No abstract

Many European towns and cities have undergone reurbanisation processes in recent decades. However, their effects on urban biodiversity have been poorly studied. Currently urbanisation processes include park remodelling, which involves the replacement of semi-natural substrates (natural grass, bare soil) with artificial ones (pavement, concrete, areas for dogs, artificial grass). Our aim was to explore, for the first time, the effects of park remodelling on the trends and abundance of a declining urban exploiter, the House Sparrow. An abundance index of House Sparrows was obtained in 32 urban parks of four towns in the Valencian Community (Spain) in four summers (2015)(2016)(2017)(2018). Of the studied parks, 10 were remodelled during the study period. Before remodelling, the trends and abundance of House Sparrows in both groups of parks were similar and stable on average, which suggest no bias between both park groups. However, House Sparrow abundance was significantly reduced in parks affected by remodelling works while in those non-remodelled it remained stable. Park remodelling might be linked to a reduction in both habitat suitability and availability of trophic resources, which could harm urban House Sparrows populations and possibly other species as well. Therefore, new park policies and urban planning measures are urgently needed to preserve urban House Sparrows.

Urbanisation processes are increasing worldwide at surprising rates affecting wildlife in many ways: changing habitat structure, reducing resources, and modifying the distribution, composition and abundance of local biota. In different countries, urban waste collection techniques are evolving and surface rubbish containers (neighbourhood receptacles for temporarily storing anthropogenic household waste located above-ground on the streets) are being replaced with underground ones (metal boxes with steel chutes that fed into large underground containers) to improve sanitation measures, to avoid bad smells and waste scattering by animals. We aimed to detect if House Sparrows were more abundant close to surface rubbish containers than close to the underground ones. We recorded an abundance index of House Sparrows during two visits in winter 2018–2019 to point counts located in groups of both container types (80 and 85 groups of underground and surface containers, respectively) in eight towns of Eastern Spain. We modelled the abundance index according to rubbish container type, and 14 other environmental variables at four scales: container, nearest buildings, near urban features, and general locality features using GLMMs. House Sparrows were more abundant close to surface than to underground rubbish containers, which may be linked with higher food debris availability. The presence of other urban features (bar terraces, private gardens, mature trees) interacting with the rubbish containers also influenced the abundance of House Sparrows. The replacement of above-ground rubbish containers with underground ones may deprive House Sparrows resources, which could lead to the decline of this species, especially in urban areas with little green cover.

No abstract

Desde los primeros asentamientos humanos permanentes del Holoceno, hace 10 000 años, hasta las ciudades contemporáneas, las aves han cohabitado con los seres humanos. En las últimas décadas la urbanización ha crecido exponencialmente en el planeta y, en 2030, más del 60% de la población mundial vivirá en zonas urbanas. En función de su tolerancia a la urbanización las aves se clasifican en tres categorías: evitadoras, adaptadoras o explotadoras urbanas. Las ciudades occidentales contemporáneas atraen a las aves por la presencia de recursos tróficos abundantes y predecibles, la reducción en la diversidad de depredadores o la provisión de estructuras donde ubicar los nidos, entre otras. Sin embargo, la urbanización es uno de los mayores problemas actuales para la biodiversidad y el modelo de ciudad contemporánea puede dejar de ser atractivo para las aves e incluso causar el declive a ciertas especies ligadas a medios urbanos. Algunas razones que explican este proceso son: la gestión urbana y la pérdida de zonas verdes, la contaminación, la comida antropogénica y las nuevas tendencias arquitectónicas. Un cambio en el modelo de ciudad contemporánea que proteja la biodiversidad, aunque es un reto difícil, es posible siguiendo ejemplos como el de la infraestructura verde y sostenibilidad ambiental de la ciudad de Vitoria-Gasteiz (España).

The Eurasian collared dove (Streptopelia decaocto) is an invader species, and its distribution is continuously on the increase. Today its expansion has spread to the American continent. In this study we describe the effects of the urban environment on the Eurasian collared dove in eastern Spain. The abundance and presence of this dove were analyzed in 46 localities using counting points. Overall, 220-point counts were surveyed between autumn 2015 and late-winter 2016. A hierarchical partitioning analysis was used to identify explanatory variables of different types such as resources, climate and urban structure, and human presence, which may influence the presence and abundance of this species. In the case of presence, the number of town inhabitants, parks, mean minimum temperature, exotic vegetation and schools had a positive association, while pedestrian number and restaurants had a negative association. Abundance was positively related to native vegetation, exotic vegetation, and water, while urban area was negatively associated with it. Exotic vegetation was the only variable that has a positive relation to presence and abundance. These results can help to predict the use of urban habitats in potential localities for its invasion.

Summary Green areas are key habitats for urban avifauna. Urban parks stand out from other anthropic habitats especially in providing trophic resources for many bird species. Consequently, modifications of these green zones can imply major changes in urban biodiversity. Potential pernicious urban remodelling is taking place in parks of eastern Spain because natural grass is being replaced with artificial grass to save water and to avoid management. This study aimed to determine whether remodelled parks with artificial grass harbour lower avian diversity (alpha, beta and gamma diversity) than traditional parks with natural grass. We surveyed 21 parks with artificial grass and 24 parks with natural grass in 18 towns of the Valencia Region in autumn 2020. In each park, we carried out 5-minute and 25-m radius point counts for determining bird species and their abundance. The effects of park area and grass type on alpha diversity (species richness, Shannon diversity index, Pielou’s Evenness and total abundance) were tested by means of GLMs. Differences in beta diversity and its components (nestedness and turnover) were also analyzed with the Bray-Curtis dissimilarity index. Gamma diversity was assessed by means of species accumulation curves. Finally, differences in community composition were tested by PERMANOVA and SIMPER tests. The parks with natural grass always harboured higher gamma diversity, species richness and abundance. Turnover was higher in parks with natural grass, whereas nestedness was higher in artificial grass parks. Differences in community composition were due mainly to abundance differences in common ground-feeding birds. We highlight that the trend of replacing natural by artificial grass in urban parks has harmful effects on urban bird communities and is a threat to bird conservation. Although artificial grass might save water, the effects on urban biodiversity should be carefully evaluated.

Despite more studies being carried out to know the impacts associated with plastic debris and much effort being spent on marine ecosystems, the impacts of plastics on terrestrial and freshwater species remain largely unknown. Here, we explored the presence of anthropogenic materials in nests of two wader species, the gull-billed tern (Gelochelidon nilotica) and the black-winged stilt (Himantopus himantopus), breeding on the inland salt lakes in the “La Mancha Húmeda” Biosphere Reserve, Central Spain. We revealed the presence of anthropogenic debris, mainly macroplastics (>5 mm), in 2.4% and 12.5% of the sampled nests of the gull-billed tern and the black-winged stilt, respectively. The fragments found in nests ranged from 8 mm to 257 mm for the gull-billed tern and from 7 mm to 19 mm for the black-winged stilt. This debris showed no clear pattern of color or size and probably originated both in the agricultural activities in the surroundings and domestic refuse. Although we did not detect any pernicious impacts on adults or chicks (e.g., entangled, injured, or dead individuals), the presence of plastics and other human waste directly placed in nests located in a protected area should warn us about the ubiquity of these pollutants, and the endocrine and immunological effects, among others, that may reduce the recruitment of new animals to the population should be assessed.