Effective Survey Method Research Articles

Scent lures and baits at camera traps improve time to first detection and detection probability of two typically elusive species of weasel

AbstractThere is a growing body of evidence that weasel species are in decline globally. More data on their ecology and distribution are needed to plan and justify any conservation management actions. Camera trapping can be an effective survey method for many species; however, the small size and quick movements of weasels present challenges in detection and little consensus exists on practices for attracting them to improve detection. This study tested different combinations of meat baits and scent and audio lures to assess the most effective methods. Camera traps were set up in clusters of three at 42 sites to test the effectiveness of these combinations, accounting for season, in terms of the time to first detection (TFD), detection probability using occupancy models, and the number and clarity of weasel photos. We also repeated TFD and detection probability analyses for setups that were ≥ 20 m apart in case of overlap of effects. The average TFD across all sites was 43 days. Fall typically had the shortest TFD with beaver bait in fall achieving the best results. After accounting for occupancy, predicted detection probability across a 60-day survey was highest in fall with the best combination being salmon lure and beaver bait. The treatment type did not impact the average number of photos captured, but the clarity of photos was significantly positively related to use of bait and lure, type of lure, and specific combinations of bait and lure.

Identifying fish and estimating abundance and swim velocities of migrating Pacific salmon using adaptive resolution imaging sonar in mobile surveys

Abstract Mobile acoustic sounding is an effective survey method for fish abundance residing or migrating in large riverine basins and marine areas. A long-standing challenge in acoustic fish surveys with conventional sonar is the uncertainty in identifying fish targets from acquired echo data. Identification errors of fish targets can significantly bias estimates of fish abundances and negatively impact the management of fisheries. In contrast to conventional sonar, adaptive resolution imaging sonar (ARIS), if deployed properly with appropriate settings, can yield high-quality images of fish targets. ARIS images acquired with adequate frame rates can form video recordings to allow for confident identification of fish targets from recorded morphological features, sizes, direction of movements, and speeds. In this paper, we present an approach of using ARIS sonar for mobile surveys of fish passage in a riverine environment. Applications of this approach are demonstrated for its practical values with results from an ARIS-based mobile survey of upstream migrating salmon at an acoustically challenging fish-counting site on the lower Fraser River in British Columbia, Canada.

Assessing the potential use of environmental DNA for multifaceted genetic monitoring of cetaceans: Example of a wandering whale in a highly disturbed bay area

Environmental DNA (eDNA) sampling of water is a powerful method for comprehensive and noninvasive monitoring of aquatic animal species. However, there have been few reports of its application to cetacean species. On June 29, 2021, a whale (nicknamed Xiaobu) appeared in Dapeng Bay off Guangdong Province, China. We used eDNA technology to obtain information related to this whale (e.g., species identification and food resources) and to trace its possible origin. Fragments of four whale mitochondrial sequences (12S rDNA, 16S rDNA, cytochrome c oxidase subunit 1, and control region) were obtained from amplicons of eDNA collected in Dapeng Bay; sequence barcoding showed that this was an Eden’s whale (Balaenoptera edeni edeni Anderson 1879). Analysis of potential prey species (PPS) suggested that this whale might enter Dapeng Bay while tracking prey, mainly sardines (Sardinella lemuru, Sardinella gibbosa and Sardinella jussieui) and anchovies (Thryssa dussumieri, Thryssa vitrirostris and Thryssa kammalensis). Retrieval of eDNA metabarcoding data from samples collected in waters adjacent to Dapeng Bay (i.e. Lingding Bay and Daya Bay) revealed that Eden’s whale had appeared outside Lingding Bay up to 2 months prior to the appearance of this whale in Dapeng Bay (early April 2021). Overall, this study showed that eDNA is a highly effective noninvasive survey method for the accurate identification of target cetacean species and prey composition; it can be used to monitor megafauna that are under strict legal protection or to monitor megafauna with unknown conditions.

An efficient environmental DNA detection method for rare species: a case study of a small salamander (Hynobius boulengeri).

