Female preference and predation risk models can explain the maintenance of a Fallow deer (<i>Dama dama</i>) lek and its ‘handy’ location

We tested the predictions of three models (female preference; hotspot; predator avoidance) on lek formation in the fallow deer population of San Rossore, Tuscany. We collected behavioural observations in two leks and radiotracking data on 67 deer over 7 years. Two deer sub-populations were present in the northern and southern sides of the area, respectively, the two sectors being delimited by a river and including one lek each. Predictions were tested for one lek (SG), located in the south-side where we set up our 7-year radiotracking program. Data from a second lek (FO, north-side) were used to test those predictions which imply the occurrence of multiple leks in the same population. We showed that the majority of females made one single visit to one lek, only during the rut. The lek was located outside areas of higher female traffic and home range overlap, and females increased home range sizes during the rut to reach it. Twilight routes of females never crossed the lek; instead, females walked atypical routes and at a faster pace to reach the lek and mate. The distance between the two leks was higher than the average diameter of female home ranges, and only one lek was present within female home ranges. Males reached the lek one month before the arrival of females, corroborating that lekking is a female-initiated process (females moving towards large clumped male aggregations) rather than a male-initiated process (males moving towards female hotspots). Our results supported the female preference model, and rejected the predictions of the hotspot model. Also, leks were located far from areas with higher predation risk, supporting the predator avoidance model. The position of lek SG resulted ‘handy’ at the sub-population level because of the optimal trade-off between travel costs for females to reach it and avoidance of human predators

A Predator on the Doorstep: Kill Site Selection by a Lone Wolf in a Peri-Urban Park in a Mediterranean Area

The aim of the study was to assess which kill site characteristics were selected by a lone wolf living in a protected Mediterranean coastal area near the city of Pisa, Italy, where both wild and domestic ungulates were available as potential prey. Between 2017 and 2019, we monitored the wolf’s predatory behaviour through a combination of camera trapping and active search for kill sites and prey carcasses. The main prey found was the fallow deer (n = 82); only two wild boars and no domestic ungulates were found preyed upon. The features and habitat ofkill sites were modelled to test for selection by the wolf. The habitat type of kill site was composed of meadows and pastures (89.3%), woods (7.3%), degraded coastal areas (1.9%), roads and rivers (1.1%), and marshes (0.5%). We calculated their distance from landscape features and ran a binomial generalised linear model to test the influence of such landscape variables. The distance of kill sites from landscape elements was significantly different from random control sites, and a positive selection for fences was found. In fact, the wolf pushed fallow deer towards a fence to constrain them and prevent them from es-caping. We also analysed the body condition of predated fallow deer as a percentage of fat content in the bone marrow of the hind legs. Our results revealed the selection of the lone wolf for deer in good body condition. This is a possible outcome of the habitat selection shown by fallow deer in the study area, where fenced open pastures are the richest in trophic resources; therefore, our findingssuggest a high efficacy for the lone wolf hunting strategy, but also the adoption of a high risk feed-ing strategy by deer. This study suggests that a lone predator can take advantage of human infra-structures to maximise its predatory effectiveness

The Impact of Crystal Light Yield Non-Proportionality on a Typical Calorimetric Space Experiment: Beam Test Measurements and Monte Carlo Simulations

Calorimetric space experiments were employed for the direct measurements of cosmic-ray spectra above the TeV region. According to several theoretical models and recent measurements, relevant features in both electron and nucleus fluxes are expected. Unfortunately, sizable disagreements among the current results of different space calorimeters exist. In order to improve the accuracy of future experiments, it is fundamental to understand the reasons of these discrepancies, especially since they are not compatible with the quoted experimental errors. A few articles of different collaborations suggest that a systematic error of a few percentage points related to the energy-scale calibration could explain these differences. In this work, we analyze the impact of the nonproportionality of the light yield of scintillating crystals on the energy scale of typical calorimeters. Space calorimeters are usually calibrated by employing minimal ionizing particles (MIPs), e.g., nonshowering proton or helium nuclei, which feature different ionization density distributions with respect to particles included in showers. By using the experimental data obtained by the CaloCube collaboration and a minimalist model of the light yield as a function of the ionization density, several scintillating crystals (BGO, CsI(Tl), LYSO, YAP, YAG and BaF2) are characterized. Then, the response of a few crystals is implemented inside the Monte Carlo simulation of a space calorimeter to check the energy deposited by electromagnetic and hadronic showers. The results of this work show that the energy scale obtained by MIP calibration could be affected by sizable systematic errors if the nonproportionality of scintillation light is not properly taken into account

