Francisco S. Tortosa

Bio: Francisco S. Tortosa is an academic researcher from University of Córdoba (Spain). The author has contributed to research in topics: Population & Predation. The author has an hindex of 21, co-authored 77 publications receiving 1318 citations. Previous affiliations of Francisco S. Tortosa include Cordoba University.

Effect of Rubbish Dumps on Breeding Success in the White Stork in Southern Spain

Abstract: Rubbish dumps provide an extra and constant food source for many birds. The White Stork (Ciconia ciconia) is one of the species that have taken advantage of these new foraging areas both during breeding season and during the winter. This study analyzes data collected in the Spanish province of Cordoba throughout five years between 1992 and 1998 on the biology and breeding success of the White Stork and the influence of rubbish dumps. Breeding success varied significantly between years and areas in two of the study years. A banding program from 1990 to 1998 resulted in 145 storks being marked as nestlings. Of these, 49 were resighted at least once by May 2001 (34% resighting rate) and 16 of these birds were resighted as breeders at a mean age of 2.87 years. 75% of them were breeding close to rubbish dumps. Fifteen birds were resighted during wintering time, of which twelve were at rubbish dumps.

Effect of food abundance on laying date and clutch size in the White Stork Ciconia ciconia

Abstract: CapsuleFood independently affects both laying date and clutch size, suggesting that seasonal decline in clutch size is related to a decrease in food availability. Aim To test the effect of food abundance on laying date and clutch size of the White Stork and identify the cause of seasonal decline in the number of eggs laid. Methods During 1991 and 1996 we recorded clutch size and laying date of pairs breeding next to rubbish dumps (food abundant and constant throughout the breeding season) and birds breeding far from rubbish dumps (using natural food sources). Results In 1991 there was no difference in mean laying date between pairs nesting at rubbish dumps and control pairs. Clutch size was significantly larger at rubbish dump nests. In contrast, mean laying date was earlier in control pairs in 1996 and there was no significant differences in clutch sizes, even when controlling for laying date effect. Conclusion The results support the hypothesis that food availability independently affects both laying da...

Towards a standardized index of European rabbit abundance in Iberian Mediterranean habitats

Abstract: European rabbits Oryctolagus cuniculus are a keystone species in Iberian Mediterranean ecosystems. However, the reliability of methods for estimating rabbit abundance, particularly when at low numbers, is not well understood. Further, better standardization of these methodologies would allow abundance estimates to be more reliably compared between areas and periods. Consequently, we compared several frequently used methods of estimating rabbit abundance and assessed their advantages and disadvantages. During the summers of 2008 and 2009, in 11 localities of central-southern Spain we undertook (a) driving transect counts of rabbits, either at dusk or at night, (b) linear transects on foot recording rabbit signs, (c) cleared-plot pellet counts at permanent plots, and (d) standing crop counts, both with and without habitat stratification. Density estimated at night from driving transects using the Distance Sampling method (the reference method against which all other indices were compared) varied from 0 to 2.69 rabbits ha−1. Most pellet-count indices were significantly related to the reference method. In particular, cleared-plot pellet counts in permanent plots corrected for pellet persistence showed the best correlation with the reference method. In contrast, latrine counts were not related to the reference method index, and we recommend against their use. A standard methodology based on cleared-plot pellets counts could be used to monitor rabbit abundance on a large scale.

Effects of density, climate, and supplementary forage on body mass and pregnancy rates of female red deer in Spain.

Abstract: The influence of short- and long-term (cohort) effects of climate and density on the life-histories of ungulates in temperate regions may vary with latitude, habitat, and management practices, but the life-histories of ungulates in the Mediterranean region are less well known. This study examined the short- and long-term effects of rainfall and absolute density on hinds in two of the southernmost populations of red deer (Cervus elaphus hispanicus) in Europe. One population received supplementary forage. Unlike more northerly latitudes, where red deer hinds lose body mass in winter as a result of adverse weather, in the Spanish populations, hinds did not lose body mass. Hinds in the population that received supplementary forage were heavier and more likely to become pregnant than were the hinds in the unsupplemented population. The likelihood of pregnancy occurring was strongly influenced by hind body mass; the proportion of yearlings that became pregnant was consequently lower in the unsupplemented population than in the population that received supplementary forage. Cohort effects on hind body mass (negative for density and positive for rainfall at birth) and on the probability of pregnancy (negative for density at birth) were apparent only in the unsupplemented population, which implies that supplemental feeding may partially compensate for negative density-dependent factors during early growth, and that supplemented deer hinds may experience reduced selection pressures. These results reflect the particular seasonal variation in the abundance and quality of food in Mediterranean habitats. The delayed effects of climate and density at birth on adult hind body mass and the prevalence of pregnancy probably affects population dynamics and constitutes a mechanism by which cohort effects affect the population dynamics in Iberian red deer. The management of Iberian red deer populations should take into account cohort effects and supplemental feeding practices, which can buffer density- and climate-dependent effects and reduce natural selection pressures.

