Understanding population dynamics and impacts on island ecology remain top priorities for the conservation management of seabirds, particularly when attempting species-recovery for island restoration. Identifying suitable nesting habitat is a keystone detail in seabird restoration which can be complicated when predator pressures impact colony productivity and population viability. The surface-nesting Kermadec Petrel Pterodroma neglecta neglecta is dispersed on remote islands through the tropics and subtropics. We examined their breeding ecology on Phillip Island, Norfolk Group in the South Pacific and considered the limitations to re-establishment at their previous breeding location on Lord Howe Island (900 km south-east). On Phillip Island, the petrels were mostly monogamous with nesting locations generally within the vicinity of the previous season’s attempts. Breeding sites were limited to sloping terrain 182–228 m above the shoreline and up to 85 m from the coast in small sub-colonies under low scrubby woodland. Based on observations of 56 pairs and data gleaned from Global Light Sensing devices, we determined that breeding (incubation and provisioning) occurs in all calendar months of the year, with a laying peak in the late austral spring. Breeding success in the first year of study was 25% but improved to 56% once management of Purple Swamphens Porphyrio melanotus was implemented. Successful nests were located at sites with naturally limited egress from cleared or lightly vegetated areas. Prudent management of the petrel population on Phillip Island could aid in the regional recovery of the species and, in the process, assist the island’s restoration by significantly increasing transfers of marine-derived nutrient. Their reintroduction to Lord Howe Island is also possible but will likely rely upon consistent productivity of the Phillip Island population for founding immigrants. Moreover, successful establishment will require adaptive management of selected sites to ensure native avian predators do not overly impact breeding.

Monitoring parrot populations is of high importance because there is a general lack of quantified population trends for one of the most threatened avian orders. We surveyed parrots in Nicaragua in 1995, 1999, 2004, and 2013 at a minimum of 227 points within 56 sites stratified among the Pacific, Central Highlands, and Caribbean biogeographical regions to assess population trends. From point-count data we calculated encounter rate, flock rate, and flock size metrics and we used presence/absence data to generate species-specific occupancy estimates. Encounter rate, flock rate, and flock size data suggested family-level declines from 1995 to 2004 with some recovery between 2004 and 2013. Patterns of parrot occupancy varied among species with four decreasing, five increasing, and two with no detectable change. Six species of conservation concern are identified, including the Critically Endangered Great Green Macaw and Yellow-naped Parrot, additionally Olive-throated Parakeet, Scarlet Macaw, Brown-hooded Parrot, and White-crowned Parrot, only listed as Least Concern. All six are likely suffering from deforestation and potential unchecked trade activity in the Caribbean. Differing population trends of the regionally disjunct Yellow-naped Parrot subspecies suggest a link to variable deforestation and trade pressure experienced between the Pacific and Caribbean. Our results highlight the importance of actively monitoring changing parrot populations, even when considered Least Concern, so that directed conservation actions can be taken if needed.

Adult sex ratios (ASRs) have proved to correlate with population trends, which make them potential useful indicators of a species’ population trajectory and conservation status. We analysed ASRs and proportion of juveniles in flocks of an endangered steppe bird, the Little Bustard Tetrax tetrax, using surveys made during the non-breeding period in seven areas within its Western European range (one in Portugal, four in Spain, and two in France). We found overall male-biased ASRs, as all the seven surveyed areas showed a male-biased ASR mean value. Five areas were below the threshold median value (female sex ratio = 0.4) considered to be consistent with an increased probability of extinction, according to earlier population viability analyses for the species. We also found a significant positive correlation between female ratio and the proportion of young individuals in the non-breeding flocks surveyed. Our results (strongly male-biased ASRs) support the hypothesis that the viability of Little Bustard populations in Western Europe is threatened by an excess of female mortality, something that should be quantified in the future, and emphasise the value of monitoring sex ratio as a population viability indicator in species where monitoring survival is difficult to achieve.

