scholarly journals First data on population estimates and dispersal of Montenegrina subcristata – a field study at Virpazar, Montenegro

2019 ◽  
Vol 26 ◽  
pp. 147-165
Author(s):  
Anđela Bulatović ◽  
Jovana Marković ◽  
Elisabeth Haring ◽  
Wilhelm Pinsker ◽  
Katharina Mason ◽  
...  
Keyword(s):  
Population Size ◽  
Seasonal Pattern ◽  
Climatic Conditions ◽  
Dispersal Ability ◽  
Population Estimates ◽  
Data Loggers ◽  
Individual Number ◽  
Temperature And Humidity ◽  
Minimum Distances ◽  
Study Sites

Background. In this study a population of the rock dwelling terrestrial gastropod Montenegrina subcristata was monitored over one season and data about life cycle, population density and dispersal were gathered. Three study sites (A, B, C) near Virpazar, Montenegro were selected. Snails were categorized into three size classes. (1) The smallest juveniles were counted but not marked because of their tiny and dainty shell, middle sized snails (2) were marked with a dot and (3) larger subadults and adults were marked with an individual number. The sites were observed 25 times from April to October 2017. The study sites were equipped with data loggers to register microclimate data like temperature and humidity. Based on counts and recapture counts population estimates were calculated. Positions of the snails were recorded throughout the season and minimum distances between each two observations were calculated.Results. Small juveniles (not marked) were observed in high numbers at the beginning of the season and disappeared during summer. Site C had to be excluded from the calculations because snails nearly disappeared as early as the second visit. Population size estimations of sites A and B provided similar results for the beginning of the season, whereas for June the high estimates stood in high contrast to the number of observed snails in that period. Concerning "minimum distances" (MD; distance between two subsequent observations), the majority of MDs with a 1-week interval resulted in 0–0.1m. Yet, some individuals were more mobile, with sums of MDs over the season of up to 8.0 m. The sum of MDs over the season was on average 1.6 m (sites A+B).The temperature and humidity curves of the data loggers showed a seasonal pattern. The average temperatures of all three sites were rather similar. However, daily oscillations in temperature and humidity were high in some periods and differed between sites. In site C temperature and humidity extremes and fluctuations were pronouncedly higher, with the highest temperatures reaching more than 60 °C and relative humidity dropping each day below 3.7% in June.Conclusions. Dispersal ability is in general low but single individuals might cover distances of at least several meters over the season. Together with further observations we conclude that fluctuations of population size can be considerable and might be strongly influenced by climatic conditions. On the other hand, also population estimates may be influenced by climatic conditions. This study provided first hints to assess the potential of migration, local extinction and recolonization in Montenegrina and other rock dwelling snails.

Developing a census method based on sight counts to estimate rabbit (Oryctolagus cuniculus) numbers

2003 ◽  
Vol 30 (5) ◽  
pp. 487 ◽  
Author(s):  
Dylan W. Poole ◽  
Dave P. Cowan ◽  
Graham C. Smith
Keyword(s):  
Population Size ◽  
Field Trials ◽  
Population Estimates ◽  
Economic Costs ◽  
Natural Conditions ◽  
Commercial Farms ◽  
The Mean ◽  
The Difference ◽  
Study Sites ◽  
Autumn And Winter

A rabbit-census method, based on systematic counts conducted at night or at dawn and dusk, was developed and validated in terms of estimating the total number of rabbits present in a given area. Initially, models were developed under semi-natural conditions to describe the relationships between the numbers of rabbits counted and population size. Confidence limits were also calculated. The models were developed by comparing rabbit counts with the actual number of rabbits present, from a known population of animals. Only spotlight counts at night were considered reliable enough to estimate rabbit population size. During the autumn and winter months these represented ~60% of the population present. The model was subsequently validated, in two different exercises, following a series of field trials conducted under a variety of conditions on commercial farms. Initially, population estimates derived from the model were compared with those calculated using an alternative census technique. Population estimates, using the two techniques, were very similar at nine of the ten study sites. A second validation exercise was also conducted whereby the number of rabbits removed at each of the sites was compared with the difference between the mean pre- and post-removal spotlight counts. The results further supported the proposition that spotlight counts represent ~60% of the population present, with the difference between the two mean spotlight counts representing 61.2% (± 11.0, s.d.) of the number of rabbits removed. The census method therefore shows considerable promise as a means to estimate rabbit numbers under a range of agricultural conditions and therefore has the potential to predict accurately the economic costs of rabbit damage and also to gauge the effectiveness of various methods of rabbit control.

scholarly journals Estimating change in the geographical range and population size of Hinde's Babbler Turdoides hindei

