The Manapany day gecko Phelsuma inexpectata is a Critically Endangered species endemic to Réunion Island in the Indian Ocean. Studying its geographical distribution and its evolution is important for developing effective biodiversity conservation strategies. We evaluated past and current distributions of P. inexpectata using records from 2008–2020 and through recent, intensive field surveys (230 person-days, 2020–2022). We found that its past distribution has declined by more than 28% (5.12 ha), from 19.44 ha to 14.32 ha. In natural habitats, the distribution of P. inexpectata has been strongly affected, declining by c. 45%, but we identified new areas of occurrence (10.72 ha) through field surveys. Most of these new areas (79%) were found in anthropogenic habitats where the species had not been documented before. The current distribution of P. inexpectata covers c. 24 ha, of which 75% is located in urban areas such as gardens and green urban spaces. Moreover, our field survey showed that at least 10% of its range is now colonized by the invasive gold-dust day gecko Phelsuma laticauda. This survey provides an essential baseline for tracking the future distribution of this threatened species and its potential invasive competitor, and for monitoring how changes to its habitat affect the distribution of P. inexpectata.

Ecosystem disturbance is known to negatively affect herpetofauna. There are, however, few studies on the impact of volcanic ash fallout on reptile species and no known publications on any impacts on the family Phyllodactylidae. The Barbados leaf-toed gecko Phyllodactylus pulcher is a Critically Endangered lizard species endemic to the island of Barbados. During 9–22 April 2021, La Soufrière volcano on the neighbouring island of Saint Vincent erupted, leading to significant ash fallout on Barbados. Following this event, indices of body condition for the Barbados leaf-toed gecko declined significantly. However, monitoring over 17 months showed a gradual return to pre-ashfall indices for both males and females. Population-wide tail autotomy rates did not change significantly following the event. The proportion of gravid females significantly declined immediately after the ashfall event, although this exceeded the pre-ash proportion of the following year. Additionally, the proportion of females bearing two rather than one egg doubled in the year following the ashfall. It is unknown whether the decline in body condition is a direct consequence of exposure to ash or a secondary effect of declines in insects and vegetation cover; however, a synergy between these factors is probable.

Climate and land-use changes are major threats to amphibian conservation. However, amphibians on tropical oceanic islands appear to have been overlooked with regards to their vulnerability to global anthropogenic threats. Here we examine whether there are gaps in research evaluating the vulnerability of tropical oceanic island amphibians to climate and land-use changes. We carried out a systematic review of the literature on experimental studies published during 1 July 1998–30 June 2022, to evaluate whether there are knowledge gaps in relation to geographical scope, taxonomic representation, life stage assessment, the factors affecting amphibians and how species and populations respond to these factors. Of 327 articles on climate change and 451 on land-use change, the research of only 18 was carried out on tropical oceanic islands, only on anurans, and < 20% of the authors were affiliated with an oceanic island institution. These 18 studies were on only five islands, and the range of families and life stages assessed was limited. We also found uneven research into the factors affecting oceanic island amphibians and their responses; analyses involving the effect of temperature on amphibian range expansion or contraction were the most common, with few studies of the effects of salinity. The scarcity and unevenness of research from oceanic islands limit our understanding of the effects of climate and land-use changes on amphibians. We discuss potential reasons for these knowledge gaps and recommend ways to address them, such as more equitable distribution of resources and provision of training and research opportunities for island-based biologists.

Island-endemic arthropods are understudied species and likely to be highly threatened with extinction. Analysis of IUCN Red List assessments can be used to highlight important microhabitats requiring conservation for the effective management of island-endemic arthropod biodiversity. We synthesized information on the 296 island-endemic arthropod species assessed as Critically Endangered as of April 2024, the geography of the islands to which they are endemic, and the broad threats they face. These species comprised 33 taxonomic orders, across which an average of 53% of species were limited entirely to tiny, confined areas of habitat: caves, high elevation areas, isolated pools or sea stacks. These micro-refugia are most utilized by crustaceans and least utilized by myriapods. Caves and pools are the most important habitats on temperate islands where habitat degradation threatens crustaceans. On small tropical islands where arachnids and hexapods are threatened by invasive species, refugia are mostly in high elevation areas. Sea stacks appear to be effective refugia from invasive species only for threatened island-endemics with notable long-distance dispersal adaptation. None of the refugia appear effective in sustaining arthropod species immediately threatened by climate change. Using the interaction between arthropod life history, habitat and threats, it is possible to generalize micro-refugia that (1) should be immediately targeted for management, and (2) could yield undescribed or presumed-extinct species. Prioritizing such refugia for management and research can guide efficient expenditure of local capacity. In our case study, on Ascension Island, micro-refugia for seven endemic arthropods covered < 0.1% of the island's total area.

Human-induced pressures such as climate and land-use changes in the Anthropocene disproportionately threaten island ecosystems and the endemic species they host. Shedding light on the ecological needs of island species is key to the conservation of these fragile ecosystems and their unique species. Here we present the ecological needs of a bat species endemic to Sardinia, the long-eared bat Plecotus sardus, and analyse the relationship between this Critically Endangered species and the insular environment at different spatial scales to inform action for its conservation. We show that besides displaying a unique phenology and roost use, the species is closely associated with the dry broadleaf forests of native oaks Quercus ilex and Quercus suber at all scales and, in contrast, is negatively affected by coniferous stands, open pastures and urban environments. Our results not only provide key information for the conservation of P. sardus but also provide insights into the unique adaptations of insular endemic species to the fragile island ecosystems, highlighting the importance of ecological studies to informing conservation in biodiversity hotspots. We also demonstrate that protection and restoration of key habitats, particularly within 2 km of roosts, are key to protecting the few known reproductive colonies.

The Covid-19 pandemic has had global impacts, leading to changes in human activities and resulting in both positive and negative outcomes for the natural environment. To more fully understand the pandemic’s impact on the conservation of ecosystems and conservation actors or organizations, this research investigated its impact on the Caribbean island nation of Trinidad and Tobago. Data were collected through an online questionnaire and targeted follow up semi-structured interviews. The results showed that the pandemic led to many challenges for some actors, including job loss and cancellation of fieldwork and outreach events. More positively, there were opportunities for some actors to adapt or find new modes of operation, which unexpectedly made some of them more effective at achieving their goals. The results also suggest that the impacts of the pandemic on ecosystems were both positive and negative. On the positive side, curfews and lockdowns restricted access to natural areas, resulting in benefits such as ecosystem recovery. More negatively, there were issues associated with spikes in illegal activities such as poaching and squatting in protected areas. Respondents suggested that better access to funding and local government support would have helped conservation actors be in a better position to adapt to the changes brought about by the pandemic. The results of this research provide much needed insight into how the Covid-19 pandemic is and will continue to impact conservation actors and their initiatives. Further studies can build on this research to explore the impact of pandemics on conservation in the long term.