Can camera trapping be used to accurately survey and monitor the Hastings River mouse (Pseudomys oralis)?

2016 ◽  
Vol 38 (1) ◽  
pp. 44 ◽  
Author(s):  
Paul D. Meek ◽  
Karl Vernes
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Survey Methods ◽  
Camera Trap ◽  
Camera Traps ◽  
Camera Trapping ◽  
Common Element ◽  
Computer Assisted ◽  
Survey Tool ◽  
Wide Range

Camera trapping is increasingly recognised as a survey tool akin to conventional small mammal survey methods such as Elliott trapping. While there are many cost and resource advantages of using camera traps, their adoption should not compromise scientific rigour. Rodents are a common element of most small mammal surveys. In 2010 we deployed camera traps to measure whether the endangered Hastings River mouse (Pseudomys oralis) could be detected and identified with an acceptable level of precision by camera traps when similar-looking sympatric small mammals were present. A comparison of three camera trap models revealed that camera traps can detect a wide range of small mammals, although white flash colour photography was necessary to capture characteristic features of morphology. However, the accurate identification of some small mammals, including P. oralis, was problematic; we conclude therefore that camera traps alone are not appropriate for P. oralis surveys, even though they might at times successfully detect them. We discuss the need for refinement of the methodology, further testing of camera trap technology, and the development of computer-assisted techniques to overcome problems associated with accurate species identification.

Pits or pictures: a comparative study of camera traps and pitfall trapping to survey small mammals and reptiles

2019 ◽  
Vol 46 (2) ◽  
pp. 104 ◽  
Author(s):  
Shannon J. Dundas ◽  
Katinka X. Ruthrof ◽  
Giles E. St.J. Hardy ◽  
Patricia A. Fleming
Keyword(s):  
Community Composition ◽  
Small Mammals ◽  
Survey Methods ◽  
Infrared Camera ◽  
Camera Traps ◽  
Camera Trapping ◽  
Survey Method ◽  
Pitfall Traps ◽  
Pitfall Trapping ◽  
Trapping Methods

Context Camera trapping is a widely used monitoring tool for a broad range of species across most habitat types. Camera trapping has some major advantages over other trapping methods, such as pitfall traps, because cameras can be left in the field for extended periods of time. However, there is still a need to compare traditional trapping methods with newer techniques. Aims To compare trap rates, species richness and community composition of small mammals and reptiles by using passive, unbaited camera traps and pitfall traps. Methods We directly compared pitfall trapping (20-L buried buckets) with downward-facing infrared-camera traps (Reconyx) to survey small reptiles and mammals at 16 sites within a forested habitat in south-western Australia. We compared species captured using each method, as well as the costs associated with each. Key results Overall, we recorded 228 reptiles, 16 mammals and 1 frog across 640 pitfall trap-nights (38.3 animal captures per 100 trap-nights) compared to 271 reptiles and 265 mammals (for species likely to be captured in pitfall traps) across 2572 camera trap nights (20.8 animal captures per 100 trap-nights). When trap effort is taken into account, camera trapping was only 23% as efficient as pitfall trapping for small reptiles (mostly Scincidae), but was five times more efficient for surveying small mammals (Dasyuridae). Comparing only those species that were likely to be captured in pitfall traps, 13 species were recorded by camera trapping compared with 20 species recorded from pitfall trapping; however, we found significant (P<0.001) differences in community composition between the methods. In terms of cost efficacy, camera trapping was the more expensive method for our short, 4-month survey when taking the cost of cameras into consideration. Conclusions Applicability of camera trapping is dependent on the specific aims of the intended research. Camera trapping is beneficial where community responses to ecosystem disturbance are being tested. Live capture of small reptiles via pitfall trapping allows for positive species identification, morphological assessment, and collection of reference photos to help identify species from camera photos. Implications As stand-alone techniques, both survey methods under-represent the available species present in a region. The use of more than one survey method improves the scope of fauna community assessments.

scholarly journals Can camera trapping provide accurate estimates of small mammal ( Myodes rutilus and Peromyscus maniculatus ) density in the boreal forest?

