scholarly journals Population trend inferred from aural surveys for calling anurans in Korea

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5568 ◽  
Author(s):  
Amaël Borzée ◽  
Desiree Andersen ◽  
Yikweon Jang
Keyword(s):  
Population Dynamics ◽  
Population Size ◽  
Population Trends ◽  
High Rate ◽  
Size Difference ◽  
Population Size Estimates ◽  
Key Factor ◽  
Species Dynamics ◽  
The Difference ◽  
The Republic

Amphibian populations fluctuate naturally in size and range and large datasets are required to establish trends in species dynamics. To determine population trends for the endangered Suweon Treefrog (Dryophytes suweonensis), we conducted aural surveys in 2015, 2016, and 2017 at each of 122 sites where the species was known to occur in the Republic of Korea. Despite being based on individual counts, the focus of this study was to establish population trends rather than population size estimates, and we found both environmental and landscape variables to be significant factors. Encroachment was also a key factor that influenced both the decreasing number of calling individuals and the negative population dynamics, represented here by the difference in the number of calling individuals between years. Generally, most sites displayed minimal differences in the number of calling males between years, although there was a large fluctuation in the number of individuals at some sites. Finally, when adjusted for the overall population size difference between years, we found the population size to be decreasing between 2015 and 2017, with a significant decrease in the number of calling individuals at specific sites. High rate of encroachment was the principal explanatory factor behind these marked negative peaks in population dynamics.

scholarly journals Consequences of barriers and changing seasonality on population dynamics and harvest of migratory ungulates

2020 ◽  
Vol 13 (4) ◽  
pp. 595-605
Author(s):  
Bram Van Moorter ◽  
Steinar Engen ◽  
John M. Fryxell ◽  
Manuela Panzacchi ◽  
Erlend B. Nilsen ◽  
...  
Keyword(s):  
Climate Change ◽  
Population Dynamics ◽  
Population Size ◽  
Spatial Dynamics ◽  
Infrastructure Development ◽  
Negative Effects ◽  
Behavioral Avoidance ◽  
Animal Populations ◽  
The Difference ◽  
Global Threat

AbstractMany animal populations providing ecosystem services, including harvest, live in seasonal environments and migrate between seasonally distinct ranges. Unfortunately, two major sources of human-induced global change threaten these populations: climate change and anthropogenic barriers. Anthropogenic infrastructure developments present a global threat to animal migrations through increased migration mortality or behavioral avoidance. Climate change alters the seasonal and spatial dynamics of resources and therefore the effects of migration on population performance. We formulated a population model with ideal-free migration to investigate changes in population size and harvest yield due to barriers and seasonal dynamics. The model predicted an increasing proportion of migrants when the difference between areas in seasonality or carrying capacity increased. Both migration cost and behavioral avoidance of barriers substantially reduced population size and harvest yields. Not surprisingly, the negative effects of barriers were largest when the population benefited most from migration. Despite the overall decline in harvest yield from a migratory population due to barriers, barriers could result in locally increased yield from the resident population following reduced competition from migrants. Our approach and results enhance the understanding of how global warming and infrastructure development worldwide may change population dynamics and harvest offtake affecting livelihoods and rural economies.

Adult population dynamics and reproductive effort of the fishing spider Dolomedes triton (Araneae, Pisauridae) in central Alberta

1992 ◽  
Vol 70 (11) ◽  
pp. 2224-2233 ◽  
Author(s):  
Manfred Zimmermann ◽  
John R. Spence
Keyword(s):  
Population Dynamics ◽  
Population Size ◽  
Adult Population ◽  
Adult Longevity ◽  
Male Population ◽  
Male Mortality ◽  
Mark Recapture ◽  
Female Population ◽  
Population Size Estimates ◽  
Dolomedes Triton

A combination of simple enumeration and more intensive Jolly–Seber and Manly–Parr mark–recapture estimation was required to give a complete picture of the population dynamics of adult Dolomedes triton on a small pond in central Alberta. The total number of spiders marked was 142 in 1986 and 210 in 1987, and annual adult emergence, using the population size estimates of the two mark–recapture methods, amounted to ca. 150 and 230 individuals in 1986 and 1987, respectively. The sex ratio was not different from 1:1 in 1986, but in 1987 more than twice as many males emerged than females. Males had significantly shorter observed residence times (life-spans) than females. Contrary to longevity estimates based on the survival probabilities given by the Jolly–Seber model, which were close to those based on enumeration, Manly–Parr survival estimates were strongly biased and even yielded impossible estimates of adult longevity. In both years the median date of male emergence preceded that of females by 5–10 days. Male population size decreased dramatically during the interval when the density of the female population increased, supporting the hypothesis that cannibalism by females is a major source of male mortality. Seventy and 55% of marked females produced egg sacs in 1986 and 1987, respectively. First egg sacs contained 472 ± 18.5 (SE) eggs. Four times as many nursery webs were found in 1986 as in 1987, suggesting that significant losses in female reproductive success occur during the period of egg sac care.

