Searcher efficiency and survey coverage affect precision of fatality estimates

Reyes, Gabriel; Rodriguez, Meredith J.; Lindke, Kenneth T.; Ayres, Katherine L.; Halterman, Murrelet D.; Boroski, Brian B.; Johnston, Dave S.

doi:10.1002/jwmg.21126

Cited by 22 publications

(24 citation statements)

References 27 publications

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“…Multiple steps can be taken to detect more of the available fatalities, including searching to a maximum radius around wind turbines that includes the majority of deposited carcasses, searching along transects spaced closer together, searching more frequently, and searching with skilled detection dogs instead of only humans. Homan et al (2001), Arnett (2006), Paula et al (2011), and Matthews et al (2013) reported that using skilled dogs greatly increased carcass detection rates over human searchers, and Reyes et al (2016) reported that dogs improved searcher efficiency and were more likely to detect fatalities of rarely represented species.…”

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confidence: 99%

Dogs Detect Larger Wind Energy Effects on Bats and Birds

Smallwood¹,

Bell²,

Standish³

2020

J Wildl Manag

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As wind turbine‐caused mortality of birds and bats increases with increasing wind energy capacity, accurate fatality estimates are needed to assess effects, identify collision factors, and formulate mitigation. Finding a larger proportion of collision victims reduces the magnitude of adjustment for the proportion not found, thus reducing opportunities for bias. We tested detection dogs in trials of bat and small‐bird carcasses placed randomly in routine fatality monitoring at the Buena Vista and Golden Hills Wind Energy projects, California, USA, 2017. Of trial carcasses placed and confirmed available before next‐day fatality searches, dogs detected 96% of bats and 90% of small birds, whereas humans at a neighboring wind project detected 6% of bats and 30% of small birds. At Golden Hills dogs found 71 bat fatalities in 55 searches compared to 1 bat found by humans in 69 searches within the same search plots over the same season. Dog detection rates of trial carcasses remained unchanged with distance from turbine, and dogs found more fatalities than did humans at greater distances from turbines. Patterns of fatalities found by dogs within search plots indicated 20% of birds and 4–14% of bats remained undetected outside search plots at Buena Vista and Golden Hills. Dogs also increased estimates of carcass persistence by finding detection trial carcasses that the trial administrator had erroneously concluded were removed. Compared to human searches, dog searches resulted in fatality estimates up to 6.4 and 2.7 times higher for bats and small birds, respectively, along with higher relative precision and >90% lower cost per fatality detection. © 2020 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.

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confidence: 99%

Dogs Detect Larger Wind Energy Effects on Bats and Birds

Smallwood¹,

Bell²,

Standish³

2020

J Wildl Manag

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“…To obtain cabin data, we invested the recording time (an observer for 33 days of round trips) and the time for review and assembly of the data (an ornithologist working for about 50 days). In comparison, field data collection in the two sub-stretches of rail line required a group of at least three ornithologists and one safety technician during 48 days (4 seasons * 6 surveys * 2 sub-stretches) as well as parallel installation of baited stations to estimate carcass removal rates and carcass detectability (Reyes et al, 2016). Added to these resources, would be preparation time for field material and datasets (total of around 24 person-days).…”

Section: Discussionmentioning

confidence: 99%

“…The infrastructure is fenced and highly restricted to human access for safety reasons, making it very difficult to run field studies (Wells et al, 1999). Also, bird carcasses from train collisions are left in a condition which makes location and identification difficult, especially in the presence of scavenger animals around railways (Heske, 2015;Reyes et al, 2016). Besides, the sheer breadth of rail networks and cost of fieldwork make it practically impossible to conduct studies that cover even a small part of a network.…”

