Survival of Greater Sage‐Grouse broods: survey method affects disturbance and age‐specific detection probability

2021 ◽  
Vol 92 (1) ◽  
pp. 88-102
Author(s):  
Ian P. Riley ◽  
Courtney J. Conway ◽  
Bryan S. Stevens ◽  
Shane Roberts
The Auk ◽  
2006 ◽  
Vol 123 (3) ◽  
pp. 735-752 ◽  
Author(s):  
Michelle L. Kissling ◽  
Edward O. Garton

Abstract Point counts are the method most commonly used to estimate abundance of birds, but they often fail to account properly for incomplete and variable detection probabilities. We developed a technique that combines distance and double-observer sampling to estimate detection probabilities and effective area surveyed. We applied this paired-observer, variable circular-plot (POVCP) technique to point-count surveys (n = 753) conducted in closed-canopy forests of southeast Alaska. Distance data were analyzed for each species to model a detection probability for each observer and calculate an estimate of density. We then multiplied each observer's density estimates by a correction factor to adjust for detection probabilities <1 at plot center. We compared analytical results from four survey methods: single-observer fixed-radius (50-m) plot; single-observer, variable circular-plot (SOVCP); double-observer fixed-radius (50-m) plot; and POVCP. We examined differences in detection probabilities at plot center, effective area surveyed, and densities for five bird species: Pacific-slope Flycatcher (Empidonax difficilis), Winter Wren (Troglodytes troglodytes), Golden-crowned Kinglet (Regulus satrapa), Hermit Thrush (Catharus guttatus), and Townsend's Warbler (Dendroica townsendi). Average detection probabilities for paired observers increased ≈8% (SE = 2.9) for all species once estimates were corrected for birds missed at plot center. Density estimators of fixed-radius survey methods were likely negatively biased, because the key assumption of perfect detection was not met. Density estimates generated using SOVCP and POVCP were similar, but standard errors were much lower for the POVCP survey method. We recommend using POVCP when study objectives require precise estimates of density. Failure to account for differences in detection probabilities and effective area surveyed results in biased population estimators and, therefore, faulty inferences about the population in question. Estimaciones de la Densidad y de las Probabilidades de Detección a Partir de Muestreos Utilizando Conteos en Puntos: Una Combinación de Muestreos de Distancia y de Doble Observador


Author(s):  
Anna Drake ◽  
Devin de Zwaan ◽  
Tomás Altamirano ◽  
Scott Wilson ◽  
Kristina Hick ◽  
...  

1. Accurate biodiversity and population monitoring is a requirement for effective conservation decision-making. Survey method bias is therefore a concern, particularly when research programs face logistical and cost limitations. 2. We employed point counts (PCs) and autonomous recording units (ARUs) to survey avian biodiversity across elevational gradients in comparable temperate mountain habitats at opposite ends of the Americas (9 mountains in British Columbia (BC), Canada and 10 in southern Chile). We compared detected species richness against multi-year species inventories and examined differences in detection probability by family. By incorporating time costs, we assessed the performance and efficiency of single vs. combined methods. 3. ARUs were predicted to capture ~92% of species present in BC but only ~58% in Chile, despite Chilean mountain communities being less diverse. Community, rather than landscape composition, appears to be the driver of this dramatic difference. Chilean communities contain less-vocal species, which ARUs missed. Further, 6/14 families in BC were better detected by ARUs while 11/11 families in Chile were better detected by PCs. Where survey conditions differentially impacted methods, PC detection varied over the morning and with canopy cover in BC and ARU detection probability mostly varied seasonally in Chile. Within a single year of monitoring, neither method alone was predicted to capture the full avian community, with the exception of ARUs in the alpine and subalpine of BC. PCs contributed little to detected diversity in BC, but including this method resulted in negligible increases in total time costs. Combining PCs with ARUs in Chile significantly increased species detections, again, for little cost. 4. Combined methods were among the most efficient and accurate approaches to capturing diversity. We recommend conducting observer point counts, where possible, when ARUs are deployed and retrieved, in order to capture additional diversity and flag methodology biases with minimal additional effort.