scholarly journals Information on population trends and biological constraints from bat counts in roost cavities: a 22-year case study of a pipistrelle bats (Pipistrellus pipistrellus Schreber) hibernaculum

2015 ◽  
Vol 42 (1) ◽  
pp. 35 ◽  
Author(s):  
Christian Kerbiriou ◽  
Jean François Julien ◽  
Sophie Monsarrat ◽  
Philippe Lustrat ◽  
Alexandre Haquart ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Population Size ◽  
Spatial Scales ◽  
Population Decline ◽  
Current Trend ◽  
Biodiversity Loss ◽  
Population Trends ◽  
Railway Tunnel ◽  
Biodiversity Indicators ◽  
Pipistrellus Pipistrellus

Context According to the current trend of biodiversity loss, information on population trends at large temporal and spatial scales is necessary. However, well documented animal population dynamics are generally based on intensive protocols requiring animal manipulation, which can be impossible to conduct in species for which conservation is a concern. Aims For many bat species, an alternative approach entails performing an appropriate analysis of counts in roost cavities. Because of managers’ perception of chaotic variations through time, relatively few count monitoring surveys are regularly analysed. Here, we present the analysis of a twenty-two-year survey of a large hibernaculum of pipistrelle bats (Pipistrellus pipistrellus) located in a railway tunnel in Paris, France. Methods We propose that using combinations of population-dynamics modelling using demographic parameters from the literature and statistical analyses helps with identifying the biological and methodological effects underlying the dynamics observed in census analyses. Key results We determined that some of the observed year-to-year variations of population size cannot be explained only by the intrinsic dynamics of the population. In particular, in 1993–94, the population size increased by >40%, which should have implied a massive immigration. This change coincided with the end of the operation of the railway line. After consideration of a drastic trend of population decline (7% year–1), we were able to detect this event and several environmental effects. Specifically, the winter conditions and the temperature in July affected the colony size, presumably because of aggregative behaviour and reproduction success, respectively. Conclusions Emigration–immigration processes might have preponderant effects on population dynamics. In addition, our analysis demonstrated that (1) the study population suffered a large decline, (2) a combination of human disturbance and meteorological variation explains these dynamics and (3) emigration–immigration processes have preponderant effects on the population dynamics. Implications To conduct a meaningful analysis of non-standard time series and provide a source of data for implementing biodiversity indicators, it is necessary to include (1) the local knowledge of the people involved in the field surveys in these analyses (the existence of disturbances and site protections) and (2) meteorological information for the appropriate seasons of the year.

scholarly journals Shifting trends: Detecting changes in cetacean population dynamics in shifting habitat

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251522
Author(s):  
Charlotte Boyd ◽  
André E. Punt
Keyword(s):  
Population Dynamics ◽  
Population Size ◽  
Wildlife Conservation ◽  
Population Change ◽  
Stock Assessment ◽  
Distance Sampling ◽  
Distribution Patterns ◽  
Population Trend ◽  
Mobile Species ◽  
Population Size Estimates

The ability to monitor population dynamics and detect major changes in population trend is essential for wildlife conservation and management. However, this is often challenging for cetaceans as surveys typically cover only a portion of a population’s range and conventional stock assessment methods cannot then distinguish whether apparent changes in abundance reflect real changes in population size or shifts in distribution. We developed and tested methods for estimating population size and trend and detecting changes in population trend in the context of shifting habitat by integrating additional data into distance-sampling analysis. Previous research has shown that incorporating habitat information can improve population size estimates for highly mobile species with dynamic spatial distributions. Here, using simulated datasets representative of a large whale population, we demonstrate that incorporating individual mark-recapture data can increase the accuracy and precision of trend estimation and the power to distinguish whether apparent changes in abundance reflect changes in population trend or distribution shifts. We recommend that similar simulation studies are conducted for specific cetacean populations to assess the potential for detecting changes in population dynamics given available data. This approach is especially important wherever population change may be confounded with long-term change in distribution patterns associated with regime shifts or climate change.

