Browsing by Author "Girardello, Marco"
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- Habitat filtering and inferred dispersal ability condition across‐scale species turnover and rarity in Macaronesian island spider assemblagesPublication . Malumbres-Olarte, Jagoba; Rigal, François; Girardello, Marco; Cardoso, Pedro; Crespo, Luís C.; Amorim, Isabel R.; Arnedo, Miquel A.; Boieiro, Mário; Carvalho, José Carlos; Carvalho, Rui; Gabriel, Rosalina; Lamelas-López, Lucas; López, Heriberto; Paulo, Octávio S.; Pereira, Fernando; Pérez‐Delgado, Antonio J.; Rego, Carla; Romeiras, Maria M.; Ros-Prieto, Alejandra; Oromí, Pedro; Vieira, Ana; Emerson, Brent C.; Borges, Paulo A. V.AIM: Habitat diversity has been linked to the diversity and structure of island communities, however, little is known about patterns and processes within habitats. Here we aim to determine the contributions of habitat type and inferred dispersal frequency to the differences in taxonomic structure between assemblages in the same island habitat. LOCATION: The Macaronesian archipelagos (Azores, Madeira, the Canary Islands and Cabo Verde). TAXON: Spiders (Araneae). METHODS: We established forest and dry habitat sites (each with five plots) on two islands per archipelago. We collected spiders using standardised sampling protocols. We tested the differences in beta diversity separately for each habitat and for each inferred category of ballooning (an aerial dispersal strategy) frequency across geographic scales through nested non-parametric permutational multivariate analyses of variance. We then tested whether ballooning and habitat influenced heterogeneity in species composition (dispersion in beta diversity) in the two habitat types. We analysed the effects of habitat and ballooning on species abundance distribution (SAD) and rarity by fitting Gambin models and evaluating the contribution of ballooning categories to SAD. RESULTS: Communities of the same archipelago and habitat were taxonomically more similar, and beta diversity increased with geographic scale, being greater in dry habitats. There was greater species replacement among assemblages in dry habitats than in forests, with greater differences for rare ballooners. There were no differences in SAD between habitats although dry habitat sites seemed to harbour more species with low abundances (rare species) than forests. MAIN CONCLUSIONS: Habitat type does not only condition the differences between spider assemblages of the same habitat but also the scale at which they occur. These differences may be determined by the heterogeneity in the physical structure of each habitat as well as how much this structure facilitates aerial dispersal (ballooning), and should be considered in theories/hypotheses on island community assembly as well as in conservation strategies.
- Potential and progress of studying mountain biodiversity by means of butterfly genetics and genomicsPublication . Wang, Shuting; Girardello, Marco; Zhang, Wei-WeiABSTRACT: Mountains are rich in biodiversity, and butterflies are species-rich and have a good ecological and evolutionary research foundation. This review addresses the potential and progress of studying mountain biodiversity using butterflies as a model. We discuss the uniqueness of mountain ecosystems, factors influencing the distribution of mountain butterflies, representative genetic and evolutionary models in butterfly research, and evolutionary studies of mountain biodiversity involving butterfly genetics and genomics. Finally, we demonstrate the necessity of studying mountain butterflies and propose future perspectives. This review provides insights for studying the biodiversity of mountain butterflies as well as a summary of research methods for reference.
- Prevalence and drivers of poison use by South African commercial farmers and perceptions of alternative livestock protection measuresPublication . Brink, Christiaan Willem; Thomson, Robert Leslie; Amar, Arjun; Girardello, Marco; Santangeli, AndreaThe use of poison to eliminate predators is causing African vulture populations to collapse. To understand the prevalence and motivations of this practice we conducted an extensive survey with South African commercial farmers. Using a specialised questioning technique and ad hoc quantitative methods we found that an estimated 22% and 31% of farmers used poison over a 1-year and 5-year period, respectively. Poison use hotspots generally coincided with small stock farming areas. The strongest predictor of poison use was whether farmers believed the practice to be common amongst their peers. Our results suggest that farmers' attitudes to vultures are primarily positive, and farmers are less likely to use poisons if they frequently encounter vultures on their farm. Overall, our findings provide an understanding on poison use that provides leverage points to change farmers' behaviour and help avert the African vulture crisis and possible cascading ecosystem impacts.
- The representation potential of raptors for globally important nature conservation areasPublication . Santangeli, Andrea; Girardello, MarcoStemming from a pervasive lack of knowledge on biodiversity, important areas for conservation are typically identified using a subset of well known species, commonly termed surrogate or indicator groups. Birds have been commonly used as biodiversity surrogates due to the good level of knowledge on their taxonomy, ecology and distribution. Raptors in particular have been often proposed as an effective surrogate for other biodiversity based on their dietary diversity, being at the top of the food chain, their preference for highly productive areas, their generally threatened status and high public appeal. However, so far the surrogacy effectiveness of raptors has been largely studied locally or using a narrow selection of surrogate and surrogated taxa. Here we use a spatial conservation planning tool to quantify the surrogacy performance of raptors, overall and by different raptor groups (hawks and eagles, falcons, vultures, owls) to represent important biodiversity areas (such as IUCN protected areas and key biodiversity areas), wilderness areas and the worlds ecoregions. We compared the above surrogacy performance with that of all other non-raptor avian species. We show that raptors perform marginally worse than all other avian species in representing important biodiversity areas and ecoregions. However, raptors representation for wilderness areas was similar or slightly better compared to that of using all non-raptor birds. We also report a large variation in the representation performance by the four raptor groups. Falcons had a particularly high potential in representing protected areas and wilderness areas, equaling or largely surpassing the representation potential provided by all raptors and all other non-raptor birds. Overall, the results suggest that raptors, and particularly falcons, can perform relatively well in representing some important areas for conservation, such as protected areas and wilderness areas, but are relatively poor surrogates for key biodiversity areas and ecoregions. These rather contrasting results call for caution on the use of raptors as global surrogates of wider biodiversity.