• The role of brain size on mammalian population densities

      González-Suárez, Manuela; Gonzalez-Voyer, Alejandro; von Hardenberg, Achaz; Santini, Luca; University of Reading; Universidad Autonoma de Mexico; University of Chester; Italian National Research Council (Wiley, 2020-12-22)
      1. The local abundance or population density of different organisms often varies widely. Understanding what determines this variation is an important, but not yet fully resolved question in ecology. Differences in population density are partly driven by variation in body size and diet among organisms. Here we propose that the size of an organism’ brain could be an additional, overlooked, driver of mammalian population densities. 2. We explore two possible contrasting mechanisms by which brain size, measured by its mass, could affect population density. First, because of the energetic demands of larger brains and their influence on life history, we predict mammals with larger relative brain masses would occur at lower population densities. Alternatively, larger brains are generally associated with a greater ability to exploit new resources, which would provide a competitive advantage leading to higher population densities among large‐brained mammals. 3. We tested these predictions using phylogenetic path analysis, modelling hypothesized direct and indirect relationships between diet, body mass, brain mass and population density for 656 non‐volant terrestrial mammalian species. We analysed all data together and separately for marsupials and the four taxonomic orders with most species in the dataset (Carnivora, Cetartiodactyla, Primates, Rodentia). 4. For all species combined, a single model was supported showing lower population density associated with larger brains, larger bodies and more specialized diets. The negative effect of brain mass was also supported for separate analyses in Primates and Carnivora. In other groups (Rodentia, Cetartiodactyla and marsupials) the relationship was less clear: supported models included a direct link from brain mass to population density but 95% confidence intervals of the path coefficients overlapped zero. 5. Results support our hypothesis that brain mass can explain variation in species’ average population density, with large‐brained species having greater area requirements, although the relationship may vary across taxonomic groups. Future research is needed to clarify whether the role of brain mass on population density varies as a function of environmental (e.g. environmental stability) and biotic conditions (e.g. level of competition).
    • Contrasting responses to salinity and future ocean acidification in arctic populations of the amphipod Gammarus setosus

      Brown, James; Whiteley, Nia; Bailey, Allison; Graham, Helen; Hop, Haakon; Rastrick, Samuel; University of Chester; Bangor University; Norwegian Polar Institute; Institute of Marine Research; Norwegian Polar Institute; Institute of Marine Research (Elsevier, 2020-10-07)
      Climate change is leading to alterations in salinity and carbonate chemistry in arctic/sub-arctic marine ecosystems. We examined three nominal populations of the circumpolar arctic/subarctic amphipod, Gammarus setosus, along a salinity gradient in the Kongsfjorden-Krossfjorden area of Svalbard. Field and laboratory experiments assessed physiological (haemolymph osmolality and gill Na+/K+-ATPase activity, NKA) and energetic responses (metabolic rates, MO2, and Cellular Energy Allocation, CEA). In the field, all populations had similar osmregulatory capacities and MO2, but lower-salinity populations had lower CEA. Reduced salinity (S = 23) and elevated pCO2 (~1000 μatm) in the laboratory for one month increased gill NKA activities and reduced CEA in all populations, but increased MO2 in the higher-salinity population. Elevated pCO2 did not interact with salinity and had no effect on NKA activities or CEA, but reduced MO2 in all populations. Reduced CEA in lower-rather than higher-salinity populations may have longer term effects on other energy demanding processes (growth and reproduction).
    • The role of specific biomarkers, as predictors of post-operative complications following flexible ureterorenoscopy (FURS), for the treatment of kidney stones: a single-centre observational clinical pilot-study in 37 patients

      Hughes, Stephen Fôn; orcid: 0000-0001-6558-9037; email: Stephen.hughes6@wales.nhs.uk; Moyes, Alyson Jayne; Lamb, Rebecca May; Ella-tongwiis, Peter; Bell, Christopher; Moussa, Ahmed; Shergill, Iqbal (BioMed Central, 2020-08-14)
      Abstract: Background: The number of patients diagnosed and subsequently treated for kidney stones is increasing, and as such the number of post-operative complications is likely to increase. At present, little is known about the role of specific biomarkers, following flexible ureterorenoscopy (FURS) for the surgical treatment of kidney stones. The main aim of the study was to evaluate the role of kidney and infection biomarkers, in patients undergoing FURS. Methods: Included were 37 patients (24 males, 13 females), who underwent elective FURS, for the treatment of kidney stones. Venous blood samples were collected from each patient: pre-operatively, and at 30 min, 2 and 4 h post-operatively. Changes to kidney (NGAL, Cystatin-C) and infection (MPO, PCT) biomarkers was quantified by means of ELISA, Biomerieux mini-vidas and Konelab 20 analysers. Results: Four patients developed post-operative complications (3 - UTIs with urinary retention, 1 - urosepsis. NGAL concentration increased significantly following FURS (p = 0.034). Although no significant changes were seen in Cystatin C, MPO and PCT (p ≥ 0.05) some key clinical observation were noted. Limiting factors for this study were the small number of patients recruited and restriction in blood sampling beyond 4 h. Conclusions: Although not confirmative, changes seen to biomarkers such as Cystatin C, NGAL and MPO in our observational clinical pilot-study may warrant further investigation, involving larger cohorts, to fully understand the role of these biomarkers and their potential association with post-operative complications which can develop following FURS.
    • White-faced Darter distribution is associated with coniferous forests in Great Britain

