The population increase of Lesser Black-backed Gulls in The Netherlands triggered investigations into life-history, migratory movements and foraging ecology during 16 years of nest-monitoring, colour-ringing and GPS-tracking on the island of Texel (Wadden Sea). The main objective was to obtain comprehensive ecological data on breeding performance within the context of the annual cycle, shifts in resources, prey types and habitat use. Migration strategies ranged from short- (France, England), medium- (Portugal, Spain) to long-distance (NW Africa), utilising marine, coastal or terrestrial, region-specific resources. Young birds travelled on average further than older individuals. Strong within-colony philopatry was found, this was strongest in males. Assessments of mate-fidelity indicated serial, social monogamy. Unexpectedly, given increasing population trends when the study commenced, fledging rates were low and declining egg volumes, smaller hatchlings, declining mass at fledging and high levels of cannibalism indicated structural food stress. Fledgling mass was well below that of chicks in historical studies, suggesting insufficient provisioning. Breeding was highly synchronised and early nesters fledged more young than late pairs. The onset of breeding was significantly delayed over the years, chick depredation rates declined, overall breeding success became more variable. Marine, urban and rural habitats, mostly within 80 km from the colony were used for foraging. Marine prey, mostly fisheries discards, formed the principal prey for most birds, supplemented with food found in agricultural areas. Human waste was found in only 7% of prey samples. A consistent decline of marine prey (in line with developing restrictions in fisheries), combined with signals pointing at food stress, suggests that the population is unable to boost reproductive success with currently existing foraging opportunities.

Since first human settlement c. 400 years ago, the Mascarene islands have undergone some of the highest rates of ecosystem transformation and species extinction recorded worldwide. One surviving species, the Mascarene Swiftlet Aerodramus francicus native to the islands of Mauritius and Réunion, is typical among Aerodramus swiftlets in presenting a paucity of distinguishable morphological characters, as well as being particularly vulnerable to anthropogenic activities. In this study, a primary objective was generating genetic data for each island population, allowing genetic divergence between them to be assessed for the first time, employing informative methods regarding the taxonomic status. We find that the two island populations are 0.8% divergent and reciprocally monophyletic in the mitochondrial ND2 gene, with nuclear data (β-fibrinogen intron 7) being largely congruent but showing incomplete lineage sorting and low resolution. Results of barcode gap and coalescent species delimitation analyses are consistent with a comparison of the genetic divergence uncovered within Mascarene Aerodramus with that among other long-established Aerodramus species. The findings of all three approaches are consistent with the two island populations representing two separate species. However, because of lack of resolution in the nuclear locus, we conservatively retain a single species pending future data. To assess the conservation status, we conducted the first quantitative assessment of population size and distribution through extensive nest counts on the islands of Mauritius and Réunion, and by considering the threats to swiftlets on each island. The survey produced estimates of 10,100–10,700 individuals for Mauritius, and 39,600–53,500 individuals for Réunion. Considering the population size data, inferred distributions, and numerous conservation concerns, an updated conservation status to Threatened (Endangered): B2 b(i,ii,iii,iv,v) c(i,ii,iii,iv) is warranted according to IUCN guidelines. Improving protection of the breeding habitat of the Mascarene Swiftlet is crucial to prevent this endemic species from being added to the Mascarene's staggering extinction toll.

The Yellow-eyed Pigeon Columba eversmanni is globally endangered and one of the rarest pigeons with a predominantly Central Asian distribution, nesting in the valleys of the Syr Darya and Ili Rivers in Kazakhstan. The causes of the sharp population decline of the species are unknown, partially due to fragmentary migration data and a lack of information on their migration routes. In this study we aimed to gather novel information on the migration patterns of Yellow-eyed Pigeons by deploying GPS/GSM transmitters. Long-term ringing data showed a clear decline in the number of captured Yellow-eyed Pigeons. Two individuals were tagged in mid-September, during autumn passage at the Shakpak Pass in Kazakhstan. Both could be tracked over a migration distance of more than 1000 km, yielding precise data about the flight direction, speed, distance and stopover behaviour of these birds during their autumn migration. During migration, the two birds achieved maximum travel rates of 257 km/day and 243 km/day, respectively, with an average of 102 km/day. The flyway during autumn migration includes several stopover sites located in south Kazakhstan, east Uzbekistan and north Afghanistan. The birds primarily utilized forest belts, crop fields and trees in rural areas as stopover sites during autumn migration, while preferred night-time roosting in trees in crop fields and on buildings. These findings are significant as they underscore the importance of using GPS/GSM trackers to study Yellow-eyed Pigeon migration on a larger scale, which could provide more comprehensive data on their habitats and movements and facilitate the identification of potential threats.