25 research outputs found
Multisource noninvasive genetics of brown bears (Ursus arctos) in Greece reveals a highly structured population and a new matrilineal contact zone in southern Europe
In humanâdominated landscapes, connectivity is crucial for maintaining demographically stable mammalian populations. Here, we provide a comprehensive noninvasive genetic study for the brown bear population in the Hellenic Peninsula. We analyze its population structuring and connectivity, estimate its population size throughout its distribution, and describe its phylogeography in detail for the first time. Our results, based on 150 multilocus genotypes and on 244âbp sequences of the mtDNA control region, show the population is comprised by three highly differentiated genetic clusters, consistent with geographical populations of Pindos, Peristeri, and Rhodope. By detecting two male bears with Rhodopean ancestry in the western demes, we provide strong evidence for the ongoing genetic connectivity of the geographically fragmented eastern and western distributions, which suggests connectivity of the larger East Balkan and PindosâDinara populations. Total effective population size (Ne) was estimated to be 199 individuals, and total combined population size (NC) was 499, with each cluster showing a relatively high level of genetic variability, suggesting that migration has been sufficient to counteract genetic erosion. The mtNDA results were congruent with the microsatellite data, and the three genetic clusters were matched predominantly with an equal number of mtDNA haplotypes that belong to the brown bear Western mitochondrial lineage (Clade 1), with two haplotypes being globally new and endemic. The detection of a fourth haplotype that belongs to the Eastern lineage (Clade 3a1) in three bears from the western distribution places the southernmost secondary contact zone between the Eastern and Western lineages in Greece and generates new hypotheses about postglacial maxima migration routes. This work indicates that the genetic composition and diversity of Europe's lowâlatitude fringe population are the outcome of ancient and historical events and highlight its importance for the connectivity and longâterm persistence of the species in the Balkans
Large carnivore expansion in Europe is associated with human population density and land cover changes
Aim: The recent recovery of large carnivores in Europe has been explained as resulting from a decrease in human persecution driven by widespread rural land abandonment, paralleled by forest cover increase and the consequent increase in availability of shelter and prey. We investigated whether land cover and human population density changes are related to the relative probability of occurrence of three European large carnivores: the grey wolf (Canis lupus), the Eurasian lynx (Lynx lynx) and the brown bear (Ursus arctos). Location: Europe, west of 64° longitude. Methods: We fitted multi-temporal species distribution models using >50,000 occurrence points with time series of land cover, landscape configuration, protected areas, hunting regulations and human population density covering a 24-year period (1992â2015). Within the temporal window considered, we then predicted changes in habitat suitability for large carnivores throughout Europe. Results: Between 1992 and 2015, the habitat suitability for the three species increased in Eastern Europe, the Balkans, North-West Iberian Peninsula and Northern Scandinavia, but showed mixed trends in Western and Southern Europe. These trends were primarily associated with increases in forest cover and decreases in human population density, and, additionally, with decreases in the cover of mosaics of cropland and natural vegetation. Main conclusions: Recent land cover and human population changes appear to have altered the habitat suitability pattern for large carnivores in Europe, whereas protection level did not play a role. While projected changes largely match the observed recovery of large carnivore populations, we found mismatches with the recent expansion of wolves in Central and Southern Europe, where factors not included in our models may have played a dominant role. This suggests that large carnivoresâ co-existence with humans in European landscapes is not limited by habitat availability, but other factors such as favourable human tolerance and policy
Brown bear attacks on humans : a worldwide perspective
The increasing trend of large carnivore attacks on humans not only raises human safety concerns but may also undermine large carnivore conservation efforts. Although rare, attacks by brown bears Ursus arctos are also on the rise and, although several studies have addressed this issue at local scales, information is lacking on a worldwide scale. Here, we investigated brown bear attacks (n = 664) on humans between 2000 and 2015 across most of the range inhabited by the species: North America (n = 183), Europe (n = 291), and East (n = 190). When the attacks occurred, half of the people were engaged in leisure activities and the main scenario was an encounter with a female with cubs. Attacks have increased significantly over time and were more frequent at high bear and low human population densities. There was no significant difference in the number of attacks between continents or between countries with different hunting practices. Understanding global patterns of bear attacks can help reduce dangerous encounters and, consequently, is crucial for informing wildlife managers and the public about appropriate measures to reduce this kind of conflicts in bear country.Peer reviewe
Recommended from our members
Movements, activity patterns and home range of a female brown bear (Ursus arctos, L.) in the Rodopi Mountain Range, Greece
Movements and activity patterns of an adult radio-tagged female brown bear accompanied by her cubs were documented for the first time in Rodopi area (NE Greece) from August 2000 to July 2002. Average daily movements were 2.45 +/- 2.26 SD km, (range 0.15-8.5 km). The longest daily range could be related to human disturbance (hunting activity). The longest seasonal distance (211 km), during Summer 2001 coincided with the dissolution of the family. With cubs, the female was more active during daytime (73 % of all radio-readings) than when solitary (28 %). The female switched to a more crepuscular behaviour, after separation from the yearling (July 2001). According to pooled data from 924 activity - recording sessions, during the whole monitoring period, the female was almost twice as active during day time while rearing cubs (51 % active) than when solitary (23 %). The autumn and early winter home range size of the family was larger (280 km(2)) than after the separation from the cubs (59 km(2)). During the family group phase, home range size varied from 258 km(2) in autumn to 40 km(2) in winter (average denning period lasted 107 days : December 2000-March 2001). The bear hibernated in the Bulgarian part of the Rodopi Range during winters of 2001 and 2002