Low-latitude penguins naturally breed in burrows dug in guano. This affords them a buffered environment that remains cool and humid, reducing the risk of hyperthermia while on land. As a conservation strategy, several versions of artificial housing units have been trialled at various breeding sites of African Penguins (Spheniscus demersus) around South Africa, where former guano exploitation forced many penguins to breed in exposed surface nests. While some units yielded a positive effect on breeding success by providing protection against predation, none of them have effectively mitigated the risk of heat stress in penguins or their eggs. Here, we investigated the microclimate of a recent double-layered design of ceramic artificial nests and compared that to natural burrows, exposed surface nests, and commonly used cement pipe nests, in austral summer 2021 on Bird Island, South Africa. We also recorded penguin behaviour during the hottest period at each of these nest types using remote camera traps to determine the onset of heat stress (panting). Double-layered ceramic nests out-performed all other nest types, including natural burrows, by remaining cooler throughout the day, with temperatures never exceeding 36.7°C. By contrast, all other nest types had multiple episodes where temperatures exceeded 40°C. Double-layered ceramic nests also maintained constant levels of high humidity (relative humidity [RH] >70%) throughout our study, whereas low humidity levels were observed in surface nests (RH ≈ 60%) and cement nests (RH <50%) during midday heat. We observed penguins panting at temperatures of 25°C in nest boxes, and at 22°C in exposed surface nests. This suggests that heat stress in African Penguins may occur much sooner than anticipated and that they are particularly vulnerable to hyperthermia as climate change-related global warming progresses. Fortunately, we are encouraged by the capacity of double-layered ceramic nest boxes to buffer environmental extremes and maintain suitable breeding conditions.

Bustards comprise a highly threatened family of birds and, being relatively fast, heavy fliers with very limited frontal visual fields, are particularly susceptible to mortality at powerlines. These infrastructures can also displace them from immediately adjacent habitat and act as barriers, fragmenting their ranges. With geographically ever wider energy transmission and distribution grids, the powerline threat to bustards is constantly growing. Reviewing the published and unpublished literature up to January 2021, we found 2,774 records of bustard collision with powerlines, involving 14 species. Some studies associate powerline collisions with population declines. To avoid mortalities, the most effective solution is to bury the lines; otherwise they should be either routed away from bustard-frequented areas, or made redundant by local energy generation. When possible, new lines should run parallel to existing structures and wires should preferably be as low and thick as possible, with minimal conductor obstruction of vertical airspace, although it should be noted that these measures require additional testing. A review of studies finds limited evidence that ‘bird flight diverters’ (BFDs; devices fitted to wires to induce evasive action) achieve significant reductions in mortality for some bustard species. Nevertheless, dynamic BFDs are preferable to static ones as they are thought to perform more effectively. Rigorous evaluation of powerline mortalities, and effectiveness of mitigation measures, need systematic carcass surveys and bias corrections. Whenever feasible, assessments of displacement and barrier effects should be undertaken. Following best practice guidelines proposed with this review paper to monitor impacts and mitigation could help build a reliable body of evidence on best ways to prevent bustard mortality at powerlines. Research should focus on validating mitigation measures and quantifying, particularly for threatened bustards, the population effects of powerline grids at the national scale, to account for cumulative impacts on bustards and establish an equitable basis for compensation measures.

