The late Pleistocene to Holocene subaerial pyroclastic deposits of the Quill stratovolcano on the Caribbean island of St Eustatius form seven stratigraphic divisions. New radiocarbon ages of charcoal are presented for the second, third and seventh divisions in order to better constrain the Quill’s eruption history. Three samples from the same layer of Division 2 at two localities on the northeast coast yield ages of 18,020 ± 40 (1σ), 18,310 ± 45 and 18,490 ± 45 14C yr BP (∼19,800–20,600 yr cal BC). These are considerably younger (∼4400 yr) than a previously published result for this division. A single sample of Division 3 gave an age of 8090 14C yr BP (∼7100 yr cal BC) and overlaps with previously published 14C ages for this division. A charred root in the pyroclastic unit deposited by the last eruption of the Quill (Division 7) gave an age of 919 14C yr BP (∼1100–1200 yr cal AD). This result is ∼600 years younger than a previously published age, and its origin is attributed to human activity. The timing of the last eruption of the Quill therefore remains poorly constrained but is older than 600 AD. Terrestrial gastropods found in paleosols and organic material found in small streams that developed in Division 3 indicate that Division 4 must be younger than 6100 ± 500 yr cal BC. The oxygen and carbon isotope composition of the terrestrial gastropods derived from Division 3 paleosols indicates that the C4 and CAM-type vegetation was dominant and that the climate subsequently changed to wetter conditions. The minimum eruption frequency for the Quill volcano is one eruption every ∼1400 years during the past 22,000 years. This eruption frequency of the Quill volcano is of the same order of magnitude as other recent northern Lesser Antilles volcanoes, Soufrière Hills (Montserrat, ∼5000 years) and Mt Liamuiga (St. Kitts, ∼2500 years).

Structural vegetation damage and food limitation are important effects of major hurricanes, particularly for fruit/seed-eating, forest-dependent Caribbean birds with restricted distributions and small populations, such as the Bridled Quail-dove Geotrygon mystacea. Motivated by the lack of abundance estimates, corrected for detection probability, we conducted distance-sampling surveys inside and outside the Quill National Park each May in 2016-2019. Detection mode was the most important covariate, with others receiving no support from the data. Detectability of available single individuals and clusters of individuals within 60 m of transect centrelines averaged 0.957 ± 0.114 standard error for audio detections, 0.434 ± 0.052 for visual detections, and 0.693 ± 0.064 for detection modes combined. Availability averaged 0.475 ± 0.138 and the product of detectability and availability averaged 0.329 ± 0.098. Density averaged 1.459 ± 0.277 individuals ha-1 and population size averaged 642 ± 122 individuals in 440 ha. Density did not differ along and away from forest trails, but was higher inside than outside the park and at elevations within 201-400 m than 100-200 m and 401-600 m. Density declined by 76% after hurricanes Irma and Maria in 2017. We suggest that major hurricanes together with free-ranging livestock overgrazing degraded foraging habitats, limited food supply, and caused a population bottleneck. Our methodology can be implemented across the distribution range to assess population status and trends and evaluate the result of management actions at key conservation sites. Bridled Quail-dove populations probably were declining on most islands before the 2017 hurricanes and population status warrants revision.