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Mardones, I. G. 2003. |
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Doñana prepares the captive breeding of the most endangered felid worldwide. |
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Martín, M. C., Marrero, P., and Nogales, M. 2003.
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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 bad 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. |
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Martins, H., Elston, D. A., Mayes, R. W., and
Milne, J. A. 2002. |
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Previous approaches to the description of complex diets, based on n-alkanes and optimisation techniques, have grouped the plant species to reduce the number of components. Diet estimates have been obtained with least-squares routines by minimizing the discrepancy between faecal alkane concentrations calculated from herbage concentrations and actual faecal alkane concentrations. The effect of diet selection within groups can only be assessed by using sensitivity tests or by giving subjective weights to the individual plants. In the current study, a new optimization algorithm was developed that selects weightings that lead to consistent estimates of group proportions. The diet of the wild rabbit in a southern Portuguese montado was used as a case study. Estimates of the diet composition obtained using the new algorithm were compared with those of a conventional routine. The new algorithm was shown to provide, on average, more accurate estimates of the proportions of the groups in the diet. The effect of grouping plant species according to criteria other than similarity in n-alkane pattern on the accuracy of estimates was shown to be non-significant. |
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Martins, H., Milne, J. A., and Rego, F. 2002. |
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The seasonal and spatial pattern of diet composition of a population of wild rabbits Oryctolagus cuniculus L. occupying a southern Portuguese montado was estimated using the n-alkane technique. The diet was analysed in terms of components that are relevant to habitat management. The dietary categories considered were gum cistus leaves and flowers, cork oak and holm oak seedlings and acorns, cereals, olive tree regrowth and grass-forb species. The objectives were to assess the changes in diet across seasons in relation to the reproductive cycle of the rabbits, and to relate these changes to herbaceous biomass availability and to habitat structure, in terms of density of scrub cover and accessibility to arable crops. The results demonstrated that the diet was dominated by grass-forbs, and cereals when they were available. Browse was an important component of the diet and became more important in a year of low herbaceous biomass availability and in areas dominated by dense scrub. A similar phenomenon was observed in relation to consumption of acorns in winter. Seasonal and spatial variation in diet composition suggested a strategy aimed at maintaining a high quality diet. This was supported by the observed high dry matter digestibility of the diet during most of the year. The relevance of growing arable crops and providing fodder, as a means of increasing the carrying capacity of montados for rabbits and protecting the natural regeneration of trees, is discussed. |
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Martins_et_al_2002_Seasonal_and_spatial_variation_in_rabbit_diet.pdf |
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Martins, H., Barbosa, H., Hodgson, M., Borralho,
R., and Rego, F. 2003. |
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This study assesses the effect of vegetation and variables related to weather and light conditions on the efficacy of rabbit Oryctolagus cuniculus (Linnaeus, 1758) counts carried out in the south of Portugal. Counts were carried out in two years using driven line transects, and correlated with vegetation type and the variables using generalised linear models. The offset was a surveyed area estimated using Distance Sampling Theory as a means of correcting for detectability bias. More rabbits were observed in dense vegetation during day-time counts and in crops during night-time counts. In 1998, day-time counts were higher with higher average daily temperatures, whilst the night-time counts were higher with higher minimum daily temperatures. In 1999, day-time counts decreased with the amount of rainfall in the previous month, and the night-time counts decreased with the accumulated rainfall in the previous two months and with the higher wind speeds. In order to increase efficacy, counts should be carried out either at dawn or at dusk during the post-breeding season, and with greater intensity in dense scrub or open vegetation with high tree cover. During the breeding season and winter, counts should be carried out after dusk and with greater intensity in arable crops. |
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Martins_et_al_2003_Effect_of_vegetation_and_environmental_factors_on_rabbit_counts.pdf |
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McCarthy, T. and Dorfman, A.
2004. |
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© T. McCarthy & A. Dorfman |
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Merino, L. 2004. |
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The situation that certain animal species live on the edge of extinction has lead to the creation of a germ plasm bank, a co-ordinated work of the Ministry of Environment and the CSIC. |
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Merino_2004_Banco_de_germoplasma_para_especies_amenazadas.pdf |
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Monnerot, M., Vigne, J. D.,
Biju-Duval, C., Casane, D., Callou, C., Hardy, C., Mougel, F., Soriguer, R. C.,
Dennebouy, N., and Mounolou, J. C. 1994. |
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New data on mitochondrial DNA polymorphism in Oryctolagus cuniculus confirm the existence of 2 maternal lineages which are geographically well separated. They provide evidence in favour of northern Spain (and possibly southern France) as a refuge area for rabbit populations during the last major glaciation. Osteological analysis leads to the discrimination of populations and the recognition of discrete qualitative characters, which provide additional markers to describe population diversity. Characterization of different domains of mtDNA from ancient bones was used as a tool to resolve the general question of the origin of present populations. Results obtained from ancient and present rabbits living in Zembra (Tunisia) showed that the present-day population has descended from animals present on the island some 2000 years ago. Archaeozoological data provide evidence for their introduction by Bronze Age, Punic or Roman people. |
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Monzón, A., Fernandes, P., and Rodrigues, N.