Regional and local studies suggest that the Tufted Puffin Fratercula cirrhata in North America is declining in portions of its range. However, whether the overall population is declining, or its range is contracting with little change to the overall population size, is unknown. To examine population trends throughout its North American range, we assembled 11 datasets that spanned 115 years (1905–2019) and included at-sea density and encounter estimates and at-colony burrow and bird counts. We assessed trends for the California Current, Gulf of Alaska, and Bering Sea/Aleutian Islands large marine ecosystems (LME). We found: (1) nearly uniform and long-term declines of Puffins breeding in the California Current ecosystem, with most ecosystem colonies surveyed, (2) declining trends at two large colonies and in one at-sea dataset in the Gulf of Alaska LME, with the fourth smaller colony exhibiting no significant trend, and (3) positive trends at four out of five colonies in the Bering Sea/Aleutian Islands ecosystem complex, with no detectable trend at the fifth very large colony. The general pattern of Tufted Puffin declines across the California Current and Gulf of Alaska LMEs may be attributable to a variety of factors, but additional study is needed to evaluate the relative influence of potential population drivers both independently and synergistically. Potential mechanisms driving population increases in the Bering Sea/Aleutian Islands ecosystem include reduced depredation and bycatch, intrinsic population growth, and immigration. We found strong evidence for declines in two of the three LMEs evaluated representing approximately three quarters of the species’ North American range. This region of decline includes the Gulf of Alaska LME, which contains a significant portion of the species’ estimated total North American population. Despite data limitations, our analysis coupled with more focused and local studies indicates that the Tufted Puffin is a species of conservation concern.

Seabirds are declining globally and are one of the most threatened groups of birds. To halt or reverse this decline they need protection both on land and at sea, requiring site-based conservation initiatives based on seabird abundance and diversity. The Important Bird and Biodiversity Area (IBA) programme is a method of identifying the most important places for birds based on globally agreed standardised criteria and thresholds. However, while great strides have been made identifying terrestrial sites, at-sea identification is lacking. The Chagos Archipelago, central Indian Ocean, supports four terrestrial IBAs (tIBAs) and two proposed marine IBAs (mIBAs). The mIBAs are seaward extensions to breeding colonies based on outdated information and, other types of mIBA have not been explored. Here, we review the proposed seaward extension mIBAs using up-to-date seabird status and distribution information and, use global positioning system (GPS) tracking from Red-footed Booby Sula sula – one of the most widely distributed breeding seabirds on the archipelago – to identify any pelagic mIBAs. We demonstrate that due to overlapping boundaries of seaward extension to breeding colony and pelagic areas of importance there is a single mIBA in the central Indian Ocean that lays entirely within the Chagos Archipelago Marine Protected Area (MPA). Covering 62,379 km2 it constitutes ~10% of the MPA and if designated, would become the 11th largest mIBA in the world and 4th largest in the Indian Ocean. Our research strengthens the evidence of the benefits of large-scale MPAs for the protection of marine predators and provides a scientific foundation stone for marine biodiversity hotspot research in the central Indian Ocean.

The little-known Bristled Grassbird Chaetornis striata is thought to be declining due to the loss of grassland habitats throughout its range, and is currently classified as globally ‘Vulnerable’. In order to investigate the current status and possible causes of the presumed decline, we assessed population density of Bristled Grassbird in Padma and Jamuna river systems of Bangladesh. The study was conducted during the breeding seasons of the Bristled Grassbird in April and May in 2016–2019, using distance sampling and habitat suitability modelling. We also examined habitat preferences and responses to environmental changes based on vegetation structure and habitat modifications at point count locations. We detected a total of 39 birds with a mean group size of 1.44 individuals. We estimated 4.52 (95% CI: 2.65–7.73) individuals per km2 with an encounter rate of 1.48 detections per point count station and 341.15 birds within the study area. Our habitat suitability model projected a total of 167.41 km2 of suitable habitat and a total of 756.7 birds in floodplain grasslands of Padma and Jamuna river systems. The Bristled Grassbird was positively associated with grass height and grass density with 92.31% of 39 detections at Saccharum spontaneum dominated grasslands. We did not find a significant effect on Bristled Grassbird detections with increasing human activities, although the detection rate decreased linearly with increasing agricultural intervention and grass harvesting. These findings indicate that the Bristled Grassbird is more widely distributed throughout Bangladesh, and may be less vulnerable to grassland modifications, than previously thought.