2015 ◽  
Vol 97 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Petra Villette ◽  
Charles J. Krebs ◽  
Thomas S. Jung ◽  
Rudy Boonstra
Keyword(s):  
Boreal Forest ◽  
Small Mammals ◽  
Small Mammal ◽  
Peromyscus Maniculatus ◽  
Camera Traps ◽  
Camera Trapping ◽  
Deer Mice ◽  
Hit Rate ◽  
Myodes Rutilus ◽  
Feasible Alternative

Abstract Estimating population densities of small mammals (< 100g) has typically been carried out by intensive livetrapping, but this technique may be stressful to animals and the effort required is considerable. Here, we used camera traps to detect small mammal presence and assessed if this provided a feasible alternative to livetrapping for density estimation. During 2010–2012, we used camera trapping in conjunction with mark–recapture livetrapping to estimate the density of northern red-backed voles ( Myodes rutilus ) and deer mice ( Peromyscus maniculatus ) in the boreal forest of Yukon, Canada. Densities for these 2 species ranged from 0.29 to 9.21 animals/ha and 0 to 5.90 animals/ha, respectively, over the course of this investigation. We determined if hit window—the length of time used to group consecutive videos together as single detections or “hits”—has an effect on the correlation between hit rate and population density. The relationship between hit rate and density was sensitive to hit window duration for Myodes with R2 values ranging from 0.45 to 0.59, with a 90-min hit window generating the highest value. This relationship was not sensitive to hit window duration for Peromyscus , with R2 values for the tested hit windows ranging from 0.81 to 0.84. Our results indicate that camera trapping may be a robust method for estimating density of small rodents in the boreal forest when the appropriate hit window duration is selected and that camera traps may be a useful tool for the study of small mammals in boreal forest habitat.

The history of wildlife camera trapping as a survey tool in Australia

2015 ◽  
Vol 37 (1) ◽  
pp. 1 ◽  
Author(s):  
Paul D. Meek ◽  
Guy-Anthony Ballard ◽  
Karl Vernes ◽  
Peter J. S. Fleming
Keyword(s):  
Quantitative Research ◽  
Reaction Times ◽  
Historical Review ◽  
Camera Trap ◽  
Recent Change ◽  
Camera Traps ◽  
Camera Trapping ◽  
Survey Tool ◽  
Trapping Methods ◽  
Effective Models

This paper provides an historical review of the technological evolution of camera trapping as a zoological survey tool in Australia. Camera trapping in Australia began in the 1950s when purpose-built remotely placed cameras were used in attempts to rediscover the thylacine (Thylacinus cynocephalus). However, camera traps did not appear in Australian research papers and Australasian conference proceedings until 1989–91, and usage became common only after 2008, with an exponential increase in usage since 2010. Initially, Australian publications under-reported camera trapping methods, often failing to provide fundamental details about deployment and use. However, rigour in reporting of key methods has increased during the recent widespread adoption of camera trapping. Our analysis also reveals a change in camera trap use in Australia, from simple presence–absence studies, to more theoretical and experimental approaches related to population ecology, behavioural ecology, conservation biology and wildlife management. Practitioners require further research to refine and standardise camera trap methods to ensure that unbiased and scientifically rigorous data are obtained from quantitative research. The recent change in emphasis of camera trapping research use is reflected in the decreasing range of camera trap models being used in Australian research. Practitioners are moving away from less effective models that have slow reaction times between detection and image capture, and inherent bias in detectability of fauna, to more expensive brands that offer faster speeds, greater functionality and more reliability.

