Phenology-based land cover classification using Landsat 8 time series

This article describes the methodology and results of a new JRC phenology-based classification algorithm able to generate accurate land cover maps in a fully automatic manner from Landsat 8 (L8) remote sensed data available since 12th April 2013 at no charge throughout the USGS website. A preliminary study aiming to bypass the single date classification inaccuracy (mainly due to seasonality) using long term MODIS time series as a “driver” to fill gaps between high resolution data, has been carried out. The high global acquisition frequency (~16 days) and distribution policy are making Landsat 8 product extremely suitable for near real time land cover mapping and monitoring. Five national parks in east Africa have been selected as study areas (Mahale Mountains, Mana Pools, West Lunga, Gorongosa, Tsimanampetsotsa); they are covering diverse eco-regions and vegetation types, from evergreen to deciduous. A buffer of 20 km around each park has been considered as well. Selected single date images were first preprocessed in order to convert raw DN values to top of atmosphere (TOA) reflectance and minimizes spectral differences caused by different acquisition time, sun elevation, sun-earth distance, and after processed by the algorithm to generate a thematic raster map with land cover classes. Is worth noting that the single date classification accuracy is closely related to the acquisition date of the image, the status of the vegetation and weather conditions such as cloud and shadows often present in tropical regions; here the need of developing a phenology based algorithm that considers the vegetation evolution and generates a more accurate land cover map including evergreen and deciduous discrimination on the basis of “frequency” rules. Land cover maps have been created for all parks and an exhaustive accuracy assessment has been carried out on Mahale Mountains and Tsimanampetsotsa. The combined overall accuracy of 82.8% demonstrates the high potentiality of this method and makes it usable at either local or regional scale.JRC.H.3-Forest Resources and Climat

Species Distribution Models: exploring patterns and processes in mammal ecology

Modelling species distribution is one of the most widely used approaches used by modern ecologists to predict species occurrence as well as to explore the environmental variables that determine the presence of a species in an habitat. Given the outstanding importance of mammals in the context of conservation or management actions, it is not surprising that an ever increasing number of mammalogists have successfully employed species distribution models over the last few years. As a scientific journal devoted to mammal natural history, Hystrix, the Italian Journal of Mammalogy is pleased to present a collection of articles forming a special issue that deals with such an important and timely matter

When management meets science: adaptive analysis for the optimization of the eradication of the Northern raccoon ( Procyon lotor )

AbstractThe EU Regulation no.1143/2014 on invasive species requires the EU Member States to respond promptly and efficiently in eradicating the invasive alien species listed as species of Union concern. The Northern raccoon (Procyon lotor) was introduced in Northern Italy along the river Adda and we carried out its eradication campaign between 2016 and 2019. We used an integrated approach of camera traps and live traps. A standardized approach to the camera trap survey (2904 camera trap-nights) revealed that the detectability of raccoons (0.27 ± 0.07 SD) increased in the proximity of the river and their occupancy (0.15 ± 0.09 SD) was higher in urban areas. These results allowed us to increase the trapping success whilst reducing the effort. During the captures, systematic collection of catch and effort data allowed to estimate population size (65 ± 7.8 raccoons) and thus to have a continuous update on how far the campaign was from the complete eradication of the species, allowing to adjust the trapping effort accordingly. We captured 69 raccoons (7279 cage trap nights) thanks to both systematic trapping and opportunistic activation of traps following stakeholders' reports. Stakeholders supported the campaign and some of them played an important role in reporting sightings, signs, and allowing access to their private land. Camera trap data also allowed us to make a Rapid Eradication Assessment that estimated an eradication probability of 99% after 6 months without detections. We finally give indications for future control campaigns on the species to increase removal success, reducing the effort

Climate is changing, are European bats too?:A multispecies analysis of trends in body size

Animal size, a trait sensitive to spatial and temporal variables, is a key element in ecological and evolutionary dynamics. In the context of climate change, there is evidence that some bat species are increasing their body size via phenotypic responses to higher temperatures at maternity roosts. To test the generality of this response, we conducted a &gt;20-year study examining body size changes in 15 bat species in Italy, analysing data from 4393 individual bats captured since 1995. In addition to examining the temporal effect, we considered the potential influence of sexual dimorphism and, where relevant, included latitude and altitude as potential drivers of body size change. Contrary to initial predictions of a widespread increase in size, our findings challenge this assumption, revealing a nuanced interplay of factors contributing to the complexity of bat body size dynamics. Specifically, only three species (Myotis daubentonii, Nyctalus leisleri, and Pipistrellus pygmaeus) out of the 15 exhibited a discernible increase in body size over the studied period, prompting a reassessment of bats as reliable indicators of climate change based on alterations in body size. Our investigation into influencing factors highlighted the significance of temperature-related variables, with latitude and altitude emerging as crucial drivers. In some cases, this mirrored patterns consistent with Bergmann's rule, revealing larger bats recorded at progressively higher latitudes (Plecotus auritus, Myotis mystacinus, and Miniopterus schreibersii) or altitudes (Pipistrellus kuhlii). We also observed a clear sexual dimorphism effect in most species, with females consistently larger than males. The observed increase in size over time in three species suggests the occurrence of phenotypic plasticity, raising questions about potential long-term selective pressures on larger individuals. The unresolved question of whether temperature-related changes in body size reflect microevolutionary processes or phenotypic plastic responses adds further complexity to our understanding of body size patterns in bats over time and space.<br/