CALOCUBE: An approach to high-granularity and homogenous calorimetry for space based detectors

Future space experiments dedicated to the observation of high-energy gamma and cosmic rays will increasingly rely on a highly performing calorimetry apparatus, and their physics performance will be primarily determined by the geometrical dimensions and the energy resolution of the calorimeter deployed. Thus it is extremely important to optimize its geometrical acceptance, the granularity, and its absorption depth for the measurement of the particle energy with respect to the total mass of the apparatus which is the most important constraint for a space launch. The proposed design tries to satisfy these criteria while staying within a total mass budget of about 1.6 tons. Calocube is a homogeneous calorimeter instrumented with Cesium iodide (CsI) crystals, whose geometry is cubic and isotropic, so as to detect particles arriving from every direction in space, thus maximizing the acceptance; granularity is obtained by filling the cubic volume with small cubic CsI crystals. The total radiation length in any direction is more than adequate for optimal electromagnetic particle identification and energy measurement, whilst the interaction length is at least sufficient to allow a precise reconstruction of hadronic showers. Optimal values for the size of the crystals and spacing among them have been studied. The design forms the basis of a three-year R&amp;D activity which has been approved and financed by INFN. An overall description of the system, as well as results from preliminary tests on particle beams will be described

Calet upper limits on X-RAY and GAMMA-RAY counterparts of GW151226

We present upper limits in the hard X-ray and gamma-ray bands at the time of the Laser Interferometer Gravitational-wave Observatory (LIGO) gravitational-wave event GW151226 derived from the CALorimetric Electron Telescope (CALET) observation. The main instrument of CALET, CALorimeter (CAL), observes gamma-rays from ∼1 GeV up to 10 TeV with a field of view of ∼2 sr. The CALET gamma-ray burst monitor (CGBM) views ∼3 sr and ∼2π sr of the sky in the 7 keV-1 MeV and the 40 keV-20 MeV bands, respectively, by using two different scintillator-based instruments. The CGBM covered 32.5% and 49.1% of the GW151226 sky localization probability in the 7 keV-1 MeV and 40 keV-20 MeV bands respectively. We place a 90% upper limit of 2 ×10-7 erg cm-2 s-1 in the 1-100 GeV band where CAL reaches 15% of the integrated LIGO probability (∼1.1 sr). The CGBM 7σ upper limits are 1.0 ×10-6 erg cm-2 s-1 (7-500 keV) and 1.8 ×10-6 erg cm-2 s-1 (50-1000 keV) for a 1 s exposure. Those upper limits correspond to the luminosity of 3-5 ×1049 erg s-1, which is significantly lower than typical short GRBs

The CALorimetric Electron Telescope (CALET) for high-energy astroparticle physics on the International Space Station

The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmic-ray electrons (and positrons) up to 20 TeV energy, of gamma rays up to 10 TeV, of nuclei with Z from 1 to 40 up to 1 PeV energy, and will detect gamma-ray bursts in the 7 keV to 20 MeV energy range during a 5 year mission. These measurements are essential to investigate possible nearby astrophysical sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. The main detector of CALET, the Calorimeter, consists of a module to identify the particle charge, followed by a thin imaging calorimeter (3 radiation lengths) with tungsten plates interleaving scintillating fibre planes, and a thick energy measuring calorimeter (27 radiation lengths) composed of lead tungstate logs. The Calorimeter has the depth, imaging capabilities and energy resolution necessary for excellent separation between hadrons, electrons and gamma rays. The instrument is currently being prepared for launch (expected in 2015) to the International Space Station ISS, for installation on the Japanese Experiment Module - Exposure Facility (JEM-EF)

Energy calibration of CALET onboard the International Space Station

In August 2015, the CALorimetric Electron Telescope (CALET), designed for long exposure observations of high energy cosmic rays, docked with the International Space Station (ISS) and shortly thereafter began to collect data. CALET will measure the cosmic ray electron spectrum over the energy range of 1 GeV to 20 TeV with a very high resolution of 2% above 100 GeV, based on a dedicated instrument incorporating an exceptionally thick 30 radiation-length calorimeter with both total absorption and imaging (TASC and IMC) units. Each TASC readout channel must be carefully calibrated over the extremely wide dynamic range of CALET that spans six orders of magnitude in order to obtain a degree of calibration accuracy matching the resolution of energy measurements. These calibrations consist of calculating the conversion factors between ADC units and energy deposits, ensuring linearity over each gain range, and providing a seamless transition between neighboring gain ranges. This paper describes these calibration methods in detail, along with the resulting data and associated accuracies. The results presented in this paper show that a sufficient accuracy was achieved for the calibrations of each channel in order to obtain a suitable resolution over the entire dynamic range of the electron spectrum measurement

uso dello spazio e selezione dell'habitat in femmine adulte di daino (Dama dama)con particolare riferimento al periodo dei parti

