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Article ; Online: Use of object detection in camera trap image identification

Mitchell Fennell / Christopher Beirne / A. Cole Burton

Global Ecology and Conservation, Vol 35, Iss , Pp e02104- (2022)

Assessing a method to rapidly and accurately classify human and animal detections for research and application in recreation ecology

2022

Abstract: Camera traps are increasingly used to answer complex ecological questions. However, the rapidly growing number of images collected presents technical challenges. Each image must be classified to extract data, requiring significant labor, and potentially ... ...

Abstract	Camera traps are increasingly used to answer complex ecological questions. However, the rapidly growing number of images collected presents technical challenges. Each image must be classified to extract data, requiring significant labor, and potentially creating an information bottleneck. We applied an object detection model (MegaDetector) to camera trap data from a study of recreation ecology in British Columbia, Canada. We tested its performance in detecting humans and animals relative to manual image classifications, and assessed efficiency by comparing the time required for manual classification versus a modified workflow integrating object detection with manual classification. We also evaluated the reliability of using MegaDetector to create an index of human activity for application to the study of recreation impacts to wildlife. In our application, MegaDetector detected human and animal images with 99% and 82% precision, and 95% and 92% recall respectively, at a confidence threshold of 90%. Processing speed was increased by over 500%, and the time required for the manual processing component was reduced by 8.4 ×. The index of human detection events from MegaDetector matched the output from manual classification, with a mean 0.45% difference in estimated human detections across site-weeks. Our test of an open-source object detection model showed it performed well in partially classifying a camera trap dataset, significantly increasing processing efficiency. We suggest that this tool could be integrated into existing camera trap workflows to accelerate research and application by alleviating data bottlenecks, particularly for surveys processing large volumes of human images. We also show how the model and workflow can be used to anonymize human images prior to classification, protecting individual privacy.
Keywords	Artificial intelligence ; Remote camera ; Computer vision ; Species Classification ; Human-wildlife Interactions ; Ecology ; QH540-549.5
Subject code	006
Language	English
Publishing date	2022-06-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Simultaneous monitoring of vegetation dynamics and wildlife activity with camera traps to assess habitat change

Catherine Sun / Christopher Beirne / Joanna M. Burgar / Thomas Howey / Jason T. Fisher / A. Cole Burton

Remote Sensing in Ecology and Conservation, Vol 7, Iss 4, Pp 666-

2021 Volume 684

Abstract: Abstract Vegetation phenology and productivity drive resource use by wildlife. Vegetation dynamics also reveal patterns of habitat disturbance and recovery. Monitoring these fine‐scale vegetation patterns over large spatiotemporal extents can be ... ...

Abstract	Abstract Vegetation phenology and productivity drive resource use by wildlife. Vegetation dynamics also reveal patterns of habitat disturbance and recovery. Monitoring these fine‐scale vegetation patterns over large spatiotemporal extents can be difficult, but camera traps (CTs) commonly used to survey wildlife populations also collect data on local habitat conditions. We used CTs (n = 73) from 2016 to 2019 to assess impacts of habitat change in a boreal landscape of northern Canada, where seismic lines for petroleum exploration disturbed wildlife habitat and prompted vegetation restoration efforts. First, we quantified vegetation dynamics from CTs, comparing them to satellite‐based estimates that are typically used to monitor vegetation at broad spatial scales. We then used understory phenology and productivity estimated from CT time‐lapse images to assess vegetation recovery on seismic lines. Finally, we related vegetation dynamics with the habitat use of three wildlife species: sandhill cranes Grus canadensis, woodland caribou Rangifer tarandus, and white‐tailed deer Odocoileus virginianus. CTs provided unique insight into vegetation dynamics that were different from signals measured by satellites, with temporally inconsistent and even some negative correlations between CT and satellite metrics. We found some indication of vegetation recovery on seismic lines that had received restoration treatment, with understory patterns more similar to undisturbed habitat than to seismic lines that did not receive restoration treatment. CTs also provided inferences about wildlife activity related to vegetation resources, which approaches using satellite data failed to detect. Wildlife habitat use tracked vegetation phenology, but did not always increase with vegetation productivity at weekly, 16‐day, or annual intervals. Instead, associations with vegetation productivity depended on species, temporal scale, and productivity metrics. Given the widespread and growing use of CTs to monitor terrestrial wildlife, we recommend their use to simultaneously monitor habitat conditions to better understand the mechanisms that govern wildlife habitat use in changing environments.
Keywords	Animal ecology ; disturbance ; phenology ; productivity ; remote camera ; satellite ; Technology ; T ; Ecology ; QH540-549.5
Language	English
Publishing date	2021-12-01T00:00:00Z
Publisher	Wiley
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Age-related declines and disease-associated variation in immune cell telomere length in a wild mammal.

