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Iason, G. R., Manso, T., Sim, D. A., and Hartley,
F. G. 2002. |
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1. The relationship between available biomass and short-term rate of intake (functional response) of herbivores is expected to provide a link between their food supply, and their distribution. 2. The functional response of captive wild rabbits (Oryctolagus cuniculus L.) on artificially produced broad-leaved (Lolium perenne L.) and narrow-leaved (Festuca ovina L.) grass swards was quantified. 3. The general prediction that habitat selection varied with biomass, and reflected the potential rate of intake defined by the functional response, was also tested. The main alternative predictions, that both intake rate and habitat selection increased asymptotically with biomass, or were biased towards intermediate habitat standing crop biomasses, were distinguished. 4. There was no relationship between biomass and short-term rate of intake on the narrow-leaved Festuca swards, but on the broad-leaved Lolium sward the short-term rate of intake increased asymptotically with biomass. 5. In a field experiment on Lolium swards, a population of free-living wild rabbits selected the shortest swards with the lowest biomasses, and which provided the lowest potential rates of intake. 6. Results demonstrate that free-living wild rabbits do not select habitats that provide the maximum potential rate of intake, nor did they select foraging habitat with intermediate standing crops. It is suggested that their selection of foraging areas in these grasslands which typify rabbit foraging habitat, is dominated by antipredator considerations rather than purely by rate of intake. |
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Iason_et_al_2002_Local_distribution_of_rabbits_on_grass_swards.pdf |
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IUCN/SSC Cat Specialist Group 2002. Iberian Lynx Declared Critically Endangered. Cat News 37: 1-2. (inclusive Editorial by P. Jackson: Cats on the Brink) |
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The Iberian lynx (Lynx
pardinus), found only in Spain and Portugal, has been declared Critically
Endangered in the IUCN Red List of Threatened Species: "With the
population having declined to less than half of the 1,200 of the early 1990s,
the Iberian lynx is close to becoming the first wild cat species to go extinct
for at least 2,000 years." |
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| © IUCN/SSC Cat Specialist Group / P. Jackson |
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Jackson, P. 1985. |
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I visited Miguel Delibes, specialist in the Spanish or pardel lynx, in the Doñana National Park, which is the principal sanctuary for the cat. Miguel reckons that there are 30-40 lynxes in Doñana. The population is continuing to decline, and the habitat is decreasing. |
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Jackson, P. 1988. |
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Plans have been announced for programmes to save the Iberian lynx Lynx pardina, also known as the Spanish and pardel lynx, which is one of the most endangered species in Europe. Only about 400 are believed to survive in widely fragmented populations, mainly in the southwestern quadrat of Spain and in two or three places in Portugal. |
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Jackson, P. 1992. |
| The first breeding centre for Iberian lynx Lynx pardinus is being established at the Doñana National Park in southern Spain, home of a wild population. |
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Jackson_1992_Injured_Iberian_Lynx_for_Captive_Breeding_Programme_-_Cat_News_No16.pdf |
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Jackson, P. 2002.
