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The European rabbit (Oryctolagus cuniculus) is a key prey species in Mediterranean ecosystems. However, it is also considered a pest on many oceanic islands, even though its true abundance and ecological effects on different island habitats are poorly understood. We present data on rabbit abundance for the best-preserved habitats of the Canary Islands, Spain (National Parks), including ecosystems differing in climate, topography, plant species richness and composition. Three methods of assessing rabbit abundance from faecal pellet density are compared to ascertain the best method to compare highly distinct habitats. The Cleaning method was used during spring, summer, autumn and winter to check whether there were differences in pellet degradation among habitats that could prevent comparisons between them. Rabbit abundance is determined by complex interactions among abiotic and biotic factor. Despite differences in climate conditions, the results obtained for rabbit density with fast methods correlated well with the slow Cleaning method. The Circular method was the most useful to work with for extensive sampling in different habitats. The best models for explaining rabbit density for all habitat types combined included tree cover, abiotic and topographic and climatic variables. Thus, factors influencing rabbit density vary depending on habitat type with Macaronesian laurel forests being the ecosystem least likely to be invaded by rabbits. The present study highlights that rabbits reach damaging densities for plant conservation in most areas on the Canary Islands. [ABSTRACT FROM AUTHOR]

The European rabbit (Oryctolagus cuniculus) is a pest and a conservation problem on many islands, where its heavy grazing pressure threatens many endemic plants with extinction. Previous studies in its native and introduced range have highlighted the high spatial variability of rabbit abundance at local and landscape scales, depending on many factors such as the existence of different habitats. Modeling of the species can be useful to better understand spatial patterns and to prioritize actions, especially in those regions in which rabbits have become invasive. Here, we investigate the distribution of the European rabbit in Tenerife (Canary Islands, Spain), where the species was introduced during the 15th century and has subsequently changed vegetation composition. Added to the direct effects of rabbits on vegetation, climate change could also have implications for rabbit populations, especially in the alpine ecosystem. To evaluate that, we estimated rabbit abundance in 216 plots randomly distributed on Tenerife island (61 in the alpine ecosystem), modeled the potential current spatial abundance of the species and considered how it might vary under different climate change scenarios. We associated rabbit abundance to a wide selection of abiotic, biotic, and human variables expected to influence rabbit abundance on the island. We found a positive correlation between rabbit abundance and temperature and a negative correlation in the case of precipitation. Hence, according to the models' projections, climate change is expected to enhance rabbit populations in the future. Current higher densities were related to land disturbance and open areas, and a remarkable increase is expected to occur in the alpine ecosystem. Overall, we consider that this study provides valuable information for land managers in the Canary archipelago as it reveals how global warming could indirectly exacerbate the conservation problems of the endemic flora in oceanic islands. [ABSTRACT FROM AUTHOR]

Islands harbour a spectacular diversity and unique species composition. This uniqueness is mainly a result of endemic species that have evolved in situ in the absence of mammal herbivores. However, island endemism is under severe threat by introduced herbivores. We test the assumption that endemic species are particularly vulnerable to generalist introduced herbivores (European rabbit) using an unprecedented dataset covering an entire island with enormous topographic, climatic and biological diversity (Tenerife, Canary Islands). With increasing endemism, plant species are more heavily browsed by rabbits than non-endemic species with up to 67% of endemics being negatively impacted by browsing, indicating a dramatic lack of adaptation to mammal herbivory in endemics. Ecosystems with high per cent endemism are most heavily browsed, suggesting ecosystem-specific vulnerability to introduced herbivores, even within islands. Protection of global biodiversity caused by disproportionally high endemism on oceanic islands via ecosystem-specific herbivore control and eradication measures is of utmost importance. [ABSTRACT FROM AUTHOR]

Disruptive effects have been described on the plants and ecosystems of oceanic islands due to the introduction of invasive herbivores. In the Canary Islands the European rabbit (Oryctolagus cuniculus L.) was introduced five centuries ago and currently is widespread in all ecosystems, although in the laurel forests it is very scarce. However, on Morello-Ericetum woodland mostly represented by disturbed laurel forest areas, rabbit density is higher. Here we analyzed the impact of rabbits on the Morello-Ericetum woodland using exclusion and control plots located in 11 sites in the Garajonay National Park (La Gomera Island). Rabbit browsing was assessed for 36 endemic species, 15 of them threatened, which were sowed in both control and exclusion plots. After three years of monitoring, our results show a significant negative effect on the establishment and seedling recruitment for 55% of the analyzed species, especially in summer when the rabbit density increases by nearly 30%. Also, plant growth (in 91% of the species) and flowering rate (36% of the species), were disrupted, which could cause a depletion of the seed bank. Among the five tree species included in the experiment, three were also significantly damaged, so rabbits could be even influencing canopy species, delaying forest recovery. The management of Morello-Ericetum woodland should be countered the effects produced by the rabbits on their tree composition, and to allow the development of an understory where endemic species recover their abundance. • Exclusion and control plots with sowing were used in this experiment. • Seedling recruitment, plant growth and flowering rate were disrupted. • At least 13 of 15 studied endangered species were browsed by the rabbits. • Seedling of some tree species was browsed, delaying the laurel forest recovery. [ABSTRACT FROM AUTHOR]