National Conservation Concern Research Articles

Landscape -scale predictors of persistence of an urban stock dove Columba oenas population

While a few species may thrive in urban areas, urban expansion is a major driver of biodiversity loss. Columbids such as feral Rock Doves (Columba livia domestica) and Common Woodpigeon (Columba palumbus) have adapted extremely well to the urban environment in Europe and beyond, but the Stock Dove (Columba oenas), a bird of farmland and woodland edge in the UK and of national conservation concern, is encountered infrequently in urban areas. Here we explore the multi-scale landscape associations of the little-studied Stock Dove within the urban matrix of Greater Manchester, UK, in order to identify its habitat requirements. We built a pilot model from historical citizen science records to identify potentially occupied sites within the city, and then surveyed these sites for Stock Dove during Spring 2019. We combined the survey results with citizen science records from the same period and described the habitat and landscape characteristics of sites occupied by Stock Dove using four variables at different scales plus twelve unscaled variables. We used a three-stage random forest approach to identify a subset of these variables for interpretation and a subset for prediction for the presence of Stock Dove within these sites. Key variables for predicting Stock Dove presence were their relative abundance in the landscape immediately beyond the core urban area, the greenness (NDVI) of the environment around sites, and the canopy cover of individual trees over 20 m high within sites. Stock Doves tended to be associated with habitats with more surface water during the non-breeding season than the breeding season. Our results highlight the importance of large trees within urban greenspace for this cavity-nesting species, softer boundaries around urban sites for Stock Doves and stock dove presence in nearby areas. While Stock Dove share many traits with species that are successful in the urban environment, they remain relatively poor urban adapters.

Odonata Assemblages in Anthropogenically Impacted Habitats in the Drava River—A Long-Term Study

Lotic freshwater ecosystems are among the most threatened ecosystems worldwide due to the effects of multiple stressors, such as intensive land use in their catchments, morphological alterations, flow regulation, pollution, and climate change. Odonata are often used as valuable indicators of ecological integrity and anthropogenic disturbance of freshwater habitats. Here, we present the results of a study on Odonata assemblages in anthropogenically impacted habitats (hydropower plant reservoirs, tailrace canals, drainage ditches, and old river channels) conducted over a nine-year period. The negative impacts of anthropogenic activities on inhabiting biota were confirmed—with only 11 species recorded, the Odonata assemblages were species-poor and had low population densities. Although most species recorded were generalists, some species of national conservation concern were detected. Among the physico-chemical water parameters, the concentrations of ammonium, orthophosphates, nitrates, and mineral oils in the water were found to be the most important determinants of Odonata assemblages. The preservation of near-natural sites in the vicinity of anthropogenically impacted and man-made habitats is important for maintaining the local Odonata fauna and for the preservation of rare species. Our results highlight the importance of long-term data for determining the occurrence of Odonata species and monitoring their population dynamics.

A review of the vascular plant flora of the Cairngorms Connect project area, Scotland, and some possible implications of forest expansion to the natural tree line

Cairngorms Connect, a partnership of four adjoining land owners, is committed to a 200-year vision to enhance and restore habitats, species and ecological processes across a 592 km2 area within the Cairngorms National Park. This will be achieved by, inter alia, expanding woodland to its natural altitudinal limit, including high altitude sub-alpine scrub. All or parts of six native Caledonian pinewoods occur here, c.26% of the national total. Ancient, semi-natural woodland within the Cairngorms Connect area is 43% of the National Park total. Modelling of the extent of potential-natural woodland (sensu Peterken, 1981, 1996) indicates that below 600 m all terrestrial habitats are potentially capable of supporting some degree of tree and scrub cover. 899 vascular plant taxa have been recorded here, of which 693 are native to the area. 7.6% of native taxa are endemic to Great Britain (and Ireland) or to Scotland; these are mainly Hieracia (Hawkweeds). Of the native taxa, 23% are of national, and 11% of regional conservation concern. Few native taxa are widespread within the Cairngorms Connect area, most are local or rare. 40% of native taxa have been recorded in five or less monads (1 km squares), with 16% recorded from just a single monad. 12% of native taxa are associated with shaded locations or semi-shade (Ellenberg Light values 3-5). 51% of taxa are found in partial shade to well lit locations (values 6 and 7) and 37% of taxa in well lit to fully lit locations (values 8 and 9). Native taxa with Light values of 6-7 are the most frequent in 92% of monads with more than 10 recorded taxa. 65% of taxa of national conservation concern favour well lit to fully lit locations (Light values 8-9). Shading of plants, at altitudes below the potential tree line, is strongly influenced by the extent of woodland and scrub and its structure, and by herbivore grazing levels determining height and structure of the field layer. To achieve forest expansion to the natural tree line by natural regeneration will require sustained low levels of grazing and browsing, for decades, or longer. This is already leading to a taller field layer and an increased density of tree regeneration. 40% of native taxa may be negatively impacted, if existing and new woodland becomes dense with a high level of shading. Of these 'at risk' taxa, 50% have maximum height less than 50 cm and may be especially at risk from sustained periods of low grazing. Limited disturbance and lack of open sites and bare ground for seedling recruitment is another potential constraint on vascular plants. The issue of vegetation succession and shading, leading to possible loss of plant diversity is likely to be much less of an issue at altitudes around and above the tree line. Here there are likely to be benefits, with possible expansion of tall herb communities.