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Over 100 participants attended an International Seminar on the Iberian Lynx in Andújar, Spain, from 29 to 31 October 2002 to coordinate efforts to save the Critically Endangered lynx from extinction. (Short summary and Recommendations). |
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Jackson_2002_International_Seminar_on_the_Iberian_Lynx_-_Cat_News_No37.pdf |
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Jaksic, F. M., and Delibes, M. 1987. |
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We conducted a comparative analysis of foodniche relationships and trophic guild structure in two assemblages of vertebrate predators (including hawks, owls, snakes, and carnivores) living in similar habitats of Chile and Spain, which differed in species richness (11 and 25 predator species, respectively), to explore how the structure of predator assemblages reflects an increase (or decrease) in the number of coexisting species. Our results indicate that the Spanish assemblage appears enriched by the symmetrical "addition" of species with disparately large and small values of body weight, diet breadth, and mean prey size, around the same median value found in Chile. Or, alternatively, the Chilean assemblage appears impoverished by the symmetrical "loss" of peripheral species -those at both tails of the frequency distribution of the above trophic estimators. Spanish predators overlap less extensively among themselves, and with smaller variance, than Chilean predators. Consequently, the higher predator richness in Spain is not ascribable to their narrower diet breadths or more extensive diet overlaps as predicted by some theoretical models. Instead, it is associated with a more spread-out use in the two countries, but in Spain guilds are less tightly packed. Some taxomically unrelated species are close diet analogues between Spain and Chile, whereas some closely related species cannot be matched well between countries. Circumstantial evidence suggests that the presence of some trophic guilds and of some specialist predators in either country is based on the high abundance attained by some particular prey types. |
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Jaksic_&_Delibes_1987_Food_niche_comparison_in_predators.pdf |
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Jaksic, F. M. and Soriguer, R.
C. 1981. |
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(1) The European Rabbit (Oryctolagus cuniculus) is a native of the mediterranean habitats of Spain, and was recently introduced to ecologically similar habitats in central Chile. (2) A survey of the quantitative information on body sizes of predators and on the importance of rabbits as prey in both southern Spain and central Chile was made. Patterns of habitat utilization by rabbits in the two areas were also compared. (3) Rabbits contribute on the average 20.6% of the vertebrate prey of twenty-nine species of Spanish predators; the figure is 2.0 in the diet of the sixteen species of Chilean predators. The statistical distribution of body sizes of predators in southern Spain is not significantly different from that of predators in central Chile. The curve of habitat utilization by rabbits in central Chile is skewed toward low values of shrub cover, and that in southern Spain toward higher values of shrub cover. (4) The low consumption of rabbits by Chilean predators is associated with higher densities of native prey, relative to southern Spain. This might render more profitable for Chilean predators hunting for native prey than for introduced rabbits. |
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Jiménez, A., Sánchez, B., García, P., Galka, M.,
Fernández, P., Benito, A., Gallego, L., Palencia, E., de Calvo, C., Sánchez,
C., and Peña, L. 2004. |
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Jimenez_et_al_2004_Membranous_glomerulonephritis_in_Iberian_lynx.pdf |
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Johnson, W. E., Godoy, J. A.,
Palomares, F., Delibes, M., Fernandes, M., Revilla, E., and O'Brien, S. J.
2004. |
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The Iberian lynx (Lynx pardinus), one of the world's most endangered cat species, is vulnerable due to habitat loss, increased fragmentation of populations, and precipitous demographic reductions. An understanding of Iberian lynx evolutionary history is necessary to develop rational management plans for the species. Our objectives were to assess Iberian lynx genetic diversity at three evolutionary timescales. First we analyzed mitochondrial DNA (mtDNA) sequence variation to position the Iberian lynx relative to other species of the genus Lynx. We then assessed the pattern of mtDNA variation of isolated populations across the Iberian Peninsula. Finally we estimated levels of gene flow between two of the most important remaining lynx populations (Don˜ana National Park and the Sierra Morena Mountains) and characterized the extent of microsatellite locus variation in these populations. Phylogenetic analyses of 1613 bp of mtDNAsequence variation supports the hypothesis that the Iberian lynx, Eurasian lynx, and Canadian lynx diverged within a short time period around 1.53–1.68 million years ago, and that the Iberian lynx and Eurasian lynx are sister taxa. Relative to most other felid species, genetic variation in mtDNA genes and nuclear microsatellites were reduced in Iberian lynx, suggesting that they experienced a fairly severe demographic bottleneck. In addition, the effects of more recent reductions in gene flow and population size are being manifested in local patterns of molecular genetic variation. These data, combined with recent studies modeling the viability of Iberian lynx populations, should provide greater urgency for the development and implementation of rational in situ and ex situ conservation plans. |