Limnology for the ornithologist: effects of Lake Maggiore water level on migratory flows

Wetlands are widely recognised as the most critical stop-over locations along migration flyways. Wetland ecology is mostly influenced by water levels and water regimes. This research focuses on Bolle di Magadino (Switzerland), an important stop-over site on Lake Maggiore, artificially regulated by a dam. In this work we examined how the artificial flooding of a wetland affects the use of this stop-over site by migrating passerines during spring. Bird presence in the area was evaluated using both data collected at the ringing station located in the wetlands and the bird traffic rate (BTR) supplied by the BirdScan MR1, an avian vertical-looking radar (VLR) capable of automatically detecting and classifying birds in flight. In an attempt to shed light on the effect of lake level on stop- over quality, we i) simulated with GIS the extent of the flooded area and of the different habitat categories as the lake level changes; ii) calculated the relationship between lake level and the ability of stop-overing birds to acquire trophic resources; iii) verified that the flux of passerines below 500 m above ground level measured by radar could be used as a proxy for the number of stop-overing birds; iv) calculated the relationship between the number of birds leaving the stop-over and the lake level. While the number of ringed passerines has proven to be representative of the migratory flow below 500 meters of altitude at the site of interest, a high lake level seems to have a negative impact on the use by some species of the Bolle di Magadino area as a stop-over site during spring. In particular, two of the target species -the blackcap and the reed bunting- have proven to be sensitive to higher water levels. While taking into account the limitations and the relative nature of the results, could be necessary for the competent authorities to take these results into consideration in order to safeguard the Bolle di Magadino's role as an important stop- over area during spring

Relationships between personality traits and the physiological stress response in a wild mammal

Glucocorticoids (GCs) are involved in the regulation of an animal\u2019s energetic state. Under stressful situations, they are part of the neuroendocrine response to cope with environmental challenges. Animals react to aversive stimuli also through behavioral responses, defined as coping styles. Both in captive and wild populations, individuals differ in their behavior along a proactive\u2013reactive continuum. Proactive animals exhibit a bold, active-explorative and social personality, whereas reactive ones are shy, less active-explorative and less social. Here, we test the hypothesis that personality traits and physiological responses to stressors covary, with more proactive individuals having a less pronounced GC stress response. In wild populations of invasive gray squirrels Sciurus carolinensis, we measured fecal glucocorticoid metabolites (FGMs), an integrated measure of circulating GCs, and 3 personality traits (activity, sociability, and exploration) derived from open field test (OFT) and mirror image stimulation (MIS) test. Gray squirrels had higher FGMs in Autumn than in Winter and males with scrotal testes had higher FGMs than nonbreeding males. Personality varied with body mass and population density. Squirrels expressed more activity-exploration at higher than at lower density and heavier squirrels had higher scores for activity-exploration than animals that weighed less. Variation in FGM concentrations was not correlated with the expression of the 3 personality traits. Hence, our results do not support a strong association between the behavioral and physiological stress responses but show that in wild populations, where animals experience varying environmental conditions, the GC endocrine response and the expression of personality are uncorrelated traits among individuals

Macroparasite fauna of alien grey squirrels (Sciurus carolinensis): composition, variability and implications for native species.

Introduced hosts populations may benefit of an "enemy release" through impoverishment of parasite communities made of both few imported species and few acquired local ones. Moreover, closely related competing native hosts can be affected by acquiring introduced taxa (spillover) and by increased transmission risk of native parasites (spillback). We determined the macroparasite fauna of invasive grey squirrels (Sciurus carolinensis) in Italy to detect any diversity loss, introduction of novel parasites or acquisition of local ones, and analysed variation in parasite burdens to identify factors that may increase transmission risk for native red squirrels (S. vulgaris). Based on 277 grey squirrels sampled from 7 populations characterised by different time scales in introduction events, we identified 7 gastro-intestinal helminths and 4 parasite arthropods. Parasite richness is lower than in grey squirrel's native range and independent from introduction time lags. The most common parasites are Nearctic nematodes Strongyloides robustus (prevalence: 56.6%) and Trichostrongylus calcaratus (6.5%), red squirrel flea Ceratophyllus sciurorum (26.0%) and Holarctic sucking louse Neohaematopinus sciuri (17.7%). All other parasites are European or cosmopolitan species with prevalence below 5%. S. robustus abundance is positively affected by host density and body mass, C. sciurorum abundance increases with host density and varies with seasons. Overall, we show that grey squirrels in Italy may benefit of an enemy release, and both spillback and spillover processes towards native red squirrels may occur