The Natura 2000 network, the pillar of biodiversity conservation in Europe, still shows some knowledge gaps after almost 30 years since its implementation. As birds are a taxonomic group that is underrepresented in the literature related to Natura 2000 compared to their importance in the EU Directives, this review investigated the characteristics of the scientific research dedicated to birds in relation to Natura 2000. This review focused on 169 peer-reviewed articles covering a period of 25 years (1995–2019). Most studies were set within single Natura 2000 site or regions within countries, and concerned terrestrial habitats, particularly wetlands. The terrestrial Mediterranean biogeographical region and marine Atlantic region had the greatest number of publications, while Spain, Italy, and France were the countries with the highest number of reviewed articles. The number of publications was correlated to Natura 2000 coverage at both country and biogeographical region level. Bird species were studied mainly at a community or single-species level and most publications studied distribution and occurrence of the bird species of interest, while very few assessed the conservation status of the species. Only a few articles set within Natura 2000 sites addressed the issues of habitat suitability for birds or the effectiveness of conservation efforts. Both Annex I and non-Annex I bird species were examined in the literature, with most species having decreasing population trends at the European scale. Future research on bird conservation and Natura 2000 should focus on marine ecosystems as well as habitats that have received less attention despite their important role in a changing future (alpine and urban types). Moreover, future studies should encompass larger spatial scales and those species for which status and trends are still not thoroughly investigated. Finally, it would be important to enhance research efforts on the conservation status and effectiveness in relation to the network.

Globally, vultures are one of the most threatened of all groups of birds. European vulture populations are benefited by several anthropogenic food sources such as landfills. Current European Union directives aim to decrease the amount of organic matter dumped in landfills, reducing this important food source for some vulture species. In this context, we assessed the effect of the reduction of organic waste available and accessible for scavengers in a landfill on the visitation probability and abundance of a local Eurasian Griffon Vulture Gyps fulvus population in Central Catalonia (NE Iberian Peninsula), using a long-term dataset of captured-marked-recaptured individuals in the period 2012–2018. Our results indicated a decrease in the visitation probability due to a significant reduction of organic matter dumped into the landfill after a waste treatment centre was built (0.82 to 0.76) that may cause a permanent emigration of vultures in response to food reduction. However, the estimated annual abundance of vultures tended to grow over time due to the positive trend that regional vulture populations have experienced in recent decades. These results suggest that population processes occurring at regional scales are more relevant to vulture populations than local waste management measures. A reduction in locally available food can make a site less attractive, but species with high dispersal capacity such as vultures may overcome this issue by moving to other suitable sites. Although Griffon Vultures obtain most of the food from domestic and wild ungulates, a regional application of European directives could threaten an important alternative feeding source, especially in food shortage seasons where landfills could be supporting the energetic requirements of the species. Conservation strategies should be planned to counteract the possible negative effects of new European directives on scavenger populations.

Phylogenetic analyses can be used to resolve taxonomic uncertainties and reconstruct a species’ evolutionary history. This can be combined with ecological data to predict missing life history traits which are important for creation of conservation management strategies. We investigated the evolutionary and life history of the ‘Critically Endangered’ Grenada Dove Leptotila wellsi by estimating its phylogenetic placement and using this new phylogeny to test the accuracy of phylogenetic comparative methods for estimating both documented and unknown life history traits. We extracted DNA from two Grenada Dove samples and obtained sequences from three mitochondrial markers: Cytochrome oxidase I (COI), NADH dehydrogenase 2 (ND2) and Cytochrome b (Cyt b); and one nuclear marker: β-Fibrinogen intron 7 (β-FIB). We present the first genetic data obtained for the Grenada Dove. Our data identify the Grey-Chested Dove Leptotila cassinii as the species which shares both a most recent common ancestor, with an estimated divergence of approximately 2.53 million years ago, and the smallest genetic distance (P = 0.0303) with the Grenada Dove. Life history trait values for the Grenada Dove predicted from our analyses using phylogenetic imputation are: clutch size = 2 (± 0.09) eggs; clutches per year = 1.4 (± 0.81); incubation time = 14.2 (± 0.75) days; hatching weight = 3.8 g (± 1.05) and single imputation: fledging age (genus median) = 15.5 days, longevity (genus median) = 8.6 years. This study contributes novel information regarding evolutionary history and life history characteristics to inform long-term conservation actions for a ‘Critically Endangered’ species.