RIASSUNTO La ricerca, svolta nella tenuta di San Rossore (PI), ha avuto lo scopo di analizzare il comportamento spaziale e la selezione dell’habitat di un campione di ventitre femmine adulte di daino (Dama dama) munite di radiocollare. L’area di studio ha una superficie di circa 4600 ettari e presenta un clima temperato, di tipo sub-mediterraneo, con inverno mite ed estate calda e secca. La eterogeneità ecologica che la caratterizza è notevole: si passa dalle zone paludose ai boschi, dalle pinete alle dune costiere, ambienti in grado di accogliere una grande diversità di specie animali e vegetali. Utilizzando la tecnica del radio tracking, che prevede l’impiego di una ricevente in grado di captare il segnale emesso dal radiocollare, è stato possibile effettuare la localizzazione di ciascun animale. Ogni singola localizzazione, o «fix», è stata rilevata per triangolazione e trasformata in coordinate cartesiane per poter essere poi analizzata con i programmi informatici opportuni. La raccolta dati, iniziata nel dicembre del 2002, si è protratta sino al dicembre successivo. Durante tale periodo, su ciascun animale, sono stati effettuati minimo 10 fix mensili, uniformemente distribuiti nell’arco delle 24 ore. Questi rilevamenti sono stati realizzati mediante la telemetria di tipo discontinuo, con un intervallo minimo tra due fix successivi pari a 12 ore. Durante la stagione autunnale, in corrispondenza del periodo riproduttivo, e durante quello dei parti, la raccolta dati è stata incrementata e supportata da osservazioni dirette. Per quel che concerne le analisi sull’uso dello spazio, le dimensioni degli home range annuali, stagionali e bimestrali sono state calcolate utilizzando il programma informatico Range V, applicando due tecniche analitiche diverse: il metodo del Minimo Poligono Convesso e il metodo di Kernel, entrambi applicati al 95% dei fix a disposizione. Le indagini sulla selezione dell’habitat si sono basate sull’analisi composizionale. Le informazioni necessarie per effettuare i due livelli di analisi previsti da questa tecnica sono state ottenute utilizzando il programma informatico MapInfo Professional 5.0, mediante il quale sono stati determinati i dati inerenti l’utilizzo da parte delle femmine monitorate delle tipologie vegetazionali disponibili in varia misura nell’area di studio. Tale analisi è stata effettuata sia su scala stagionale che bimestrale: in particolare sono stati considerati gli home range determinati con il metodo di Kernel (95%), che risulta il più appropriato in questo tipo di analisi. In questo modo sono state determinate, per ciascun animale e per ogni bimestre e stagione, le seguenti informazioni: composizione percentuale delle tipologie vegetazionali contenute in ciascun home range femminile (1° livello di analisi) e percentuale dei fix contenuti nelle varie tipologie vegetazionali all’interno di ciascun home range (2° livello di analisi). I dati così ottenuti sono stati elaborati con il programma Resource Selection che, tenendo conto delle tipologie vegetazionali utilizzate dagli animali in rapporto a quanto esse risultano disponibili nell’area di studio, permette di ordinare per rango le tipologie selezionate. A fianco dell’analisi di base sono state testate alcune variabili indipendenti, come le differenze nella selezione dell’habitat al variare del periodo e delle dimensioni degli home range, e sono state verificate differenze tra femmine appartenenti ad aree della Tenuta o tra femmine con o senza il piccolo. Questo tipo di analisi è stata condotta applicando l’analisi multivariata della varianza alle matrici di Wilks In aggiunta ai dati raccolti con la tecnica del radio tracking, è stato effettuato uno studio sulla produttività sia dei boschi di querce, monitorando la produzione mensile di ghiande, sia dei principali pascoli presenti nell’area di studio, prendendo in esame dieci transetti campione nei quali, con cadenza quindicinale, sono stati monitorati i seguenti parametri: indice di erba verde, copertura erbacea e lunghezza dell’erba. La ricerca ha evidenziato dimensioni medie degli home range annuali, stagionali e bimestrali superiori a quelle riscontrate nella scarsa letteratura presente inerente la specie. Le dimensioni degli home range stagionali e bimestrali mostrano cambiamenti stagionali legati all’alternarsi delle condizioni ambientali e climatiche che caratterizzano l’area di studio. L’home range di dimensioni minori è stato registrato in estate, stagione ritenuta critica in ambiente sub-mediterraneo a causa dell’assenza di precipitazioni e del conseguente calo della qualità dei pascoli. La ripresa vegetativa erbacea registrata in autunno ed in primavera comporta un incremento delle dimensioni degli home range riferiti a tali periodi, quando le femmine del campione selezionano sia le aree aperte sia i boschi di querce. Il presente lavoro ha inoltre mostrato una risposta comportamentale differente tra femmine che risiedono in aree differenti dell’area di studio, evidenziando come individui residenti in ambienti più eterogenei occupino superfici superiori rispetto a quelli che utilizzano aree caratterizzate da una maggiore omogeneità nella distribuzione delle risorse, mostrando scelte dell’habitat completamente differenti. È stato evidenziato come la presenza dei nuovi nati influenzi gli spostamenti della madre solo nei primi 2-3 mesi successivi alla nascita, ovverosia durante il bimestre luglio-agosto. L’uso dell’habitat delle femmine con piccolo è risultato differente da quello mostrato dalle femmine che non hanno avuto un piccolo durante il periodo di studio. In particolare, tali differenze sono risultate statisticamente significative nel periodo compreso tra maggio ed agosto, in concomitanza delle ultime fasi della gestazione e le prime settimane dopo il parto