Personality traits, sex and food abundance shape space use in an arboreal mammal

Animal space use is affected by spatio-temporal variation in food availability and/or population density and varies among individuals. This inter-individual variation in spacing behaviour can be further influenced by sex, body condition, social dominance, and by the animal’s personality. We used capture-mark-recapture and radio-tracking to examine the relationship between space use and personality in Eurasian red squirrels (Sciurus vulgaris) in three conifer forests in the Italian Alps. We further explored to what extent this was influenced by changes in food abundance and/or population density. Measures of an individual’s trappability and trap diversity had high repeatability and were used in a Principal Component Analysis to obtain a single personality score representing a boldness-exploration tendency. Males increased home-range size with low food abundance and low female density, independent of their personality. However, bolder males used larger core-areas that overlapped less with other males than shy ones, suggesting different resource (food, partners) utilization strategies among personality types. For females, space use-personality relationships varied with food abundance, and bolder females used larger home ranges than shy ones at low female density, but the trend was opposite at high female density. Females’ intrasexual core-area overlap was negatively related to body mass, with no effect of personality. We conclude that relationships between personality traits and space use in free-ranging squirrels varied with sex, and were further influenced by spatio-temporal fluctuations in food availability. Moreover, different personality types (bold-explorative vs. shy) seemed to adopt different space-use strategies to increase access to food and/or partners. © 2021, The Author(s).Ministero dell’Istruzione, dell’Università e della RicercaOpen access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Food habits of the stone marten (&lt;em&gt;Martes foina&lt;/em&gt;) in the upper Aveto Valley (Northern Apennines, Italy)

&lt;strong&gt;Abstract&lt;/strong&gt; The diet of the stone marten (&lt;em&gt;Martes foina&lt;/em&gt;) was studied analysing 63 faeces collected from February 1990 to December 1991. The results were expressed as relative percentage of frequency (Fr%) and as percentage of mean bulk (Vm%). Mammals, mainly rodents, were the staple in the diet (annual Vm% = 62.9) and reached a maximum peak in winter (Vm% = 79.4). Vegetables were mostly represented by Rosaceae fruits (annual Vm% = 22.3) and were consumed during all year round. Insects, mainly Coleoptera and Orthoptera, were fairly frequently eaten, although their volume was not remarkable (annual Vm% = 4.1). Birds and garbage were scarcely used. The trophic niche breadth of the stone marten, evaluated using the Levin's index (B), varied from 2.49 in winter to 4.8 in summer. In the same study area the diet of the red fox (&lt;em&gt;Vulpes vulpes&lt;/em&gt;) was studied. The niche overlap between this canid and the stone marten was not extensive (Op = 0.52; Os = 0.51). &lt;strong&gt;Riassunto&lt;/strong&gt; &lt;strong&gt;Indagine sul comportamento trofico della faina (&lt;em&gt;Martes foina&lt;/em&gt;) in alta Val d'Aveto (Appennino Ligure-Emiliano)&lt;/strong&gt; - La dieta della Faina (&lt;em&gt;Martes foina&lt;/em&gt;) è stata studiata analizzando 63 feci raccolte dal febbraio 1990 al dicembre 1991. I dati ottenuti, espressi come frequenza relativa percentuale (Fr%) e come volume medio percentuale (Vm%), evidenziano che i Mammiferi, in particolare i Roditori, sono la componente alimentare principale (Vm% annuale = 62,9), con maggior consumo durante il periodo invernale (Vm% = 79,4). I vegetali, rappresentati per la maggior parte dai frutti delle Rosacee (Vm% annuale = 22,3), sono la seconda categoria trofica per importanza e compaiono per tutto l'arco dell'anno. Gli Insetti, quasi esclusivamente Coleotteri ed Ortotteri, presentano una discreta percentuale di utilizzo (Fr% annuale = 21,2) pur non avendo un'incidenza volumetricamente importante (Vm% annuale = 4,1). Gli Uccelli costituiscono una fonte di cibo poco utilizzata. L'ampiezza di nicchia trofica, valutata mediante l'indice di Levins (B), variava da 2,49 (inverno) a 4,8 (estate). Il confronto dello spettro trofico della faina con quello della volpe (&lt;em&gt;Vulpes vulpes&lt;/em&gt;), rilevato nella stessa area di studio, evidenzia una limitata sovrapposizione di nicchia (Op = 0,52; Os = 0,51)

"Chi ha mai visto la verit\ue0 avere la peggio in uno scontro libero e aperto?"

Il saggio introduce il volume e si sofferma sulla importanza e sulla gravit\ue0 della diffusione delle fake news nella costruzione dell'opinione pubblica