Loss of biodiversity is a serious concern, and amphibians are particularly threatened. Most small salamanders in Japan are endangered. Distributional information is fundamental to the conservation of these rare species; however, small salamanders are generally difficult to locate or catch. Environmental DNA analysis is an effective survey method for monitoring such rare species. The conventional polymerase chain reaction (PCR) method, which combines PCR amplification with subsequent electrophoresis, and the real-time PCR method, which uses fluorescent material, are commonly used for this purpose. In this study, a comparison of these two detection methods was conducted using a rare salamander species, Hynobius boulengeri, as a model case. We compared three points: (i) detection sensitivity, (ii) influence of environmental factors related to detection, and (iii) time and financial costs of the two methods. To perform this comparison, we developed a real-time PCR detection assay, conducted field surveys, and compared the time and financial costs of conventional and real-time PCR methods. The comparison showed no statistical difference in the detection sensitivity from field samples, and the effects of environmental factors tended to be similar. In addition, the financial cost was lower for the conventional PCR method while the time cost was lower for the real-time PCR method. Therefore, selecting eDNA detection methods based on objectives, time, and financial costs will promote efficient monitoring and contribute to the conservation of rare species.

Analysis of the GPR signal for moisture detection: application to heritage buildings

ABSTRACT Moisture is one of the main causes of degradation of heritage buildings. Early detection of zones affected by moisture is crucial information for preservation and maintenance of those structures. Ground-penetrating radar (GPR) is an effective survey method to assess damage in civil engineering and structures. Several methodologies involving this technique have been applied to determine the extension of damping in concrete, stone, and brick structures. This article summarizes the different signal analysis techniques generally used to detect moisture from GPR data. Four different case studies are included, covering different types of buildings. The case studies include the description of the problem, the results, the methodology (data acquisition, survey parameters, and processing), and the limits and advantages. Comparing the different studies, the limitations and advantages are associated with each type of problem and a final discussion describes other non-destructive testing techniques, numerical simulations and methodologies that could provide more reliable understanding when combined with GPR data.

Using environmental DNA method to clarify the distribution of Pampus echinogaster in the East China Sea

Environmental DNA (eDNA) is becoming a potentially valuable survey technique to monitor marine organisms, especially when the research spans wide-ranging temporal or spatial dimensions. Pampus echinogaster plays an important role in China’s marine fisheries. However, the stock of P. echinogaster is gradually declining, so the fishery protection and management of P. echinogaster are becoming crucial. To achieve the non-invasive and large-scale monitoring of P. echinogaster, we developed a specific quantitative real-time PCR (qPCR) method based on eDNA technology. Results showed that positive signals of P. echinogaster eDNA were successfully detected at 36 sites (82% of the total) in the East China Sea. Significant differences in eDNA concentrations between the southern and northern stations in the East China Sea suggested differences between the life histories of P. echinogaster in these two sea areas. The hotspot was found around the central areas of the East China Sea, especially around the Taizhou seawater (Jiaojiang Estuary). Vertical distribution showed that the eDNA hotspots were primarily concentrated in the middle and upper layers (0–40 m). The distribution results of eDNA hotspots were similar to those of previous findings through motor–trawl capture, indicating the validity of the eDNA results. The relationship between environmental factors and the eDNA concentration showed that PO43-− was significantly correlated with the P. echinogaster eDNA concentration. Overall, our study indicated that the eDNA approach was an effective survey method and can be used as a monitoring tool. We advocate this monitoring approach as supplementary means to guide the management and conservation of large-scale sea areas and thus enable the initially surveying to provide the best information about species-specific distribution.