The pitfalls of wildlife camera trapping as a survey tool in Australia

2015 ◽  
Vol 37 (1) ◽  
pp. 13 ◽  
Author(s):  
Paul D. Meek ◽  
Guy-Anthony Ballard ◽  
Peter J. S. Fleming
Keyword(s):  
Detection System ◽  
Objective Evaluation ◽  
Camera Trap ◽  
Camera Traps ◽  
Camera Trapping ◽  
Camera Model ◽  
Survey Tool ◽  
Key Issues ◽  
Ecological Science ◽  
Technological Constraints

Camera trapping is a relatively new addition to the wildlife survey repertoire in Australia. Its rapid adoption has been unparalleled in ecological science, but objective evaluation of camera traps and their application has not kept pace. With the aim of motivating practitioners to think more about selection and deployment of camera trap models in relation to research goals, we reviewed Australian camera trapping studies to determine how camera traps have been used and how their technological constraints may have affected reported results and conclusions. In the 54 camera trapping articles published between 1991 and 2013, mammals (86%) were studied more than birds (10%) and reptiles (3%), with small to medium-sized mammals being most studied. Australian camera trapping studies, like those elsewhere, have changed from more qualitative to more complex quantitative investigations. However, we found that camera trap constraints and limitations were rarely acknowledged, and we identified eight key issues requiring consideration and further research. These are: camera model, camera detection system, camera placement and orientation, triggering and recovery, camera trap settings, temperature differentials, species identification and behavioural responses of the animals to the cameras. In particular, alterations to animal behaviour by camera traps potentially have enormous influence on data quality, reliability and interpretation. The key issues were not considered in most Australian camera trap papers and require further study to better understand the factors that influence the analysis and interpretation of camera trap data and improve experimental design.

scholarly journals Estimating forest antelope population densities using distance sampling with camera traps

Oryx ◽  
2021 ◽  
pp. 1-7
Author(s):  
Rajan Amin ◽  
Hannah Klair ◽  
Tim Wacher ◽  
Constant Ndjassi ◽  
Andrew Fowler ◽  
...  
Keyword(s):  
Survey Methods ◽  
Distance Sampling ◽  
Common Species ◽  
Camera Trap ◽  
Camera Traps ◽  
Individual Species ◽  
Survey Tool ◽  
Terrestrial Mammals ◽  
Detection Probabilities ◽  
The Status

Abstract Traditional transect survey methods for forest antelopes often underestimate density for common species and do not provide sufficient data for rarer species. The use of camera trapping as a survey tool for medium and large terrestrial mammals has become increasingly common, especially in forest habitats. Here, we applied the distance sampling method to images generated from camera-trap surveys in Dja Faunal Reserve, Cameroon, and used an estimate of the proportion of time animals are active to correct for negative bias in the density estimates from the 24-hour camera-trap survey datasets. We also used multiple covariate distance sampling with body weight as a covariate to estimate detection probabilities and densities of rarer species. These methods provide an effective tool for monitoring the status of individual species or a community of forest antelope species, information urgently needed for conservation planning and action.

scholarly journals Can citizen science analysis of camera trap data be used to study reproduction? Lessons from Snapshot Serengeti program

2020 ◽  
Author(s):  
Thel Lucie ◽  
Chamaillé-Jammes Simon ◽  
Keurinck Léa ◽  
Catala Maxime ◽  
Packer Craig ◽  
...  
Keyword(s):  
Citizen Science ◽  
Camera Trap ◽  
Camera Traps ◽  
Life History Trait ◽  
List Type ◽  
Breeding Phenology ◽  
Science Data ◽  
Morphological Criteria ◽  
Wide Range ◽  
Trained Observers

