Seasonal variation in the diet of wild rabbitsOryctolagus cuniculus on a semiarid Atlantic island (Alegranza, Canarian Archipelago)

Abstract

P. and Nogales M. 2003. Seasonal variation in the diet of wild rabbits Oryctolagus cuniculus on a semiarid Atlantic island (Alegranza, Canarian Archipelago). Acta Theriologica 48: 399-410.The diet of the wild rabbit Oryctolagus cuniculus (Linnaeus, 1758) on Alegranza Island (Canary Islands) was studied by microhistological examination of faecal samples. We compared the presence of each food-plant species in the faeces across a year in comparison with plant availability. Two areas were studied, Llano de la Vega and La Caldera. At the first site, Suaeda vera and Chenoleoides tomentosa were the most common plants, while at the latter it was Euphorbia regis-jubae. In general, species belonging to the Chenopodiaceae were most commonly eaten by rabbits. Plants such as Chenoleoides tomentosa and Salsola vermiculata were most important in the diet in every season. Levin's niche-breadth was broader across the seasons in the study site of La Caldera than at Llano de la Vega. Furthermore, this parameter yielded the highest values (broadest niche) during the spring at both sites. Most important plants eaten by rabbits showed green vegetative parts through all seasons. Rabbits selected some plants independently of their availability, even in this reduced insular environment. The feeding behaviour of rabbits in Alegranza, selecting certain species, must have had important consequences on the composition and distribution of the vegetation over the years. This negative effect on island vegetation has been shown to occur on many oceanic islands of the world where rabbits have been introduced.

Trophic ecology of feral cats (Felis silvestris f. catus) in the main environments of an oceanic archipelago (Canary Islands): An updated approach

“…This result is explained by the fact that the fauna on this islet is rather poor and the rabbit is very abundant (Martín et al 2003). However, in some habitats (the laurel forest, the thermophilous forest and the xerophytic shrub of Fuerteventura) where other prey items are relatively abundant, consumption of rabbits is the lowest recorded.…”

Micro-scale distribution of rabbits on Fuerteventura Island

“…If these plant species are food resources, we should expect them to be part of rabbits' diet in the archipelago. In the semiarid small islet of Alegranza, rabbits consume at least 12 plants species (Martín et al 2003). Numerous dry or fleshy-fruited seeds in their pellets indicate that they also eat reproductive parts of many plants species in other islands (Nogales et al 1995(Nogales et al , 2005López-Darias and Nogales 2008).…”

“…This is in spite of the fact that designing appropriate conservation plans implies proper monitoring of the ecology and distribution patterns of invasive species (Genovesi and Shine 2003). There are a number of studies of diet (Martín 1999;Martín and Marrero 1999;Marrero and Martín 2000;Martín et al 2003), and there is some knowledge of its consumption of endemic and introduced plants fruits (Nogales et al 1995(Nogales et al , 2005López-Darias and Nogales 2008). Other studies have explored factors affecting rabbit abundance in La Palma Island and Alegranza, a small islet of the archipelago (Cabrera- Rodríguez 1998Rodríguez , 2006Martín et al 2003).…”

Ecological effects and distribution of invasive non‐native mammals on the Canary Islands

“…Rabbits were brought to the Canaries during the conquest of the archipelago in the 15th century (De Abreu Galindo, 1977) and although data on their abundance are limited (Cabrera Rodríguez, 1998; Martín, Marrero & Nogales, 2003), the species presently occupies all the habitats of the main islands, being also present in the main islets of Lobos, La Graciosa and Alegranza, but have been eradicated from Montaña Clara (Martín et al ., 2002).…”

“…Despite the potential interest of studying the impact of this herbivore on the flora of the different habitats of this archipelago, only specific contributions to rabbit diet have been made in some xeric habitats of Alegranza (Martín, 1999; Martín & Marrero, 1999; Marrero & Martín, 2000; Martín et al ., 2003); in this islet rabbits selected certain plant species (especially of the family Chenopodiaceae) (Martín et al ., 2003). Lastly, mutualistic interactions with the Canarian endemic plant Plocama pendula (Rubiaceae) have been described by Nogales, Valido & Medina (1995) in coastal habitats of Tenerife.…”