Influence of fawning on the spatial behaviour and habitat selection of female fallow deer (<i>Dama dama</i>) during late pregnancy and early lactation

Home-range sizes and habitat selection among calving and non-calving female fallow deer Dama dama were analysed during the last months of pregnancy and following parturition. The study was carried out in central Italy using radio-tracking techniques. It was based on data collected on 23 adult females (calving n=15, non-calving n=8) from March 2003 to August 2003. Seasonal and bimonthly home-range analyses showed marked differential spatial behaviour between calving and non-calving females only when fawns were present. These were born during June, and the summer and July–August home ranges of calving females were significantly lower than those recorded for non-calving ones. Although differences between spatial use of calving and non-calving females became significant only after the birth of fawns, habitat choices were significantly different from late pregnancy, when females had already reached parturition sites. Therefore, whereas during March–April calving and non-calving females showed similar habitat choices, from May, habitat selection proved to be significantly different between the two classes of females. In particular, major differences were detected in the use of marshes and meadows. That female fallow deer adopt anti-predator tactics during the calving season was shown by their higher use of marshes, the habitat that offers the greatest cover and provides good concealment for fawns. Calving females avoided meadows, because these are open areas without any concealment for fawns; however they were selected by non-calving females as a function of their high productivity, as shown by analysis of the grass quality of the study site. The use of sub-optimal habitats by calving females because of the presence of fawns confirmed the findings of previous studies. These showed that ungulate mothers may move to poorer but safer habitats, compromising their energy intakes, to reduce the predation risk to their neonates

Nonkin associations in wild boar social units

We investigated the social organization of wild boars (Sus scrofa) using genetic and spatial data from a study population in Tuscany, Italy. In total, 120 wild boars of different sexes and age classes were captured and monitored from 2002 to 2006. All of them were genetically analyzed by using 10 polymorphic microsatellites (HE = 0.693, k = 6.6) and a matrix of pairwise relatedness was calculated. In addition, a reference sample of fully related individuals was created by genotyping 11 adult females and their fetuses (n = 56). Spatial data were gathered for 65 animals that had been fitted with either radiocollars or ear transmitters. Sixteen social units were identified by capture data and confirmed by observations and telemetry. A correlation between interindividual spatial distance and relatedness was observed only in summerearly autumn and seemed to be associated to the presence of piglets. The prediction of matrilinearity in wild boar social units was not confirmed, because a low degree of relatedness among boars was observed within groups. Aggregations of unrelated adult females (with their litters) were detected in the study population. The high turnover in the population due to human-caused mortality seems to be the main factor responsible for this altered social structure. Accordingly, we suggest that the observed social organization would result from grouping of unrelated survivors that is promoted by the presence of wolves in the area