AbstractEcologists increasingly rely on camera trap data to estimate a wide range of biological parameters such as occupancy, population abundance or activity patterns. Because of the huge amount of data collected, the assistance of non-scientists is often sought after, but an assessment of the data quality is a prerequisite to their use.We tested whether citizen science data from one of the largest citizen science projects - Snapshot Serengeti - could be used to study breeding phenology, an important life-history trait. In particular, we tested whether the presence of juveniles (less than one or 12 months old) of three ungulate species in the Serengeti: topi Damaliscus jimela, kongoni Alcelaphus buselaphus and Grant’s gazelle Nanger granti could be reliably detected by the “naive” volunteers vs. trained observers. We expected a positive correlation between the proportion of volunteers identifying juveniles and their effective presence within photographs, assessed by the trained observers.We first checked the agreement between the trained observers for age classes and species and found a good agreement between them (Fleiss’ κ > 0.61 for juveniles of less than one and 12 month(s) old), suggesting that morphological criteria can be used successfully to determine age. The relationship between the proportion of volunteers detecting juveniles less than a month old and their actual presence plateaued at 0.45 for Grant’s gazelle and reached 0.70 for topi and 0.56 for kongoni. The same relationships were however much stronger for juveniles younger than 12 months, to the point that their presence was perfectly detected by volunteers for topi and kongoni.Volunteers’ classification allows a rough, moderately accurate, but quick, sorting of photograph sequences with/without juveniles. Obtaining accurate data however appears more difficult. We discuss the limitations of using citizen science camera traps data to study breeding phenology, and the options to improve the detection of juveniles, such as the addition of aging criteria on the online citizen science platforms, or the use of machine learning.

Camera Trapping Technology and Related Advances: into the New Millennium

2020 ◽  
Vol 40 (3) ◽  
pp. 392-403 ◽  
Author(s):  
Paul D. Meek ◽  
Guy Ballard ◽  
Greg Falzon ◽  
Jaimen Williamson ◽  
Heath Milne ◽  
...  
Keyword(s):  
Wildlife Management ◽  
Survey Methods ◽  
Camera Traps ◽  
Camera Trapping ◽  
Engineering Statistics ◽  
The Usa ◽  
Computational Sciences ◽  
Processing And Storage ◽  
Methods Analytical ◽  
Analytical Tools

Camera trapping has advanced significantly in Australia over the last two decades. These devices have become more versatile and the associated computer technology has also progressed dramatically since 2011. In the USA, the hunting industry drives most changes to camera traps; however the scientific fraternity has been instrumental in incorporating computational engineering, statistics and technology into camera trap use for wildlife research. New survey methods, analytical tools (including software for image processing and storage) and complex algorithms to analyse images have been developed. For example, pattern and texture analysis and species and individual facial recognition are now possible. In the next few decades, as technology evolves and ecological and computational sciences intertwine, new tools and devices will emerge into the market. Here we outline several projects that are underway to incorporate camera traps and associated technologies into existing and new tools for wildlife management. These also have significant implications for broader wildlife management and research.

scholarly journals FoxMask: a new automated tool for animal detection in camera trap images

2019 ◽  
Author(s):  
Eric Devost ◽  
Sandra Lai ◽  
Nicolas Casajus ◽  
Dominique Berteaux
Keyword(s):  
Moving Objects ◽  
Data Extraction ◽  
Cost Effective ◽  
Camera Trap ◽  
Biological Data ◽  
Camera Traps ◽  
Computer Assisted ◽  
List Type ◽  
Background Estimation ◽  
Animal Detection

SUMMARYCamera traps now represent a reliable, efficient and cost-effective technique to monitor wildlife and collect biological data in the field. However, efficiently extracting information from the massive amount of images generated is often extremely time-consuming and may now represent the most rate-limiting step in camera trap studies.To help overcome this challenge, we developed FoxMask, a new tool performing the automatic detection of animal presence in short sequences of camera trap images. FoxMask uses background estimation and foreground segmentation algorithms to detect the presence of moving objects (most likely, animals) on images.We analyzed a sample dataset from camera traps used to monitor activity on arctic fox Vulpes lagopus dens to test the parameter settings and the performance of the algorithm. The shape and color of arctic foxes, their background at snowmelt and during the summer growing season were highly variable, thus offering challenging testing conditions. We compared the automated animal detection performed by FoxMask to a manual review of the image series.The performance analysis indicated that the proportion of images correctly classified by FoxMask as containing an animal or not was very high (> 90%). FoxMask is thus highly efficient at reducing the workload by eliminating most false triggers (images without an animal). We provide parameter recommendations to facilitate usage and we present the cases where the algorithm performs less efficiently to stimulate further development.FoxMask is an easy-to-use tool freely available to ecologists performing camera trap data extraction. By minimizing analytical time, computer-assisted image analysis will allow collection of increased sample sizes and testing of new biological questions.

