scholarly journals A comparison of sex, morphology, physiology and behavior of black-capped chickadees trapped using two common capture methods

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10037
Author(s):  
Sara M. Burns ◽  
Frances Bonier
Keyword(s):  
Individual Variation ◽  
Behavioral Response ◽  
Population Level ◽  
Sampling Bias ◽  
Sample Mean ◽  
Novel Object ◽  
Biological Studies ◽  
Audio Stimulus ◽  
Capture Techniques ◽  
Selection Of

Many biological studies require the capture of individuals for sampling, for example for measurement of morphological or physiological traits, or for marking individuals for later observations. Capture methods employed often vary both within and between studies, and these differing methods could be more or less effective in capture of different individuals based on their morphology or behavior. If individuals that are prone to capture by the selected method differ with respect to traits of interest, such sampling bias could generate misleading or simply inaccurate results. The selection of capture methods could introduce two different forms of sampling bias, with the individuals that are sampled differing from the population at large or with individuals sampled via one method differing from individuals that could be sampled using a different method. We investigated this latter form of sampling bias by comparing individual birds sampled using two common capture techniques. We caught free-ranging black-capped chickadees (Poecile atricapillus) using walk-in traps baited with seed and mist nets paired with playback of an audio stimulus (conspecific mobbing calls). We measured 18 traits that we expect might vary among birds that are trappable by these differing methods—one that targets birds that are food motivated and potentially less neophobic and another that targets birds that respond readily to a perceived predation risk. We found no differences in the sex, morphology, initial and stress-induced corticosterone concentrations, behavioral response to a novel object, or behavioral response to a predator between individuals captured by these two methods. Individual variation in the behavioral response to a novel object was greater among birds caught by mist nets, suggesting this method might provide a sample that better reflects population-level individual variation. We do not know if the birds caught by these two methods provide a representative sample of the population at large, but can conclude that selection of either of these two common capture methods can similarly sample mean trait values of a population of interest. To accurately assess individual variation, particularly in behavior, mist nets might be preferable.

Condition-dependent foraging strategies in a coastal seabird: evidence for the rich get richer hypothesis

2018 ◽  
Vol 30 (2) ◽  
pp. 356-363 ◽  
Author(s):  
Brock Geary ◽  
Scott T Walter ◽  
Paul L Leberg ◽  
Jordan Karubian
Keyword(s):  
Individual Variation ◽  
Multiple Scales ◽  
Foraging Ecology ◽  
Population Level ◽  
Foraging Strategies ◽  
Significant Relationships ◽  
Fitness Consequences ◽  
Brown Pelicans ◽  
The Rich ◽  
Foraging Movements

Abstract The degree to which foraging individuals are able to appropriately modify their behaviors in response to dynamic environmental conditions and associated resource availability can have important fitness consequences. Despite an increasingly refined understanding of differences in foraging behavior between individuals, we still lack detailed characterizations of within-individual variation over space and time, and what factors may drive this variability. From 2014 to 2017, we used GPS transmitters and accelerometers to document foraging movements by breeding adult Brown Pelicans (Pelecanus occidentalis) in the northern Gulf of Mexico, where the prey landscape is patchy and dynamic at various scales. Assessments of traditional foraging metrics such as trip distance, linearity, or duration did not yield significant relationships between individuals. However, we did observe lower site fidelity and less variation in energy expenditure in birds of higher body condition, despite a population-level trend of increased fidelity as the breeding season progressed. These findings suggest that high-quality individuals are both more variable and more efficient in their foraging behaviors during a period of high energetic demand, consistent with a “rich get richer” scenario in which individuals in better condition are able to invest in more costly behaviors that provide higher returns. This work highlights the importance of considering behavioral variation at multiple scales, with particular reference to within-individual variation, to improve our understanding of foraging ecology in wild populations.

scholarly journals Intrinsic and extrinsic drivers of intraspecific variation in seed dispersal are diverse and pervasive

AoB Plants ◽  
2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Eugene W Schupp ◽  
Rafal Zwolak ◽  
Landon R Jones ◽  
Rebecca S Snell ◽  
Noelle G Beckman ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Intraspecific Variation ◽  
Individual Variation ◽  
Habitat Structure ◽  
Ecological Context ◽  
Seed Colour ◽  
Crop Size ◽  
Starting Point ◽  
Evolutionary Consequences ◽  
Selection Of

