scholarly journals Men and wolves: are anthropogenic causes the main driver of wolf mortality in human-dominated landscapes in Italy?

2021 ◽  
Author(s):  
Carmela Musto ◽  
Jacopo Cerri ◽  
Marco Galaverni ◽  
Romolo Caniglia ◽  
Elena Fabbri ◽  
...  
Keyword(s):  
Linear Models ◽  
Significant Proportion ◽  
Null Model ◽  
Gray Wolf ◽  
Sampling Schemes ◽  
Main Driver ◽  
Predator Interactions ◽  
Temporal And Spatial ◽  
Historical Range ◽  
Human Density

Over the last 40 years the gray wolf (Canis lupus) re-colonized its historical range in Italy increasing human-predator interactions. However, temporal and spatial trends in wolf mortality, including direct and indirect persecution, were never summarized. This study aims to fill this gap by focusing on the situation of Tuscany and Emilia-Romagna regions, believed to host a significant proportion of the Italian wolf population, by: (i) identifying the prevalent causes of wolf mortality, (ii) summarizing their temporal and spatial patterns and (iii) applying spatially-explicit Generalized Linear Models to predict wolf persecution. Between October 2005 and February 2021, 212 wolf carcasses were collected and subjected to necropsy, being involved in collisions with vehicles (n = 104), poisoned (n = 45), wounded with gunshot (n = 24) or blunt objects (n = 4) and being hanged (n = 2). The proportion of illegally killed wolves did not increase through time. Most persecution events occurred between October and February. None of our candidate models outperformed a null model and covariates such as the density of sheep farms, number of predations on livestock, or human density were never associated to the probability of having illegally killed wolves, at the municipal scale. Our findings show that conventional correlates of wolf persecution, combined with a supposedly high proportion of non-retrieved carcasses, fail to predict illegal wolf killings in areas where the species have become ubiquitous. The widespread spatial distribution of illegal killings indicates that persecution probably arises from multiple kinds of conflicts with humans, beyond those with husbandry. Wolf conservation in Italy should thus address cryptic wolf killings with multi-disciplinary approaches, such as shared national protocols, socio-ecological studies, the support of experts’ experience and effective sampling schemes for the detection of carcasses.

Human density, economic level and frequency of canine helminths in Buenos Aires

2021 ◽  
Vol 95 ◽  
Author(s):  
D. Rubel ◽  
N. Flaibani
Keyword(s):  
Linear Models ◽  
Buenos Aires ◽  
Toxocara Canis ◽  
The Other ◽  
Green Spaces ◽  
Cross Sectional ◽  
Independent Variables ◽  
Economic Level ◽  
Faecal Samples ◽  
Human Density

Abstract The aim of this study was to explore through cross-sectional study the variation in the prevalence of parasitic helminths in canine faeces collected from green spaces of Buenos Aires according to the human density (HD) and economic level (EL) in the surroundings. HD and EL were considered as independent variables with three categories each. Twenty public squares (one hectare of surface) were randomly selected for each existing combination of the two independent variables. Ten random samples of fresh canine faeces were obtained in each square and analysed for helminths by the sedimentation and flotation techniques. The prevalence for each of the species was analysed using generalized linear models (GLM). The prevalence was modelled with a binomial error distribution and a logit link function. Helminth eggs were detected in 45 out of the 200 (22.5%) faecal samples collected and in 18 of the 20 green spaces sampled. The species observed were Ancylostoma caninum (13% of samples), Trichuris vulpis (8%) and Toxocara canis (4.5%). The GLM indicated that the prevalence of A. caninum in the slum areas (very high HD and very low EL) was higher than that in the other areas studied. However, the HD seemed to contribute more than the EL to the variations in the prevalence of A. caninum in faecal samples. The GLM showed no differences in the prevalence of the other parasite species for the different levels of the independent variables.

Seasonal use of waterholes and pathways by macrofauna in the dry forest of Costa Rica

2019 ◽  
Vol 35 (2) ◽  
pp. 68-73 ◽  
Author(s):  
Victor H. Montalvo ◽  
Carolina Sáenz-Bolaños ◽  
Luis D. Alfaro ◽  
Juan C. Cruz ◽  
Flavio H. Guimarães-Rodrigues ◽  
...  
Keyword(s):  
Costa Rica ◽  
Linear Models ◽  
Bird Species ◽  
Dry Forest ◽  
Ecological Understanding ◽  
Large Bird ◽  
Temporal And Spatial ◽  
Trail Cameras ◽  
Almost All ◽  
North Western

