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Gaona, P., Ferreras, P., and
Delibes, M. 1998. |
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The use of metapopulation models in conservation biology is growing exponentially, but there is a need for empirical studies that support theoretical approaches, especially for species with large and long-lived individuals. In this paper we explore the viability and dynamics of a real metapopulation of an endangered mammal by combining field work and modeling in order to support conservation decisions and evaluate theoretical approaches. The Iberian lynx (Lynx pardinus), considered the most vulnerable felid in the world, is restricted to the Iberian Peninsula in southwestern Europe, The persistence of the species is handicapped by the high fragmentation of its populations. Fewer than 1000 individuals are distributed in nine isolated populations, each of them also fragmented but with their patches connected by dispersers, in what could be called metapopulations. One of these metapopulations, including similar to 60 individuals, inhabits the Donana National Park (DNP) and its surroundings. Demographic and behavioral data gathered over one decade for this lynx population were employed to develop a spatially realistic structured model with density-dependent fecundity and migration, including demographic and environmental stochasticity. Such a model is used to identify the demographic features that determine the dynamics of this population and to predict its risk of decline under a set of alternative assumptions. A hypothetical lynx metapopulation with values of the parameters such as those observed in Donana, but without stochastic events, could sustain itself over time. Results of this deterministic model show how females occupy all the potential breeding territories, while males are below the carrying capacity. The metapopulation has a source-sink structure, with the sources internal and the sinks external to the national park. Sinks result from reduced survival rather than reduced fecundity, as generally assumed. High mortality in sink patches is deterministic, deriving both from within-patch risks and from factors related to the landscape matrix among patches. The survival rate of adults with territories in the sources was the most sensitive parameter, leading the dynamics of the metapopulation. When we include demographic stochasticity in the model, the population becomes extinct 22% of the time within 100 yr, and this value increases to 33.8% when environmental stochasticity is also considered. Most of the metapopulation extinctions occurred because of the disappearance of males due to sex differences in demographic parameters related to behavioral aspects (e.g., dispersal rate). Different scenarios were simulated as modifications affecting either within- or between-patch dynamics. Changes in the carrying capacity of source and sink patches would have very different consequences in terms of metapopulation persistence: one breeding territory increase in the largest source reduces metapopulation extinction risk from 33.8 to 17.2% in 100 yr, while an increase of three territories in the largest sink does not modify the extinction risk. In this sense, results suggest that the best management strategy for conservation should be restoring habitat at the source patches and reducing mortality at the sinks. The results of our models emphasize the need for empirical studies to characterize metapopulations in nature and distinguish between such terms as source-sink, mainland-island, nonequilibrium, or even ''refuge'' metapopulations. |
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Garcia,
N., and Arsuaga, J. L. 1999. |
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The carnivores from Trinchera Dolina level 6 (TD6) in Sierra de Atapuerca include Ursus sp., Crocuta crocuta, Mustela palerminea, Lynx sp., Canis mosbachensis and Vulpes praeglacialis. Approximately 80 human remains belonging to Homo antecessor were found in the Aurora Stratum (AS): located in the upper part of the TD6 level (TD6, T36–43). The carnivores from AS are taxonomically similar to the rest of the TD6 level, differing only in the occurrence of Lynx sp. The spotted hyaena (Crocuta crocuta) inhabited the Atapuerca Sierra during the Early Pleistocene and up to the Middle Pleistocene, after which it is absent. According to palaeomagnetic, U/Th and ESR results, the fossils from TD6 are dated to the Early Pleistocene, which is the earliest certain occurrence in Europe of Crocuta crocuta. It is associated with Mimomys savini, the arrival of which in Europe can be correlated with the beginning of the Early Biharian. Crocuta crocuta may have arrived during the late Early Pleistocene (''Bavelian complex''), and subsequently invaded the rest of the continent during the Middle and Late Pleistocene. Atapuerca TD6-AS represents the most ancient deposits in Europe where Homo and spotted hyaenas coexisted and, they probably competed ecologically. The carnivores from TD6 are biochronologically consistent with the end of the Early Pleistocene or early Cromerian (corresponding with the Biharian biochron). The timespan could correspond with oxygen isotope stages 19, 20 or 21. |
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Garcia_&_Arsuaga_1999_Carnivores_from_the_Early_Pleistocene_Sierra_de_Atapuerca.pdf |
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García, F. J. and Guzman, J. N. 2005. |
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Garcia_&_Guzman_2005_Actuaciones_para_el_conejo_en_Espana.pdf |
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© F.J. García |
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Garcia, N., Arsuaga, J. L., and Torres,
T. 1997. |
