Browsing by Author "Marengo, Ilaria"
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- Combining survey and remotely sensed environmental data to estimate the habitat associations, abundance and distribution of breeding thin-billed prions Pachyptila belcheri and Wilson’s storm-petrels Oceanites oceanicus on a South Atlantic tussac islandPublication . Stokes, Allan W.; Catry, Paulo; Matthiopoulos, Jason; Boldenow, Megan; Clark, T. J.; Guest, Amy; Marengo, Ilaria; Wakefield, EwanSmall petrels are the most abundant seabirds in the Southern Ocean. However, because they breed in burrows on remote and often densely vegetated islands, their colony sizes and conservation status remain poorly known. To estimate the abundance of these species on Bird Island in the Falkland archipelago, we systematically surveyed their breeding burrow density and occupancy across this near-pristine tussac (Poa flabellata)-covered island. By modelling burrow density as functions of topography and Sentinel 2 satellite-derived Normalised Difference Vegetation Index data, we inferred habitat associations and predicted burrow abundance of the commonest species—Thin-billed Prions (Pachyptila belcheri) and Wilson’s Storm-petrels (Oceanites oceanicus). We estimate that there are 631,000 Thin-billed Prion burrows on the island (95% CI 496,000–904,000 burrows). Assuming that burrow occupancy lies between 12 and 97%, this equates to around 76,000–612,000 breeding pairs, making Bird Island the second or third largest P. belcheri colony in the world, holding approximately 3–27% of the species’ breeding population. We estimate that 8200–9800 (95% CI 5,200–18,300 pairs) pairs of Wilson’s Storm-petrels also breed on the island. Notably, the latter burrowed predominantly under and within tussac pedestals, whereas they are usually assumed to breed in rock cavities. Thin-billed Prions are declining in the Kerguelen archipelago, but their population trends in the Falklands are unknown. Given the wide confidence intervals around our own and other population estimates for these cryptic species, we recommend that their populations should be monitored regularly, at multiple sites.
- Island-based Information Management System-GIS Data Centre as a key tool for spatial planning in the South Atlantic UK Overseas TerritoriesPublication . Marengo, Ilaria; Augé, Amélie A.; Campioni, Letizia; Blake, Denise; Cherrett, Samantha; Richardson, Andrew; Weber, Sam B.Environmental data require fit-for-purpose data management systems and related spatial applications to be used effectively for management. Geographic Information Systems (GIS) have become a key tool to analyse and visualise spatial data with their increasing volume and variety. Well-designed data centres that combine a data management system with GIS, reduce costs and improve efficiency for spatial planning processes. Small or remote territories and islands such as the South Atlantic UK Overseas Territories (SAUKOT), with limited financial resources and capacity, face many challenges to develop such centres. In 2013 an island-based Information Management System (IMS)-GIS Data Centre was established in the SAUKOT. Until then, governments did not have the ability to use spatial planning effectively to manage their environments. The IMS-GIS Data Centre has been operating as: 1) repository of high-quality reference datasets to support decision making, 2) interactive data visualisation to share maps and information with stakeholders and 3) data portals to assist data discovery and sharing. This paper describes i) how the SAUKOT have built their own IMS-GIS Data Centres ii), how these Data Centres have provided effective and manageable solutions to support terrestrial and marine spatial planning processes and iii) the challenges the Data Centres are still facing. Thanks to relatively simple data management concepts and the use of open-source programs, the IMS-GIS Data Centre is transferable to other contexts sharing similar challenges to those faced by the SAUKOT
- Mud-puddling on roadsides: a potential ecological trap for butterfliesPublication . Campioni, Letizia; Marengo, Ilaria; Román, Jacinto; D'Amico, MarcelloRoad-kill represents a major threat for butterflies and more generally for pollinators. Here we report an observation of conspicuous aggregations of butterflies mud-puddling on roadsides and, for this reason, being massively road-killed by farm vehicles.