An update to the species list of fungi in the Red Data Book of Ukraine

The Red Data Book of Ukraine is an official national Red List of threatened species of plants, animals and fungi that are protected by law in Ukraine. This state document contains information about the current status of these species, threats and measures for their conservation and reproduction. According to the Law of Ukraine On the Red Book Data of Ukraine, the Cabinet of Ministers of Ukraine provides official publication of the printed version of the Red Data Book of Ukraine at least once a decade. In 2021, based on the results of the studies carried out over the past decade, the list of fungi in the Red Data Book of Ukraine was extended to include twenty more species (Amylocystis lapponica, Battarrea phalloides, Butyriboletus appendiculatus, B. fechtneri, B. fuscoroseus, B. subappendiculatus, Chalciporus rubinus, Hemileccinum depilatum, Hericium erinaceum, Kavinia alboviridis, Montagnea radiosa, Mythicomyces corneipes, Phellinidium ferrugineofuscum, Plectania melastoma, Poronia punctata, Rubroboletus lupinus, R. rhodoxanthus, R. rubrosanguineus, R. satanas, and Suillus plorans), while nine species of fungi were excluded for various reasons (Anthurus archeri, Clathrus ruber, Entoloma nidorosum, Gyromitra slonevskii, Laricifomes officinalis, Morchella steppicola, Mutinus ravenelii, Phallus duplicatus, and Pseudocolus fusiformis). The article provides brief information and original photographs of the added twenty species of fungi of national conservation concern.

Shorebird Surveys of the Lahontan Valley Nevada, 1986–2019, with Recommendations on Monitoring and Management

Stillwater National Wildlife Refuge and Carson Lake and Pasture are the key components of the Lahontan Valley wetlands, designated in 1988 as a site of hemispheric importance in the Western Hemisphere Shorebird Reserve Network. In 1990, Congress authorized transfer of Carson Lake and Pasture from federal ownership to the state of Nevada, provided that the area be managed consistent with its designation as part of the network. To enhance protection and management of the site, and specifically to inform development of a management plan for Carson Lake and Pasture, we analyzed spring and fall surveys for shorebirds, 1986–2019, archived by the Nevada Department of Wildlife. Over the 34 years of surveys, we documented 28 species, 19 of which occurred in ≥50% of the years surveyed. Annual counts of all shorebirds combined exceeded 100,000 in 24% of the survey years and 20,000 in 94%. Annual counts of the American Avocet (Recurvirostra americana) exceeded 10% (45,000 individuals) of the estimated global population in three years, and of the Long-billed Dowitcher (Limnodromus scolopaceus; 50,000 individuals) in two years. On the basis of their numbers and frequency of occurrence or status as species of national conservation concern, we identified these two species plus nine others as priorities for management. We recommend conducting more consistent surveys and identifying specific opportunities to manage water quantity and quality, vegetation, livestock grazing, or other factors to benefit shorebirds.

Asperula L. Species Preserved in ‘Alexandru Beldie’ Herbarium

This paper provides a quantitative and general description of the main representatives of the genus Asperula L. present in the ‘Alexandru Beldie’ Herbarium. Currently, Asperula genus comprises 25 different taxa (18 with a status of species and 7 as intraspecific units), harvested mainly from the Romanian forests. The majority of plants are kept in very good conservation conditions (first and second conservation degrees). Two of the species (Asperula rumelica Boiss and A. graveolens subsp. graveolens) present in the Herbarium should be given high conservation priority since they are of national conservation concern, being included on the ‘Red List of Superior Plants from Romania’. The Asperula genus is widespread across the country and is mostly associated with mesobasic and eubasic forest soils, representatives of this genus having the value of indicator species.