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Remains of carnivores from the Sima de los Huesos site representing at least 158 adult individuals of a primitive (i.e., not very speleoid) form of Ursus deningeri Von Reichenau 1906, have been recovered through the 1995 field season. These new finds extend our knowledge of this group in the Sierra de Atapuerca Middle Pleistocene. Material previously classified as Cuoninae indet. is now assigned to Canis lupus and a third metatarsal assigned in 1987 to Panthera cf. gombaszoegensis, is in our opinion only attributable to Panthera sp. The family Mustelidae is added to the faunal list and includes Martes sp. and a smaller species. The presence of Panthera leo cf. fossilis, Lynx pardina spelaea and Felis silvestris, is confirmed. The presence of a not very speloid Ursus deningeri, together with the rest of the carnivore assemblage, points to a not very late Middle Pleistocene age, i.e., oxygen isotope stage 7 or older. Relative frequencies of skeletal elements for the bear and fox samples are without major biases. The age structure of the bear sample, based on dental wear stages, does not follow the typical hibernation mortality profile and resembles a catastrophic profile. The site was not a natal or refuge den. The hypothesis that the site was a natural trap is the most plausible. If the Sima de los Huesos functioned as a natural trap (without an egress out), the human accumulation cannot be attributed to carnivore activities and must be explained differently. |
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Garcia-Perea, R. 1992. |
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I conducted a morphological study of the genus Lynx based on a large sample, 488 specimens, consisting of skins, skulls and postcranial skeletons, and representing ther four extant species of the genus. Criteria for age and sex estimation were identified, based on tooth replacement, annual growth layers of cementum, rates of sutures, synchondroses and epiphyscal cartilages ossification, as well as on biometrical variables. The development of these characters was then analized by age and sex, morphological and mensuaral differences between the species were described, and variation within and between populations was analyzed. A principal focus of my research involved a reevalutaion of the taxonomic status of the Iberian lynx. My own findings, as summarized below, support recognition of four recent species: Lynx lynx, Lynx pardinus, Lynx canadensis and Lynx rufus. |
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Garcia-Perea_1992_New_Data_on_the_Systematics_of_Lynxes_-_Cat_News_No16.pdf |
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Garcia-Perea, R. 1996. |
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Studies on ossification patterns and other ontogenetic events associated with postnatal cranial growth of wild felids are scarce. An analysis of developmental processes undergone by several cranial structures (presphenoidal and sphenooccipital synchondroses, temporal and sagittal crests, and deciduos and permanent teeth) during postnatal growth has been conducted on a sample of 336 specimens belonging to the four Recent species of lynxes (Lynx pardinus, Lynx lynx, Lynx rufus, and Lynx canadensis). Age has been estimated based on tooth replacement, skull size, and by counting the annual lines of cementum growth. Comparison of the results obtained for each of the four species reveal (1) a single pattern for both tooth replacement and ossification of the sphenooccipital synchondrosis, (2) two ossification patterns for the presphenoidal synchondrosis, (3) a common pattern for development of temporal ridges and sagittal crest showing different degrees of morphological expression, and (4) evidence suggesting the involvement of a heterochronic process, neoteny, in the morphological differentiation of several populations and species of the genus Lynx. These data also support the hypothesis that processes involved in the replacement of carnassials are based on functional requirements. |
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Garcia-Perea, R. 1997. |
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Reaction to a letter by Beltrán et al. published in Nature (1996). In the letter, Beltrán et al. claim the demonstration of the monophyly of genus Lynx to be a relevant finding, and the taxonomic status of the Iberian lynx Lynx pardinus to be controversial. I feel suprise regarding these statements. |
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Garcia-Perea_1997_Phylogeny_and_Conservation_of_Iberian_Lynxes_-_Cat_News_No27.pdf |
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Garcia-Perea, R. 2000. |
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Captures and observations of handicapped carnivores living in the wild have been occasionally reported, but no information has been found in the scientific literature about survival or reproductive success of such individuals. In this study, a sample of 44 Iberian lynx (Lynx pardinus), collected from central-southern Spain between 1960 and 1983, has been analyzed. Evidence is presented of several lynx that had recovered in the wild from serious physical injuries, and causes of non-natural mortality are described. Results indicate that some lynx were even able to produce offspring, despite suffering physical limitations such as an amputated limb. Results suggest that, as in Doñana National Park, trapping (for predator control and capture of rabbits) was the main cause of non-natural mortality in central-southern Spain for the period considered. |
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García-Perea, R. 2002. |
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Basic information on the European wildcat in Spain: Taxonomy, description, distribution, habitat, reproduction, feeding habits, abundance, social organization & behaviour, threats, and other subjects. |
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Garcia-Perea_2002_Felis_sivestris_en_Espana_Atlas_Mamiferos.pdf |
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Garcia-Perea, R. and Gisbert, J. 1986.