농촌 공간 환경영향요인 분석을 위한 무인항공기 적용 가능성에 관한 실험적 연구 - 홍성군 갈산면의 태양광 발전시설과 빈집을 중심으로 -

Rural spaces are increasingly valuable as areas for introducing renewable energy infrastructure to achieve carbon neutrality. Rural areas are the living grounds of rural residents, and the balance of conservation and development for rural areas is important for the introduction of reasonable facilities. In order to maintain a balance between development and preservation and to introduce reasonable renewable energy facilities, it is necessary to develop a current status survey and an effective survey method to utilize a space capable of introducing renewable energy facilities such as idle land and vacant houses. Therefore, this study was conducted to verify the readability using an unmanned aerial vehicle, and the main results are as follows. The detection of photovoltaic power generation facilities using unmanned aerial vehicles was effective in analyzing the location and area of photovoltaic panels located on the roofs of buildings, and it was possible to calculate the expected power generation by region through the area calculation of photovoltaic panels. The vacant house detection can be used to select an investigation target for an vacant house condition survey as it can identify damage to buildings that are expected to be empty houses, management status, and electricity supply facilities through aerial photos. It is judged that the unmanned aerial vehicle detection capability can be utilized as a method to improve the efficiency of investigation and supplement the data related to solar power generation facilities and vacant houses provided by public institutions. Although this study detected the status of solar power generation facilities and vacant houses through high-resolution aerial image analysis, as a follow-up study, automatic measurement methods using the temperature difference of solar power generation facilities and general characteristics of vacant houses that can be read from the air were investigated. If the deriving research is carried out, it is judged that it will be possible to contribute to the improvement of the accuracy of the detection result using the unmanned aerial vehicle and the expansion of the application range.

Differences in accuracy of height, weight, and body mass index between self-reported and measured using the 2018 Korea Community Health Survey data.

OBJECTIVESThis study aimed to determine an effective survey method for the accurate calculation of obesity prevalence by comparing the self-reported and measured height, weight, and body mass index (BMI) using the 2018 Korea Community Healthy Survey (CHS) data.METHODSRaw data from the 2018 CHS were used to analyze the differences, correlation, and agreement between self-reported and measured height, weight, and BMI.RESULTSThe self-reported height was over-reported than the measured height (0.59 cm greater for men and 0.71 cm greater for women), while the self-reported weight was under-reported than the measured weight (0.55 kg less for men and 0.67 kg less for women). Subsequently, the self-reported BMI was under-estimated (0.35 kg/m2 lower for men and 0.49 kg/m2 lower for women) compared with the measured BMI. The kappa statistic and agreement between measured and self-reported values per BMI category (underweight, normal, overweight, and obesity) were 0.82 and 79.6%, respectively.CONCLUSIONSThe prevalence of obesity should be calculated using the measured values provided in the CHS in order to promote local health projects based on accurate evidence.

Comparison of Two Methods for Detecting Atlantic Salt Marsh Mink

ABSTRACTThe Atlantic salt marsh mink (ASMM; Neovison vison lutensis) has a limited distribution in Florida and may be vulnerable to extirpation through habitat loss or degradation. To evaluate ASMM population status, survey methods are needed that are effective and practical in salt marsh habitat where mink are difficult to detect. In 2013–2014, we compared the effectiveness of 2 survey methods, spotlight surveys and floating camera traps, to estimate site occupancy and detectability of ASMM in northeast Florida. Using spotlight surveys, we sampled 148, 1‐km2 units over 3 months and detected ASMM in 9% of the sampled units. With floating camera traps, we sampled 42, 1‐km2 units over 10 months and detected ASMM in 36% of sampled units. Floating cameras traps were a more effective survey method for ASMM, resulting in higher estimated site occupancy (Ψ = 0.36) and detection probability (P = 0.46) when compared to spotlight surveys (Ψ = 0.15, P = 0.24). Spotlight surveys for ASMM were effective only at peak high tide when water levels rise to the height of the marsh grass and many individuals take cover on floating vegetation. We conducted all spotlight surveys during times of peak high tide, but tide height varied by location across the study area and likely affected detection rates. As a result, we detected ASMM only during spotlight surveys in the northern part of our study area, where mean tide height was 1.97 m compared with 1.46 m in the southern part of the study area. Therefore, we recommend floating camera traps for future surveys of ASMM to estimate site occupancy. © 2021 The Wildlife Society.

Masonry texture reconstruction for building seismic assessment: Practical evaluation and potentials of Ground Penetrating Radar methodology

Within the context of masonry texture identification and geometrical reconstruction, Ground Penetrating Radar (GPR) could emerge as an effective survey method, due to its high-resolution, scalable and non-destructive approach. This study has methodologically assessed operational advantages and weaknesses of the methodology when implemented for a seismic assessment purpose. In particular, the scope was to examine acquisition and post-processing strategies that could reliably highlight the presence or absence of specific construction features on which to develop a quantitative indication of the quality of the masonry. For this purpose, a high frequency 3D GPR acquisition on a plastered masonry wall incorporating different brick geometries, has been carried out. The acquisition was made along two different survey directions and analysing unfocussed and migrated radar slices. Thanks to a favourable antenna pattern alignment and achieved resolution enhancement, the focussed GPR data collected along the vertical mortar joints orientation have proven to be able to properly reconstruct the wall texture, providing therefore detailed and crucial information on its geometrical appearance.