Section: Introductionmentioning

confidence: 99%

On-Board Video Recording Unravels Bird Behavior and Mortality Produced by High-Speed Trains

et al. 2017

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Large high-speed railway (HSR) networks are planned for the near future to accomplish increased transport demand with low energy consumption. However, high-speed trains produce unknown avian mortality due to birds using the railway and being unable to avoid approaching trains. Safety and logistic difficulties have precluded until now mortality estimation in railways through carcass removal, but information technologies can overcome such problems. We present the results obtained with an experimental on-board system to record bird-train collisions composed by a frontal recording camera, a GPS navigation system and a data storage unit. An observer standing in the cabin behind the driver controlled the system and filled out a form with data of collisions and bird observations in front of the train. Photographs of the train front taken before and after each journey were used to improve the record of killed birds. Trains running the 321.7 km line between Madrid and Albacete (Spain) at speeds up to 250-300 km/h were equipped with the system during 66 journeys along a year, totaling approximately 14,700 km of effective recording. The review of videos produced 1,090 bird observations, 29.4% of them corresponding to birds crossing the infrastructure under the catenary and thus facing collision risk. Recordings also showed that 37.7% bird crossings were of animals resting on some element of the infrastructure moments before the train arrival, and that the flight initiation distance of birds (mean ± SD) was between 60 ± 33 m (passerines) and 136 ± 49 m (raptors). Mortality in the railway was estimated to be 60.5 birds/km year on a line section with 53 runs per day and 26.1 birds/km year in a section with 25 runs per day. Our results are the first published estimation of bird mortality in a HSR and show the potential of information technologies to yield useful data for monitoring the impact of trains on birds via on-board recording systems. Moreover, recordings point to the use of the infrastructure by birds as a key issue leading to bird train-kill.

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“…Wind facility carcass search detection probabilities are complicated because they depend on the timing of seasonal carcass arrivals, search start date, search end date, search interval, number of searched turbines, searcher efficiency (detection given presence), carcass removal rates, and the proportion of the carcasses that fall in the searched area. Here, we rely on established formulas implemented in the genest R package (west-inc.shinyapps.io/GenEst/; cran.r-project.org/GenEst) to compute detection probabilities and variation given study design elements Reyes et al, 2016). Whether using genest or not, we assume field data collection elements have been evaluated and that site-specific and have been computed.…”

Section: Eoar Model Definitionmentioning

confidence: 99%

Evidence of Absence Regression: A Binomial N-Mixture Model for Estimating Fatalities at Wind Energy Facilities

McDonald

Bay

Studyvin

et al. 2020

Preprint

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Estimating bird and bat fatalities caused by wind-turbine facilities is challenging when fatalities are rare and the number of observed carcasses is either exactly zero or very near zero. The rarity of found carcasses is exacerbated when particular species are rare, when carcasses degrade quickly, when they are removed by scavengers, or when they are not detected by observers. With few observed fatalities, common statistical methods like logistic, Poisson, or negative binomial regression are biased and prone to fail due to complete or quasi-complete separation. Here, we propose a binomial N-mixture model to estimate fatality rates and totals that incorporates study covariates and separate information on probability of detection. Our model extends the 'evidence of absence' model by relating carcass deposition rates to study covariates and by incorporating the number of turbines. Our model, which we call Evidence of Absence Regression (EoAR), can retrospectively and prospectively estimate the total number of birds or bats killed at a single wind-power facility or a fleet of wind-power facilities given covariates in the relation. Furthermore, with accurate prior distributions the model's results are extremely robust to complete or quasi-complete separation. In this paper, we describe the model, show its low bias and high precision via computer simulation, and apply it to bat fatalities observed on 21 wind power facilities in Iowa.

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Searcher efficiency and survey coverage affect precision of fatality estimates

Cited by 22 publications

References 27 publications

Dogs Detect Larger Wind Energy Effects on Bats and Birds

Dogs Detect Larger Wind Energy Effects on Bats and Birds

On-Board Video Recording Unravels Bird Behavior and Mortality Produced by High-Speed Trains

Evidence of Absence Regression: A Binomial N-Mixture Model for Estimating Fatalities at Wind Energy Facilities

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