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87 lynx from the Montes de Toledo and Sierra Morena were analyzed in regard of their cause of mortality. The principal cause of mortality was trapping of rabbits. |
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Garcia_Perea_&_Gisbert_1986_Causas_de_mortalidad_del_lince_iberico.pdf |
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Garcia-Perea, R., Gisbert, J., and Palacios,
F. 1985. |
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Fifty-four osseous specimens of Lynx pardina, most of unknown sex, were studied. The criterium of Valvere & Hidalgo (1973), confirmed by the data from the specimens of known sex, was used to determine the sex of the rest of the adults in the sample. The cranial biometry of male and female adults of Lynx pardina was studied separately, revealing significant differences between sexes in most of the variables examined, the males being larger than the females. Likewise, the cranial dimensions of Lynx pardina were compared with those of Lynx lynx found in the literature, observing that Lynx lynx was larger, with no overlap in the ranges of the variables. Finally, we analyzed the variability in Lynx pardina of seven morphological characteristics of the skull and teeth (interorbitary convexity, temporal lines, presphenoid, condylar foramina, Mt metaconid, maxillopalatine sureres and horizontal palatine plates), reviewing their diagnostic value. The comparison with Lynx lynx demonstrated that only the first five features, taken as a group, were valid for differentiating these species |
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Gil Sanchez, J. M. 2002. |
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Data of a series of interviews with wardens of the Sierra the Andújar are presented with the objective to contribute data which help to clarify and understand the evolution of the lynx during the second half of the 20 century. This information is fundamental in order to establish a zonification which allows to maximally optimize the actions for the recovery of the species. |
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Gil_Sanchez_2002_Evolucion_de_la_distribucion_del_lince_iberico.pdf |
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Gil Sanchez, J. M., Molino Garrido, F.,
and Valenzuela Serrano, G. 1997. |
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We report on Iberian Lynx food habits in Eastern Sierra Morena (Andújar Natural Park), as determined by the analysis of 52 faeces. Diet composition was: 90.9% rabbit, 5.4% Cervidae and 3.6% red-legged partridge. Data confirmed the key role of rabbit in the Iberian lynx diet. |
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Gil_Sanchez_et_al_1997_Nota_sobre_la_alimentacion_del_lince_iberico.pdf |
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Gil Sanchez, J. M., Sanchez Clemot, J.
F., Molino Garrido, F., Valenzuela Serrano, G., and Meleon, M. 1998.
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The present works confirmes the current presence of the Iberian lynx in two population nuclei in the Province of Granada. Between May 1996 and March 1998, 52 UTM squares of 5x5 were surveyed, 33 in the Subbetical mountains and 19 in the Granadian coastal mountains, localizing four tracks to which three locations with footprints accompanied by photographs have to be added. Three tracks were localized in the Subbetical mountains and four in the coastal. The data obtained extend the distribution area previously suggested, emphasizing the extension of the coastal population to the Sierra de la Almijira in Malaga, a province where the lynx was considered to be extinct. |
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Gil_Sanchez_et_al_1998_Presencia_del_lince_iberico_en_la_provincia_de_Granada.pdf |
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Gil-Sanchez, J. M., Valenzuela, G., and Sanchez, J.
F. 1999. |
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Functional response and prey age selection have been studied for predator-prey relationships between the Iberian wild cat Felis silvestris tartessia Miller, 1907 and the rabbit Oryctolagus cuniculus (Linnaeus, 1758) through the study of the seasonal wild cat's diet and variations in rabbit availability in south-east Spain. This prey formed 73.7% of the total consumed biomass and was negatively correlated with trophic diversity. The wild cat showed a functional response approximate to Holling's type 2, exhibiting a high dependence on rabbit. The age class preferred was that of the juvenile rabbit, the smallest age class, and such hunting behaviour may be considered to be oppotunistic. Results are discussed within the context of the relationship between the great size of this wild cat subspecies and the body size of the principal Iberian prey in Mediterranean areas, the rabbit. |
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Gil_Sanchez_et_al_1999_Iberian_wild_cat_predation_on_rabbit.pdf |
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Gonzalez Oreja, J. A. 1998.
