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Ramos, B. and Soriguer, R. C. 2003. |
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Ramos_&_Soriguer_2003_Mamiferos_Parque_Nacional_Donana_p317-327.pdf | ||
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Đ B. Ramos & R.C. Soriguer |
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Rau, J. R., Beltran, J. F., and Delibes, M. 1985.
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The number of red foxes (Vulpes vulpes) has increased dramatically over the last few years in the Doņana National Park (S.W. Spain) whereas a noticeable decrease in the numbers of lynx (Lynx pardina) has apparently taken place during the same period. The Spanish authorities and private organizations concerned with nature conservation related both phenomena, and called for measures to control Fox numbers. In order to determine whether competitive pressures might have affected the already endangered Lynx population we will attempt here to use the data available on Fox and Lynx abundance and food habits to provide a preliminary answer to the questions raised, pending further research. |
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Rau_et_al_1985_Fox_density_increase_and_lynx_density_decrease_in_Donana.pdf |
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Rau, J. R., Beltran, J. F.,
and Delibes, M. 1987. |
| The authors presented a paper on a study of the relationship of fox and lynx in the Doņana National Park at a Seminar in October 1985 on the Ecopathology of Wild and Errant Dogs in the Palaearctic Zone. The following is their summary. |
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Rau_et_al_1987_Fox_and_lynx_in_Donana_NP_Spain_-_Cat_News_No6.pdf |
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Revilla, E., Wiegand, T., Palomares, F., Ferreras,
P., and Delibes, M. 2004. |
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Mounting theoretical and empirical evidence shows that matrix heterogeneity may have contrasting effects on metapopulation dynamics by contributing to patch isolation in nontrivial ways. We analyze the movement properties during interpatch dispersal in a metapopulation of Iberian lynx (Lynx pardinus). On a daily temporal scale, lynx habitat selection defines two types of matrix habitats where individuals may move: open and dispersal habitats (avoided and used as available, respectively). There was a strong and complex impact of matrix heterogeneity on movement properties at several temporal scales (hourly and daily radiolocations and the entire dispersal event). We use the movement properties on the hourly temporal scale to build a simulation model to reconstruct individual dispersal events. The two most important parameters affecting model predictions at both the individual (daily) and metapopulation scales were related to the movement capacity (number of movement steps per day and autocorrelation in dispersal habitat) followed by the parameters representing the habitat selection in the matrix. The model adequately reproduced field estimates of population-level parameters (e.g., interpatch connectivity, maximum and final dispersal distances), and its performance was clearly improved when including the effect of matrix heterogeneity on movement properties. To assume there is a homogeneous matrix results in large errors in the estimate of interpatch connectivity, especially for close patches separated by open habitat or corridors of dispersal habitat, showing how important it is to consider matrix heterogeneity when it is present. Movement properties affect the interaction of dispersing individuals with the landscape and can be used as a mechanistic representation of dispersal at the metapopulation level. This is so when the effect of matrix heterogeneity on movement properties is evaluated under biologically meaningful spatial and temporal scales. |
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Revilla_et_al_2004_Effects_of_matrix_heterogeneity_on_animal_dispersal.pdf |
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Robinson, I. H. and Delibes, M. 1988. |
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The distribution of faeces of the Spanish lynx was observed in the Biological Reserve of Doņana during October 1985. Faeces were non-randomly distributed on tracks through the vegetation, and occurred more frequently than expected beside intersections of deer trails with the tracks. A computer simulation showed that a randomly moving lynx was more likely to encounter faeces when thy occurred at intersection points than when they occurred randomly on tracks. |
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Robinson_&_Delibes_1988_Distribution_of_faeces_by_Spanish_lynx.pdf |
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Rodriguez, A. 1995. |
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In December 1992, the National Institute for Nature Conservation (ICONA) opened a captive breeding centre for lynx, with the capacity to house eight adult individuals, in the Doņana National Park. Three 'unrecoverables', two females (2.5 and 2 years old) and a male (9.5 years old), were brought ot the centre in 1992. |
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Rodriguez_1995_Captive_breeding_and_reintroduction_of_Iberian_lynx_in_Spain.pdf |
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Rodriguez, A. 2002. |
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An analysis of the subsequent range contraction during a 35-year period shows that only lynx populations inhabiting areas larger than 500 square km were able to persist. The establishment of large nature reserves is recommended. |
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Rodriguez, A. 2002. |
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Basic information on the Iberian lynx in Spain: Taxonomy, description, distribution, habitat, reproduction, feeding habits, abundance, social organization & behaviour, threats and other subjects. |
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Rodriguez, A. and Carbonell, E. 1998.
