Andrea Sforzi

Intolerance amongst deer species at feeding : Roe deer are uneasy banqueters

The function of inter-specific interactions in large herbivore assemblies is under debate. We have studied inter-specific interactions between roe and fallow deer on pastures, to assess whether competition between these Cervidae occurs through behavioural interference. Roe were displaced by fallow deer (i.e. the former moved away from the latter at a distance of >50 m) in 83% of cases (N=127). Ninety-four percentage (N=83) of displacement events occurred while roe deer were feeding; in 50% of these cases (N=78), roe stopped grazing and left the feeding ground. Even when fallow deer did not show any sign of direct aggression to roe, these moved away from fallow in 72% of cases (N=127). Vigilance rate was significantly greater in roe than in fallow deer, irrespectively of the presence of the other species. When roe and fallow deer grazed within 50 m from each other, vigilance rate increased significantly in roe, but not in fallow deer. Roe deer, in a group, were significantly more tolerant of the presence of fallow deer (even in group), than when solitary. Fallow deer seemed to be able to exclude roe deer from feeding sites through behavioural intolerance.

Black coats in an admixed wolf × dog pack is melanism an indicator of hybridization in wolves?

The use of functional mutations, in addition to standard noncoding molecular markers, can help to detect hybridization and gene introgression in wild canid populations. We analyzed ancestry of a canid pack breeding in Central Italy that showed black coats and other unusual morphological traits suggesting wolf × dog hybrid origins. Individuals were identified by genotyping excremental DNA at 13 autosomal microsatellites, mtDNA control region sequences, a male-specific restriction site on the ZFX/Y gene to determine the gender of the individuals, four Y-linked microsatellites to determine male haplotypes, and two melanistic mutations: a SNP at exon 4 of the Agouti locus and a 3-bp deletion at a β-Defensin gene, the K locus. Results showed that: (1) the pack was founded by a single breeding pair of related individuals, probably brother and sister, and no immigrant was detected; (2) parents and offspring showed signals of admixture at autosomal microsatellites; and (3) the melanistic K locus deletion was present in the black-coated female parent and in 8/14 offspring, but it was absent in the wild type male parent. This deletion was found also in 17/40 village dogs randomly sampled from nearby areas, but it was absent in a random sample of 40 Italian wolves. These findings suggest that the pack received the K locus deletion from dogs. Admixture analyses of empirical and simulated genotypes indicate the parents of the pack originated through a single hybridization event at least two generations back. Genetic and phenotypic assessments of coat color mutations can contribute to investigation of the origin and dynamics of functional polymorphisms in hybridizing wolf populations and to develop appropriate guidelines to contrast hybridization with their domesticated relatives.

Site selection and fidelity by crested porcupines for denning

The crested porcupine is a large rodent living in Central and North Africa, with a European distribution limited to Italy. Its biology and particularly its denning habits are inadequately known. Our study was carried out in a Mediterranean coastal area of central Italy. We radiotagged 13 adult porcupines, assessing their den site selection and use each month, from February 1998 to September 1999. Porcupines preferred steep, compact soils covered with dense vegetation, for denning. Each den was always used by the same 2 individuals, possibly forming a reproductive pair. Paired individuals seemed to show a greater site fidelitythan single ones. Intepretations of this behaviour are discussed.

Roe and fallow deer: are they compatible neighbours?

The analysis of the relationships between population density and habitat features is important to evaluate the ecological needs of a species, its potential impact on ecosystems and its interspecific interactions. We analysed the spatial variation of roe deer Capreolus capreolus and fallow deer Dama dama densities in a Mediterranean area in summer 2007 and winter 2007/2008. Previous research has shown that fallow deer can actively displace and exclude roe deer from natural feeding sites. Here we show that both species have the greatest densities in ecotone habitats between wood and open fields (abandoned olive groves and pastures), but with contrasting geographic patterns. The fallow deer showed the greatest densities in the central northern part of the study area near to local historical release sites. The densities of roe deer were great where fallow deer were rare and low where fallow deer were abundant. Spatial overlap was great at the habitat scale, indicating a high potential for competition, but was low at the plot scale, suggesting that partitioning of space occurred at a fine scale. Supporting great numbers of deer, the ecotone areas are crucial for the management of ecosystems. We suggest that roe deer avoid areas with great densities of fallow deer and that interspecific interference from the latter affects the density and distribution of the former both at a fine and at a large scale.

Habitat richness affects home range size in a monogamous large rodent

In monogamous species, after pair formation, the main reason for ranging movements is not searching for a mate, but for other important resources e.g. food. We monitored a total of 20 radio-tagged adult, paired crested porcupines in four areas of different habitat richness. No sexual size dimorphism was assessed. Body mass and habitat richness showed collinearity. For both sexes, home range size was correlated to habitat richness, with a significant inverse exponential regression. Opposite to natural foragers, living in poor habitats, crop foragers had smaller home ranges, with their dens significantly closer to cultivations. Both availability of food resources and den sites are key variables to determine home range size.