      Geary, Matthew; von Hardenberg, Achaz; Conservation Biology Research Group, Department of Biological Science, University of Chester, Chester, CH1 4BJ (Wiley, 2020-08-11)
      Abstract 1) Understanding of dragonfly distributions is often geographically comprehensive but less so in ecological terms. 2) White-faced darter (Leucorhinnia dubia) is a lowland peatbog specialist dragonfly which has experienced population declines in Great Britain. White-faced darter are thought to rely on peat-rich pool complexes within woodland but this has not yet been empirically tested. 3) We used dragonfly recording data collected by volunteers of the British Dragonfly Society from 2005 to 2018 to model habitat preference for white-faced darter using species distribution models across Great Britain and, with a more detailed landcover dataset, specifically in the North of Scotland. 4) Across the whole of Great Britain our models used the proportion of coniferous forest within 1km as the most important predictor of habitat suitability but were not able to predict all current populations in England. 5) In the North of Scotland our models were more successful and suggest that habitats characterised by native coniferous forest and areas high potential evapotranspiration represent the most suitable habitat for white-faced darter. 6) We recommend that future white-faced darter monitoring should be expanded to include areas currently poorly surveyed but with high suitability in the North of Scotland. 7) Our results also suggest that white-faced darter management should concentrate on maintaining Sphagnum rich pool complexes and the maintenance and restoration of native forests in which these pool complexes occur.
    • Seascape genomics reveals population isolation in the reef-building honeycomb worm, Sabellaria alveolata (L.)

      Dubois, Stanislas; Muir, Anna P; orcid: 0000-0002-6896-6915; Ross, Rebecca; Firth, Louise; Knights, Antony; Lima, Fernando; Seabra, Rui; Corre, Erwan; Le Corguillé, Gildas; Nunes, Flavia; et al. (BMC, 2020-08-10)
      Background: Under the threat of climate change populations can disperse, acclimatise or evolve in order to avoid fitness loss. In light of this, it is important to understand neutral gene flow patterns as a measure of dispersal potential, but also adaptive genetic variation as a measure of evolutionary potential. In order to assess genetic variation and how this relates to environment in the honeycomb worm (Sabellaria alveolata (L.)), a reef-building polychaete that supports high biodiversity, we carried out RAD sequencing using individuals from along its complete latitudinal range. Patterns of neutral population genetic structure were compared to larval dispersal as predicted by ocean circulation modelling, and outlier analyses and genotype-environment association tests were used to attempt to identify loci under selection in relation to local temperature data. Results: We genotyped 482 filtered SNPs, from 68 individuals across nine sites, 27 of which were identified as outliers using BAYESCAN and ARLEQUIN. All outlier loci were potentially under balancing selection, despite previous evidence of local adaptation in the system. Limited gene flow was observed among reef-sites (FST = 0.28 ± 0.10), in line with the low dispersal potential identified by the larval dispersal models. The North Atlantic reef emerged as a distinct population and this was linked to high local larval retention and the effect of the North Atlantic Current on dispersal. Conclusions: As an isolated population, with limited potential for natural genetic or demographic augmentation from other reefs, the North Atlantic site warrants conservation attention in order to preserve not only this species, but above all the crucial functional ecological roles that are associated with their bioconstructions. Our study highlights the utility of using seascape genomics to identify populations of conservation concern.
    • The importance of long-term genetic monitoring of reintroduced populations: inbreeding in the natterjack toad (Epidalea calamita)