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Between 1991 and 1995 fresh fecal samples from Iberian lynx (Lynx pardinus), wildcats (Felis silvestris), red foxes (Vulpes vulpes), and other carnivore species were collected in two areas of central Spain for isolation of parasite eggs and larvae. Twenty-three gastrointestinal coccidia, cestoda and nematoda species were identified. Common (more than 20% prevalence) species were Isospora felis, I. rivolta, Ancylostoma spp., Toxascaris leonina, Toxocara cati, Aelurostrongylus spp., and Physaloptera spp. for the wildcat, I. felis, Taenia spp., Ancylostoma spp., T. leonina, and Toxocara canis for the Iberian lynx, and I. canis, I. vulpis, and Physaloptera spp. for the red fox. In contrast to the pattern found in most similar studies, the distribution of parasitic forms among individual hosts was not overdispersed. Differences in prevalence between host populations were only detected for Physaloptera spp. in the wildcat. Sexual differences in occurrence, prevalence and intensity were no found in any host. The number of parasite species per individual was significantly higher in adult than in subadult hosts, and negatively correlated with a rough index of host body condition. The consistence of parasite species across samples of the same individual host taken at different times was low. In this paper we provide the first data on intestinal parasites for the rare Iberian lynx. |
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Rodriguez_&_Carbonell_1998_Gastrointestinal_parasites_of_carnivores_in_Spain.pdf |
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Rodriguez, A. and Delibes, M. 1992. |
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The current distribution of the Iberian lynx Felis pardina is outlined and its population size in Spain estimated at about 95% of its world range. There are 48 separate breeding areas, generally small in size. In addition, 32 non-breeding areas have been located, and 50 areas where lynx presence is uncertain, some associated with, and others separated from, breeding areas. A major part of the range supports low lynx densities. Range fragmentation is the most noteworthy feature of the distribution pattern, although dispersal might link some adjacent nuclei. Nine genetically isolated populations are recognized, although probably only two, accounting for about 70% of the total population, are viable in the short term. The Spanish population size is estimated at about 1100 individuals, with fewer than 350 reproductive females. The risks arising form this situation are analysed and conservation policies proposed. |
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Rodriguez, A. and Delibes, M. 2002. |
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The current distribution of the Iberian lynx Felis pardina is outlined and its population size in Spain estimated at about 95% of its world range. There are 48 separate breeding areas, generally small in size. In addition, 32 non-breeding areas have been located, and 50 areas where lynx presence is uncertain, some associated with, and others separated from, breeding areas. A major part of the range supports low lynx densities. Range fragmentation is the most noteworthy feature of the distribution pattern, although dispersal might link some adjacent nuclei. Nine genetically isolated populations are recognized, although probably only two, accounting for about 70% of the total population, are viable in the short term. The Spanish population size is estimated at about 1100 individuals, with fewer than 350 reproductive females. The risks arising form this situation are analysed and conservation policies proposed. |
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Rodriguez_&_Delibes_2002_Internal_structure_in_Iberian_lynx_habitat.pdf |
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Rodriguez, A. and Delibes, M. 2003. |
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We studied the relationship between extinction frequencies of Iberian lynx subpopulations (Lynx pardinus) and their size and isolation during a 35-year period of strong geographic range contraction. At the end of this period there were fewer fragmentation events, fewer lynx populations of small size, and less isolation between them, than in simulated geographic ranges derived from a random distribution of local extinctions. Only small populations occupying <500 km2 went extinct. Local extinction in large, selfsustainable populations probably resulted from the sole action of deterministic factors, e.g. widespread prey decline. As compared with large populations, small ones experienced increased contraction per unit occupied area, which may reflect demographic unstability. The consistent effect of isolation on extinction suggests that such unstability was often prompted by reduced immigration and the subsequent disruption of metapopulation equilibrium. Several practical recommendations could be derived. Provided that habitat quality was adequate, a lynx population should avoid extinction within 35 years if it occupied an area of at least 500 km2. The persistence of small populations will also be enhanced by minimizing the distances to neighbouring populations within 30 km, and by maximizing the area occupied by these neighbours. Therefore, habitat management, or any other restoration action, directed to expand the area occupied by a small lynx population should be best located at points of its boundaries oriented towards other existing nearby populations. |
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Rodriguez_&_Delibes_2003_Population_fragmentation_and_extinction_in_Iberian_lynx.pdf |
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Rodriguez, A., Barrios, L., and Delibes, M. 1995.