Dietary preference of key microhabitat Diadema setosum: a step towards holistic Banggai cardinalfish conservation

The sea urchins Diadema setosum and D. savignyi are key symbionts of the Banggai cardinalfish Pterapogon kauderni, a species of global and national conservation concern. There is growing interest in Diadema propagation for conservation and human consumption; however little is known about the dietary preferences of Indo Pacific Diadema species. This study explored the feeding preference of Diadema setosum offered a choice of two macroalgae (Ulva reticulata, Gracilaria sp.) and two seagrasses (Thalassia hemprichii, Enhalus acoroides). Portions (5g) of the four feeds were attached to the corners of rectangular plastic cages and one D. setosum released in the centre of each cage. Uneaten feed was weighed after 24 hours. This procedure was repeated for 5 days with 8 replicates. Mean daily feed consumption/urchin was 4.31g,. All urchins ate a varied diet comprising all four feed types, with a significant preference (p < 0.01) for macroalgae (on average 80%). Our results point to an important role of D. setosum in macroalgal control; however this urchin might graze on cultivated seaweeds. Further research avenues include the use of macroalgae in prepared feeds for Diadema culture, including in the context of P. kauderni microhabitat rehabilitation.

The butterfly fauna of the Pilliga Forest, a large woodland remnant in the Brigalow Belt South bioregion in northern inland New South Wales, Australia

Sixty-three butterfly species representing five families have been recorded from the Pilliga Forest in northern inland New South Wales – the largest surviving remnant of native forest on the western slopes of the Great Dividing Range. This is one of the richest recorded butterfly faunas of any location on the New South Wales western slopes and adjacent plains, reflecting the location of the Pilliga Forest in a biogeographic overlap zone between northern and southern faunal assemblages with proximity to both the western plains and outliers of the mesic eastern highlands. No narrow-range endemic species or species of state or national conservation concern were recorded; however, half of the species recorded have patchy, discontinuous distributions within their broad range due to specific habitat requirements. Some minor western range extensions are recorded and two hilltopping sites are documented. This study highlights the significant biodiversity conservation value of the Pilliga Forest in the predominantly cleared western slopes bioregions.

An Evaluation of the Contemporary Uses and Cultural Significance of Mammals in Mexico

We evaluated current uses of wild mammals by indigenous and mestizo communities in Mexico by extracting data from 59 sources published or produced between 1987–2017, covering data from 240 localities and 3,905 questionnaires. We then calculated a Cultural Value Index (CVI) previously applied to plants to quantify resource use and assess the cultural significance of each mammal. A total of 82 species were reported, and the animals with the highest cultural importance according to their CVI (in brackets) were two species of deer (Odocoileus virginianus [18.32] and Mazama temama [10.04]), as well as the nine-banded armadillo (Dasypus novemcinctus [14.18]), white-nosed coati (Nasua narica [14.75]), collared peccary (Pecari tajaccu [11.90]), northern raccoon (Procyon lotor [11.28]) and spotted paca (Cuniculus paca [9.84]). The most common uses were for food, to reduce the damage or harm they cause, and for medicinal purposes, with O. virginianus, P. lotor, N. narica, and D. novemcinctus frequently hunted for all these reasons. Our analysis also highlighted the hunting of rarer species of national conservation concern, including commercial trading of body parts of the felids Panthera onca, Leopardus pardalis, and Leopardus wiedii. By quantifying the ethnozoological significance of wildlife to indigenous communities, indices such as CVI provide a robust measure of the extent of use and preference for particular species or taxa. This adds to the body of evidence used to develop effective regulations and laws related to harvesting and hunting, and helps promote a more sustainable and long-term approach to the use of natural resources.

Assessing the importance of High Nature Value farmlands for the conservation of Lesser Kestrels Falco naumanni

