Nutritional ecology of a prototypical generalist predator, the red fox (Vulpes vulpes).

Generalist species, which exploit a wide range of food resources, are expected to be able to combine available resources as to attain their specific macronutrient ratio (percentage of caloric intake of protein, lipids and carbohydrates). Among mammalian predators, the red fox Vulpes vulpes is a widespread, opportunistic forager: its diet has been largely studied, outlining wide variation according to geographic and climatic factors. We aimed to check if, throughout the species' European range, diets vary widely in macronutrient composition or foxes can combine complementary foods to gain the same nutrient intake. First, we assessed fox's intake target in the framework of nutritional geometry. Secondly, we aimed to highlight the effects of unbalanced diets on fox density, which was assumed as a proxy for Darwinian fitness, as assessed in five areas of the western Italian Alps. Unexpectedly, the target macronutrient ratio of the fox (52.4% protein-, 38.7% lipid- and 8.9% carbohydrate energy) was consistent with that of hypercarnivores, such as wolves and felids, except for carbohydrate intakes in urban and rural habitats. The inverse relation between density and the deviation of observed macronutrient ratios from the intake target suggests that fox capability of surviving in a wide range of habitats may not be exempt from fitness costs and that nutrient availability should be regarded among the biotic factors affecting animal abundance and distribution.

Expert-based versus habitat-suitability models to develop resistance surfaces in landscape genetics.

Landscape genetics aims to investigate functional connectivity among wild populations by evaluating the impact of landscape features on gene flow. Genetic distances among populations or individuals are generally better explained by least-cost path (LCP) distances derived from resistance surfaces than by simple Euclidean distances. Resistance surfaces reflect the cost for an organism to move through particular landscape elements. However, determining the effects of landscape types on movements is challenging. Because of a general lack of empirical data on movements, resistance surfaces mostly rely on expert knowledge. Habitat-suitability models potentially provide a more objective method to estimate resistance surfaces than expert opinions, but they have rarely been applied in landscape genetics so far. We compared LCP distances based on expert knowledge with LCP distances derived from habitat-suitability models to evaluate their performance in landscape genetics. We related all LCP distances to genetic distances in linear mixed effect models on an empirical data set of wolves (Canis lupus) from Italy. All LCP distances showed highly significant (P ≤ 0.0001) standardized ß coefficients and R 2 values, but LCPs from habitat-suitability models generally showed higher values than those resulting from expert knowledge. Moreover, all LCP distances better explained genetic distances than Euclidean distances, irrespective of the approaches used. Considering our results, we encourage researchers in landscape genetics to use resistance surfaces based on habitat suitability which performed better than expert-based LCPs in explaining patterns of gene flow and functional connectivity.

Big bad wolf or man's best friend? Unmasking a false wolf aggression on humans.

The return of the wolf in its historical range is raising social conflicts with local communities for the perceived potential threat to people safety. In this study we applied molecular methods to solve an unusual case of wolf attack towards a man in the Northern Italian Apennines. We analysed seven biological samples, collected from the clothes of the injured man, using mtDNA sequences, the Amelogenin gene, 39 unlinked autosomal and four Y-linked microsatellites. Results indicated that the aggression was conducted by a male dog and not by a wolf nor a wolf x dog hybrid. Our findings were later confirmed by the victim, who confessed he had been attacked by the guard dog of a neighbour. The genetic profile of the owned dog perfectly matched with that identified from the samples previously collected. Our results prove once again that the wolf does not currently represent a risk for human safety in developed countries, whereas most animal aggressions are carried out by its domestic relative, the dog.

Enchancement of deficient pituitary response to luteinizing hormone releasing hormone in patients with primary amenorrhea.

Although the absence of pituitary response to the luteinizing hormone releasing hormone (LHRH) test has been considered proof of a lesion primarily localized at the pituitary level, the possibility exists that an absent pituitary response may represent only the effect of a chronic deficiency of hypothalamic secretion. To verify this hypothesis, 4 patients with primary amenorrhea, hypogonadotropic hypogonadism, and deficient or absent responses to a 25 mug LHRH rapid IV test were treated with 400 mug LHRH infused in 7 hours during each of 3 successive days. The finding that patients with deficient LH responses to a rapid LHRH test became normally responsive to a second equivalent test after a slow and prolonged treatment with the decapeptide suggests that, in these patients, besides a lesion at the pituitary level, a primary defect at the hypothalamic or higher centers may also be suspected.

[Gonadotropins]. / Gonadotropine

The clinical usefulness of plasma LH and FSH radioimmunoassays, both in basal and dynamic conditions, is briefly discussed. While occasional LH and FSH determinations may indicate only a serious gonad failure, at least when high values are found, dynamic studies before and after LH-RH i.v. injection may suggest a hypothalamic or pituitary lesion. In this regard the LH-RH test is presented as the most evident demonstration of the utility of gonadotropin radioimmunoassay. Different patterns of response are presented and their correlation with menstrual disorders is discussed in view of different distribution (Tab.1). Moreover, the AA. suggest a primary hypothalamic deficiency in LH-RH in the cases of "deficient" response that, being a constant finding in different days, became a "normal" response after 3 days therapy with LH-RH infusion and returned to basal levels 2 months later. Equally, an "exaggerated" response consistenly found in some patients with secondary amenorrhea, is suspected to be of hypothalamic origin since "normalization" may be obtained after a similar LH-RH treatment.