Christopher Beirne / Richard Delahay / Michelle Hares / Andrew Young

PLoS ONE, Vol 9, Iss 9, p e

2014 Volume 108964

Abstract: Immunosenescence, the deterioration of immune system capability with age, may play a key role in mediating age-related declines in whole-organism performance, but the mechanisms that underpin immunosenescence are poorly understood. Biomedical research on ...

Abstract	Immunosenescence, the deterioration of immune system capability with age, may play a key role in mediating age-related declines in whole-organism performance, but the mechanisms that underpin immunosenescence are poorly understood. Biomedical research on humans and laboratory models has documented age and disease related declines in the telomere lengths of leukocytes ('immune cells'), stimulating interest their having a potentially general role in the emergence of immunosenescent phenotypes. However, it is unknown whether such observations generalise to the immune cell populations of wild vertebrates living under ecologically realistic conditions. Here we examine longitudinal changes in the mean telomere lengths of immune cells in wild European badgers (Meles meles). Our findings provide the first evidence of within-individual age-related declines in immune cell telomere lengths in a wild vertebrate. That the rate of age-related decline in telomere length appears to be steeper within individuals than at the overall population level raises the possibility that individuals with short immune cell telomeres and/or higher rates of immune cell telomere attrition may be selectively lost from this population. We also report evidence suggestive of associations between immune cell telomere length and bovine tuberculosis infection status, with individuals detected at the most advanced stage of infection tending to have shorter immune cell telomeres than disease positive individuals. While male European badgers are larger and show higher rates of annual mortality than females, we found no evidence of a sex difference in either mean telomere length or the average rate of within-individual telomere attrition with age. Our findings lend support to the view that age-related declines in the telomere lengths of immune cells may provide one potentially general mechanism underpinning age-related declines in immunocompetence in natural populations.
Keywords	Medicine ; R ; Science ; Q
Subject code	612
Language	English
Publishing date	2014-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: African forest elephant movements depend on time scale and individual behavior

Christopher Beirne / Thomas M. Houslay / Peter Morkel / Connie J. Clark / Mike Fay / Joseph Okouyi / Lee J. T. White / John R. Poulsen

Scientific Reports, Vol 11, Iss 1, Pp 1-

2021 Volume 11

Abstract: Abstract The critically endangered African forest elephant (Loxodonta cyclotis) plays a vital role in maintaining the structure and composition of Afrotropical forests, but basic information is lacking regarding the drivers of elephant movement and ... ...

Abstract	Abstract The critically endangered African forest elephant (Loxodonta cyclotis) plays a vital role in maintaining the structure and composition of Afrotropical forests, but basic information is lacking regarding the drivers of elephant movement and behavior at landscape scales. We use GPS location data from 96 individuals throughout Gabon to determine how five movement behaviors vary at different scales, how they are influenced by anthropogenic and environmental covariates, and to assess evidence for behavioral syndromes—elephants which share suites of similar movement traits. Elephants show some evidence of behavioral syndromes along an ‘idler’ to ‘explorer’ axis—individuals that move more have larger home ranges and engage in more ‘exploratory’ movements. However, within these groups, forest elephants express remarkable inter-individual variation in movement behaviours. This variation highlights that no two elephants are the same and creates challenges for practitioners aiming to design conservation initiatives.
Keywords	Medicine ; R ; Science ; Q
Subject code	333
Language	English
Publishing date	2021-06-01T00:00:00Z
Publisher	Nature Portfolio
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Fluid hunter motivation in Central Africa