AbstractAgricultural areas, such as cereal cultivations, that support species of European and/or national conservation concern are considered as ‘High Nature Value’ farmlands (HNVf) and are very important for the preservation of biodiversity in Europe. The lesser kestrel Falco naumanni is a migratory falcon breeding largely in the HNVf of the Mediterranean basin. The main cause of its decline in Europe has been habitat loss and degradation as a result of agricultural intensification driven largely by the EU Common Agricultural Policies (CAP). In Greece, its population dropped by about 50% since the 1970s and its preferred habitats have shrunk. The aim of this study was to assess habitat preferences of breeding Lesser Kestrels in agro-ecosystems of Greece and relate these habitats to HNVf for conservation purposes. The study area is located in the plain of Thessaly, Central Greece, holding the main lesser kestrel breeding populations in the country, where dry cereal crops have been significantly depleted over the past decades. Species distribution models were developed with generalised additive models for the analyses. Predicted probability of lesser kestrel occurrence was found to be positively associated with farmed landscapes of dry cereal cultivations. Other important predictors were cultivated irrigated farmland and landscape heterogeneity. Main results of the statistical models agree with the findings of other habitatbased studies that highlight the importance of low-input farming systems, that is, HNVf, for safeguarding vital Lesser Kestrels habitats in their breeding grounds in the Mediterranean. A key conservation priority for conserving species dependant on HNVf is the maintenance of those low-input farming systems and the implementation of a greener CAP that would promote environmental-friendly farming practices to preserve and enhance biodiversity in the agro-ecosystems of Europe.

Reserva Natural Laguna Blanca, Departamento San Pedro: Paraguay’s First Important Area for the Conservation of Amphibians and Reptiles?

Geographical sampling bias and restricted search methodologies have resulted in the distribution of Paraguayan reptiles and amphibians being patchily known. Available data is almost entirely based on brief collecting trips and rapid ecological inventories, often several decades apart, which inevitably struggle to detect more inconspicuous species and patterns of abundance. This has led to a deficit in our knowledge of the true distribution and abundance of Paraguayan reptiles and amphibians. The establishment of the NGO Para La Tierra at Reserva Natural Laguna Blanca (RNLB), Depto. San Pedro, Paraguay allowed the first modern sustained, multi-method inventory of Paraguayan reptiles and amphibians to be performed at a single site. Despite the small size of the reserve (804 ha), a total of 57 reptiles (12 of national conservation concern) and 32 amphibians (one of national conservation concern) were collected during five years of random sampling, qualifying RNLB as the most biodiverse reserve for reptiles and amphibians in the country. Six species occurring at RNLB have been found at no other Paraguayan locality. Legal protection for this private reserve expired in January 2015 and the conservation implications of the inventory results are discussed. It is proposed that the long term legal protection of the reserve be considered a national conservation priority and that the diversity of the herpetofauna be recognized with the designation of RNLB as Paraguay’s first Important Area for the Conservation of Amphibians and Reptiles.

Breeding persistence of Slavonian Grebe (Podiceps auritus) at long-term monitoring sites: predictors of a steep decline at the northern European range limit

The Slavonian Grebe (Podiceps auritus) has its European northern range limit in northern Norway, and is a species of national conservation concern due to its small population size and unknown population trend. Long-term monitoring at the range limit suggests breeding site use is in decline. We used annual occupancy data from 104 breeding lakes monitored since 1991 in northern Norway to investigate correlates of change in occupancy. Persistence was 100 % until 1999, but thereafter decreased to 25 % (26 lakes with breeding pairs). A particularly steep decrease occurred between 2010 and 2012. Persistence increased with the number of pairs present in each lake in the initial monitoring year of 1991. The number of grebe pairs also decreased in the lakes that had continuous breeding persistence over the entire 22-year monitoring period, suggesting that a large-scale factor caused the population decline. Over the last year of the monitoring series, lake altitude was negatively related to the probability of persistence, indicative that locally harsh climate played some role in breeding distribution. The temporal pattern of persistence was not related to mean winter temperature at the breeding sites; however, the decrease between 2010 and 2011 coincided with a late ice melt in 2010. Monitoring that includes a larger area of the species’ range is required to conclude whether the observed decline can indicate an overall decline in population size, or range fluctuations at the edge of the species’ range. However, investigating the processes that determine population range borders can give insights into important limiting factors pertinent to the conservation of species in the long term.

Scale-dependent and multi-metric nest habitat thresholds for Red-headed Woodpeckers at the northern periphery of their range

ABSTRACT The relation between species occurrence and the structure or composition of habitat can be complex and often varies in a species-specific manner. Sometimes, species–habitat relations are defined by thresholds, or abrupt nonlinear responses to a habitat gradient. Threshold responses are expected when certain habitat features are required for species occurrence. For example, primary cavity-nesting woodpeckers often typify the threshold concept because in the absence of appropriate substrates (decadent wood) large enough for nest cavities, woodpeckers will not occur. In such cases, identifying thresholds is important to ensure that management activities meet minimal (or maximal) habitat requirements of target species. The Red-headed Woodpecker (Melanerpes erythrocephalus) is a species of national conservation concern, and loss of suitable nesting habitat has been suggested as a primary factor in its population declines. Threshold responses may partly explain why this species has gone locally extinct...