2015 ◽  
Vol 11 (9) ◽  
pp. 29 ◽  
Author(s):  
Junfeng Qiao ◽  
Sanyang Liu ◽  
Jianke Zhang ◽  
Yujun Niu

We consider the sensor deployment problem in the context of distance uncertainty. It is characterized by differentiated arrangement of specific detection probability thresholds at different locations. The problem is formulated as an integer linear programming (ILP) model firstly, aiming at optimizing the number of sensors and their locations. Based on the robust discrete optimization methodology, the uncertain model is transformed into an equivalent ILP problem considering distance uncertainty. The proposed approach can control the tradeoff between optimality and robustness by varying the parameters named protection levels. Uniform and non-uniform event detection probabiliy distributions are considered in the experiment. The results show that, as the distance uncertainty increases, the constraint violation can be avoided in the robust model and the robust solution can provide a significant improvement at the expense of a small loss in optimality when compared to the optimal solution of a deterministic scenario.


2017 ◽  
Vol 95 (11) ◽  
pp. 885-890
Author(s):  
Shannon M. Crowley ◽  
Dexter P. Hodder

Barbed and scented rub pads that rely on a cheek-rubbing behavioural response are a standard survey design that has been used extensively across the range of Canada lynx (Lynx canadensis Kerr, 1792). However, there have not been any published studies evaluating the effectiveness of rub stations for detecting lynx by comparing other simultaneous survey methods. We used a combination of paired rub stations and remote cameras at 41 sites to compare detection probabilities between the two methods and conduct a mark–recapture population estimate of Canada lynx using rub stations to further interpret our findings. The detection probability calculated using cameras approached 1.0 for most of the winter season (mean = 0.88), whereas it remained less than 0.52 for hair rub stations (mean = 0.27). The low and variable detection probability using hair snags, high detection probability using cameras, and the potential gender or individual bias in rubbing behaviour based on our mark–recapture analysis suggest that rub stations are not the most efficient survey method available for Canada lynx. Until additional research incorporating spatial scale, seasonal timing, gender bias, and survey design is conducted, we urge caution in the use of hair stations that rely on the cheek-rubbing behaviour of Canada lynx.


2013 ◽  
Vol 70 (7) ◽  
pp. 1055-1062 ◽  
Author(s):  
Trevor B. Haynes ◽  
Amanda E. Rosenberger ◽  
Mark S. Lindberg ◽  
Matthew Whitman ◽  
Joel A. Schmutz

Studies examining species occurrence often fail to account for false absences in field sampling. We investigate detection probabilities of five gear types for six fish species in a sample of lakes on the North Slope, Alaska. We used an occupancy modeling approach to provide estimates of detection probabilities for each method. Variation in gear- and species-specific detection probability was considerable. For example, detection probabilities for the fyke net ranged from 0.82 (SE = 0.05) for least cisco (Coregonus sardinella) to 0.04 (SE = 0.01) for slimy sculpin (Cottus cognatus). Detection probabilities were also affected by site-specific variables such as depth of the lake, year, day of sampling, and lake connection to a stream. With the exception of the dip net and shore minnow traps, each gear type provided the highest detection probability of at least one species. Results suggest that a multimethod approach may be most effective when attempting to sample the entire fish community of Arctic lakes. Detection probability estimates will be useful for designing optimal fish sampling and monitoring protocols in Arctic lakes.


Author(s):  
R. E. Heffelfinger ◽  
C. W. Melton ◽  
D. L. Kiefer ◽  
W. M. Henry ◽  
R. J. Thompson

A methodology has been developed and demonstrated which is capable of determining total amounts of asbestos fibers and fibrils in air ranging from as low as fractional nanograms per cubic meter (ng/m3) of air to several micrograms/m3. The method involves the collection of samples on an absolute filter and provides an unequivocal identification and quantification of the total asbestos contents including fibrils in the collected samples.The developed method depends on the trituration under controlled conditions to reduce the fibers to fibrils, separation of the asbestos fibrils from other collected air particulates (beneficiation), and the use of transmission microscopy for identification and quantification. Its validity has been tested by comparative analyses by neutron activation techniques. It can supply the data needed to set emissions criteria and to serve as a basis for assessing the potential hazard for asbestos pollution to the populace.