Graden Z. L. Froese / Alex Ebang Mbélé / Christopher Beirne / Blaise Bazza / Sylvain Dzime N’noh / Jovin Ebeba / Jocelin Edzidzie / Serge Ekazama Koto / Jonas Landry Metandou / Clotaire Mossindji / Irma Ngoboutseboue / Eric Nzemfoule / Daniel J. Ingram / Christopher Krapu / Abhishek Baral / Srishti Saha / John R. Poulsen

People and Nature, Vol 5, Iss 5, Pp 1480-

Effects on behaviour, bushmeat and income

2023 Volume 1496

Abstract: Abstract Individual motivation for the rural use of common‐pool resources (CPRs) can be fluid, with the line between subsistence and commercial often unclear and in flux. Implications of fluid motivation are understudied yet important for social– ... ...

Abstract	Abstract Individual motivation for the rural use of common‐pool resources (CPRs) can be fluid, with the line between subsistence and commercial often unclear and in flux. Implications of fluid motivation are understudied yet important for social–ecological systems (SESs), such as bushmeat hunting throughout Central Africa that is essential to local protein/nutrition, income and culture. Making locally informative predictions of multiple SESs nested within a landscape‐scale SES has been historically difficult, but community‐driven participatory approaches provide new kinds and quantities of data, opening previously inaccessible doors for research and governance. We apply hierarchical Bayesian structural equation modelling to a novel dataset of 910 hunts from 111 gun and trap hunters across nine villages in Gabon, generated in a participatory process whereby hunters conducted GPS self‐follows in conjunction with paraecologist surveys of their motivation, behaviour and offtake. We (i) establish the human behaviour driving gun‐hunting and trapping success and predict its effect on offtake across villages and (ii) link fluid motivation of gun hunters to their behaviour, number of animals hunted, biomass yielded and income earned. Gun hunts across villages yielded more animals during the night than the day, and when hunters brought high amounts of ammunition and walked far distances from villages. Gun hunts were less successful when coupled with trapping while per‐hunt success of trapping itself was generally low and difficult to predict. Fluid gun hunters hunted fewer animals when motivated strictly by subsistence, despite no reduction in ammunition brought or distance walked, while offtake from strictly commercial versus mixed motivation was the same. Numbers of animals hunted, biomass and income were tightly linked. We discuss the implications of these results for the ecological sustainability of hunting and participatory forecasting in bushmeat research and policy. Read the free Plain Language Summary for this ...
Keywords	common‐pool resource ; community hunting management ; Gabon ; human ecology ; paraecology ; rural livelihoods ; Human ecology. Anthropogeography ; GF1-900 ; Ecology ; QH540-549.5
Subject code	390
Language	English
Publishing date	2023-10-01T00:00:00Z
Publisher	Wiley
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Climatic and Resource Determinants of Forest Elephant Movements

Christopher Beirne / Amelia C. Meier / Gabriela Brumagin / Liam Jasperse-Sjolander / Matthew Lewis / Juliana Masseloux / Kimberly Myers / Mike Fay / Joseph Okouyi / Lee J. T. White / John R. Poulsen

Frontiers in Ecology and Evolution, Vol

2020 Volume 8

Abstract: As a keystone megafaunal species, African forest elephants (Loxodonta cyclotis) influence the structure and composition of tropical forests. Determining the links between food resources, environmental conditions and elephant movement behavior is crucial ... ...