Management decisions and knowledge gaps: learning by doing in a case of a declining population of slavonian grebe Podiceps auritus

Species of national conservation concern require management action to reduce the threat of extinction. As part of its obligations to reduce national loss of biodiversity, the Norwegian authority for nature management (The Norwegian Environment Agency) published an action plan in 2010 for one of these species, the Slavonian grebe Podiceps auritus. The American mink Neovison vison, a non‐native, invasive species with wide spread negative effects on native fauna, was highlighted as a major potential treat. We used an adaptive management approach that included management trials with the aim to assess whether mink predation is likely to be affecting grebe numbers significantly. We monitored mink activity, and put in place mink control measures at three of our seven study lakes. We then used 35 pairs of artificial nests, with one of each pair equipped with cameras, to measure predation at all seven lakes. The combined use of progressive experiments in an adaptive management/monitoring framework showed that mink activity was generally low with a mean activity at raft stations of between 0.41–1.22 per lake (n = 5), a range of zero to three excavations executed as a result of hunting (n = 3), and no incidences of mink nest predation (n = 35). Hence we conclude that mink is presently not likely to be a significant negative factor on grebe breeding success in the targeted lakes. We found a high nest predation rate by hooded crow with 18 of 21 identified predation events being identified to this species. Future effort should investigate non mink related threats to the Slavonian grebe such as the role of hooded crow in nest predation. This case study exemplifies the usefulness of the adaptive management/monitoring framework as a powerful means of testing hypotheses and to inform management, especially when knowledge of the focal system is poor.

Morphometrics of Cerrado Birds from the Reserva Natural Laguna Blanca (Ne Paraguay)

Abstract Smith P., Onley D., Northcote-Smith E, Atkinson K. 2012. Morphometrics of cerrado birds from the Reserva Natural Laguna Blanca (NE Paraguay). Ring 34: 51-67. Morphometric data are provided for 204 individuals of 61 species from the Reserva Natural Laguna Blanca in Departamento San Pedro in north-eastern Paraguay. Measurements were taken according to Svensson (1984). Data for 2 cerrado endemic species, 2 species of global conservation concern and 5 species of national conservation concern are presented. These are the first published biometric data for birds of the Paraguayan cerrado.

Perennial Agroenergy Feedstocks as En Route Habitat for Spring Migratory Birds

Increased production of bioenergy crops in North America is projected to exacerbate already heavy demands upon existing agricultural landscapes with potential to impact biodiversity negatively. Grassland specialist birds are an imperilled avifauna for which perennial-based, next-generation agroenergy feedstocks may provide suitable habitat. We take a multi-scaled spatial approach to evaluate the ability of two candidate second-generation agroenergy feedstocks (switchgrass, Panicum virgatum, and mixed grass–forb plantings) to act as spring migratory stopover habitat for birds. In total, we detected 35 bird species in mixed grass–forb plantings and switchgrass plantings, including grassland specialists and species of state and national conservation concern (e.g., Henslow’s Sparrow, Ammodramus henslowii). Some evidence indicated that patches with higher arthropod food availability attracted a greater diversity of migrant bird species, but species richness, total bird abundance, and the abundance of grassland specialist species were similar in fields planted with either feedstock. Species richness per unit area (species density) was relatively higher in switchgrass fields. The percent land cover of forest in landscapes surrounding study fields was negatively associated with bird species richness and species density. Habitat patch size and within-patch vegetation structure were unimportant in predicting the diversity or abundance of spring en route bird assemblages. Our results demonstrate that both switchgrass and mixed grass–forb plantings can attract diverse assemblages of migrant birds. As such, industrialized production of these feedstocks as agroenergy crops has the potential to provide a source of en route habitat for birds, particularly where fields are located in relatively unforested landscapes. Because industrialization of cellulosic biomass production will favor as yet unknown harvest and management regimes, predicting the ultimate value of perennial-based biomass plantings for spring migrants remains difficult.

The vertebrate fauna of Currawananna State Forest and adjacent agricultural and aquatic habitats in the New South Wales South Western slopes bioregion

The New South Wales South Western Slopes bioregion has been significantly altered by agricultural development and is likely to experience additional significant impacts as a result of anthropogenic climate change. A simple inventory survey of the vertebrate fauna of Currawananna State Forest, a small woodland remnant on the Murrumbidgee River in the south of the bioregion, over the period 2002-2010 identified 172 vertebrate fauna species. This included three species of national conservation concern (the Trout Cod Maccullochella macquariensis, Murray Cod Maccullochella peelii and Superb Parrot Polytelis swainsonii) and another 16 species (5 fishes, 8 birds and 3 mammals) of state-level concern, as well as diverse frog, reptile, woodland and wetland bird and microchiropteran bat assemblages. This study demonstrates that even small remnants play an important role in supporting biodiversity in agricultural landscapes.

