Abstract
BackgroundClassifying behaviour with animal-borne accelerometers is quickly becoming a popular tool for remotely observing behavioural states in a variety of species. Most accelerometry work in pinnipeds has focused on classifying behaviour at sea often quantifying behavioural trade-offs associated with foraging and diving in income breeders. Very little work to date has been done to resolve behaviour during the critical period of lactation in a capital breeder. Capital breeding phocids possess finite reserves that they must allocate appropriately to maintain themselves and their new offspring during their brief nursing period. Within this short time, fine-scale behavioural trade-offs can have significant fitness consequences for mother and offspring and must be carefully managed. Here, we present a case study in extracting and classifying lactation behaviours in a wild, breeding pinniped, the grey seal (Halichoerus grypus).ResultsUsing random forest models, we were able to resolve 4 behavioural states that constitute the majority of a female grey seals’ activity budget during lactation. Resting, alert, nursing, and a form of pup interaction were extracted and classified reliably. For the first time, we quantified the potential confounding variance associated with individual differences in a wild context as well as differences due to sampling location in a largely inactive model species.ConclusionsAt this stage, the majority of a female grey seal’s activity budget was classified well using accelerometers, but some rare and context-dependent behaviours were not well captured. While we did find significant variation between individuals in behavioural mechanics, individuals did not differ significantly within themselves; inter-individual variability should be an important consideration in future efforts. These methods can be extended to other efforts to study grey seals and other pinnipeds who exhibit a capital breeding system. Using accelerometers to classify behaviour during lactation allows for fine-scale assessments of time and energy trade-offs for species with fixed stores.
Highlights
Classifying behaviour with animal-borne accelerometers is quickly becoming a popular tool for remotely observing behavioural states in a variety of species
Accelerometers sampling at a higher frequency (50 Hz in 2015; Fig. 2) was better able to classify behaviours such as Alert than those sampling at a lower frequency (25 Hz in 2016; Table 3), resulting in an F1 of 45% greater for 2015
While we could detect no bias in Presenting/Nursing towards lying on the left or right, our result indicates that some grey seal females may exhibit a preference towards left handed flippering of the pup irrespective of affective state, which is consistent with research indicating that this will keep the pup in the left eye allowing control by the right hemisphere of the brain, associated kin recognition and threat recognition in mammals [88, 89, 91,92,93]
Summary
Classifying behaviour with animal-borne accelerometers is quickly becoming a popular tool for remotely observing behavioural states in a variety of species. These accelerometry deployments focus on building coarse-scale activity budgets for resolving energetics associated with foraging and diving or towards more finescale event detection, such as head-striking behaviour, to infer the rate of prey consumption relative to energy expenditure at sea [17,18,19,20] These studies tend to focus on species who exhibit an income approach to the reproductive period of their life history, in which they must regularly supplement their energy stores to maintain and provision their pups, or focus on detecting and classifying behaviour outside of the reproductive period While accelerometers have been used extensively to study the behaviour of terrestrial animals, rarely has any accelerometry research been geared to the consequences of behaviour associated with the brief, but important onland portion of seal life history (e.g. [21,22,23,24,25,26])
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