2003 ◽  
Vol 13 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Philip Shaw ◽  
John Musina ◽  
Patrick Gichuki
Keyword(s):  
Protected Areas ◽  
Population Size ◽  
Geographical Range ◽  
Population Estimates ◽  
Extent Of Occurrence ◽  
Area Of Occupancy ◽  
Species Area ◽  
Gains And Losses ◽  
Global Population

Hinde's Babbler Turdoides hindei is a globally threatened Kenyan endemic, which during the 1990s, was known from just seven localities. Based mainly on surveys undertaken in 2000–2001, we estimate the species's global population size and compare recent changes in its “extent of occurrence” and “area of occupancy”. Historically, Hinde's Babbler has been recorded from c. 40 10 × 10 km squares; 27 pre-1980 and 19 subsequently, suggesting that its area of occupancy has declined by about 30%. In contrast, its extent of occurrence has declined by only 8%, this measure being less sensitive to the balance of gains and losses occurring near the centre of its range. During surveys in 1994 and 2000–2001, 157 groups were located, containing 665 birds, 75% of which were found at two intensively cultivated sites. Some 97% of birds were located in, or adjacent to, five Important Bird Areas, but only 8% were found within legally protected areas. Two extrapolated population estimates are presented, based on the number of birds likely to have been missed at survey sites, and the species' area of occupancy. These suggest that the global population of Hinde's Babbler is likely to fall within the range of 1,500–5,600 birds.

Robustness of HPHC Reduction in THS 2.2 Aerosol Relative to 3R4F Reference Cigarette Smoke under Extreme Climatic Conditions

2021 ◽  
Vol 30 (3) ◽  
pp. 109-126
Author(s):  
Laurent Poget ◽  
Catherine Goujon ◽  
Samuel Kleinhans ◽  
Serge Maeder ◽  
Jean-Pierre Schaller
Keyword(s):  
Cigarette Smoke ◽  
Heating System ◽  
Tobacco Product ◽  
Climatic Conditions ◽  
Mainstream Smoke ◽  
Humid Climate ◽  
Experimental Conditions ◽  
Puff Volume ◽  
Temperature And Humidity ◽  
Health Canada

Summary In order to assess robustness for the reduction of harmful and potentially harmful constituent (HPHC) levels generated by the Tobacco Heating System 2.2 (THS 2.2), a heated tobacco product, we compared the aerosol of this product with mainstream smoke from the 3R4F reference cigarette under different conditions of temperature and humidity. The desired climatic conditions were achieved by using an air-conditioning system coupled with the smoking-machine housing. Two extreme climatic conditions were selected, representing a “Hot and Dry” climate (30 °C and 35% relative humidity RH) and a “Hot and Very Humid” climate (30 °C and 75% RH). In addition, aerosol and smoke were generated using the standard conditions recognized for smoking-machine analyses of tobacco products (22 °C and 60% RH), which were close to the climatic conditions defined for “Subtropical and Mediterranean” environments (25 °C and 60% RH). The experimental conditions were chosen to simulate the use of THS 2.2 and cigarettes under extreme conditions of temperature and humidity. HeatSticks and cigarettes taken from freshly opened packs were subjected to short-term conditioning from two to a few more days under the same experimental conditions. We analyzed 54 HPHCs in THS 2.2 aerosol and 3R4F cigarette smoke, generated in accordance with the Health Canada Intense (HCI) standard, using modified temperature and humidity conditions for sample conditioning and machine-smoking experiments. We used a volume-adjusted approach for comparing HPHC reductions across the different climatic conditions investigated. Although a single puffing regimen was used, the total puff volume recorded for the 3R4F cigarette smoke varied due to the influence of temperature and humidity on combustion rate, which justified the use of a volume-adjusted approach. Volume-adjusted yields were derived from HPHC yields expressed in mass-per-tobacco stick normalized per total puff volume. The results indicated that, regardless of the considered climatic conditions, the HPHC levels investigated in THS 2.2 aerosol were reduced by at least 90%, on average, when compared with the concentrations in 3R4F cigarette mainstream smoke. This confirmed the robustness in performance for THS 2.2 to deliver reduced levels of HPHCs under the extreme climatic conditions investigated in this study. In order to further characterize the robustness of these reductions, the lowest reduction performance achieved for individual HPHCs across all climatic conditions was used to define the threshold for a robust reduction. The majority of the 54 HPHCs investigated in THS 2.2 aerosol showed more than 90% reduction. Calculations derived from nicotine-adjusted yields also confirmed robust reductions for all investigated HPHCs. The small differences in absolute reduction between the volume- and nicotine-adjusted approaches were predominantly attributed to a combination of the differences in both nominal nicotine deliveries and total puff volumes between THS 2.2 and 3R4F cigarettes; however, this did not influence the determination of robustness. Our findings confirm the value of this approach for assessing the robustness of a product’s performance under different climatic conditions.

