, once factors such as garden size and number of blooming plant species were taken into account, butterfly diversity for 12 generalist species would decrease as urbanization increased. We found that there were systematic decreases (with one exception) in diversity from rural to suburban to urban gardens only for medium-sized gardens (0.10 to 0.20 ha) with one to ten types of blooming plants, and large gardens (>0.20 ha) with over 20 types of blooming plants. Gardens of other sizes or plant communities showed some decreases in diversity from rural to suburban to urban sites, but these differences were not consistent across the urban/rural gradient. Results of this study indicate that local butterfly diversity is negatively affected by increasing levels of human population, but that the matrix is just one factor determining generalist species diversity.     

Nature of vegetation and building morphology characteristics across a city: Influence on shadow patterns and mean radiant temperatures in London

Vegetation and building morphology characteristics are investigated at 19 sites on a north-south LiDAR transect across the megacity of London. Local maxima of mean building height and building plan area density at the city centre are evident. Surprisingly, the mean vegetation height (z_v3) is also found to be highest in the city centre. From the LiDAR data various morphological parameters are derived as well as shadow patterns. Continuous images of the effects of buildings and of buildings plus vegetationon sky view factor (Ψ) are derived. A general reduction of Ψ is found, indicating the importance of including vegetation when deriving Ψ in urban areas. The contribution of vegetation to the shadowing at ground level is higher during summer than in autumn. Using these 3D data the influence on urban climate and mean radiant temperature (T _mrt ) is calculated with SOLWEIG. The results from these simulations highlight that vegetation can be most effective at reducing heat stress within dense urban environments in summer. The daytime average T _mrt is found to be lowest in the densest urban environments due to shadowing; foremost from buildings but also from trees. It is clearly shown that this method could be used to quantify the influence of vegetation on T _mrt within the urban environment. The results presented in this paper highlight a number of possible climate sensitive planning practices for urban areas at the local scale (i.e. 10²- 5 × 10³ m).     

How protecting a suburban forest as a natural reserve effected small mammal communities

Restoration of mammal communities was studied between 1975–1984 and 2001–2009 (over ca. 30 years) in two suburban forests in central Poland: one protected as a natural reserve and one not protected. The mammal community in the legally protected forest showed more extensive changes than in the case of the nonprotected forest. In the natural reserve, the numbers of Microtus subterraneus, Apodemus agrarius, Rattus norvegicus and Mus musculus decreased while insectivores (mostly Sorex araneus), bats and Apodemus flavicollis increased in numbers. The community of small mammals in the reserve became more similar to the community from the relatively natural area – Białowieża Primeval Forest (eastern Poland). A protection supported restoration processes of tree stands and consequently started to increase the numbers of mammalian species typical of more natural habitats, as well as to reduce the numbers of synanthropic species and those connected to open areas. In the nonprotected forest, fewer species changed their abundance (M. subterraneus decreased, insectivores, bats and A. flavicollis increased). However, an increase in the percentage of bats and a decrease of M. subterraneus in mammal communities of both forests could reflect general trends in their populations noted in recent decades. The population decline of Warsaw’s urban species – A. agrarius perhaps is the best indicator of the restoration of suburban forests.     

Frugivory and habitat use by thrushes (Turdus spp.) in a suburban area in south Brazil

Thrushes (Turdus spp., Turdidae) are among the most common frugivorous birds in urban areas around the world, where they disperse the seeds of a variety of plant species. We studied the abundance, habitat use, foraging behavior and diet of four thrush species (Turdus rufiventris, T. amaurochalinus, T. leucomelas, and T. albicollis) in a suburban area in south Brazil. Abundance, habitat use and foraging behavior were based on birds surveyed along a 3,240 m transect crossing open (formed by lawns, streets, and buildings) and forested areas. Diet was based on fecal samples collected from mist-netted birds. Turdus rufiventris was the most abundant species, followed by T. amaurochalinus, T. leucomelas, and T. albicollis. All species used forest fragments more frequently than expected by chance. A total of 91.8% (n = 147) of the fecal samples contained fruit remains, while 42.2% contained only animal matter. Most of the foraging records were on the ground, where birds got mainly invertebrates. Fruits and invertebrates were eaten more frequently in open than in forested areas. A total of 25 seed morfospecies were found in the droppings, including five exotic plant species. Thrushes overlapped widely in the fruit composition of their diets. The high abundance and degree of frugivory, coupled with the frequent use of forest patches, indicate that thrushes are among the great bird contributors to the seed dispersal occurring in urban forest patches, potentially influencing the vegetation dynamics of such habitats so important for the maintenance of the biodiversity in urban areas.