Use of Remote Camera Traps to Evaluate Animal-Based Welfare Indicators in Individual Free-Roaming Wild Horses

Abstract

We previously developed a Ten-Stage Protocol for scientifically assessing the welfare of individual free-roaming wild animals using the Five Domains Model. The protocol includes developing methods for measuring or observing welfare indices. In this study, we assessed the use of remote camera traps to evaluate an extensive range of welfare indicators in individual free-roaming wild horses. Still images and videos were collected and analysed to assess whether horses could be detected and identified individually, which welfare indicators could be reliably evaluated, and whether behaviour could be quantitatively assessed. Remote camera trapping was successful in detecting and identifying horses (75% on still images and 72% on video observation events), across a range of habitats including woodlands where horses could not be directly observed. Twelve indicators of welfare across the Five Domains were assessed with equal frequency on both still images and video, with those most frequently assessable being body condition score (73% and 79% of observation events, respectively), body posture (76% for both), coat condition (42% and 52%, respectively), and whether or not the horse was sweating excessively (42% and 45%, respectively). An additional five indicators could only be assessed on video; those most frequently observable being presence or absence of weakness (66%), qualitative behavioural assessment (60%), presence or absence of shivering (51%), and gait at walk (50%). Specific behaviours were identified in 93% of still images and 84% of video events, and proportions of time different behaviours were captured could be calculated. Most social behaviours were rarely observed, but close spatial proximity to other horses, as an indicator of social bonds, was recorded in 36% of still images, and 29% of video observation events. This is the first study that describes detailed methodology for these purposes. The results of this study can also form the basis of application to other species, which could contribute significantly to advancing the field of wild animal welfare.

Evaluating Potential Cetacean Welfare Indicators from Video of Live Stranded Long-Finned Pilot Whales (Globicephala melas edwardii)

“…Despite many videos being short in duration, we were able to identify and evaluate physical and environmental indicators and characterise behaviour. Similar video lengths have been used elsewhere [ 10 , 94 ]. However, these data are unlikely to provide accurate estimates of the behavioural time budgets and respiratory rates of stranded cetaceans.…”

“…Although the need to assess wild animal welfare has been highlighted [ 6 , 7 , 8 , 9 ], there are limited systematic, scientific protocols for such assessments [ 10 ]. Furthermore, detailed behavioural and physiological data from species in the wild are often lacking [ 11 ], hindering the development of welfare assessments for wild populations [ 12 ].…”

“…To successfully apply indicators in a welfare assessment framework, the feasibility of measuring the indicators, methods of measurement, and validity for inferring welfare states (i.e., mental states) from observable indicators must be evaluated [ 10 , 41 , 42 ]. In this study we examined the feasibility of assessing animal-based and resource-/management-based indicators proposed by experts at live cetacean stranding events [ 38 ].…”

Identification of potential welfare and survival indicators for stranded cetaceans through international, interdisciplinary expert opinion

“…Three resource-/management-based indicators considered valuable and practical to assess both welfare and survival likelihood included the length of time stranded/number of re-strandings, and features related to human intervention in terms of knowledge and available resources, such as equipment. These indicators provide relevant information on the potential risks of each stranding situation to animal welfare and survival likelihood [ 12 , 88 ]. For example, the length of time stranded and number of re-strandings will affect the level of compounding damage that a stranded cetacean undergoes since prolonged and/or multiple strandings probably cause sustained physiological stress responses [ 72 , 89 ].…”

“…age class, reproductive status), but also include all resource-/management-based indicators. Importantly, this kind of contextual information regarding the animal's situation at the time of assessment is always required to appropriately interpret, and give valence to, animal-based indicators [ 12 , 30 ].…”