Reconciling the Chicago River for birds and people

The Chicago River’s north branch intersects multiple urban land uses, including residential, industrial, commercial, and recreational. The north branch also supports a diversity of birds exploiting a variety of resources and structures along the river as habitat. From three breeding seasons of point count surveys, I assess the breeding bird communities in four different sections, representing four different restoration or management styles. These four river sections are also very different with regards to the surrounding neighborhood demographics. These data serve as both a baseline for future studies to evaluate restoration projects along the Chicago River, and as a snapshot to compare bird diversity and community composition between these river sections given current conditions. Unsurprisingly, the section of the river with the most extensive and longest established restoration effort had the highest species richness (number of species) of native birds. In terms of aquatic and riparian birds, however, that section was comparable to river sections with much less management in measures of both species richness and species composition. I discuss ways that river restoration efforts can be sensitive to demographic context, to avoid contributing to eco-gentrification and displacement.

Owens Valley nesting willow flycatcher under pressure

Willow flycatchers (Empidonax traillii; WIFL) nest along the Owens River and Horton Creek in the Owens Valley. Migrating WIFL visit these sites as well as many other tributaries to both the Owens River and Mono Lake. We estimate there are approximately 35 WIFL territories in the Owens valley, or 5% of territories in California. Nesting WIFL in the Owens Valley are likely the federally endangered southwestern subspecies (E. t. extimus; SWIFL). The Chalk Bluff nesting site is particularly important as large nesting areas tend to be both rare and important for SWIFL and it contains more than half (63%) of all known WIFL territories in the region, which also represents 12% of all nesting SWIFL in California. Between 2014 and 2016, WIFL territory numbers declined from 37 to 27 across the three largest breeding sites. Territory numbers may have been influenced by drought conditions or brown-headed cowbird (Molothrus ater; BHCO) nest parasitism. In 2015 and 2016, comprehensive nest monitoring found nest parasitism rates were >40%, and nest success was lower in parasitized nests (16%; N = 5/31) compared with non-parasitized nests (60%; N = 31/52). BHCO management could potentially improve nest success for WIFL as well as many other open-cup nesting riparian birds in the Owens Valley.

The Analysis of Urban Fluvial Landscapes in the Centre of Spain, Their Characterization, Values and Interventions

River areas are undoubtedly among the most valuable territorial areas in Europe, not only in terms of their eco-landscape and use but also, culturally. However, there is currently a sharp reduction in the extension and increase of deterioration of riverbanks around the world. A substantial part of losses and deterioration are associated with the artificialization of the territories, derived mainly from a less than respectful urbanization around these landscapes. Urban and peri-urban riverbanks are landscapes in expansion due to the continuous growth of built-up spaces. Therefore, they should be areas of preferential consideration, especially in territories with a marked tendency to dryness, like the centre of the Iberian Peninsula. This article aims to contribute to our understanding of these spaces through the study of four distinct cases in the centre of the peninsula, in particular: the river Manzanares running through the city of Madrid, the river Tagus in Toledo and running through Talavera de la Reina, and the river Henares in Guadalajara. Three of the four urban water courses analyzed are zones of special interest for waterfowl: they sustain a winter population that varies between 745 and 1529 birds and they provide a home to some globally threatened species. The density of the riparian birds is also very high during winter, these values oscillating between a mean of 141.16 and 240.12 birds/10 ha. It should be noted that the diversity of this group of birds in the four regions studies is also high (H > 2.4 nats). The article also examines the interventions and the urban planning criteria applied to these urban and peri-urban river spaces, inferring the need to reassess urban planning in river areas to ensure it is compatible with their operation, values and possible uses.

Hydroecological Problems of Dairy Estuary in Connection with the Instable of its Communication with the Azov Sea

Purpose. To identify the existing hydrological problems of the connecting channel between the Milky Liman and the Sea of Azov, due to insufficient morphometric performance of the channel. Methods. The analysis of hydroecological changes in the Dairy Way is the creation of a bulk model of the water body. Given the lack of a depth map, field mapping of the bottom of the studied reservoir was carried out. In order to calculate the volume of the water body of the Dairy estuary in 2012, eight transects were laid on which depth measurements were carried out through each 200 m measuring track. Measurement points were recorded using GPS. On the basis of the obtained data using the 3D Analyst module, a digital bottom relief model was constructed. His made it possible to calculate the volume of water in the estuary. Retrospective data of water volumes were calculated on the basis of measurements of the maximum depth of the estuary, obtained by the authors by way of measurements in certain years. To calculate the elements of water balance, the data of O. Dyakov was used.The transverse profile of the connecting channel is obtained as a result of field depth measurements in transects. The velocity of the flow in the channel and its throughput were determined according to the standard methods adopted in the hydrology, taking into account the direction and force of the offensive phenomena. Results. The hydrological and hydrochemical problems of the Dairy Estuary as the key territory of the Azov National Natural Park, a hydrological reserve of national importance and a wetland of international importance are analyzed. Their direct dependence on the unstable functioning of the connecting channel between the estuary and the Sea of Azov has been revealed. A historical cut of the features of the functioning of the ravine channel is shown. A digital 3D model of the estuary bottom has been built and the changes in the water level during different time periods are shown. A spatio-temporal analysis of the dependence of hydrological and hydrochemical indicators of the estuary on the channel functioning state has been made. It is revealed that the existing parameters of the connecting channel do not ensure the full functioning of the Molochny Liman and the fulfillment of ecological functions by it. Environmental changes that occur as a result of unstable and periodic connection of the estuary to the sea through the channel are analyzed: changes in water salinity, species diversity of invertebrates, fish and birds, areas of shallow water areas as feeding places for riparian birds, changes in the biological productivity of the estuary water area. Scientific novelty: On the basis of morphometric measurements of the connecting channel and the waters of the Milky Way, we have attempted to calculate the water supply capabilities of the estuary through the connecting channel and its functioning as a hydrological object. Conclusion: The adequate width and depth of the connecting channel and the regular connection of the Dairy estuary with the sea will lead to the restoration of hydrological and hydrochemical regimes to the ecologically optimal parameters. On the basis of this biological diversity in the estuary will be restored, its socio-economic and ecosystem functions will be renewed.