Abstract	As a keystone megafaunal species, African forest elephants (Loxodonta cyclotis) influence the structure and composition of tropical forests. Determining the links between food resources, environmental conditions and elephant movement behavior is crucial to understanding their habitat requirements and their effects on the ecosystem, particularly in the face of poaching and global change. We investigate whether fruit abundance or climate most strongly influence forest elephant movement behavior at the landscape scale in Gabon. Trained teams of “elephant trackers” performed daily fruit availability and dietary composition surveys over a year within two relatively pristine and intact protected areas. With data from 100 in-depth field follows of 28 satellite-collared elephants and remotely sensed environmental layers, we use linear mixed-effects models to assess the effects of sites, seasons, focal elephant identification, elephant diet, and fruit availability on elephant movement behavior at monthly and 3-day time scales. At the month-level, rainfall, and to a lesser extent fruit availability, most strongly predicted the proportion of time elephants spent in long, directionally persistent movements. Thus, even elephants in moist tropical rainforests show seasonal behavioral phenotypes linked to rainfall. At the follow-level (2–4 day intervals), relative support for both rainfall and fruit availability decreased markedly, suggesting that at finer spatial scales forest elephants make foraging decisions largely based on other factors not directly assessed here. Focal elephant identity explained the majority of the variance in the data, and there was strong support for interindividual variation in behavioral responses to rainfall. Taken together, this highlights the importance of approaches which follow individuals through space and time. The links between climate, resource availability and movement behavior provide important insights into the behavioral ecology of forest elephants that can contribute to understanding their role as seed dispersers, improving management of populations, and informing development of solutions to human-elephant conflict.
Keywords	behavior ; path segmentation ; resource availability ; human-elephant conflict ; individual variation ; Evolution ; QH359-425 ; Ecology ; QH540-549.5
Subject code	333
Language	English
Publishing date	2020-04-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Bamboo traps as refugia for Pristimantis olivaceus (Anura

Lawrence Whittaker / Andrew Whitworth / Alex Fowler / Marcus Brent-Smith / Christopher Beirne / Jaime Villacampa

Phyllomedusa: Journal of Herpetology, Vol 14, Iss

Craugastoridae) and as breeding site for Osteocephalus castaneicola (Anura: Hylidae)

2015 Volume 2

Keywords	bamboo internodes ; breeding site ; neotropics ; phytotelmata ; PVC traps ; Biology (General) ; QH301-705.5
Language	English
Publishing date	2015-12-01T00:00:00Z
Publisher	Universidade de São Paulo
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article: Secondary forest is utilized by Great Curassows (Crax rubra) and Great Tinamous (Tinamus major) in the absence of hunting

Whitworth, Andrew / Christopher Beirne / Eleanor Flatt / Ruthmery Pillco Huarcaya / Juan Carlos Cruz Diaz / Adrian Forsyth / Péter K. Molnár / Juan S. Vargas Soto

Condor. 2018 Nov., v. 120, no. 4

2018

Abstract: Deforestation and hunting are the leading human-driven disturbances causing population declines of the vulnerable Great Curassow (Crax rubra) and the near threatened Great Tinamou (Tinamus major). These threats typically co-occur, with synergistic ... ...

Title translation	Utilizacion de bosque secundario por el Crax rubra y el Tinamus major en ausencia de caza
Abstract	Deforestation and hunting are the leading human-driven disturbances causing population declines of the vulnerable Great Curassow (Crax rubra) and the near threatened Great Tinamou (Tinamus major). These threats typically co-occur, with synergistic effects. We investigated habitat use of Great Curassows and Great Tinamous in the Matapalo corridor of the Osa Peninsula, southwest Costa Rica, where they are not hunted, to understand whether disturbed habitats can be suitable for these species. We analyzed camera trap data from 56 locations and 5579 trapping days using occupancy modeling. We obtained 195 independent captures of Great Curassows at 33 of 56 locations (59%) and 429 independent captures of Great Tinamous at 37 of 56 locations (66%). Great Curassow occupancy did not vary with habitat type but was negatively influenced by distance from roads and by elevation; detection probability varied with habitat type. Great Tinamou occupancy probability was principally related to habitat type; primary, secondary and plantation forest areas all displayed high occupancy probabilities, but occupancy of agricultural land was low. Our work suggests that secondary-growth forests can offer valuable complementary habitat to assist in the recovery of these declining species, at least when hunting is controlled and intact forests are nearby.
Keywords	Crax rubra ; Tinamus ; cameras ; deforestation ; forest plantations ; habitat destruction ; habitat preferences ; habitats ; models ; population dynamics ; probability ; roads ; secondary forests ; synergism ; trapping ; Costa Rica
Language	English
Dates of publication	2018-11
Size	p. 852-862.
Publishing place	The Cooper Ornithological Society
Document type	Article
ZDB-ID	2066173-3
ISSN	1938-5129 ; 0010-5422
ISSN (online)	1938-5129
ISSN	0010-5422
DOI	10.1650/CONDOR-18-57.1
Database	NAL-Catalogue (AGRICOLA)

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Article ; Online: Long Distance Seed Dispersal by Forest Elephants

Frontiers in Ecology and Evolution, Vol

2021 Volume 9

Abstract: By dispersing seeds long distances, large, fruit-eating animals influence plant population spread and community dynamics. After fruit consumption, animal gut passage time and movement determine seed dispersal patterns and distances. These, in turn, are ... ...