Avian population trends in Scalesia forest on Floreana Island (2004-2013): Acoustical surveys cannot detect hybrids of Darwin’s tree finches Camarhynchus spp.

2017 ◽  
Vol 28 (2) ◽  
pp. 319-335 ◽  
Author(s):  
KATHARINA J. PETERS ◽  
SONIA KLEINDORFER
Keyword(s):  
Population Size ◽  
Bird Species ◽  
Population Trends ◽  
Dendroica Petechia ◽  
Galapagos Archipelago ◽  
Population Size Estimates ◽  
Acoustic Surveys ◽  
Land Bird ◽  
Size Estimates ◽  
Hybrid Group

SummaryFloreana Island has the highest proportion of local land bird extinctions on the Galápagos Archipelago, and is home to the range-restricted and critically endangered Medium Tree Finch Camarhynchus pauper. We used acoustic surveys during 2004, 2008 and 2013 to compare the estimated population size of C. pauper and other land bird species in a remnant patch of Scalesia forest. First, we compared song in C. pauper and C. parvulus and the recently discovered Camarhynchus hybrid group to justify our use of acoustic surveys to detect population trends given contemporary hybridisation between C. pauper and C. parvulus. Song differed significantly between C. pauper versus C. parvulus and hybrid birds, but not between C. parvulus versus hybrid birds. Second, we compared population size estimates. Camarhynchus pauper declined by 52% between 2004 and 2013 (with a 10% increase since 2008); C. parvulus/hybrid increased by 45% between 2004 and 2013 (with 28% decrease since 2008). In 2013, there were ∼ 419 C. pauper males in the Scalesia forest (estimate for Scalesia habitat only) and ∼ 2,537 males on Floreana Island (estimate for the entire available highland habitat). Not all species showed a pattern of decline in the highland Scalesia habitat between 2004 and 2013: Dendroica petechia (+256%), Crotophaga ani (+254%) Geospiza fuliginosa (+23%), and Myiarchus magnirostris (+11%) increased, while the ground finch G. fortis (-76%) decreased. Understanding why C. pauper is declining while other land bird species are increasing in the same habitat requires continued inquiry and monitoring efforts.

scholarly journals Global association of obesity and COVID-19 death rates

2021 ◽  
Author(s):  
Mary L. Adams
Keyword(s):  
Least Squares ◽  
Population Size ◽  
World Population ◽  
Death Rates ◽  
Death Toll ◽  
Key Factor ◽  
The Difference ◽  
Best Fit ◽  
Global Population ◽  
Death Data

AbstractImportanceCOVID-19 was responsible for an enormous global death toll with large variation among countries.ObjectiveTo examine the possible impact of obesity on COVID-19 death rates.DesignMeasure associations between obesity rates in 2016 and COVID-19 deaths/million population through 2/25/2021, across countries.SettingGlobalParticipants167 countries for which obesity and death data were available, grouped by population size, with multiples of 10 countries in each of 8 groups plus a group including all 57 countries with obesity rates <15%.Outcome and measuresUsing Excel, COVID-19 deaths/million were regressed on the obesity rate for each country, based on obesity being a key factor in COVID hospitalizations and deaths. Using the least squares formula for the best fit for each model, R2, components of the formula, and the percentage of world population represented, were recorded for each group.ResultsObesity rates ranged from 2.1% to 37.9% and death rates ranged from 0.4/million to 1,892/million for groups representing up to 91% of global population. Results for the 8 population groups had R2 from 0.30 to 0.90 with slopes of the fitted line ranging from 27.9-51.0. Countries with obesity rates <15% had consistently low death rates (≤233/million), R2 of 0.003 and slope of the line=1.01.ConclusionsFor most countries about one-third of the difference in COVID death rates was due to obesity while in countries with obesity <15%, consistently low death rates were not associated with obesity. Reduced obesity rates could potentially have lowered the COVID death toll.

scholarly journals Can effective population size estimates be used to monitor population trends of woodland bats? A case study of Myotis bechsteinii

2021 ◽  
Vol 11 (5) ◽  
pp. 2015-2023
Author(s):  
Patrick G. R. Wright ◽  
Henry Schofield ◽  
Fiona Mathews
Keyword(s):  
Population Size ◽  
Effective Population Size ◽  
Population Trends ◽  
Effective Population ◽  
Population Size Estimates ◽  
Myotis Bechsteinii ◽  
Size Estimates

Peritoneal Fluid and Plasma Fibrinolytic Activity in Women with Pelvic Inflammatory Disease