AbstractTemporal and spatial scarcity of water in semi-arid and seasonal ecosystems often leads to changes in movements and behaviour of large vertebrates, and in the neotropics this dynamic is poorly understood due to logistical and methodological limitations. Here we used camera trapping to elucidate variation in patterns of seasonal use of waterholes and pathways by 10 large-mammal and four large-bird species in the dry forest of north-western Costa Rica. From 2011 to 2015, we deployed trail cameras at 50 locations, including waterholes and three types of pathway (roads, human trails and animal paths). We used Generalized Linear Models to evaluate the effect of location and seasonality on the rates at which independent photographs were taken. We found interacting effects of location and seasonality for the capuchin monkey (Cebus capucinus), the tiger heron (Trigrisoma mexicanum), the white-tailed deer (Odocoileus virginianus) and the tapir (Tapirus bairdii) suggesting that these species were the most influenced by waterholes during the dry season. Comparison of waterhole sites and specific types of pathways (roads, animal paths and human trails) showed that location influenced photo-capture rates of almost all species, suggesting a useful insight to avoid and account for bias in camera trap studies. Furthering our ecological understanding of seasonal water regimes and large vertebrates’ behaviours allow for better understanding of the consequences of climate change on them.

Patterns of human–crocodile conflict in Queensland: a review of historical estuarine crocodile (Crocodylus porosus) management

2017 ◽  
Vol 44 (4) ◽  
pp. 281 ◽  
Author(s):  
M. L. Brien ◽  
C. M. Gienger ◽  
C. A. Browne ◽  
M. A. Read ◽  
M. J. Joyce ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
Public Safety ◽  
Linear Models ◽  
East Coast ◽  
Adult Males ◽  
Wet Season ◽  
Temporal And Spatial Patterns ◽  
Crocodylus Porosus ◽  
Temporal And Spatial ◽  
The Government

Context In Queensland, the management of estuarine crocodiles (Crocodylus porosus) by the government is important for ensuring public safety, especially along the populated east coast, where there is a large human population. Aims The present study aimed to determine historical, temporal and spatial patterns of human–crocodile conflict in Queensland. Methods The study used Queensland Government records of estuarine crocodile attacks (1971–2015), sightings by the general public (2003–2015), and removals and relocations for management purposes (1985–2015) to develop General Linear Models describing historical, temporal and spatial patterns. Key results The highest number of attacks, sightings, removals and relocations occurred along the populated east coast between Townsville and the Daintree during wet season months (November–February). There have been 35 crocodile attacks in Queensland since 1971 (total 0.8 per year; fatal 0.3 per year), mostly involving local people or regular visitors (77.1%), specifically adult males (71.4%; mean age 44). There has been an increase in the rate of crocodile attacks over time, with an average of 1.3 per year since 1996, most of which were non-fatal (84%). The number of crocodile sightings has been increasing annually (with a mean of 348 per year since 2011), while the number of crocodiles removed or relocated for management purposes (n = 608) has fluctuating widely each year (range 1–57). Conclusions The level of human–crocodile conflict in Queensland is increasing, and this is likely to be a consequence of increasing human and crocodile populations. While conflict is highest during the wet season, estuarine crocodiles pose a threat to public safety year round. Implications With the increase in conflict, the ongoing management of estuarine crocodiles, through targeted removals in and around areas of higher human habitation and through education, is essential for ensuring public safety into the future.

Sampling Schemes and the Selection of Log-Linear Models for Longitudinal Data

2001 ◽  
Vol 16 (2) ◽  
pp. 221-234 ◽  
Author(s):  
Alexander Von Eye ◽  
Christof Schuster ◽  
Kurt Kreppner
Keyword(s):  
Longitudinal Data ◽  
Linear Models ◽  
Sampling Schemes ◽  
Log Linear ◽  
Selection Of

scholarly journals Exhaled NO reference limits in a large population-based sample using the Lambda-Mu-Sigma method

2018 ◽  
Vol 125 (5) ◽  
pp. 1620-1626 ◽  
Author(s):  
Tiago Jacinto ◽  
Rita Amaral ◽  
Andrei Malinovschi ◽  
Christer Janson ◽  
João Fonseca ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Clinical Practice ◽  
Linear Models ◽  
Large Population ◽  
Significant Proportion ◽  
The United States ◽  
Exhaled Nitric Oxide ◽  
Additive Models ◽  
Reference Equations ◽  
Lms Method