Genetic Analysis and Status of Brown Bear Sub-Populations in Three National Parks of Greece Functioning as Strongholds for the Speciesâ Conservation
In order to optimize the appropriate conservation actions for the brown bear (Ursus arctos L.) population in Greece, we estimated the census (Nc) and effective (Ne) population size as well as the genetic status of brown bear sub-populations in three National Parks (NP): Prespa (MBPNP), Pindos (PINDNP), and Rhodopi (RMNP). The Prespa and Pindos sub-populations are located in western Greece and the Rhodopi population is located in eastern Greece. We extracted DNA from 472 hair samples and amplified through PCR 10 microsatellite loci. In total, 257 of 472 samples (54.5%) were genotyped for 6â10 microsatellite loci. Genetic analysis revealed that the Ne was 35, 118, and 61 individuals in MBPNP, PINDNP, and RMNP, respectively, while high levels of inbreeding were found in Prespa and Rhodopi but not in Pindos. Moreover, analysis of genetic structure showed that the Pindos population is genetically distinct, whereas Prespa and Rhodopi show mutual overlaps. Finally, we found a notable gene flow from Prespa to Rhodopi (10.19%) and from Rhodopi to Prespa (14.96%). Therefore, targeted actions for the conservation of the bears that live in the abovementioned areas must be undertaken, in order to ensure the speciesâ viability and to preserve the corridors that allow connectivity between the bear sub-populations in Greece. © 2022 by the authors
Tear physiology in dry eye associated with chronic GVHD
The purpose of this study was to compare tear physiology characteristics of chronic GVHD (cGVHD)-associated dry eye to dry eye caused by Sjogrens syndrome (SS), a extreme form of aqueous-deficient dry eye, and meibomian gland dysfunction (MGD), the major cause of evaporative dry eye. Tear turnover rate, evaporation and osmolarity along with meibomian gland dropout and lipid layer interferometric patterns were assessed in the right eyes of 12 patients with dry eye associated with cGVHD, 12 age-matched patients with SS and 12 age-sex matched subjects with MGD. In cGVHD, the decrease in tear turnover rate was similar (P=0.33), but the number of non-functioning meibomian glands was significantly higher (P<0.01) than in SS. Tear evaporation rate in cGVHD dry eye was found to be similar to that in MGD (P=0.36) and significantly higher than in SS (P<0.01). The lipid layer was most unstable in cGVHD compared with other groups. There was no variation in tear volume across all groups. Although statistical significance was not detected, the mean tear osmolarity (333.51ñ14.67mOsm/L) was highest in cGVHD. Major aspects of tear physiology were severely impaired in cGVHD-associated dry eye
Bears in human-modified landscapes: The case studies of the Cantabrian, Apennine, and Pindos Mountains
Brown bears Ursus arctos were historically persecuted and almost eradicated from Southern Europe in the 20th century as a result of hunting and direct persecution (Zedrosser et al. 2011; MartĂnez Cano et al. 2016). The effects of human induced mortality were exacerbated by other threats, such as habitat loss and fragmentation, due to the expansion of human populations (Swenson et al.
2000). As a result, nowadays there are only small fragmented populations of bears in Southern Europe, where brown bears frequently inhabit human modified landscapes. These areas are characterised by the widespread presence of people and infrastructures, which potentially have ecological impacts on bears. The close coexistence of brown bears and humans generates multiple human-driven disturbances (Ordiz et al. 2017) and causes bear mortality (Bischof et al. 2009), affecting the distribution, demography, behaviour and
viability of bear populations (Penteriani et al. 2018a; Zarzo-Arias et al. 2018). Brown bears in the Cantabrian (north-western Spain), Apennine (central Italy) and Pindos (north-western Greece) mountains (Figure 19.1) represent three examples of small and threatened bear populations in human-modified landscapes (Figure 19.2). Most of their range is characterised by high human densities, widespread agricultural activities, livestock raising and urban development, connected by dense networks of transport infrastructures
(Penteriani et al. submitted; Mateo-SĂĄnchez et al. 2016). This has resulted in a reduction of continuous habitat suitable for the species (MartĂnez Cano et al. 2016). Here, we summarise the past and present histories and fates of these three populations as examples on how the coexistence of bears and people in human-modified landscapes can take different turns depending on human
attitudes
Symptom Burden of Patients with Dry Eye Disease: A Four Domain Analysis
PURPOSE: To determine which sensory (symptom persistence and intensity) and reactive (activity and affective interference) domains of symptom analysis are essential for assessing symptom burden in dry eye disease (DED) patients. METHODS: A symptom domain tool was developed to investigate all four symptom domains in DED. In a cross-sectional pilot study, we administered the symptom burden tool and the Ocular Surface Disease Index (OSDI) questionnaire to 48 DED patients. Total and domain scores from the symptom burden tool and the OSDI were normalized to achieve comparability. Spearman correlation coefficients were calculated to measure the relationship between domains and subscales. Agreement between the symptom burden tool and OSDI was assessed by Bland-Altman plot. Assigned treatments were compared by symptom burden to determine whether treatment aggressiveness is linked to symptom intensity. RESULTS: There was high agreement between the symptom burden tool and the OSDI. Symptom persistence had a stronger correlation with affective interference (r â=â 0.62 for the symptom burden tool and râ=â0.73 for the OSDI) than activity interference (râ=â0.58 for the symptom burden tool and râ=â0.60 for the OSDI). Symptom intensity correlated weakly with affective interference (râ=â0.38) and activity interference (râ=â0.37) in the symptom burden tool (OSDI does not have a subscale for intensity). In patients with equal persistence of symptoms, those having high symptom intensity were receiving more aggressive treatment (66.7%) than those with lower symptom intensity (33.3%). CONCLUSIONS: Persistence of symptoms correlates better with affective interference than activity interference. Intensity of symptoms may be important for treatment decisions