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Ferreira C.,University of Porto | Ferreira C.,Institute Investigacion en Recursos Cinegeticos CSIC UCLM JCCLM | Pauperio J.,University of Porto | Alves P.C.,University of Porto
Wildlife Research | Year: 2010

Context. The wild rabbit (Oryctolagus cuniculus) is a keystone species from the Iberian Peninsula that has suffered a strong decline in Spain during the past decades. Data on historical and current population trends in Portugal are virtually non-existent. Aims. To investigate changes in rabbit abundance at the national level so as to inform conservation status assessments, and to evaluate the usefulness of hunting bags as a rabbit abundance index. Methods. Field surveys based on latrine counts in linear transects were performed in two periods (1995 and 2002) to assess variation in population abundance. Hunting bags were also analysed for the same period to verify whether these data showed the same trends. General trends of rabbit abundance were estimated using TRIM software. Key results. Field data revealed that most of the sampling units across Portugal have low abundances, despite the observation of local high-density spots. A population reduction of 27% was estimated. Although some fluctuations were observed in hunting bags, global results obtained from these data suggest a slightly increasing trend in rabbit abundance. Conclusions. A discrepancy between field data and hunting statistics was observed. Because hunting bags may be influenced by sporadic management operations undertaken by hunters and the lack of systematic procedures in data collection, we believe that hunting statistics are not representative of real changes in rabbit populations. Thus, observed reduction in rabbit abundance estimated by field data, combined with the high initial morbidity due to rabbit haemorrhagic disease (RHD) after 1988 and the potential for continuing decline in population trends because of other factors, led to an inference of a reduction of >30% in rabbit abundance in Portugal during the past decade. Implications. Taking into account the estimated reduction, the species' biology and socioeconomic implications, wild rabbit in Portugal was listed in 2005 in the Near Threatened category under IUCN criteria. Because of its ecological and economic importance, this classification prompted the definition of several conservation actions aimed at the recovery of the species in Portugal. © CSIRO 2010. Source


Martinez-Padilla J.,CSIC - National Museum of Natural Sciences | Martinez-Padilla J.,Macaulay Institute | Vinuela J.,Institute Investigacion en Recursos Cinegeticos CSIC UCLM JCCLM
Ibis | Year: 2011

The onset of incubation before the end of laying imposes asynchrony at hatching and, therefore, a size hierarchy in the brood. It has been argued that hatching asynchrony might be a strategy to improve reproductive output in terms of quality or quantity of offspring. However, little is known about the mediating effect of hatching asynchrony on offspring quality when brood reduction occurs. Here, we investigate the relationship between phenotypic quality and hatching asynchrony in Common Kestrel Falco tinnunculus nestlings in Spain. Hatching asynchrony did not increase breeding success or nestling quality. Furthermore, hatching asynchrony and brood reduction had different effects on nestlings' phytohaematogglutinin (PHA)-mediated immune response and nestling growth. In asynchronous and reduced broods (in which at least one nestling died), nestlings showed a stronger PHA-mediated immune response and tended to have a smaller body size compared with nestlings raised in synchronous and reduced broods. When brood reduction occurred in broods hatched synchronously, there was no effect on nestling size, but nestlings had a relatively poor PHA-mediated immune response compared with nestlings raised in asynchronous and reduced broods. We suggest that resources for growth can be directed to immune function only in asynchronously hatched broods, resulting in improved nestling quality, as suggested by their immune response. We also found that males produced a greater PHA-mediated immune response than females only in brood-reduced nests without any effect on nestling size or condition, suggesting that females may trade off immune activities and body condition, size or weight. Overall, our results suggest that hatching pattern and brood reduction may mediate resource allocation to different fitness traits. They also highlight that the resolution of immune-related trade-offs when brood reduction occurs may differ between male and female nestlings. © 2011 The Authors. Ibis © 2011 British Ornithologists' Union. Source


Alda F.,Institute Investigacion en Recursos Cinegeticos CSIC UCLM JCCLM | Alda F.,Smithsonian Tropical Research Institute | Ruiz-Lopez M.J.,University of Missouri | Gompper M.E.,University of Missouri | And 2 more authors.
Biological Invasions | Year: 2013

The common raccoon (Procyon lotor) is endemic to Central and North America, although non-native populations have become established around the world. In Spain, growing evidence of the introduction of raccoons has been reported across the country in the last decade, especially in Central Spain where the largest population is thought to occur. We used mitochondrial and microsatellite DNA data to investigate the genetics of invasive raccoons in Central Spain and to infer: the number of introduction events, the number of founders and the genetic variability of the introduced populations compared to a native population. We found that at least two introduction events have occurred along the Jarama and Henares Rivers in Central Spain, which currently constitute two genetically differentiated subpopulations. In both localities the number of effective founders from a native population was estimated as 2-4 individuals. These newly founded populations have expanded and show evidence of incipient contact and reproduction between them. This may allow for an increase in the genetic variability and adaptive potential of the population(s), possibly increasing the difficulty of controlling this invasive species. Our results reveal the ability to longitudinally monitor the genetics of the raccoon range expansion and emphasize the urgent need to control the pet trade of potentially invasive species. © 2012 Springer Science+Business Media B.V. Source


Ferreira C.,Institute Investigacion en Recursos Cinegeticos CSIC UCLM JCCLM | Ferreira C.,University of Porto | Villafuerte R.,Institute Investigacion en Recursos Cinegeticos CSIC UCLM JCCLM | Villafuerte R.,University of Cordoba, Spain | And 10 more authors.
Population Ecology | Year: 2014

In Mediterranean ecosystems, the European rabbit is a keystone species that has declined dramatically, with profound implications for conservation and management. Predation and disease acting on juveniles are considered the likely causes. In the field, these processes are managed by removing predators, increasing cover to reduce predation risk and by vaccinating against myxomatosis. These manipulations can be costly and, when protected predators are killed, they can also be damaging to conservation interests. Our goal was to test the effectiveness of cover and vaccination on juvenile survival in two large enclosures, free of mammalian predators, by adding cover and vaccinating juveniles. Rabbit warrens were our experimental unit, with nine replicates of four treatments: control, cover, vaccination, and cover and vaccination combined. Our results showed that improved cover systematically increased juvenile rabbit survival, whereas vaccination had no clear effect and the interactive effect was negligible. Our experimental data suggest that improved cover around warrens is an effective way of increasing rabbit abundance in Mediterranean ecosystems, at least when generalist mammalian predators are scarce. In contrast the vaccination programme was of limited benefit, raising questions about its efficacy as a management tool. © 2013 The Society of Population Ecology and Springer Japan. Source

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