The Great Black-backed Gull Larus marinus is a generalist species that inhabits temperate and arctic coasts of the north Atlantic Ocean. In recent years, there has been growing concern about population declines at local and regional scales; however, there has been no attempt to robustly assess Great Black-backed Gull population trends across its global range. We obtained the most recent population counts across the species’ range and analysed population trends at a global, continental, and national scale over the most recent three-generation period (1985–2021) following IUCN Red List criteria. We found that, globally, the species has declined by 43%–48% over this period (1.2–1.3% per annum, respectively), from an estimated 291,000 breeding pairs to 152,000–165,000 breeding pairs under two different scenarios. North American populations declined more steeply than European ones (68% and 28%, respectively). We recommend that Great Black-backed Gull should be uplisted from ‘Least Concern’ to ‘Vulnerable’ on the IUCN Red List of Threatened Species under criterion A2 (an estimated reduction in population size >30% over three generations).

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.

The ‘Critically Endangered’ Black-winged Trumpeter Psophia obscura is endemic to the Belém Centre of Endemism in extreme eastern Amazonia and has a declining population and range. Here we report on a five-year (2016–2020) systematic camera-trap (n = 61) study of the species in Gurupi Biological Reserve, one of its most important conservation areas. We used a multi-season occupancy model to identify factors affecting occupancy rates and to assess occupancy trends in the reserve. Occupancy was negatively related to elevation and site-level tree density, and was positively related to post-logging recovery times. Average annual occupancy rates remained stable throughout the study period (ranging between 0.57 and 0.67) and this stability was largely driven by high between-year survival rates. Results confirm that the Black-winged Trumpeter is an interior-forest specialist that is highly sensitive to forest disturbance, which underlines the importance of the Gurupi Biological Reserve as a core site for the conservation of the species. However, the species is long-lived, so continuous monitoring is needed to further clarify population trends. We also recommended that the status of the species in other forest remnants, most of which remain unprotected, is assessed.

Understanding space use of endangered species is critical for conservation planning and management. The advances in technology and data analysis allow us to collect data with unprecedented quality and inform us about the movements and habitat use of individuals and groups. With only about 700 individuals left in the wild, the Northern Bald Ibis Geronticus eremita is currently categorised as ‘Endangered’. However, little is known about the movements of this avian species in relation to breeding and individual differences. Using GPS transmitters we studied the movements of 32 Northern Bald Ibis from a semi-wild free-flying colony at the Konrad Lorenz Research Center in Austria during 1–4 years per individual. We investigated how sex, age class, breeding and non-breeding season affect space use and site fidelity. We found that individuals consistently showed high site fidelity, adults more than juveniles, and space use was highly overlapping between individuals and over successive years. When moving between different areas birds used consistent flyways thereby avoiding direct routes over mountainous areas. Adults had more expansive space use during the breeding season as compared to the non-breeding season, while juveniles only showed a slight decrease during the non-breeding season. We found no sex differences regarding space use or site fidelity. Our results lead to a better understanding of how Northern Bald Ibis move through their environment and how they use foraging areas, roosting sites, and space in general that in turn can help to inform conservation management of extant colonies and reintroduction programmes for new colonies.