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Reintroduction to the wild of threatened species has become a modern additional justification for captive propagation. This conservation procedure is costly, and both economic resources and the absence of optimal conditions in the field limit the IUCN recommendations for reintroduction to a small proportion of potential candidate species. Furthermore reintroduction attempts often fail. In carnivores, reintroduction failure is attributed to unsuitable adaptation in the field by captive-reared animals, due to their lack of hunting skills, their tendency to leave the target area, their inadequate interaction with conspecifics or their excessive confidence in humans. This list of causes is based on very few studies of carnivore adaptation after reintroduction. In very rare and endangered species, monitoring individual case-histories is the only way to evaluate reintroduction success. We report a successful experimental release of an Iberian lynx (Lynx pardinus) which grew up in captivity. Careful feeding-training and avoidance of human contact during the captive phase, as well as good habitat quality and correct interaction with other wild lynx in the release site, seem to account for the observed success. Permanence of the lynx within the release area might be related to availability of territory vacancies in the receiving population. Our results allow some optimism for future reintroductions of this endangered species in areas where it has become extinct recently. |
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Rodriguez_et_al_1995_Experimental_release_of_an_Iberian_lynx.pdf |
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Rodriguez, A., Revilla, E., and Fernandez, N.
2002. |
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The knowledge accumulated during the last decades on the biology and ecology of the Iberian lynx has generated several hypothesis on the main factors generating the pronounced decline of the species. This knowledge should be also the basis for the species recovery. First, the lynx is a species with a low recruitment rate, due to a low reproductive rate and a high mortality of juveniles. Population persistence is achieved through low levels of adult mortality and a relatively long life-span. Therefore, any human induced mortality added, especially of adults, destabilises the dynamic equilibrium of lynx population, anything else held the same. Second, it is a specialised stalking predators, thriving on European rabbits, and virtually excluding young rabbits and other prey. This attribute predicts a numberic response after a decline of rabbit populations. Third, lynx are linked to Mediterranean shrubland, probably because this is the type of vegetation where rabbits occur and because it offers other essential resources, such as stalking, breeding and denning sites. To these three potential factors we have to add the extinction risk due to stochastic factors. |
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Rodriguez, A. 2004. |
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On Iberian lynx identification, conservation status, distribution, habitat, ecology, reproduction, behaviour, interactions, bibliography. |
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Rogers, P. M. 1978. |
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A collection of 351 Lynx (Lynx pardina) faeces made from December 1972 to October 1973 in the Reserva Biológica de Doņana (Spain) was analysed for food remains. Rabbit (Oryctolagus cuniculus) remains were found in 84%, duck (Anas spp.) remians in 11% and small mammal remains in 3% of the faeces. Distribution of faeces showed a similar pattern to that of rabbits as determined by sight counts along transects. It is suggested that Lynx and Rabbit in Europe may have evolved an ecological relationship similar to that between L. canadensis and Snowshoe hare Lepus americanus in North America. |
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Rogers, P. M., Arthur, C. P.,
and Soriguer, R. C. 1994. |
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Content: 1. Palaeontology and history, 2. Present distribution and regional variations in numbers, 3. Status as a game species and as a pest, 4. Rabbit-plant ecology, 5. Population ecology, 6. Myxomatosis, 7. Viral haemorrhagic disease, 8. Conclusion |
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Ruiz, R. 2001. |
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The joy of the Iberian fauna, the lynx, is on the edge of extinction. Only a few hundreds are left. The days of the big spotted cat are numbered. Urgent measures are needed. |