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Monitoring European rabbit (Oryctolagus cuniculus) populations using suitable methods is crucial, especially in those areas in which endangered predators remain and rabbits occur at low densities. We first counted the number of rabbits, the number of scattered pellets, and the number of latrines counted within 16 plots established in areas of low rabbit density, showing that the number of rabbits counted inside the plots was more closely correlated with the number of pellets counted than with the number of latrines. In addition, no latrines were found in 8 plots. In 53 walking transects, the number of pellets m−2 and the number of latrines km−1 had a positive relationship, but no significant correlation was obtained between the two methods when only the transects with a low rabbit abundance were selected. These results suggest that although counting latrines can be useful to compare areas with different abundances, it may underestimate rabbit abundance at low abundances where counting scattered pellets is, therefore, the most accurate alternative. [ABSTRACT FROM AUTHOR]

In recent decades, the intensification of agricultural practices in olive orchards, including intensive use of agrochemicals, along with the absence of natural herb layer, has led to a decline in songbird communities. Increased nest predation has been suggested as another important factor in the decline of farmland birds. High abundances of alternative prey species, such as European Rabbits Oryctolagus cuniculus may attract generalist predators, which may increase predation rates on bird nests, a phenomenon known as hyperpredation. In this work, we evaluate artificial nest predation in intensively farmed olive orchards, using quail eggs (one plaster and two natural eggs in each nest) placed on the ground (97 nests) and on trees (106 nests). 53.7% of nests (109 out of 203) were predated; 51 of these nests had at least one egg with signs of predation and in 58 nests all eggs were predated. Nests placed on the ground (61%) were predated more frequently than those on trees (46%). Rabbit abundance was identified as one of the main factors increasing the probabilities of a nest being predated. Despite lower rates of nest predation in areas with low rabbit abundance, we found a higher diversity of nest predators, such as Mustela nivalis, Mustela putorius, Martes foina or Erinaceus europaeus in these areas. This study suggests that conservation efforts aimed at increasing the breeding success of farmland birds should avoid areas with high abundance of rabbits owing to the phenomenon of hyperpredation. [ABSTRACT FROM AUTHOR]

Abstract: Rabbit populations in Iberia remain at low densities in several areas in which their endangered predators still coexist, and the recovery of these populations is therefore urgent if the integrity of Iberian Mediterranean ecosystems is to be maintained. The enhancement of wild rabbit populations has been attempted through the use of in situ extensive rabbit captive breeding enclosures (restocking plots), which reduce mortality caused by terrestrial predators and dispersal movements and permit the breeding of young individuals which can then naturally disperse to settle in the surrounding areas. However, their effectiveness, the role of its size, the optimal habitat management that should be promoted around them and the habitat features remains uncertain. Here, we show results from a four year study of an ambitious rabbit restocking plan on a landscape scale. We measured rabbit abundance in a vast area in which thirty-two restocking plots were built to create an initial rabbit population for further dispersion, in addition to an intensive habitat management program. We also compared rabbit abundance between managed and unmanaged UTM cells of 2.5km×2.5km. Our results showed that rabbit abundance was three times higher in managed cells, but four years after restocking, rabbit abundances had only reached the threshold needed to support stable Iberian lynx presence (at least 10 latrines per km−1) in 9 of the 23 managed cells. Rabbit abundance was strongly affected by habitat treatment and scrub coverage. The increase of shelter was useful in low cover areas but ineligible in places with high scrub cover, where the increase of refuge plus scrub clearing to create pastures improve rabbit abundance more effectively. In the light of our results, restocking plots should be built only in places with suitable habitat, whereas pastures should be created in dense scrublands and refuge in low cover areas. [Copyright &y& Elsevier]

Damage caused by wildlife foraging can lead to significant agricultural losses and the problem can be further complicated if the damage-inducing animal is a valuable resource in its own right. Provision of alternative food sources such as cover crops might be a means of reducing the damage which appears to be linked to scarcity of alternative foods in intensively-managed agroecosystems. Cover crops may provide other benefits to agroecosystems, i.e. preventing soil erosion but can potentially have some undesired consequences, i.e. water competition with the cash crop. In our study, we tested the effectiveness of cover crops in reducing the damage caused by foraging European rabbit Oryctolagus cuniculus to vineyards in a semi-arid agroecosystem in southern Spain. Experimental treatments consisted of a combination of the presence/absence of sown cover crops (70% oat Avena sativa and 30%garden vetch Vicia sativa) with/without rabbit exclusion. In the 2009 growing season, we assessed rabbit-induced damage using a browsing index on vine shoots, rabbit use of plots was estimated based on faecal pellet counts and grapevine yield was measured at harvest. Rabbits ate the cover crops, and rabbit use was highest in the plots sown with the oat and vetch cover crop. However, the effect of the presence of the cover crop on the amount of damage caused by rabbits was limited and, moreover, the presence of the cover crop had a negative effect on grapevine yield. Exclosure fences effectively reduced rabbit damage by keeping rabbit densities close to zero, but even a low rabbit number (;1 rabbit/ha) can cause significant damage.Although cover crops provided rabbits with an alternative food source, they acted as attractants for rabbits and were not effective in reducing the damage caused to vineyards by higher rabbit numbers. Therefore, adding cover crops might not be an effective measure in controlling rabbit-induced damage in semi-arid wine-growing regions. [ABSTRACT FROM AUTHOR]

