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Demographic and behavioural responses of the roe deer (Capreolus capreolus) to landscape modifications and landscape of fear
Full text linkBehind wolf predation on wild ungulates: environmental factors influencing the distribution of kill sites in Northern Italy
No full textPredation is a hierarchical process whereby predators are constrained to kill prey within the area they select
while hunting. Therefore kill sites are not randomly distributed, rather where kill sites occur is a function of prey
distribution and predictability and environmental factors that influence prey detection, access, or the success of
an attack [1]. Wolves (Canis lupus) are considered generalist apex predators, preying mainly on wild ungulates.
Being socially organized in packs, usually consisting of the breeding pair and their offspring, wolves roam within
their exclusive territory and cooperate during the hunt. Wolves are well adapted for cursorial predation with
chases ranging from 100 m to more than 5 km [2].
The aim of this research is to identify the main environmental factors influencing the distribution of wolf kill sites,
so at the same time determine which factors influenced the vulnerability of prey once the hunt began.
The study was carried out in Liguria (5343 km2 region in Northern Italy; Fig. 1) The wild ungulate community
includes the wild boar (Sus scrofa) and the roe deer (Capreolus capreolus), widely distributed with high
densities, the fallow deer (Dama dama) and the chamois (Rupicapra rupicapra) more localized. Moreover, the
red deer (Cervus elaphus) has a sporadic presence along the boundaries of the region. Wolves reached the
Ligurian Apennines in the late 1980s (the first illegally killed wolf was found in 1990) and the Ligurian Alps in
the late 1990s (the first illegally killed wolf was found in 1997). The most recent research estimated the
presence of minimum five wolf packs by non-invasive genetic sampling [3].
Using data collected through a monitoring project carried out between 2007-2014 [3], we delineated wolf range
using the sampled wolf genotypes by a fixed kernel estimator. We considered all claimed and verified cases of
wolf predation upon wild ungulates recorded during 2007-2016, reporting the preyed species and possibly
some related information (sex, age, proportion of consumption). Around each kill site we defined a buffer
corresponding to the potential hunting area of wolves. We used a width of 13 km, corresponding to the average
travel distance of wolves during the night to go from dens or resting sites to hunting sites in Italy [4]. We
compared the plots where kill sites were recorded and an equal number of random plots within the estimated
wolf range. We formulated a habitat suitability model following an approach presence vs. availability by binary
logistic regression analysis (BLRA, forward stepwise method); we tested the hypothesis that wolf choice of kill
sites is influenced by the morphology and the land use of the area. In each plot, we measured from the Corine
Land Cover III level and the Digital Elevation Models (DEM) the environmental variables used as covariates:
four slope classes (range between 0° and >60°), road density, path density, forests (broad-leaved, coniferous,
and mixed forests), urban and cultivated areas, scrublands, open areas (pastures and grasslands), and bare
ground (rocks and areas with little or no vegetation cover). We considered even two-way interactions between
covariates. We tested the model performance by the percentage of correct classifications of original cases,
Nagelkerke’s R2, and receiver operating characteristic (ROC) curve analysis.
We identified 74 distinct wolf genotypes, corresponding to 189 non-invasive DNA samples (98% faeces, 1%
urines and 1% hairs), collected in the study area from 2007 to 2014. Wolf range had a total extent of 5068 km2.
We mapped and digitized 62 wolf kill sites; among the preyed wild ungulates, we identified 23 roe deer, 18
fallow deer, 16 wild boars, and 5 chamois (Fig. 1). BLRA showed a negative effect of the road density, the
urban areas, the mixed forests, and the medium slopes (20-40°), a positive effect of steep slopes (>60°), open
areas, and bare ground, the latter without statistical significance (Tab. 1). The logistic model explained 56.4%
of the variance of the response variable and correctly classified 78.2% of original cases, 82.3% of kill sites and
74.2% of control ones. The area under the ROC curve was significantly greater than that of a model that
randomly classifies the cases (AUC=0.883±0.029; P<0.001).
Wolves kill sites in Liguria were steep, open habitats (pastures and grasslands) far from roads and urban areas.
Wolves tend to avoid areas with high road and human settlement densities, as they may be barriers to wolf
movements and a cause of direct mortality both from vehicle collisions and illegal killing. Moreover, human
disturbance associated with roads and urban areas may deter or interfere with wolves when attempting to kill
prey, or afterward during carcass consumption. Wolves seemed to select steep slopes, probably because they
may find a suitable habitat in terms of advantage during hunting activities. We found that hiding-cover levels
were lower at kill sites than at random sites. Indeed, dense cover can affect the prey capacity to exploit refuges,
thus enhance its chances of escaping an attack, and can increase the chance of detection the predator,
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because of its noisier approach. From the predator point of view, in open habitats prey were easier to locate
and catch. Wild ungulates mainly use open habitats during the night as feeding areas, because of the higher
quality resources, and more closed habitats during the day, with less forage but a higher degree of shelter. Wild
ungulates have to face a constant trade-off between the choice of better food patches and predation risk. This
trade-off is mediated by the vigilance behaviour, which requires exclusive visual attention to scan the
environment, thereby interrupting or slowing down foraging activity. Wolves usually take advantage of this
wavering behaviour to start the rush. Moreover, wolves are mainly active from dawn to dusk and this is
probably closely related to their hunting pattern, which matches with the activity patterns of wild ungulates.
