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

Abstract

Despite the known benefit of considering welfare within wildlife conservation and management, there remains a lack of data to inform such evaluations. To assess animal welfare, relevant information must be captured scientifically and systematically. A key first step is identifying potential indicators of welfare and the practicality of their measurement. We assessed the feasibility of evaluating potential welfare indicators from opportunistically gathered video footage of four stranded odontocete species (n = 53) at 14 stranding events around New Zealand. The first stranded cetacean ethogram was compiled, including 30 different behaviours, 20 of which were observed in all four species. Additionally, thirteen types of human intervention were classified. A subset of 49 live stranded long-finned pilot whales (Globicephala melas edwardii) were assessed to determine indicator prevalence and to quantify behaviours. Four ‘welfare status’ and six ‘welfare alerting’ non-behavioural indicators could be consistently evaluated from the footage. Additionally, two composite behavioural indicators were feasible. Three human intervention types (present, watering, and touching) and five animal behaviours (tail flutter, dorsal fin flutter, head lift, tail lift, and head side-to-side) were prevalent (>40% of individuals). Our study highlights the potential for non-invasive, remote assessments via video footage and represents an initial step towards developing a systematic, holistic welfare assessment framework for stranded cetaceans.

Assessing animal welfare during a stranding of pygmy killer whales (Feresa attenuata)

“…In terms of physical state due to environmental conditions (Domain 2), no skin blistering was evident on either animal, which contrasts with the common occurrence at some stranding events (Boys et al, 2022c;Groch et al, 2018). Although both animals stranded at the end of austral summer on a day with high UV index, both were discovered and monitored on an overcast day and were rapidly protected with sheets and cooling water.…”

“…of welfare assessment articulated byBoys et al (2022c) in the context of cetacean strandings, this study provides further evidence of the ability to undertake holistic assessments using a variety of potential noninvasive welfare indicators. Opportunistic collection of tissue samples postmortem enabled exploration of potential relationships among external welfare indicators and histopathology to support inferences about welfare state.…”

“…Equipment availability was noted based on the use of sheets over the animals' body and water being poured over the animal for cooling, as well as the availability of spades for digging, and refloatation mats. The substrate type, weather, sea swell, and tidal conditions were also observed (Boys et al, 2022c), with those most prevalent (>50% duration) throughout the filmed stranding period being recorded. UV intensity was based on the UV index calculated by National Institute of Water and Atmospheric Research (National Institute of Water and Atmospheric Research, 2020) for the specific date, time, and location of the stranding.…”

“…Additionally, information on conspecific age class and sex were collected where possible. Finally, human intervention was characterized based on the number of people and following the ethogram constructed for intervention types (Boys et al, 2022c; Table S2). Duration of each intervention type was quantified based on its occurrence per animal and was coded in BORIS.…”

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

“…Behavioural indicators probably reflect how the animal's ability to exercise agency or choice is impacted by its unnatural situation and can be used to infer how it is experiencing its current situation. Unfortunately, there has been only one ethological study undertaken on stranded cetaceans [ 83 ], therefore assessing abnormal movements and what they may reflect in these animals is currently limited. Nevertheless, some behaviours have been noted previously as informing refloat decisions based on animal disposition [ 15 , 16 , 84 ].…”