Absolute values are used in the interpretation of the fraction of exhaled nitric oxide (FeNO), but it has been suggested that equations to calculate reference values may be a practical and clinically useful approach. We hypothesize that the application of the Lambda-Mu-Sigma (LMS) method may improve FeNO reference equations and their interpretation. Our aims were to develop FeNO reference equations with the LMS method and to describe the difference between this method and the absolute fixed cut-offs of the current recommendations. We utilized the United States National Health and Nutrition Examination Surveys 2007–2012 and included healthy individuals with no respiratory diseases and blood eosinophils <300/mm3 ( n = 8,340). Natural log-transformed FeNO was modeled using the LMS method, imbedded in the generalized additive models for location, scale, and shape models. A set of FeNO reference equations was developed. The explanatory variables were sex, age, height, smoking habits, and race/ethnicity. A significant proportion of individuals with normal FeNO given by the equations were classified as having intermediate levels by the current recommendations. Further lower predicted FeNO compared with previous linear models was seen. In conclusion, we suggest a novel model for the prediction of reference FeNO values that can contribute to the interpretation of FeNO in clinical practice. This approach should be further validated in large samples with an objective measurement of atopy and a medical diagnosis of asthma and rhinitis. NEW & NOTEWORTHY Novel reference equations and fraction of exhaled nitric oxide (FeNO)-predicted values to improve interpretation of FeNO in clinical practice are presented. These may increase the accuracy of ruling out airway inflammation in patients with asthma or suspected asthma.

Temporal and spatial segregation in an assemblage of Afrotropical subterranean snakes

2014 ◽  
Vol 35 (3) ◽  
pp. 345-353 ◽  
Author(s):  
Fabio Petrozzi ◽  
Edem A. Eniang ◽  
Nioking Amadi ◽  
Godfrey C. Akani ◽  
Luca Luiselli
Keyword(s):  
Niger Delta ◽  
Null Model ◽  
Wet Season ◽  
Spatial Niche ◽  
Temporal And Spatial ◽  
Habitat Generalist ◽  
Positive Correlations ◽  
Randomization Algorithms ◽  
Dimension One ◽  
Niche Dimension

Niche partititioning patterns have not been studied so far in burrowing tropical snakes of the families Typhlopidae and Leptotyphlopidae. In this study, we analyze temporal (= monthly activity) and spatial (= habitat use) niche dimensions in three species of burrowing snakes from the Niger Delta, Nigeria. Null model analyses, using two randomization algorithms and 30 000 Monte Carlo permutations, showed that there was random resource partitioning patterns as for the spatial niche dimension. One species (Rhinotyphlops punctatus) clearly dominated in the sample, and appeared to be more habitat generalist than the others. All three species showed an uneven monthly activity, with peaks occurring by wet season, and statistically significant positive correlations between mean monthly rainfall and number of captured snakes. However, there were significantly negative correlations between mean monthly temperature and number of captured snakes in two of the three species (Rhinotyphlops congestus;Leptotyphlopscfr.sundewalli).

Comparison of Sampling Schemes for Dynamic Linear Models

2006 ◽  
Vol 74 (2) ◽  
pp. 203-214 ◽  
Author(s):  
Edna A. Reis ◽  
Esther Salazar ◽  
Dani Gamerman
Keyword(s):  
Linear Models ◽  
Sampling Schemes ◽  
Dynamic Linear Models

scholarly journals Biodiversity and Spatial-Temporal Dynamics of Margalefidinium Species in Jiaozhou Bay, China

2021 ◽  
Vol 18 (21) ◽  
pp. 11637
Author(s):  
Shuya Liu ◽  
Mengjia Zhang ◽  
Yongfang Zhao ◽  
Nansheng Chen
Keyword(s):  
Temporal Dynamics ◽  
Harmful Algal Bloom ◽  
Jiaozhou Bay ◽  
Spatial Dynamics ◽  
High Genetic Diversity ◽  
Sequence Variations ◽  
Main Driver ◽  
Temporal And Spatial ◽  
Shed Light ◽  
Rule Out

Many Margalefidinium species are cosmopolitan harmful algal bloom (HAB) species that have caused huge economic and ecological damage. Despite extensive research on Margalefidinium species, the biodiversity and spatial-temporal dynamics of these species remain obscure. Jiaozhou Bay is an ideal area for HAB research, being one of the earliest marine survey areas in China. In this study, we carried out the first metabarcoding study on the temporal and spatial dynamics of Margalefidinium species using the 18S rDNA V4 region as the molecular marker and samples collected monthly at 12 sampling sites in Jiaozhou Bay in 2019. Two harmful Margalefidinium species (M. polykrikoides and M. fulvescens) were identified with potentially high genetic diversity (although we cannot rule out the possibility of intra-genome sequence variations). Both M. polykrikoides and M. fulvescens demonstrated strong temporal preference with a sharp peak of abundance in early autumn (September), but without showing strong location preference in Jiaozhou Bay. Our results revealed that temperature might be the main driver for their temporal dynamics. Knowledge of biodiversity and spatial-temporal dynamics of the Margalefidinium species may shed light on the understanding of mechanisms underlying strongly biased occurrences of Margalefidinium blooms recorded globally.

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