scholarly journals A first survey of the global population size and distribution of the Scottish Crossbill Loxia scotica

2010 ◽  
Vol 21 (2) ◽  
pp. 186-198 ◽  
Author(s):  
RON W. SUMMERS ◽  
STEPHEN T. BUCKLAND
Keyword(s):  
Population Size ◽  
Habitat Management ◽  
Disjunct Distribution ◽  
Population Estimates ◽  
Modal Number ◽  
Habitat Requirement ◽  
Bird Population ◽  
Different Seasons ◽  
Common Crossbill ◽  
Global Population

SummaryA survey of Scottish Crossbills Loxia scotica was carried out in 3,506 km2 of conifer woodland in northern Scotland during January to April 2008 to provide the first estimate of the global population size for this endemic bird. Population estimates were also made for Common Crossbills L. curvirostra and Parrot Crossbills L. pytyopsittacus within this range. Crossbills were lured to systematically selected survey points for counting, sexing and recording their calls for later call-type (species) identification from sonograms. Crossbills were located at 451 of the 852 survey points, and adequate tape-recordings made at 387 of these. The Scottish Crossbill had a disjunct distribution, occurring largely within the eastern part of the study area, but also in the northwest. Common Crossbills had a mainly westerly distribution. The population size of post-juvenile Scottish Crossbills was estimated as 13,600 (95% C.I. 8,130–22,700), which will approximate to 6,800 (4,065–11,350) pairs. Common Crossbills were more abundant within this range (27,100, 95% C.I. 14,700–38,400) and Parrot Crossbills rare (about 100). The sex ratio was not significantly different from parity for Scottish Crossbills. The modal number at survey points was two but numbers were larger in January than later in the survey. The numbers and distribution of all crossbill species are likely to vary between years, depending upon the size of the cone crops of the different conifers: all were coning in 2008. Common Crossbill and Parrot Crossbill numbers will also be affected by irruptions from continental Europe. A monitoring scheme is required to detect any population trend, and further work on their habitat requirement (e.g. conifer selection at different seasons) is needed to inform habitat management of native and planted conifer forests to ensure a secure future for this endemic bird.

scholarly journals A description of the physical properties of selected sediments of the Weichselian and Wartanian glaciations

2016 ◽  
Vol 10 (1) ◽  
pp. 123-132
Author(s):  
Ewa Labak-Mechowska
Keyword(s):  
Physical Properties ◽  
Relative Density ◽  
Climatic Conditions ◽  
Plasticity Index ◽  
Geotechnical Parameters ◽  
Constrained Modulus ◽  
North Eastern ◽  
Subsurface Sediments ◽  
Engineering Parameters ◽  
Study Sites

Abstract Subsurface sediments in Poland were deposited mainly in the Pleistocene, and have varying origins and, consequently, differing geological and engineering parameters. Fluvioglacial deposits were formed during both the glacial and interglacial periods, which differed from each other in climatic conditions. Based on the results of laboratory analysis and fieldwork, till and fluvioglacial sands were compared in Central and North-Eastern Poland. The research included consistency limits, relative density, plasticity index, constrained modulus of initial compressibility and modulus of initial deformation. Despite the existing view that there exists a large diversity of geological, engineering and geotechnical parameters of variously-aged deposits in Poland, no major differences in their properties were determined at the study sites.

scholarly journals Endophytic fungi and latent pathogens in the sedge Carex secalina (Cyperaceae), a critically endangered species in Europe

2019 ◽  
Vol 55 (No. 2) ◽  
pp. 102-108 ◽  
Author(s):  
Górzyńska Karolina ◽  
Węgrzyn Ewa ◽  
Sandecki Rafał ◽  
Lembicz Marlena
Keyword(s):  
Endangered Species ◽  
Population Size ◽  
Endophytic Fungi ◽  
Critically Endangered ◽  
Critically Endangered Species ◽  
Colletotrichum Destructivum ◽  
Leaf Tissues ◽  
Study Sites ◽  
Roadside Area ◽  
Latent Pathogens

Endophytic fungi are widespread in plants and affect the host fitness and population size. We found 12 fungal taxa in C. secalina, a critically endangered species in several European countries, at two study sites in Poland. The most frequently occurring fungal taxa were Colletotrichum destructivum and Acremonium sp. Both taxa were found in half of the examined tussocks. The highest number of fungal taxa was noted in the C. secalina plants growing in the roadside area, where 7 of the 12 identified fungal taxa occurred. These fungi, inhabiting leaf tissues, are known for their pathogenicity but no visible symptoms of any diseases were observed on C. secalina leaves. This suggests that these fungi are latent pathogens.

