Summary The Goliath Heron Ardea goliath is the largest heron in the world, and has a range spanning sub-Saharan Africa, the Middle East, and the Indian subcontinent. Despite its large range, its breeding distribution is poorly known, especially in isolated populations outside Africa. We assessed breeding distribution by collating records from literature, citizen science databases and other sources. We located 216 breeding records from 22 countries between 1881 and 2026, most of which came from southern Africa and, to a lesser extent, East Africa. Records from central and West Africa were scarce. We identified the first evidence of breeding in Iran in nearly 50 years, but the status of this isolated population remains uncertain. We found no breeding records in the Sundarbans of India, but repeated observations there suggest that nesting may have gone undetected in this remote wetland landscape. Our assessment identified substantial information gaps in parts of Africa and showed that the remnant populations in the Mesopotamian Marshes and Sundarbans warrant further study in the face of conservation threats.
Summary This study provides the first comprehensive analysis of morbidity and mortality in Dalmatian Pelican Pelecanus crispus and Great White Pelican P. onocrotalus in Greece. Data were collected over a 24-year period (1998–2021), using specific questionnaires to highlight the temporospatial, age and aetiological causes of morbidity and mortality to advance conservation efforts. Overall, 316 incidents of morbidity/mortality and 23 mass mortality events were recorded while the two species differed significantly in all parameters of morbidity/mortality. Annual rate of mortality was higher in Dalmatian Pelican (44.5 deaths per annum) than the Great White Pelican (2.4 deaths per annum). Dalmatian Pelican mortality tended to occur more during late winter/early spring and late summer/autumn, while Great White Pelican mortality occurred during autumn, matching with the presence of pre-migratory concentrations and migration. Dalmatian Pelican tended to be found dead in areas where pelicans congregated (e.g. colonies, feeding, wintering) while Great White Pelican were equally found in both areas with and without pelican congregations. A total of 30% of Great White Pelican mortality/morbidity happened in south Greece away from pelican areas and along the migration route whilst adult Dalmatian Pelicans and juvenile Great White Pelicans were the prevalent age groups. In Dalmatian Pelicans, 70% of mortality accumulated in the mass mortality events, while the sympatric Great White Pelican was unaffected during these events. Dalmatian Pelican mortality was mostly attributed to environmental (biotoxin) and infectious (viral/avian influenza) causes, while Great White Pelican mostly to anthropogenic (trauma/illegal shooting). Specific causes in Dalmatian Pelican mortality showed significant seasonal variation with viral causes in spring, biotoxin and entrapment in autumn, and illegal shooting and emaciation in winter. In Great White Pelicans, illegal shooting tended to occur in spring. A total of 25% of rescued Dalmatian Pelicans were released. Limitations of this study were that only 1% of the dead pelicans underwent a veterinary post-mortem investigation, in 26% of the dead pelicans the cause was completely unknown, the sex was not determined, and the age remained unidentified in a high percentage (43-46%) of individuals. In future, more veterinary input and a national preparedness plan for mass mortality events are needed.
Summary Understanding migratory patterns helps guide conservation efforts in response to environmental change by identifying the breeding populations that contribute to different non-breeding regions. To examine these patterns, we analysed stable hydrogen isotope (δ²H) values in feathers of birds captured at nine non-breeding sites across Mexico to map the migratory connectivity of the Orange-crowned Warbler Leiothlypis celata , which breeds in Canada and the United States (US). We integrated isotopic assignments with long-term Breeding Bird Survey (BBS) and eBird abundance data and found weak migratory connectivity (MC = 0.18), showing that most non-breeding sites host a mixture of individuals from six breeding clusters. However, a northwestern breeding population exhibited strong connectivity, suggesting a possible crosswise migration to an easternmost non-breeding region in Mexico. Additionally, we found divergent demographic trajectories among populations, with those along the Pacific Coast showing severe declines. Mixing of populations with non-uniform trends on the non-breeding grounds hinders effective conservation by limiting the detection of population-specific declines. Our study emphasises the importance of analysing trends at the population level rather than the species level. We show that species-wide conservation designations may be insufficient, while our data-driven clusters provide a more effective framework for identifying management units.
Summary The Red-breasted Goose Branta ruficollis is a globally threatened migratory species that faces increasing pressures from habitat loss and climate change along its flyway between Siberia and the Black Sea. This study presents detailed insights into the annual migratory patterns of the species based on GPS telemetry data collected between May 2019 and February 2023. We tracked 41 individuals fitted with GPS transmitters, of which 23 provided data spanning at least one full migratory season. The resulting dataset of over 150,000 GPS positions revealed fine-scale patterns of seasonal movement across a total area of 3.6 million km 2 . There was a nearly equal temporal division among seasonal phases. At the population level, the spring and autumn migration windows lasted 96 and 97 days, respectively, while individual completed journeys averaged 93.0 days in spring and 98.3 days in autumn. Migration pathways featured distinct, non-overlapping spatial corridors and key staging areas identified in northern Kazakhstan and the Orenburg region of Russia. Red-breasted Geese travelled an average of 17,725 km annually, with peak movement in April–May and September–November. Wintering birds occupied three discrete core areas within a larger wintering extent (116,751 km 2 ): coastal Romania (with adjacent areas in Bulgaria and Ukraine), the Sivash area in Crimea, and the Veselovskoie region in southern Russia. The data also enabled inferences about breeding success and moulting periods, confirming high breeding site philopatry and no evidence of major previously undocumented wintering areas. The findings directly supported conservation planning, including the designation of temporary hunting restrictions in priority staging areas. This study highlights the conservation value of GPS tracking for delineating core and critical seasonal habitats, assessing threats, and informing flyway-scale management strategies essential for the long-term survival of the Red-breasted Goose and other long-distance migratory waterbirds.
Summary The Orinoco Goose Neochen jubata is a nomadic migratory waterbird occurring at low densities along the Amazon and Orinoco river basins. Listed as Least Concern on the IUCN Red List, the species faces ongoing population declines, primarily driven by overhunting. Despite its conservation concern, knowledge of its reproduction, behavior, movement patterns, and habitat use remains limited, hindering the development of effective management strategies. In this study, we combined Local Ecological Knowledge (LEK) with GPS telemetry to investigate population trends and the movement ecology of the Orinoco Goose in the western Brazilian Amazon. LEK revealed a recovery in population abundance over the past 20 years within protected areas, providing clear evidence of the positive effect of conservation interventions. Additionally, GPS data from four tagged individuals (two males and two females) showed highly individual-specific patterns of space use, with no overlap among them, with home range size varying substantially among individuals; notably, one female maintained a home range roughly twice the size of the other tracked individuals, while tracked individuals shared a distinct dry-season preference for beach habitats across years. These findings provide novel insights into the species’ use of space and patterns of habitat selection, contributing critical information to guide evidence-based conservation actions for this vulnerable Amazonian bird.