2005 ◽  
Vol 173 (4S) ◽  
pp. 18-18
Author(s):  
Joseph C. Liao ◽  
Mitra Mastali ◽  
David A. Haake ◽  
Bernard M. Churchill

2018 ◽  
Vol 16 (2) ◽  
pp. 90
Author(s):  
Rohmial Rohmial

The objective of this study are : 1) the application of service delivery system that can be applied by Bank Goveerment in Palembang, 2) the influence of physical support on customers, 3) the influence of contact personnel on loyalty of the customers of Bank Goverment in Palembang, 4) the influence of service delivery system on customer loyalty at Bank Goverment in Palembang. This study is done by survey method so as to describe the response from respondents. The samples are taken by using simple random sampling with 100 respondents. The instruments are observation, quesionares and interview, the data analysis is done by using descriptive and matrix analysis. The results of this research shows that all independent variables (physical support and contact personnel) significantly and positively influence the dependent variables (loyalty of the customers).


2018 ◽  
Vol 1 (2) ◽  
pp. 89-94
Author(s):  
Intan Sari

Low Birth Weight (LBW) is an infant born with a birth weight of less than 2500 grams regardless of gestation. Birth weight is the weight of the baby weighed in 1 hour after birth. (Depkes RI, 2009). Based on WHO and UNICEF data, in 2013 about 222 million babies were born in the world, of which 16% were born with low birth weight. The percentage of LBW in developing countries is 16.5% twice that of developed countries (7%) (Scholar Unand, 2014). The purpose of this study was to determine whether there is a relationship between anemia and Smoking Habit in Pregnant Women with LBW occurrence in General Hospital Dr. Mohammad Hoesin Palembang Year 2016. This research use analytical survey method with cross sectional approach. The population in this study were all mothers who gave birth monthly in Midwifery Installation of Dr. General Hospital Mohammad Hoesin Palembang in 2016 as many as 315 respondents. The sample of this research is some of mothers who give birth enough month in Midwifery Installation of Dr. General Hospital Mohammad Hoesin Palembang Year 2016 as many as 315 respondents. ". From the results of bivariate analysis of anemic respondents with the occurrence of LBW obtained statistical test X2 count = 23.22 which means there is a significant relationship between anemia with the incidence of BBLR. Respondents smoking with the occurrence of LBWR obtained statistical test X2 count = 41.20 which means there is a relationship Meaningful between smoking and LBW incidence. From the results of this study is expected that this research can be a reference material and is a complete information and useful for the development of knowledge about LBW.


2018 ◽  
Vol 1 (1) ◽  
pp. 43-50
Author(s):  
Juliana Widyastuti Wahyuningsih

Childbirthis a processLabor of opening and depleting the cervix and the fetus down into the birth canal. Birth is a process in which the fetus and amniotic are pushed out through the birth canal. (Sarwono, 2008). According to the World Health Organization (WHO) estimates more than 585,000 mothers annually die during pregnancy or childbirth. Indonesia Health Demographic Survey (SDKI) Survey in 2012, Maternal Mortality Rate in Indonesia is still high at 359 per 100,000 live births. The purpose of this study is the knowledge of maternal knowledge, maternal age, and maternal parity associated with normal birth events at Palembang Bari Hospital 2017. This study used analytical survey method with cross sectional approach. The population in this study were all maternal mothers at the Palembang Bari Hospital in 2017. Sampling in the study was conducted non-randomly with the technique of "Accidental Sampling". Data analysis was done univariat and bivariate with Chi-Square statistical test with significance level α = 0,05. The result of this research shows that there is correlation between mother's knowledge with normal delivery incidence with p value 0,001, there is correlation between mother age with normal delivery incidence with p value 0,009, there is relation between mother parity with normal delivery incidence with p value 0,001. From result of this research hopes healthcare workers can improve normal delivery care services and more often to carry out maternal safety counseling.


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