Abstract	By dispersing seeds long distances, large, fruit-eating animals influence plant population spread and community dynamics. After fruit consumption, animal gut passage time and movement determine seed dispersal patterns and distances. These, in turn, are influenced by extrinsic, environmental variables and intrinsic, individual-level variables. We simulated seed dispersal by forest elephants (Loxodonta cyclotis) by integrating gut passage data from wild elephants with movement data from 96 individuals. On average, elephants dispersed seeds 5.3 km, with 89% of seeds dispersed farther than 1 km. The longest simulated seed dispersal distance was 101 km, with an average maximum dispersal distance of 40.1 km. Seed dispersal distances varied among national parks, perhaps due to unmeasured environmental differences such as habitat heterogeneity and configuration, but not with human disturbance or habitat openness. On average, male elephants dispersed seeds farther than females. Elephant behavioral traits strongly influenced dispersal distances, with bold, exploratory elephants dispersing seeds 1.1 km farther than shy, idler elephants. Protection of forest elephants, particularly males and highly mobile, exploratory individuals, is critical to maintaining long distance seed dispersal services that shape plant communities and tropical forest habitat.
Keywords	seed dispersal ; elephant ; tropical forest ; animal movement ; central Africa ; gut passage time ; Evolution ; QH359-425 ; Ecology ; QH540-549.5
Language	English
Publishing date	2021-12-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Forest elephant movement and habitat use in a tropical forest-grassland mosaic in Gabon.

Emily C Mills / John R Poulsen / J Michael Fay / Peter Morkel / Connie J Clark / Amelia Meier / Christopher Beirne / Lee J T White

PLoS ONE, Vol 13, Iss 7, p e

2018 Volume 0199387

Abstract: Poaching of forest elephants (Loxodonta cyclotis) for ivory has decimated their populations in Central Africa. Studying elephant movement can provide insight into habitat and resource use to reveal where, when, and why they move and guide conservation ... ...

Abstract	Poaching of forest elephants (Loxodonta cyclotis) for ivory has decimated their populations in Central Africa. Studying elephant movement can provide insight into habitat and resource use to reveal where, when, and why they move and guide conservation efforts. We fitted 17 forest elephants with global positioning system (GPS) collars in 2015 and 2016 in the tropical forest-grassland mosaic of the Wonga Wongué Presidential Reserve (WW), Gabon. Using the location data, we quantified movement distances, home ranges, and habitat use to examine the environmental drivers of elephant movements and predict where elephants occur spatially and temporally. Forest elephants, on average, traveled 2,840 km annually and had home ranges of 713 km2, with males covering significantly larger home ranges than females. Forest elephants demonstrated both daily and seasonal movement patterns. Daily, they moved between forest and grassland at dawn and dusk. Seasonally, they spent proportionally more time in grassland than forest during the short-wet season when grasses recruit. Forest elephants also traveled faster during the short-wet season when fruit availability was greatest, likely reflecting long, direct movements to preferred fruiting tree species. Forest elephants tended to select areas with high tree and shrub density that afford cover and browse. When villages occurred in their home ranges elephants spent a disproportionate amount of time near them, particularly in the dry season, probably for access to agricultural crops and preferred habitat. Given the importance of the grassland habitat for elephants, maintenance of the forest-grassland matrix is a conservation priority in WW. Law enforcement, outreach, and education should focus on areas of potential human-elephant conflict near villages along the borders of the reserve. GPS-tracking should be extended into multi-use areas in the peripheries of protected areas to evaluate the effects of human disturbance on elephant movements and to maintain connectivity among elephant ...
Keywords	Medicine ; R ; Science ; Q
Subject code	333
Language	English
Publishing date	2018-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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