2004. |
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The aim of this work is to assess whether there is a specific structural vegetation pattern for the wild rabbit Oryctolagus cuniculus (L., 1758) that might explain its spatial distribution. The species presence was approached through logistic regression modelling based on selected descriptors of vegetation landscape structure: number of homogeneous vegetation units, their areas and diversity values and heterogeneity indexes. All variables were derived for two hunting areas within the National Park of Peneda-Gerês in northern Portugal. The results show the wild rabbit preference for types of vegetation cover that offer, first of all, shelter, mainly in the form of shrub cover, and secondly, vegetation cover that always displays high fragmentation or high availability of resources. This animal avoids landscapes with homogeneous and continuous vegetation cover. The results obtained are suggestive of management actions to improve the habitat in order to encourage development of the species, whose presence will also favour the threatened and endangered predators that occur in the National Park of Peneda-Gerês. |
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Monzon_et_al_2004_Vegetation_structure_regulating_rabbit_presence.pdf |
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Moreira, F., Rego, F. C., and Ferreira, P. G.
2001. |
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In this paper we test the hypothesis that landscape changes in a region of Northern Portugal (Minho) in the last 40 years could be predicted from socioeconomic and political history. The major predicted changes were related to agricultural abandonment and afforestation. We further predicted that these changes contributed to increased fire risk. Analysis of aerial photography for the years 1958, 1968, 1983 and 1995 in a study area of 3700 ha revealed a significant decline in agricultural areas and low shrublands and an increase in tall shrublands and forests. This represented a 20-40% increase in fuel accumulation at a landscape level, suggesting that the abandonment of farming activities is a major driving force of increasing fire occurrence in the region. With one exception, all the predictions were partly or totally confirmed. This study confirms that socioeconomic factors might explain a significant part of the variation in landscape composition across time, in the Mediterranean region. |
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Moreira_et_al_2001_Temporal_pattern_of_change_in_a_landscape_of_Portugal.pdf |
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Moreno, S. and Villafuerte, R.
1995. |
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Several endangered carnivores and raptors in Mediterranean Spain are very dependent on rabbits Oryctolagus cuniculus, which have shown a progressive decline in abundance for several decades. Land use neglect, and the consequent abandonment of traditional land use methods such as burning, is considered one of the factors responsible for this decrease. To examine this hypothesis we have compared rabbit use of experimentally burned and unburned scrubland areas. Rabbit activity was found to be significantly higher in burned areas, with the greatest use in less productive habitats in close proximity to scrub cover. The promotion of traditional land practices for nature conservation in the natural ecosystems of the Mediterranean Basin is discussed. |
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Moreno_&_Villafuerte_1995_Management_of_scrubland_for_rabbit_conservation.pdf |
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Moreno, S., Villafuerte, R.,
and Delibes, M. 1996. |
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The use of protective cover by prey animals is commonly associated with high predation risk. Rabbits (Oryctolagus cuniculus) in southern Spain use vegetated patches in daylight but open prairie during the night, although predation rates are high during both periods. Hiding under vegetation may be adaptive for rabbits during the day because they suffer predation by visually oriented birds of prey, but may be dangerous during the night, when they are hunted by carnivorous mammals that need cover to stalk. Therefore, the heavily predated Spanish rabbits may leave dense cover in nighttime and exploit the rich prairie food. |
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Moreno_et_al_1996_The_use_of_vegetation_by_European_wild_rabbits.pdf |
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Moreno, S., Villafuerte, R., Cabezas, S., and
Lombardi, L. 2004. |
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The decline of rabbit (Oryctolagus cuniculus) populations in Mediterranean Spain has been shown to be one of the main threats to rabbit-specialist predators such as the Iberian lynx (Lynx pardina) and the Spanish imperial eagle (Aquila adalberti), two species which are in serious danger of extinction. Consequently, corrective measures such as increasing rabbit populations by restocking have been carried out to help the recovery of predator populations. In order to determine the general applicability of rabbit restocking for predator conservation, we performed three experimental restockings and evaluated their success in relation to season, habitat quality and the number of animals introduced. Rabbits were released either in large or small numbers in all four seasons of the year, and in habitat types defined as poor or rich according to the food availability for rabbits. For each restocking we evaluated rabbit survival, degree of residency and expected population increase. As a rule, the highest restocking success occurred whenever smaller number of rabbits were released in the richest quality habitat. Restocking during the breeding season was less successful than in other seasons. Problems concerning intraspecific competition, reproductive failure and diseases are discussed. |
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Moreno_et_al_2004_Rabbit_restocking_for_predator_conservation_in_Spain.pdf |
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Muñoz Igualada, J., San Miguel Ayanz, A., and
Martínez Jaúregui, M. 2004. |
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Notes on the current problems of the rabbit. |
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Munoz_Igualada_et_al_2004_La_problematica_actual_del_conejo.pdf |