Abstract There is growing realization that intraspecific variation in seed dispersal can have important ecological and evolutionary consequences. However, we do not have a good understanding of the drivers or causes of intraspecific variation in dispersal, how strong an effect these drivers have, and how widespread they are across dispersal modes. As a first step to developing a better understanding, we present a broad, but not exhaustive, review of what is known about the drivers of intraspecific variation in seed dispersal, and what remains uncertain. We start by decomposing ‘drivers of intraspecific variation in seed dispersal’ into intrinsic drivers (i.e. variation in traits of individual plants) and extrinsic drivers (i.e. variation in ecological context). For intrinsic traits, we further decompose intraspecific variation into variation among individuals and variation of trait values within individuals. We then review our understanding of the major intrinsic and extrinsic drivers of intraspecific variation in seed dispersal, with an emphasis on variation among individuals. Crop size is the best-supported and best-understood intrinsic driver of variation across dispersal modes; overall, more seeds are dispersed as more seeds are produced, even in cases where per seed dispersal rates decline. Fruit/seed size is the second most widely studied intrinsic driver, and is also relevant to a broad range of seed dispersal modes. Remaining intrinsic drivers are poorly understood, and range from effects that are probably widespread, such as plant height, to drivers that are most likely sporadic, such as fruit or seed colour polymorphism. Primary extrinsic drivers of variation in seed dispersal include local environmental conditions and habitat structure. Finally, we present a selection of outstanding questions as a starting point to advance our understanding of individual variation in seed dispersal.

scholarly journals Resource‐related variables drive individual variation in flowering phenology and mediate population‐level flowering responses to climate in an asynchronously reproducing palm

Biotropica ◽  
2020 ◽  
Vol 52 (5) ◽  
pp. 845-856
Author(s):  
Tadeo Ramirez‐Parada ◽  
Domingo Cabrera ◽  
Zoe Diaz‐Martin ◽  
Luke Browne ◽  
Jordan Karubian
Keyword(s):  
Individual Variation ◽  
Population Level ◽  
Flowering Phenology

scholarly journals Dataset of Targeted Metabolite Analysis for Five Taxanes of Hellenic Taxus baccata L. Populations

Data ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 22
Author(s):  
Eleftheria Dalmaris ◽  
Evangelia V. Avramidou ◽  
Aliki Xanthopoulou ◽  
Filippos A. Aravanopoulos
Keyword(s):  
Natural Populations ◽  
Population Level ◽  
Primary Sources ◽  
Taxus Baccata ◽  
Metabolite Analysis ◽  
Data Set ◽  
Baccatin Iii ◽  
Significant Seasonal Variation ◽  
Increasing Demand ◽  
Selection Of

Novel primary sources of one of the world’s leading anticancer agent, paclitaxel, as well as of other antineoplastic taxanes such as 10-deacetylbaccatin-III, are needed to meet an increasing demand. Among the Taxus species the promise of Taxus baccata L. (European or English yew) has been documented. In this study, the metabolite analysis of two marginal T. baccata populations in Greece (Mt. Cholomon and Mt. Olympus), located at the southeastern edge of the species natural distribution, are being explored. A targeted liquid chromatography – mass spectrometry (LC-MS/MS) analysis was used to determine the content of 10-deacetylbaccatin III, baccatin III, 10-deacetyltaxol, paclitaxel and cephalomannine in the needles of each of the populations from three sampling periods (spring, summer and winter). This is the first survey to generate a taxane targeted metabolite data set, since it derives from Hellenic natural populations that have not been explored before. Furthermore, it has used an extensive sample design in order to evaluate chemodiversity at the population level. The analysis revealed significant levels of chemodiversity within and among the investigated populations and significant seasonal variation that could be exploited for the selection of superior germplasm native to Greece, for yew plantations and further exploitation which is necessary for the production of important taxanes.

scholarly journals Estimating the movements of terrestrial animal populations using broad-scale occurrence data