      Muir, Anna P.; Phillips, Susanna; Geary, Matt; Allmark, Matthew; Bennett, Sarah; Norman, Kim; Ball, Rachel J; Peters, Catherine; University of Chester; Cheshire Wildlife Trust; Eni UK Ltd (British Herpetological Society, 2020-07-31)
      Genetic monitoring is an important, but frequently lacking, component of management actions to support long-term persistence in reintroduced populations. Populations that remain small, due to demographic processes and genetic diversity, are more likely to experience a second extinction event. The natterjack toad (Epidelea calamita) is legally protected in Britain and was the subject of a reintroduction programme in the 1990s. However, subsequent genetic assessment has been mostly lacking. The aim of this study was to assess the genetic diversity of two reintroduced populations of natterjack toads in order to inform conservation management. Adults were sampled and nine microsatellites amplified to assess neutral genetic variation within each site and for comparison with the source population. Inbreeding was observed at the reintroduction sites, as evidenced by high FIS values (0.43 and 0.72), low observed compared to expected heterozygosities, and significant deviation from Hardy-Weinberg equilibrium. Observed heterozygosity is currently lower in the reintroduction sites than it was in the source population at the time of the reintroductions (Red Rocks: 0.15±0.20; Talacre: 0.12±0.20; Ainsdale (source): 0.29). Evidence for a bottleneck was not found, although this is likely a result of sampling overlapping generations. No within-site population structuring was observed. Such low genetic diversity has not previously been recorded in any natterjack population. Genetic rescue, combined with pool creation, is the most viable option for safeguarding the species at these sites into the future. Our work highlights the importance of ongoing genetic monitoring, in collaboration with conservation organisations, to support conservation management.
    • Social Experience of Captive Livingstone’s Fruit Bats (Pteropus livingstonii)

      Stanley, Christina R; Smith, Tessa; Welch, Morgan J; Hosie, Charlotte; Wormell, Dominic; Price, Eluned; University of Chester; Jersey Zoo (MDPI, 2020-07-30)
      Social network analysis has been highlighted as a powerful tool to enhance the evidence-based management of captive-housed species through its ability to quantify the social experience of individuals. We apply this technique to explore the social structure and social roles of 50 Livingstone’s fruit bats (Pteropus livingstonii) housed at Jersey Zoo, Channel Islands, through the observation of associative, affiliative, and aggressive interactions over two data collection periods. We implement binomial mixture modelling and characteristic-based assortment quantification to describe the complexity and organisation of social networks, as well as a multiple regression quadratic assignment procedural (MRQAP) test to analyse the relationship between network types. We examine the effects of individual characteristics (i.e., sex, age, and dominance rank) on social role by fitting models to explain the magnitude of node metrics. Additionally, we utilize a quadratic assignment procedural (QAP) test to assess the temporal stability of social roles over two seasons. Our results indicate that P. livingstonii display a non-random network structure. Observed social networks are positively assorted by age, as well as dominance rank. The frequency of association between individuals correlates with a higher frequency of behavioural interactions, both affiliative and aggressive. Individual social roles remain consistent over ten months. We recommend that, to improve welfare and captive breeding success, relationships between individuals of similar ages and dominance levels should be allowed to persist in this group where possible, and separating individuals that interact frequently in an affiliative context should be avoided.
    • Margaret Chorley Crosfield, FGS: the very first female Fellow of the Geological Society

      Burek, C. V.; orcid: 0000-0002-7931-578X (Geological Society of London, 2020-07-10)
      AbstractIn May 1919 the first female Fellows of the Geological Society were elected and from then on attended meetings at the Society. The first person on the female fellows’ list was Margaret Chorley Crosfield. She was born in 1859 and died in 1952. She lived all her life in Reigate in Surrey. After studying and then leaving Cambridge, Margaret had sought to join the Geological Society of London for many years, in order to gain recognition of her research work, but also to attend meetings and use the library. This paper will look at her history and trace her geological achievements in both stratigraphy and palaeontology, as well as her extraordinary field notebooks that she left to the Geological Survey. She worked closely with two female geological colleagues, Mary Johnston and Ethel Skeat. Margaret Crosfield epitomizes the educated, amateur, independent woman who wanted to be recognized for her work, especially fieldwork, at a time when female contributions, especially in the field sciences, were not always acknowledged or even appreciated.
    • Mangrove or mudflat: Prioritising fish habitat for conservation in a turbid tropical estuary