A Logistic Regression Extension for the Randomized Response Simple and Crossed Models: Theoretical Results and Empirical Evidence

We propose some theoretical and empirical advances by supplying the methodology for analyzing the factors that influence two sensitive variables when data are collected by randomized response (RR) survey modes. First, we provide the framework for obtaining the maximum likelihood estimates of logistic regression coefficients under the RR simple and crossed models, then we carry out a simulation study to assess the performance of the estimation procedure. Finally, logistic regression analysis is illustrated by considering real data about cannabis use and legalization and about abortion and illegal immigration. The empirical results bring out certain considerations about the effect of the RR and direct questioning survey modes on the estimates. The inference about the sign and the significance of the regression coefficients can contribute to the debate on whether the RR approach is an effective survey method to reduce misreporting and improve the validity of analyses.

Surveying frogs from the bellies of their parasites: Invertebrate-derived DNA as a novel survey method for frogs

Biodiversity conservation is reliant on thorough species occurrence data. However, the collection of such data is often difficult for species with poor detectability. Recently, invertebrate-derived DNA (iDNA) has emerged as a potentially powerful survey method to increase the detectability of terrestrial vertebrates. Parasitic invertebrates are effective samplers of some vertebrate diversity and can be used to detect and identify their host species by sequencing the DNA contained in their meals. Among taxa that can be very difficult to detect using traditional survey methods are many frog species, which are often of a high conservation priority. However, the potential for frog-specific iDNA surveys has not been explored; most iDNA surveys have targeted mammals. We carried out traditional audio-visual and iDNA frog surveys in eastern Australia to determine whether frog-biting midges (Corethrella and Sycorax spp.) can be used as an effective survey method for frogs. The frog species detected through each method differed. Five species were detected only during traditional surveys, three by both methods, and one exclusively via iDNA. We demonstrate for the first time that iDNA can be used in targeted surveys of frog diversity and that it may increase the detectability of some species compared to traditional surveys. iDNA holds particular promise in the search for rare species, including those that are missing, feared extinct, and may also be useful in biosecurity, detecting invasive species.

An effective survey method for studying volant species activity and behavior at tall structures.

The effects of anthropogenic modification of air space on wildlife, particularly volant species, is not fully understood. Thus, it is essential to understand wildlife-interactions with tall structures to implement effective mitigation strategies. Yet, we are currently lacking standard protocols for visual surveys of wildlife behavior at such heights. Our study sought to determine an effective, repeatable method using readily available night vision and thermal technology to survey wildlife at tall structures. Using bats as the taxonomic group of interest, we (1) created a key to identify bats and their behavior, (2) compared the effectiveness of 2 different technologies, and (3) assessed optimal equipment placement to visually capture bat activity and behavior in proximity to wind turbine towers. For the latter, we tested thermal cameras at four distances from the base of the tower. The results of our study revealed that thermal cameras captured ∼34% more flying animals than night vision at a 2 m distance. However, due to the heat signature of the turbine towers themselves, it was challenging to identify behaviors and interactions that occurred in close proximity to the towers. In contrast, it was difficult to identify bats approaching the towers using night vision, yet we were able to clearly observe interactions with the towers themselves. With regards to equipment placement, we visually captured more bats with the thermal cameras placed 2 m from the tower base compared to farther distances. From our findings, we recommend that when using either thermal or night vision technology at tall structures, they be placed 2 m from the base to effectively observe interactions along the length of these structures. In addition, we further recommend that consideration be given to the use of these two technology types together to effectively conduct such surveys. If these survey techniques are incorporated into standard protocols, future surveys at a variety of tall structures are likely to become comparable and repeatable, thereby more effectively informing any mitigation strategies that may be required.