Chemical Immobilization of Crested Porcupines with Tiletamine HCl and Zolazepam HCl (Zoletil®) under Field Conditions

The combination of tiletamine HCl and zolazepam HCl has been used on many species of wild mammals. Short induction time, low dosage, satisfactory safety margins, relatively constant immobilization time, and smooth recovery are benefits reported. This combination (Zoletil® 100) was used during a study on behavioural ecology of the crested porcupine (Hystrix cristata) in a Mediterranean coastal area (Maremma Regional Park, Tuscany, Italy). We used this mixture 42 times on 31 individuals. Mean adult dose was (±SE) 7.24±0.37 mg/kg (74.0±3.0 mg/individual). Average adult induction time was 5.3 min (±1.1) and average adult immobilization time was 22.6 min (±6.0). One adult male porcupine died after chemical restraints. The use of tiletamine-zolazepam seems adequate for chemical immobilization of crested porcupines under field conditions, mainly because of its short induction time, small volume to be injected and wide safety margin.

Two-stage estimation of ungulate abundance in Mediterranean areas using pellet group count

A design-based strategy for estimating wildlife ungulate abundance in a Mediterranean protected area (Maremma Regional Park) is considered. The estimation is based on pellet group count (clearance count technique) in a set of plots, whose size and number is established on the basis of practical considerations and available resources. The sampling scheme involves a preliminary stratification and subsequent two-stage sampling. In the first stage, large strata (defined through habitat features) are partitioned into spatial units and a sample of units is selected by means of a sampling scheme ensuring inclusion probabilities proportional to unit size, but avoiding the selection of contiguous units. Then, the abundances of the selected units are estimated in a second stage, in which plots are located using a random scheme ensuring an even coverage of the units. In small strata, only the second stage is performed. Unbiased estimators of abundance and conservative estimators of their variances are derived for each strata and for the whole study area. The proposed strategy has been applied since the Summer of 2006 and the estimation results reveal substantial improvement with respect to the previous results obtained by means of an alternative strategy.

The BOS™ as a species-specific method to deliver baits to wild boar in a Mediterranean area

The impact of wild boar Sus scrofa and feral pigs on ecosystems and human activities is of interest worldwide. Bait-delivered pharmaceuticals such as contraceptives or disease vaccines are increasingly advocated to assist the management of such impacts. We evaluated the Boar-Operated-System (BOS™) to deliver baits to wild boar in a Mediterranean area with a large community of potential nontarget species. In a pre-trial phase (BOS™ open), both wild boar and 12 nontarget species (wildlife and livestock) visited the BOS™ and eight species consumed the baits. In the trial phase, when the BOS™ were closed, only wild boar consumed baits. From pre-trial to trial, the rate of visits by nontarget species to the BOS™ decreased significantly, but that of wild boar did not change. We observed that crested porcupines Hystrix cristata prevented the wild boar from using BOS™. We confirmed the effectiveness of BOS™ to deliver baits selectively to wild boar in a Mediterranean area.

The Osprey reintroduction in Central Italy: dispersal, survival and first breeding data

Capsule Sex-biased dispersal and an age-dependent effect in survival rate accounted for the pattern of first settlement and reproduction in a newly reintroduced Osprey population. Aims We estimate the survival of translocated individuals, describe juvenile movements and evaluate the success of first breeding events to document the re-establishment of an Osprey breeding population. Methods Between 2006 and 2010, 32 fledgling Ospreys were reintroduced via hacking techniques in Maremma Regional Park, Italy. We evaluated the effects of age on survival through multistate capture-mark-recapture analyses. Movements were investigated by radiotracking and using records of resightings. Results Survival was high for juveniles after the release (0.87), markedly decreased during the first winter (0.26), and improved again in subsequent years (annual apparent survival of 0.69 for immatures and 0.93 for adults). Mean distance covered in initial dispersal was greater for females (246.2 km) than for males (38.7 km). Conclusion Our results provided information on dispersal and survival rate of reintroduced Ospreys in a Mediterranean area. Despite low apparent survival in the first year, the high survival rates found in immatures and adults suggested favourable conditions for this new population. The study of demographic parameters is important for calibrating management actions aimed at the establishment of a self-sustaining Osprey population.

Alien shades of grey: new occurrences and relevant spread of Sciurus carolinensis in Italy

Abstract The eastern grey squirrel is listed among the worst invasive species throughout the world. This species of American origin is currently replacing the native Eurasian red squirrel in most of the Great Britain, as well as in parts of Ireland and Italy. It may debark trees and exert damages to woodlands and tree plantations. Therefore, its spread may be deleterious for biodiversity and environment, emphasising the need for a rapid detection in new areas of occurrence. In this work, we reported for the first time, the presence of new populations of this invasive species in Tuscany (Central Italy) and some updates and analyses regarding the status of this species in Veneto (North-Eastern Italy). Occurrences were collected through citizen-science contributory approach supported by photos, road-kills, and/or hair-tube sampling. Field investigations ad hoc were carried out in Veneto and Tuscany to confirm the repeated reports in the surroundings of Arezzo and in the province of Siena. Although records can be possibly related to erratic or single individuals escaped from captivity, reproductive nuclei have also been detected in both regions, with the observations of juveniles and/or lactating females. The occurrence of the species in these regions is still scarce and localised, but considering the surrounding favourable wooded habitats, a rapid removal of the animals would be required to prevent their spread.