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Human-related cuases of mortality were studied in the Iberian lynx (Lynx pardinus Temminck, 1827) population located in Sierra de Gata (W Spain). By means of 233 interviews to residents in the study area, 50 cases of lynx mortality were documented, ranging from 0.6 lynxes/year from the 1950-59 decade to 2.3 lynxes/year between 1990 and 1995. Illegal hunting activities were the first two most important causes of non-natural mortality, with 54% of all lynxes killed by shooting, and 24% by trapping. Road accidents were the third most important cause, increasing from 8% in the 1980-89 decade to 29% in the 1990-95 period. The need for a regional conservation action plan for the species is stressed. |
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Gonzalez_Oreja_1998_Non_natural_mortalities_in_Iberian_lynx.pdf |
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Gortázar, C. 2002. |
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Basic information on the Red fox in Spain: Taxonomy, description, distribution, habitat, reproduction, feeding habits, abundance, social organization & behaviour, threats, pathology & parasites, and other subjects. |
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Graells, M. P. 1897. |
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On the natural history, taxonomy and morphology of the felids in Spain. |
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Gragera Diaz, F. 1993. |
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Until the beginning of the 70s, the Iberian lynx (Felis pardina) existed in several enclaves in the centre and south-west of de Province of Badajoz, probably connected with the populations of Northern Huelva and Portugal. Currently, it is possible that only a small nucleus is surviving in the mountains of Alconera and Salvaleon. |
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Gragera_1993_Distribucion_del_lince_iberico_en_la_provincia_de_Badajoz.pdf |
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Gragera Diaz, F. 1995. |
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The objective of this study is to look at the historical distribution of the Iberian lynx (Lynx pardina), one globally threatened mammal, in Low Extremadura. Nowadays, status of this carnivore in southern Badajoz province is poorly known. Further researchs to find out new populations in Alconera and Hornachos mountains is needed, intending to carry out a recovery plan of Iberian lynx within the studied area. |
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Gragera_1995_Distribucion_historica_del_lince_en_Extremadura.pdf |
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Gragera Diaz, F. 2000. |
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Gragera_2000_Distribucion_historica_del_lince_iberico_en_Extremadura.pdf |
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© J. B. Ruiz / F. Gragera Diaz |
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Griffith, B., Scott,
J. M., Carpenter, J. W., and Reed, C. 1989. |
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Surveys of recent (1973 to 1986) intentional releases of native birds and mammals to the wild in Australia, Canada, Hawaii, New Zealand, and the United States were conducted to document current activities, identify factors associated with success, and suggest guidelines for enhancing future work. Nearly 700 translocations were conducted each year. Native game species constituted 90 percent of translocations and were more successful (86 percent) than were translocations of threatened, endangered, or sensitive species (46 percent). Knowledge of habitat quality, location of release area within the species range, number of animals released, program length, and reproductive traits allowed correct classification of 81 percent of observed translocations as successful or not. |
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Griffith_et_al_1989_Translocation_as_a_species_conservation_tool.pdf |
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Guzman, J. N., García, F. J.,
Garrote, G., Perez de Ayala, R., and Iglesias Llamas, M. C. 2002. |
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Guzman_et_al_2002_Iberian_lynx_distribution_and_status_Spain.pdf |
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Guzman, J. N., García, F. J.,
Garrote, G., Perez de Ayala, R., and Iglesias Llamas, M. C. 2003. |
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The Iberian lynx (Lynx pardinus) is a species critically endangered only surviving in Spain and Portugal, tightly linked to mountain habitats and mediterranian scrubland. The Strategy for the Conservation of the Iberian lynx (February, 1999) considers the necessity, within the basic lines of actions (priority actions), to realize a study to solve the "insufficient knowledge on the distribution and abundance of the species, necessary data for the design and adoption of conservation measures". This has been the main object of the present study. The areas chosen for its realization were obtained according to the distribution considered for the species after Rodriguez and Delibes in 1988, and of additional data obtained by means of partly works during the 1990s in the Communities Autonomous with presence of the species (Andalucia, Castilla-La Mancha, Castilla-Leon, Extermadura, and Madrid). |
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Guzman_et_al_2003_Censo_diagnostico_de_las_poblaciones_del_lince_iberico.pdf |