Low input parks strategy can work: Dynamic profile of Mishmi Takins under constrained conservation management in Mt. Gaoligong, China

Getting enough financial support for conservation in China has been a problem, to the point that about 1/3 of its nature reserves are poorly funded and lack effective management. Thus, preserving wildlife habitats under these circumstances represents a challenging mission. As a measure to promote conservation, in recent years the Chinese government issued very strict laws and regulations together with extensive public education and propaganda directives. To evaluate the effectiveness of such particular approach, an assessment of Mishmi Takin (Budorcas taxicolor) in Mt. Gaoligong National Nature Reserve was carried out. Using data collected by interviewing local residents, literature review and field survey, we analyzed the dynamic profiles of population size and distribution alteration of this endangered species in China. The temporal comparison of the profiles was organized in 3 periods: pre-1980s (before the setting up of the reserve), 1980–2000 and after the 2000s. The results indicate that, after the creation of the park, takin individuals were sighted more frequently within the reserve areas and the distribution range increased. Main anthropogenic disturbances came from hunting, which was banned in 1980, as well as from the depletion and collection of natural resources. These findings demonstrate a representative case of successful conservation policy in the particular social and political context of China, implemented with authoritative legislation coupled with education and awareness plans, under very constrained financial and manpower resources support. Moreover, this study highlights an economic and convenient, yet effective survey method ideal for research in remote regions characterized by access difficulties due to high mountains, deep valleys, and harsh environment such as the Qinghai-Tibet Plateau and the Hengduan Mountains.

Comparative use of active searches and artificial refuges to detect amphibians in terrestrial environments

AbstractArtificial refuges (cover boards) are commonly used to survey and monitor herpetofauna in many parts of the world. Despite the extensive use of artificial refuges in mesic environments, their effectiveness for detecting amphibians in temperate zones has rarely been examined. We compared amphibian detection probabilities between two survey methods; active searches of natural habitat and artificial refuges of three different types (corrugated steel, roofing tiles and timber railway sleepers). Our study area included five bioregions encompassing a 1180‐km latitudinal gradient across a modified, temperate eucalypt woodland vegetation community in south‐eastern Australia. We deployed 14 778 artificial refuges in terrestrial environments, within patches of remnant vegetation, and collected presence and abundance data on herpetofauna between 1999 and 2017. We used Bayesian logistic regression to identify the most effective survey method for detecting frog species across all bioregions. We modelled frog detections by fitting survey method, time since refuge deployment and rainfall prior to each survey. We detected 3970 individuals from 18 frog species. Overall, we found active searches and timber substrates most effective for detecting a broad range of species, although detection rates were driven by the numerically abundant spotted marsh frog Limnodynastes tasmaniensis. Timber refuges were effective for detecting several burrowing species, whereas active searches were effective at detecting habitat generalists. Quadratic effects of rainfall prior to survey as opposed to linear effects of time since artificial refuge placement was important in explaining frog detection rates in some bioregions. Active searches, timber railway sleepers and sheets of corrugated steel provide complimentary survey methods for detecting amphibians, although detection rates are influenced by rainfall patterns. Artificial refuges provide a time‐effective and standardized method for studying amphibians in their non‐breeding terrestrial environment and should be incorporated into future surveys and biodiversity monitoring programmes.

Application of wavelet shrinkage to acoustic imaging of buried asari clams using high-frequency ultrasound

Acoustic imaging using high-frequency ultrasound can be an effective survey method to clarify the distribution of asari clams, which live in a relatively shallow layer of sediment. However, the propagation of ultrasound dramatically changes depending on grain size, resulting in visibility deterioration of acoustic images. In this study, the effects of grain size on the visibility of acoustic images were investigated by experiments using glass beads. Then, the effects were discussed using theoretical attenuation models (Biot–Stoll model and multiple scattering model developed by Schwartz and Plona [J. Appl. Phys. 55, 3971 (1984)]) and time–frequency analysis based on the continuous wavelet transform (CWT). In addition, wavelet shrinkage was applied to improve the visibility of acoustic images. The results suggest that multiple scattering and velocity dispersion strongly affected the sharpness and contrast of acoustic images depending on grain size. In addition, it was found that wavelet shrinkage was effective in reducing speckle noise and increasing the visibility of acoustic images of buried asari clams.