Shade coffee is a well-studied cultivation strategy that creates habitat for tropical birds while also maintaining agricultural yield. Although there is a general consensus that shade coffee is more “bird-friendly” than a sun coffee monoculture, little work has investigated the effects of specific shade tree species on insectivorous bird diversity. This study involved avian foraging observations, mist-netting data, temperature loggers, and arthropod sampling to investigate bottom-up effects of two shade tree taxa - native Cordia sp. and introduced Grevillea robusta - on insectivorous bird communities in central Kenya. Results indicate that foliage-dwelling arthropod abundance, and the richness and overall abundance of foraging birds were all higher on Cordia than on Grevillea. Furthermore, multivariate analyses of the bird community indicate a significant difference in community composition between the canopies of the two tree species, though the communities of birds using the coffee understorey under these shade trees were similar. In addition, both shade trees buffered temperatures in coffee, and temperatures under Cordia were marginally cooler than under Grevillea. These results suggest that native Cordia trees on East African shade coffee farms may be better at mitigating habitat loss and attracting insectivorous birds that could promote ecosystem services. Identifying differences in prey abundance and preferences in bird foraging behaviour not only fills basic gaps in our understanding of the ecology of East African coffee farms, it also aids in developing region-specific information to optimize functional diversity, ecosystem services, and the conservation of birds in agricultural landscapes.

Species restoration through reintroduction and reinforcement is widely considered as an effective method for the conservation of threatened animals. Although these approaches have been increasingly implemented over the last half-century, many attempts have failed. Dispersal behaviour is one of the key factors determining reintroduction success. We reported the demographic composition and dispersal pattern (i.e., post-release and natal dispersal) of a reintroduced Oriental Stork Ciconia boyciana population in Japan and identified the determinants of breeding success in 2005–2019. We hypothesized that one of the key determinants of breeding success is the density-dependent effect through post-release and natal dispersal. The F1 generation occurrence corresponded to two years, F2 to seven, F3 to 11, and F4 to 14 years after initial reintroduction. Wild-born birds accounted for 74% of the reintroduced population at F4 occurrence. Post-release dispersal distances were shorter than natal dispersal. Inter-nest distance was selected as the key factor determining breeding success. These results may have been due to feeding habitat restoration and conspecific interactions. In conclusion, steady recruitment to the next generation is thought to be due to a moderate natal dispersal and the subsequent low breeding density of wild-born birds.

Since 2005, the world population of Great Bustards Otis tarda has decreased at an annual rate of 3.23%. The current world total is estimated at 31,000–36,000 birds, 34% (range 30–38%) less than 16 years ago. The declines have been observed in nine of 17 countries with extant breeding populations, with highest values in China (-89%) and European Russia (-72%). Marked decreases have also occurred in the Iberian Peninsula, which is still the stronghold for the species with 70–75% of the world population. Within Iberia, declines are particularly alarming in Portugal (-50%), although perhaps even more concerning in Spain, where the -28% (range 25–30%) decrease implies a loss of more than 8,000 individuals. Increases have been only recorded in Germany, Austria, and at a smaller scale in Hungary (respectively, 202%, 91%, and 5%), thanks to continued and intensive conservation actions, and also in the small group breeding in Romania, likely due to dispersal from the increasing West Pannonian population. The isolated populations of Morocco and Iran are on the brink of extinction. More surveys are still needed in Russia, Ukraine, Kazakhstan, China, and Mongolia, to confirm numbers and trends. It is urgent to reinforce conservation actions worldwide to stop negative demographic trends and ensure the survival of the species. If current trends continue, IUCN should perhaps consider whether (a) conditions are met to upgrade the species’ Red List category from globally ‘Vulnerable’ to ‘Endangered’, and (b) the two subspecies should be treated as separate conservation units and require different conservation strategies.

Global biodiversity is at a heightened risk of extinction and we are losing species faster than at any other time. It is important to understand the threats that drive a species towards extinction in order to address those drivers. In this paper, we assess our knowledge of the threats faced by 24 Himalayan Galliformes species by undertaking a review of the threats reported in the published literature and the supporting evidence that the threat is having an impact on the species’ populations. Only 24 papers were deemed suitable to be included in the study. We found that biological resource use and agriculture and aquaculture are the predominant threats to the Galliformes in the Greater Himalaya but the evidence available in the studies is quite poor as only one paper quantified the impact on species. This study shows that major gaps exist in our understanding of threats to species, and it is imperative to fill those gaps if we want to prevent species from going extinct.