Avian Use of Perennial Biomass Feedstocks as Post-Breeding and Migratory Stopover Habitat

Increased production of biomass crops in North America will require new agricultural land, intensify the cultivation of land already under production and introduce new types of biomass crops. Assessing the potential biodiversity impacts of novel agricultural systems is fundamental to the maintenance of biodiversity in agricultural landscapes, yet the consequences of expanded biomass production remain unclear. We evaluate the ability of two candidate second generation biomass feedstocks (switchgrass, Panicum virgatum, and mixed-grass prairie) not currently managed as crops to act as post-breeding and fall migratory stopover habitat for birds. In total, we detected 41 bird species, including grassland specialists and species of state and national conservation concern (e.g. Henslow's Sparrow, Ammodramus henslowii). Avian species richness was generally comparable in switchgrass and prairie and increased with patch size in both patch types. Grassland specialists were less abundant and less likely to occur in patches within highly forested landscapes and were more common and likely to occur in larger patches, indicating that this group is also area-sensitive outside of the breeding season. Variation in the biomass and richness of arthropod food within patches was generally unrelated to richness and abundance metrics. Total bird abundance and that of grassland specialists was higher in patches with greater vegetation structural heterogeneity. Collectively, we find that perennial biomass feedstocks have potential to provide post-breeding and migratory stopover habitat for birds, but that the placement and management of crops will be critical factors in determining their suitability for species of conservation concern. Industrialization of cellulosic bioenergy production that results in reduced crop structural heterogeneity is likely to dramatically reduce the suitability of perennial biomass crops for birds.

Identification and Status of the Olympic Shrew (Sorex rohweri) in British Columbia

In 2007, a new species of shrew, Sorex rohweri, was described from western Washington. We examined historical museum and recent voucher specimens to assess identification criteria and status of this new species in British Columbia. Most similar morphologically to Sorex cinereus and Sorex vagrans, S. rohweri can be identified by a combination of dental and skull traits. Three-group discriminant analyses of 100 specimens based on as few as 6 skull measurements correctly assigned 98% of individuals to the 3 species. The available records, consisting of 18 specimens from 13 locations, suggest that S. rohweri has a small range extent of about 360 km2 in the lower Fraser River basin confined to the south side of the Fraser River. The combination of the shrew's association with forested habitats in a region greatly affected by agricultural and urban development, the concentration of recent records from Burns Bog, a fragmented 3000-ha patch of natural habitat, and the isolation of the British Columbian population from populations in Washington make it a species of national conservation concern in Canada.

How many birds are there in a city of half a million people?

ABSTRACTAim Urban environments are often characterized as supporting a few abundant, generalist species best adapted to living alongside humans, and as such, cities are seen as agents of biotic homogenization. However, there are surprisingly few descriptions of biological populations found in cities. Here, we provide the first complete citywide population estimates of birds for any UK city, and examine the conservation status of the assemblage in comparison with the country's avifauna at large.Location Sheffield city, central UKMethods We surveyed birds in every 500 m × 500 m square across the 160 km2of the city. Using a Distance sampling protocol, we estimated bird population sizes for the city and compared these with the size of the human population. We also compared the conservation status of the city's avian population with that of birds across the UK as a whole.Results Aggregation of population estimates for the 77 species observed during the surveys produced a total estimate of 602,995 (95% confidence interval (CI): 404,565–942,573) breeding birds, equating to 1.18 birds per person. The size of the non‐breeding population was similar at 578,603 (464,396–728,574) individuals, or 1.13 birds per person. Surveys revealed only three non‐native species, but relatively few species of national conservation concern. However, some species of conservation concern achieved very high population densities within the city, and the overall density of birds was more than six times that of the nation at large.Main conclusions If declines in some species are to be arrested or reversed, conservation effort will need to focus much more strongly on understanding and managing urban populations, because these might buffer some species against wholesale regional population depletion, particularly where intensive agriculture in the surrounding hinterland has led to declines in bird populations at large. Such a focus will require a significant increase in the priority and resources devoted to conservation activities in urban areas.