Survey by knocking the door and response rate enhancement technique in international business research

Low response rate has been considered as a matter in a survey. Even though researcher has applied techniques to enhance the response rate, they very often still experience low rate of response. This paper tries to share the challenging experience in dealing with low response rate in the context of international business research. This is a questionnaire survey of small firms in Indonesia that were doing business abroad. The results show that it is more important to select the most effective survey method rather than techniques to enhance response rate in order to deal with local condition. Survey by knocking the door is found to be the best suited alternative for maximizing the response rate.

Investigating the Impact of Simple and Mixture Priors on Estimating Sensitive Proportion Through a General Class of Randomized Response Models

Randomized response is an efficacious and effective survey method to collect subtle information. It entitles respondents to respond to over-sensitive issues and defensive questions (such as criminal behavior, gambling habits, addiction to drugs, abortions, etc) while maintaining confidentiality. In this paper, we conducted a Bayesian analysis of a general class of randomized response models by using different prior distributions, such as Beta, Uniform, Jeffreys and Haldane, under squared error, precautionary and Degroot loss functions. We have also expanded our proposal for the case of mixture of Beta priors under squared error loss function. The performance of the Bayes and maximum likelihood estimators is evaluated in terms of mean squared errors. Moreover, an application with real data set is also provided to explain the proposal for practical considerations.

A Comparison of Four Survey Methods for Detecting Fox Squirrels in the Southeastern United States

Fox squirrel Sciurus niger populations in the southeastern United States appear to have declined, and 3 (S. n. cinereus, S. n. shermani, and S. n. avicennia) of the 10 subspecies are currently listed with a conservation status of protection. Efforts to conserve and manage fox squirrels in the southeastern United States are constrained by difficulties in studying their populations because of low densities and low detectability. There is a need for an effective survey method to fill knowledge gaps on southeastern fox squirrel ecology. To address this need and to identify a cost-effective and reliable technique to survey and monitor southeastern fox squirrel populations, we compared four survey methods across seasons: live-trapping; camera-trapping; point counts; and line-transect surveys, in regard to whether a detection occurred at a survey point, the total number of detections at a survey point, and the total cost for each method. We assessed the effectiveness of capture and detection methods and the influence of seasonality using generalized linear mixed models. We found camera-trapping to be the most effective survey method for assessing the presence and distribution of southeastern fox squirrels. In total, camera-traps produced significantly more detections (n = 223) of fox squirrels than all other methods combined (n = 84), with most detections occurring in spring (n = 97) and the fewest in the autumn (n = 60). Furthermore, we detected fox squirrels at more survey points with camera-traps (73%) than all other methods (63%), and we identified 16% more individuals from camera-trap photographs than live-trapped. We recommend future monitoring of southeastern fox squirrels to be conducted using camera-trapping during the spring unless handling of animals is needed for other research purposes.

A Comparison of Four Survey Methods for Detecting Fox Squirrels in the Southeastern United States

Abstract Fox squirrel Sciurus niger populations in the southeastern United States appear to have declined, and 3 (S. n. cinereus, S. n. shermani, and S. n. avicennia) of the 10 subspecies are currently listed with a conservation status of protection. Efforts to conserve and manage fox squirrels in the southeastern United States are constrained by difficulties in studying their populations because of low densities and low detectability. There is a need for an effective survey method to fill knowledge gaps on southeastern fox squirrel ecology. To address this need and to identify a cost-effective and reliable technique to survey and monitor southeastern fox squirrel populations, we compared four survey methods across seasons: live-trapping; camera-trapping; point counts; and line-transect surveys, in regard to whether a detection occurred at a survey point, the total number of detections at a survey point, and the total cost for each method. We assessed the effectiveness of capture and detection methods and the influence of seasonality using generalized linear mixed models. We found camera-trapping to be the most effective survey method for assessing the presence and distribution of southeastern fox squirrels. In total, camera-traps produced significantly more detections (n = 223) of fox squirrels than all other methods combined (n = 84), with most detections occurring in spring (n = 97) and the fewest in the autumn (n = 60). Furthermore, we detected fox squirrels at more survey points with camera-traps (73%) than all other methods (63%), and we identified 16% more individuals from camera-trap photographs than live-trapped. We recommend future monitoring of southeastern fox squirrels to be conducted using camera-trapping during the spring unless handling of animals is needed for other research purposes.