Starvation physiology: reviewing the different strategies animals use to survive a common challenge.

Abstract: All animals face the possibility of limitations in food resources that could ultimately lead to starvation-induced mortality. The primary goal of this review is to characterize the various physiological strategies that allow different animals to survive starvation. The ancillary goals of this work are to identify areas in which investigations of starvation can be improved and to discuss recent advances and emerging directions in starvation research. The ubiquity of food limitation among animals, inconsistent terminology associated with starvation and fasting, and rationale for scientific investigations into starvation are discussed. Similarities and differences with regard to carbohydrate, lipid, and protein metabolism during starvation are also examined in a comparative context. Examples from the literature are used to underscore areas in which reporting and statistical practices, particularly those involved with starvation-induced changes in body composition and starvation-induced hypometabolism can be improved. The review concludes by highlighting several recent advances and promising research directions in starvation physiology. Because the hundreds of studies reviewed here vary so widely in their experimental designs and treatments, formal comparisons of starvation responses among studies and taxa are generally precluded; nevertheless, it is my aim to provide a starting point from which we may develop novel approaches, tools, and hypotheses to facilitate meaningful investigations into the physiology of starvation in animals.

Diseases shared between wildlife and livestock: a European perspective

Abstract: Wildlife diseases are in fashion. This is creating an explosion of related knowledge. Despite this, the dynamics of both wildlife and diseases and the changes in livestock and wildlife management make it increasingly difficult to overview the current situation of wildlife diseases in Europe. This paper aims to discuss the available management possibilities and to highlight current research priorities. One area that causes severe concern to authorities is diseases largely under control in domestic populations but still existing as a reservoir in wildlife. Multihost situations are also of concern for wildlife management and conservation, as diseases can affect the productivity and density of wildlife populations with an economic or recreational value. Concern about emerging diseases is rising in recent years, and these may well occur at the fertile livestock-wildlife interface. Wildlife-related zoonoses are a diverse and complex issue that requires a close collabora- tion between wildlife ecologists, veterinarians and public health professionals. A few risk factors can be identified in most of the relevant wildlife diseases. Among them are (1) the introduction of diseases through movements or trans- locations of wild or domestic animals, (2) the consequences of wildlife overabundance, (3) the risks of open air livestock breeding, (4) vector expansion and (5) the expansion or introduction of hosts. Wildlife disease control requires the integration of veterinary, ecology and wildlife management expertise. In addition to surveillance, attempts to control wildlife diseases or to avoid disease transmission between wildlife and livestock have been based on setting up barriers, culling, hygienic measures, habitat manage- ment, vector control, treatments and vaccination. Surveil- lance and descriptive studies are still valuable in regions, species or diseases that have received less attention or are (at least apparently) emerging. Nonetheless, limiting the research effort to the mere reporting of wildlife disease outbreaks is of limited value if management recommenda- tions are not given at the same time. Thus, more experimental approaches are needed to produce substantial knowledge that enables authorities to make targeted management recommendations. This requires policy mak- ers to be more aware of the value of science and to provide extra-funding for the establishment of multidisciplinary scientific teams.

A proposed unified framework for biological invasions.

Abstract: There has been a dramatic growth in research on biological invasions over the past 20 years, but a mature understanding of the field has been hampered because invasion biologists concerned with different taxa and different environments have largely adopted different model frameworks for the invasion process, resulting in a confusing range of concepts, terms and definitions. In this review, we propose a unified framework for biological invasions that reconciles and integrates the key features of the most commonly used invasion frameworks into a single conceptual model that can be applied to all human-mediated invasions. The unified framework combines previous stage-based and barrier models, and provides a terminology and categorisation for populations at different points in the invasion process.

The signal functions of early infant crying.

Abstract: In this article I evaluate recent attempts to illuminate the human infant cry from an evolutionary perspective. Infants are born into an uncertain parenting environment, which can range from indulgent care of offspring to infanticide. Infant cries are in large part adaptations that maintain proximity to and elicit care from caregivers. Although there is not strong evidence for acoustically distinct cry types, infant cries may function as a graded signal. During pain-induced autonomic nervous system arousal, for example, neural input to the vocal cords increases cry pitch. Caregivers may use this acoustic information, together with other cues, to guide caregiving behavior. Serious pathology, on the other hand, results in chronically and severely abnormal cry acoustics. Such abnormal crying may be a proximate cause of adaptive infant maltreatment, in circumstances in which parents cut their losses and reduce or withdraw investment from infants with low survival chances. An increase in the amount of crying during the first few months of life is a human universal, and excessive crying, or colic, represents the upper end of this normal increase. Potential signal functions of excessive crying include manipulation of parents to acquire additional resources, honest signaling of need, and honest signaling of vigor. Current evidence does not strongly support any one of these hypotheses, but the evidence is most consistent with the hypothesis that excessive early infant crying is a signal of vigor that evolved to reduce the risk of a reduction or withdrawal of parental care.