1992 ◽  
Vol 68 (02) ◽  
pp. 102-105 ◽  
Author(s):  
P J Dörr ◽  
E J P Brommer ◽  
G Dooijewaard ◽  
H M Vemer
Keyword(s):  
Pelvic Inflammatory Disease ◽  
Inflammatory Disease ◽  
Peritoneal Fluid ◽  
Fibrinolytic Activity ◽  
Degradation Products ◽  
Adhesion Formation ◽  
High Rate ◽  
Control Group ◽  
The Difference ◽  
Fibrinolytic Parameters

SummaryPrevious studies have shown that the fibrinolytic activity of peritoneum is depressed in local inflammation. We measured fibrinolytic parameters in peritoneal fluid and in plasma of 10 women with pelvic inflammatory disease (PID). Nine women, in whom laparoscopy for sterilisation was performed, served as a control group.In the peritoneal fluid of women with PID, PAI-Ag, t-PA-Ag and u-PA-Ag were many times higher than in the control group. In contrast to the antigens which may be present in inert complexes, the potentially active compounds, measured as t-PA activity and plasmin-activable scu-PA, were not significantly different in the two groups, and in none of the samples was the active enzyme tcu-PA detectable. Nevertheless, the mean peritoneal fluid TDP and FbDP concentrations were about twenty times higher in the PID group than in the control group. In plasma of PID patients, none of the parameters except u-PA-Ag differed from those in the control group. The difference between control and patient plasma u-PA-Ag was statistically significant, but too small to attach any relevance to the observation.Our data suggest that, in contrast to the classical concept of decreased fibrinolytic activity as a cause of adhesion formation, intraperitoneal fibrinolysis is enhanced in peritoneal inflammation through stimulation of the local production of t-PA and u-PA. Despite concomitant production of PAI, fibrinolysis occurs at a high rate, resulting in high levels of fibrin degradation products. Since this activated fibrinolysis does not meet the demand, therapeutic enhancement should be considered to prevent adhesions.

Persistence of giants: population dynamics of the limpet Scutellastra laticostata on rocky shores in Western Australia

2020 ◽  
Vol 646 ◽  
pp. 79-92
Author(s):  
RE Scheibling ◽  
R Black
Keyword(s):  
Population Dynamics ◽  
Western Australia ◽  
Size Structure ◽  
Survival Rates ◽  
Maximum Size ◽  
High Rate ◽  
Adult Survival ◽  
Rocky Shores ◽  
Adult Size ◽  
Decadal Time Scale

Population dynamics and life history traits of the ‘giant’ limpet Scutellastra laticostata on intertidal limestone platforms at Rottnest Island, Western Australia, were recorded by interannual (January/February) monitoring of limpet density and size structure, and relocation of marked individuals, at 3 locations over periods of 13-16 yr between 1993 and 2020. Limpet densities ranged from 4 to 9 ind. m-2 on wave-swept seaward margins of platforms at 2 locations and on a rocky notch at the landward margin of the platform at a third. Juvenile recruits (25-55 mm shell length) were present each year, usually at low densities (<1 m-2), but localized pulses of recruitment occurred in some years. Annual survival rates of marked limpets varied among sites and cohorts, ranging from 0.42 yr-1 at the notch to 0.79 and 0.87 yr-1 on the platforms. A mass mortality of limpets on the platforms occurred in 2003, likely mediated by thermal stress during daytime low tides, coincident with high air temperatures and calm seas. Juveniles grew rapidly to adult size within 2 yr. Asymptotic size (L∞, von Bertalanffy growth model) ranged from 89 to 97 mm, and maximum size from 100 to 113 mm, on platforms. Growth rate and maximum size were lower on the notch. Our empirical observations and simulation models suggest that these populations are relatively stable on a decadal time scale. The frequency and magnitude of recruitment pulses and high rate of adult survival provide considerable inertia, enabling persistence of these populations in the face of sporadic climatic extremes.

Population trends and migration patterns in the critically endangered Yellow-breasted Bunting (Emberiza aureola) in the Republic of Korea

2020 ◽  
Vol 27 (1) ◽  
pp. 56-63
Author(s):  
Jong-Gil Park ◽  
Chang-uk Park ◽  
Kyoung-Soon Jin ◽  
Yang-Mo Kim ◽  
Hee-Young Kim ◽  
...  
Keyword(s):  
Population Trends ◽  
Critically Endangered ◽  
Republic Of Korea ◽  
Migration Patterns ◽  
The Republic ◽  
And Migration
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