scholarly journals Major Regularities of Transformation of the Small Mammal Ovaries in Unfavourable Environmental Conditions: Ecological and Morphological Aspects

2021 ◽  
Vol 10 (4) ◽  
pp. 28-35
Author(s):  
E. V. Blinova ◽  
N. N. Shevlyuk
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Environmental Conditions ◽  
Functional Organization ◽  
Common Shrew ◽  
Mammal Species ◽  
Wood Mice ◽  
Wide Range ◽  
Mole Vole ◽  
Cortical Substance

The aim of the study was to determine the patterns of structural and functional organization of the ovaries of female small mammals inhabiting technogenically altered ecosystems.Material and methods. We studied the ovaries of small mammal species belonging to the insectivore and rodent families (common shrew, field and pygmy wood mice, common and bank voles, mole vole, steppe pied) that live in anthropogenically altered ecosystems (zones of influence of ferrous and nonferrous metallurgy, as well as gas processing factory). The resulting material was processed using observational histological, histochemical, immunohistochemical and morphometric tests.Results. The results obtained demonstrated that in technogenically altered ecosystems the intensified reproduction results in a complex of morphofunctional reactive and adaptive changes in the ovaries of females of the studied species. The size of the ovaries was reduced; the area of the cortical substance was reduced. In the cortex, there was revealed a decrease in the number of follicles varying over a wide range - from a moderate decrease to their almost complete absence. There was found a decrease in the area of the vessels of the microvasculature; this was one of the major reasons for the increased follicular atresia. In follicles of various types, there was an increase in the proportion of cells expressing the proapoptotic protein P53. A decrease in the number of follicles resulted in the connective tissue overgrowth. The presence of cysts lined with epithelium of various heights was revealed in the cortex and medulla. Conclusion. The results obtained evidence that in technogenically altered ecosystems a decreased ovarian reserve is observed in the ovaries of female small mammals; it is associated with a more rapid depletion of the follicle reserve in the cortex due to both - intensification of reproduction and more rapid death of follicles in unfavourable environmental conditions.

Identification of threatened rodent species using infrared and white-flash camera traps

2018 ◽  
Vol 40 (2) ◽  
pp. 188 ◽  
Author(s):  
Phoebe A. Burns ◽  
Marissa L. Parrott ◽  
Kevin C. Rowe ◽  
Benjamin L. Phillips
Keyword(s):  
Small Mammal ◽  
Infrared Camera ◽  
Camera Traps ◽  
Camera Trapping ◽  
Rodent Species ◽  
Mammal Species ◽  
Accurate Identification ◽  
Adequate Image Quality ◽  
Observer Experience ◽  
Small Mammal Species

Camera trapping has evolved into an efficient technique for gathering presence/absence data for many species; however, smaller mammals such as rodents are often difficult to identify in images. Identification is inhibited by co-occurrence with similar-sized small mammal species and by camera set-ups that do not provide adequate image quality. Here we describe survey procedures for identification of two small, threatened rodent species – smoky mouse (Pseudomys fumeus) and New Holland mouse (P. novaehollandiae) – using white-flash and infrared camera traps. We tested whether observers could accurately identify each species and whether experience with small mammals influenced accuracy. Pseudomys fumeus was ~20 times less likely to be misidentified on white-flash images than infrared, and observer experience affected accuracy only for infrared images, where it accounted for all observer variance. Misidentifications of P. novaehollandiae were more common across both flash types: false positives (>0.21) were more common than false negatives (<0.09), and experience accounted for only 31% of variance in observer accuracy. For this species, accurate identification appears to be, in part, an innate skill. Nonetheless, using an appropriate setup, camera trapping clearly has potential to provide broad-scale occurrence data for these and other small mammal species.

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