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Sarah R. Supp ◽  
Gil Bohrer ◽  
John Fieberg ◽  
Frank A. La Sorte
Keyword(s):  
Population Level ◽  
Sampling Bias ◽  
Population Movements ◽  
Spatial And Temporal Scales ◽  
Temporal Sampling ◽  
Multiple Observations ◽  
Occurrence Data ◽  
Population Distributions ◽  
Animal Populations ◽  
Broad Scale

AbstractAs human and automated sensor networks collect increasingly massive volumes of animal observations, new opportunities have arisen to use these data to infer or track species movements. Sources of broad scale occurrence datasets include crowdsourced databases, such as eBird and iNaturalist, weather surveillance radars, and passive automated sensors including acoustic monitoring units and camera trap networks. Such data resources represent static observations, typically at the species level, at a given location. Nonetheless, by combining multiple observations across many locations and times it is possible to infer spatially continuous population-level movements. Population-level movement characterizes the aggregated movement of individuals comprising a population, such as range contractions, expansions, climate tracking, or migration, that can result from physical, behavioral, or demographic processes. A desire to model population movements from such forms of occurrence data has led to an evolving field that has created new analytical and statistical approaches that can account for spatial and temporal sampling bias in the observations. The insights generated from the growth of population-level movement research can complement the insights from focal tracking studies, and elucidate mechanisms driving changes in population distributions at potentially larger spatial and temporal scales. This review will summarize current broad-scale occurrence datasets, discuss the latest approaches for utilizing them in population-level movement analyses, and highlight studies where such analyses have provided ecological insights. We outline the conceptual approaches and common methodological steps to infer movements from spatially distributed occurrence data that currently exist for terrestrial animals, though similar approaches may be applicable to plants, freshwater, or marine organisms.

scholarly journals Etiology of bloodstream infections at a population level during 2013-2017 in the Autonomous Community of Valencia, Spain

2020 ◽  
Vol 33 (3) ◽  
pp. 200-206
Author(s):  
Laura Ruiz-Azcona ◽  
Miguel Santibañez ◽  
Adelina Gimeno ◽  
Francisco Javier Roig ◽  
Hermelinda Vanaclocha ◽  
...  
Keyword(s):  
Antibiotic Therapy ◽  
Bloodstream Infections ◽  
Population Level ◽  
Empirical Treatment ◽  
Autonomous Community ◽  
Coagulase Negative Staphylococci ◽  
Mortality And Morbidity ◽  
Enterococcus Spp ◽  
Key Factor ◽  
Selection Of

Introduction. Bloodstream Infections has become in one of the priorities for the antimicrobial stewardship teams due to their high mortality and morbidity rates. Usually, the first antibiotic treatment for this pathology must be empirical, without microbiology data about the microorganism involved. For this reason, the population studies about the etiology of bacteremia are a key factor to improve the selection of the empirical treatment, because they describe the main microorganisms associated to this pathology in each area, and this data could facilitate the selection of correct antibiotic therapy. Material and methods. This study describes the etiology of bloodstream infections in the Southeast of Spain. The etiology of bacteremia was analysed by a retrospective review of all age-ranged patients from every public hospital in the Autonomous Community of Valencia (approximately 5,000,000 inhabitants) for five years. Results. A total of 92,097 isolates were obtained, 44.5% of them were coagulase-negative staphylococci. Enterobacteriales was the most prevalent group and an increase in frequency was observed along the time. Streptococcus spp. were the second microorganisms more frequently isolated. Next, the most prevalent were Staphylococcus aureus and Enterococcus spp., both with a stable incidence along the study. Finally, Pseudomonas aeruginosa was the fifth microorganism more frequently solated. Conclusions. These data constitute a useful tool that can help in the choice of empirical treatment for bloodstream infections, since the knowledge of local epidemiology is key to prescribe a fast and appropriate antibiotic therapy, aspect capital to improve survival.