scholarly journals Diversity and Geographic Distribution of Ligninolytic Fungi Associated With Castanopsis sieboldii Leaf Litter in Japan

2020 ◽  
Vol 11 ◽  
Author(s):  
Takashi Osono ◽  
Shunsuke Matsuoka ◽  
Dai Hirose
Keyword(s):  
Leaf Litter ◽  
Variation Partitioning ◽  
Climatic Conditions ◽  
Mean Annual Temperature ◽  
Priority Effect ◽  
Internal Transcribed Spacer Region ◽  
Biogeographic Patterns ◽  
Ligninolytic Fungi ◽  
Castanopsis Sieboldii ◽  
Study Sites

The diversity and geographic pattern of ligninolytic fungi were investigated within the distribution range of an evergreen tree, Castanopsis sieboldii (Fagaceae), in Japan. Fungal isolates obtained from 18 sites in subtropical and temperate regions in Japan were classified into 50 operational taxonomic units in Ascomycota and Basidiomycota according to the base sequence of the rDNA internal transcribed spacer region. Ordination by nonmetric multidimensional scaling showed the separation of fungal compositions between the study sites which was significantly related to the latitude, longitude, and mean annual temperature (MAT) of the study sites. We applied variation partitioning to separate the magnitude of the climatic, spatial, and leaf property factors and found the roles of MAT and spatial factors in structuring fungal assemblages, suggesting the importance of both niche processes and such non-niche processes as priority effect and dispersal limitation. The bleached area on leaf litter was greater at sites with higher MAT and precipitation located at lower latitudes and at sites where some major ligninolytic fungi occurred at greater relative frequencies, indicating that not only the climatic conditions but also the biogeographic patterns of distribution of ligninolytic fungi influence the decomposition of lignin in leaf litter.

scholarly journals Influence of temperature and humidity on hand, foot, and mouth disease in Guangzhou, 2013–2017

2020 ◽  
Vol 48 (6) ◽  
pp. 030006052092989
Author(s):  
Chun Chen ◽  
Qinqin Jiang ◽  
Zhuangzhi Song ◽  
Yilan Li ◽  
Hui Wang ◽  
...  
Keyword(s):  
Seasonal Pattern ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Distributed Lag ◽  
Foot And Mouth ◽  
Temperature And Humidity ◽  
Low Humidity ◽  
Long Term Trends ◽  
Public Health Strategies

Objective To explore associations between temperature, humidity and hand, foot and mouth disease (HFMD) incidence in Guangzhou, China from 2013 to 2017. Methods A distributed lag non-linear model was applied to estimate the effects of daily temperature and humidity on HFMD incidence after adjusting for long-term trends, seasonal trends, and day of the week. Results In total, 353,431 confirmed HFMD cases were reported in Guangzhou over the study period. A bimodal seasonal pattern was observed. High temperatures had acute short-term effects on HFMD incidence that declined quickly over time. The effects of low humidity declined over lag periods, but increased when the humidity surpassed 60.5%. Temperature and humidity were both inversely associated with HFMD incidence during lag days 0 to 3 and with lag periods Conclusions Temperature and humidity play important roles in HFMD incidence. These data are important for developing public health strategies.

scholarly journals Marked Cards in the Pack: Using Playing Cards to Teach the Importance of Sample Size & Testing Assumptions in Capture–Recapture Estimations of Population Size

2020 ◽  
Vol 82 (6) ◽  
pp. 396-401
Author(s):  
Michael Calver ◽  
Timothy Blake
Keyword(s):  
Secondary School ◽  
Sample Size ◽  
Population Size ◽  
Confidence Intervals ◽  
Population Ecology ◽  
Simple Approach ◽  
Population Estimates ◽  
Index Method ◽  
Capture Recapture ◽  
Approach To Teaching

Estimating population size is essential for many applications in population ecology, so capture–recapture techniques to do this are often taught in secondary school classrooms and introductory university units. However, few classroom simulations of capture–recapture consider the sensitivity of results to sampling intensity, the important concept that the population size calculated is an estimate with error attached, or the consequences of violating assumptions underpinning particular capture–recapture models. We describe a simple approach to teaching the Lincoln index method of capture–recapture using packs of playing cards. Students can trial different sampling intensities, calculate 95% confidence intervals for population estimates, and explore the consequences of violating specific assumptions.

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