Overall, the environmental factors of the kill sites identified in this study are consistent with the cursorial hunting
strategy of wolves
Wolves and wild ungulates in the Ligurian Alps (Western Italy): prey selection and spatial-temporal interactions
Full text linkWe propose the integration of different noninvasive sampling methods to the study of predator-prey interactions. We analyzed the diet of the wolf (Canis lupus) to point out its elective prey and we investigated its spatial and temporal interactions with prey species from December 2012 to November 2014 in the Ligurian Alps (Southern Alps, Italy). In this area, the wolf is the only large predator, and there is a rich wild ungulate community consisting of four species. Our analyses showed that the most consumed species by wolves were the wild boar (Sus scrofa) and the roe deer (Capreolus capreolus). To successfully hunt these species, wolves need to share their spatial range, searching for them in the most suitable habitat types and in the periods of the diel cycle during which they are mainly active. Fallow deer (Dama dama) and chamois (Rupicapra rupicapra) consumption was low, and wolves showed also relatively low overlap with these species. Our results suggest that wolves might be firstly specialized on wild boar predation, as they showed substantial spatial and temporal overlap with this species, and secondly on roe deer predation, especially during the denning season when they probably take advantage of the presence of fawns
Changes in Wolf Occupancy and Feeding Habits in the Northern Apennines: Results of Long-Term Predator–Prey Monitoring
No full textThe comprehension of the factors that have influenced the recent changes in wolf (Canis lupus) range and diet that have occurred in our study area, characterized by a highly heterogeneous landscape, can shed light on their current process of expansion toward the plain. Wolf presence was monitored using a standardized protocol from 2007 to 2022 by carrying out eight monitoring sessions organized in seasonal surveys, during which, we collected wolf presence data. To model wolf range dynamics, we used dynamic occupancy models considering land cover types and wild ungulate abundances as covariates. Moreover, we studied the wolf diet through scat analysis, identifying the consumed items from undigested remains. Wolf occupancy in the study area progressed from mountains to lower hills gradually; the observed range dynamics were driven by prey abundance and human presence: in particular, the probability of colonization increased with roe deer (Capreolus capreolus) abundance, whereas the probability of extinction increased with urban areas. The wolf diet showed a gradual shift from the prevalent consumption of wild boar (2007–2008 and 2011–2012) to the prevalent consumption of roe deer (continuously increasing from 2015 onward). Our results might be related to a specific adaptation of the predator to the local ecology of the most consumed species: the roe deer
Wolf predation on wild ungulates: How slope and habitat cover influence the localization of kill sites
Full text linkBased on data collected along the Ligurian Apennines and Alps (N-W Italy), we analysed the main environmental and human-related factors influencing the distribution of kill sites of the wolf Canis lupus. We mapped and digitized 62 kill sites collected during 2007-2016. Around each kill site, we defined a buffer corresponding to the potential hunting area of wolves. We compared kill site plots and an equal number of random plots. We formulated a model of kill site distribution following an approach presence versus availability by binary logistic regression analysis; we tested the hypothesis that wolf choice of kill sites is influenced by the physiography and the land use of the area. Among the preyed wild ungulates, we identified 23 roe deer Capreolus capreolus, 18 fallow deer Dama dama, 16 wild boars Sus scrofa, and 5 chamois Rupicapra rupicapra. Binary logistic regression analysis showed a negative effect of the road density, the urban areas, the mixed forests, and a positive effect of steep slopes and open habitats. Prey are more vulnerable to predators under certain conditions and predators are capable of selecting for these conditions. Wolves achieved this by selecting particular habitats in which to kill their prey: they preferred steep, open habitats far from human presence, where wild ungulates are more easily detectable and chasable
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Why do wolves eat livestock?:Factors influencing wolf diet in northern Italy
No full textThanks to protection by law and increasing habitat restoration, wolves (Canis lupus) are currently re-colonizing
Europe fromthe surviving populations of Russia, the Balkan countries, Spain and Italy, raising the need to update
conservation strategies. A major conservation issue is to restore connections and gene flow among fragmented
populations, thus contrasting the deleterious consequences of isolation. Wolves in Italy are expanding from the
Apennines towards the Alps, crossing the Ligurian Mountains (northern Italy) and establishing connections
with the Dinaric populations. Wolf expansion is threatened by poaching and incidental killings, mainly due to
livestock depredations and conflicts with shepherds, which could limit the establishment of stable populations.
Aiming to find out the factors affecting the use of livestock by wolves, in this study we determined the composition
of wolf diet in Liguria. We examined 1457 scats collected from 2008 to 2013. Individual scats were genotyped
using a non-invasive genetic procedure, and their content was determined using microscopical analyses.
Wolves in Liguria consumed mainly wild ungulates (64.4%; in particular wild boar Sus scrofa and roe deer
Capreolus capreolus) and, to a lesser extent, livestock (26.3%; in particular goats Capra hircus). We modeled the
consumption of livestock using environmental features, wild ungulate community diversity, husbandry characteristics
and wolf social organization (stable packs or dispersing individuals).Wolf diet varied according to years
and seasons with an overall decrease of livestock and an increase ofwild ungulate consumption, but also between
packs and dispersing individuals with greater livestock consumption for the latter. The presence of stable packs,
instead of dispersing wolves, the adoption of prevention measures on pastures, roe deer abundance, and the
percentage of deciduous woods, reduced predation on livestock. Thus, we suggest promoting wild ungulate
expansion, the use of prevention tools in pastures, and supporting wolf pack establishment, avoiding lethal
control and poaching, to mitigate conflicts between wolf conservation and husbandry
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