Summation of disinfection by-product CHO cell relative toxicity indices: sampling bias, uncertainty, and a path forward

2020 ◽  
Vol 22 (3) ◽  
pp. 708-718 ◽  
Author(s):  
Elizabeth McKenna ◽  
Kyle A. Thompson ◽  
Lizbeth Taylor-Edmonds ◽  
Daniel L. McCurry ◽  
David Hanigan
Keyword(s):  
Water Samples ◽  
Treatment Process ◽  
Sampling Bias ◽  
Relative Toxicity ◽  
Cho Cell ◽  
Toxicological Profile ◽  
Samples Selection ◽  
Toxicity Indices ◽  
Selection Of

Predicted toxicity has been used to determine if a treatment process is either beneficial or detrimental to the overall DBP toxicological profile of water samples. Selection of the DBPs to measure is important and may result in biased conclusions.

scholarly journals Walking behaviour in the ground beetle, Poecilus cupreus: dispersal potential, intermittency and individual variation

2020 ◽  
pp. 1-10
Author(s):  
Joseph D. Bailey ◽  
Carly M. Benefer ◽  
Rod P. Blackshaw ◽  
Edward A. Codling
Keyword(s):  
Individual Variation ◽  
Community Dynamics ◽  
Ground Beetle ◽  
Management Strategies ◽  
Population Level ◽  
Poecilus Cupreus ◽  
Individual Level ◽  
Dispersal Potential ◽  
Simple Movement ◽  
Dispersal Distances

Abstract Dispersal is a key ecological process affecting community dynamics and the maintenance of populations. There is increasing awareness of the need to understand individual dispersal potential to better inform population-level dispersal, allowing more accurate models of the spread of invasive and beneficial insects, aiding crop and pest management strategies. Here, fine-scale movements of Poecilus cupreus, an important agricultural carabid predator, were recorded using a locomotion compensator and key movement characteristics were quantified. Net displacement increased more rapidly than predicted by a simple correlated random walk model with near ballistic behaviour observed. Individuals displayed a latent ability to head on a constant bearing for protracted time periods, despite no clear evidence of a population level global orientation bias. Intermittent bouts of movement and non-movement were observed, with both the frequency and duration of bouts of movement varying at the inter- and intra-individual level. Variation in movement behaviour was observed at both the inter- and intra- individual level. Analysis suggests that individuals have the potential to rapidly disperse over a wider area than predicted by simple movement models parametrised at the population level. This highlights the importance of considering the role of individual variation when analysing movement and attempting to predict dispersal distances.

Abstract 15: Temporal Trends of Drug Eluting Stent Use After Myocardial Infarction: Does More Selective Utilization Impact Health Status Outcomes?

2011 ◽  
Vol 4 (suppl_1) ◽  
Author(s):  
Joshua M Stolker ◽  
Harshal Patil ◽  
Adnan K Chhatriwalla ◽  
Lakshmi Venkitachalam ◽  
Kevin F Kennedy ◽  
...  
Keyword(s):  
Health Status ◽  
Temporal Trends ◽  
Population Level ◽  
Drug Eluting Stent ◽  
Complete Health ◽  
Angina Frequency ◽  
Acute Mi ◽  
Drug Eluting ◽  
The Mean ◽  
Selection Of

BACKGROUND Despite widespread acceptance of drug eluting stents (DES), concerns about cost and safety contributed to lower DES use by late 2006, particularly in off-label scenarios such as acute MI. The population-level impact of this trend on health status is unknown. METHODS We evaluated Seattle Angina Questionnaire (SAQ) scores among patients (pts) undergoing in-hospital PCI in TRIUMPH, a 24-center registry of acute MI. For each 3-month period of enrollment, we calculated the frequency of DES use and the mean 6-month Angina Frequency (SAQ-AF) score for pts treated that quarter. We then constructed a linear regression model to evaluate whether DES use, or time periods of high vs. low DES use, were independently associated with 6-month SAQ-AF scores. RESULTS Among 1744 MI pts undergoing PCI with complete health status assessments, 1033 were treated with DES (59%). DES use decreased significantly in late 2006, but overall 6-month angina burden remained stable ( Figure ). After adjusting for multiple clinical factors, SAQ-AF scores exhibited a borderline association with DES use (ß-coefficient 1.86 ± 1.0, p=0.06). When dichotomizing pts into years with high (2005-06) and low (2007-08) DES use, there was no relationship between high vs. low DES use on SAQ-AF in the multivariable model (ß=0.01 ± 1.0, p=0.99). CONCLUSION More selective use of DES after 2006 has not impacted population-level angina control at 6 months among MI pts treated with PCI. This suggests that clinicians were able to reduce DES use through better selection of those pts most likely to benefit from DES therapy, but further research is needed to better understand the processes of care associated with these findings.

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