Early detection of predators by their prey is an essential element of antipredator tactics, and for many mammalian predator prey interactions, detection comes mainly via a predators olfactory cues. The avoidance of predator odors can reduce the likelihood of encountering predators and increases the chances of prey survival. However, the role of coevolutionary history in the exploitation of odors in mammalian predator–prey interactions is not so well understood. The prey naiveté hypothesis predicts the lack of effective antipredator behaviors given the lack of a coevolution between predator and prey but has so far been only tested on native prey. In this study, we describe the short-time responsiveness of an introduced prey species, the European rabbit (Oryctolagus cuniculus), to scents from coevolved and novel predators in Australia. We quantified rabbit activity rates by means of pellet counting and activity indices based on footprints, in a series of experimental plots treated with predator odors, and both methods yielded consistent results. Rabbits responded to coevolved predators by reducing their activity rates to scented experimental plots, whereas no avoidance was found for novel allopatric predators. These results suggest a shared evolutionary history between the antipredatory responses of rabbits and their natural predators. [ABSTRACT FROM PUBLISHER]

Sustainability is a key attribute for the future of the olive grove. Cover crops can be considered as an effective tool to achieve sustainability of olive orchards to reduce soil erosion, improve soil fertility and increase biodiversity. However, wild herbivores may forage on cover crops when natural food resources are scarce. In this study we assessed the impact of European rabbit grazing on the implantation of herbaceous cover crops of two native plant species, one palatable ( Bromus rubens L.) and the other unpalatable ( Anthemis arvensis L.) in two olive orchards with very scarce vegetation cover in Andalusia, Southern Spain. Eight rabbit exclusion plots, close to eight other unfenced plots, were planted where the aboveground biomass, height and the ground covered by each species were measured. The results showed that the biomass, height and the ground cover by B. rubens were higher in the rabbit exclusion areas (ground cover: 36.5 ± 3.3%; height: 30.3 ± 3.9 cm, averaged over the entire measuring period; and biomass: 158 ± 36 g/m 2 , in April) than in unfenced areas (ground cover: 1.9 ± 0.2%; height: 5.6 ± 0.7 cm; biomass: ≅0), while A. arvensis showed no difference in biomass, height or ground cover between the two treatments (ground cover: 11.3 ± 6.3%; height: 12.2 ± 7.9 cm, averaged over the entire measuring period; and biomass: 49.5 ± 10 g/m 2 , in April). The results further showed that the damage by rabbits was caused from the early stages of development of B. rubens , which avoid its growth; notwithstanding the plant biomass consumption was minimal, the damage caused was critical. These findings suggest that unpalatable species such as A. arvensis could be a suitable tool for establishing herbaceous cover crops in olive groves at high rabbit densities, where other palatable species (e.g., B. rubens ) are strongly consumed, thus contributing to soil conservation and improvement in olive groves with soils already degraded by erosion. [ABSTRACT FROM AUTHOR]

Exploring predator–prey systems in diverse ecosystems increases our knowledge about ecological processes. Predator population growth may be positive when conspecific density is low but predators also need areas with prey availability, associated with competition, which increases the risk of suffering losses but stabilises populations. We studied relationships between European rabbits Oryctolagus cuniculus (prey) and adult eagle owls Bubo bubo (predators) in south-western Europe. We assessed models explaining the predator population growth and stability. We estimated the abundance of rabbits and adult eagle owls during three years in eight localities of central-southern Spain. We explored models including rabbit and adult eagle owl abundance, accounting for yearly variations and including the locality as a random variable. We found that population growth of adult eagle owls was positive in situations with low conspecific abundance and tended to be negative but approaching equilibrium in situations of higher conspecific abundance. Population growth was also positively related to previous summer rabbit density when taking into account eagle owl conspecific abundance, possibly indicating that rabbits may support recruitment. Furthermore, abundance stability of adult eagle owls was positively related to previous winter–spring rabbit density, which could suggest predator population stabilisation through quick territory occupation in high-quality areas. These results exemplify the trade-off between prey availability and abundance of adult predators related to population growth and abundance stability in the eagle owl–rabbit system in south-western Europe. Despite rabbits have greatly declined during the last decades and eagle owls locally specialise on them, eagle owls currently have a favourable conservation status. As eagle owls are the only nocturnal raptor with such dependence on rabbits, this could point out that predators may overcome prey decreases in areas with favourable climate and prey in the absence of superior competitors with similar foraging mode. [ABSTRACT FROM AUTHOR]