      Marley, Guy; Deacon, Amy; Philip, Dawn; Lawrence, Andrew; University of the West Indies, University of the West Indies, University of the West Indies, University of Chester (Elsevier, 2020-04-26)
      Mangrove habitats are typically the focus of conservation efforts in tropical estuaries because their structural complexity is thought to support greater biodiversity and nursery function than unvegetated habitats. However, evidence for this paradigm has been equivocal in turbid tropical estuaries where unvegetated mudflats are also highly productive. The present study compared the community composition, biodiversity, nursery-role and commercial fish biomass in two mangrove habitats and one mudflat habitat in the Gulf of Paria, Trinidad. A total of 12 705 fishes, comprising 63 species from 26 families, were sampled in mangrove creeks, seaward mangrove fringe and the subtidal margin of an intertidal mudflat from June 2014 to June 2015. The composition of the creek and mudflat communities were distinct, while the community of the mangrove fringe more closely resembled the mudflat than the mangrove creeks. Mean species richness (MSR), total species richness (TSR) extrapolated from species accumulation curves, and juvenile species richness (JSR) were significantly greater in the mudflat (MSR = 11.4 ± 1.0; TSR = 75 ± 14; JSR = 9.1 ± 0.8) than mangrove creeks (MSR = 9.0 ± 0.5; TSR = 49 ± 3; JSR = 6.1 ± 0.4) and the seaward mangrove fringe (MSR = 6.4 ± 0.7; TSR = 58 ± 14; JSR = 5.2 ± 0.4). Meanwhile, Shannon Weiner diversity, juvenile fish abundance and commercial fish biomass were comparable between habitats. These findings caution against the generalisation that mangroves are the most important habitat for fishes in turbid tropical estuaries. There is now a growing body of evidence that mudflats warrant consideration as important repositories of biodiversity and nursery function for juvenile fishes.
    • Distribution, status and recent population dynamics of Alpine ibex Capra ibex in Europe

      Brambillla, Alice; von Hardenberg, Achaz; Nelli, Luca; Bassano, Bruno; University of Zurich, University of Chester, University of Glasgow, Gran Paradiso National PArk (Wiley, 2020-04-20)
      1. Despite its recent successful and well-documented reintroduction history, a comprehensive and current update of the distribution and status of the Alpine ibex Capra ibex is lacking. As some concerns persist about its conservation, a status update appears essential for future conservation and management strategies on a large scale. 2. We provide an exhaustive update of the geographic range of the species, alongside estimates of its current abundance and population trends from 2004 to 2015. 3. We gathered census and distribution data for all the Alpine ibex colonies from management authorities and research groups that monitor them in different countries, and from the literature and publicly available reports. We produced a distribution map, reported the number of individuals observed in the most recent censuses, and estimated global, national, and local population trends using Bayesian hierarchical models. 4. Our model estimated that there were a total of 55297 Alpine ibex in the Alps in 2015 (lower 95% Credible Interval [CrI]: 51157; upper 95% CrI: 62710). The total number of individuals appears to have increased slightly over the last 10 years from the 47000-51000 estimated in previous reports. Positive population trends were observed in Switzerland and Italy, while no trend was apparent in France. For Austria, Germany, and Slovenia, there were insufficient data to estimate a trend. The slopes of the colonies’ trends were positively correlated with the year of colony foundation. 5. The geographic range of the Alpine ibex does not seem to have increased in size in recent years, although the accuracy of the spatial data varies among countries. 6. The periodic and standardised collection of census data for all colonies and a common policy of data-sharing at a European level appear essential for monitoring the global trend of this species and for planning balanced conservation and management actions.
    • Current strength, temperature, and bodyscape modulate cleaning services for giant manta rays

      Murie, Calum; Spencer, Matthew; Oliver, Simon; University of Chester (Springer, 2020-04-07)
      The cleaner-client system among reef teleosts has received considerable attention in both wild and captive environments, but the spatially and taxonomically diverse associations between cleaner fish and elasmobranchs are less understood. Using remote video, we investigated interactions between giant manta rays (Mobula birostris) and cleaner wrasse at a seamount in the Philippines. Cleaning events occurred between 11:00 and 16:00 hours on a seasonal basis and were constrained by current strengths and ambient water temperatures. The frequency with which giant manta rays interacted with cleaner fish varied on an individual basis. Blue streaked cleaner wrasse (Labroides dimidiatus) and moon wrasse (Thalassoma lunare) selectively foraged on manta rays’ gills and pelvis, with L. dimidiatus also demonstrating slight preferences for the pectoral fins. Cleaners’ foraging preferences may indicate ectoparasitic infections in specific areas of a manta ray’s body. The exclusivity with which giant manta rays visited a particular cleaning station on the seamount may be a response to the quality of services that cleaners provide there. Giant mantas’ fidelity to this site may also be attributed to localised concentrations of food that are available nearby. The seamount provides habitat that appears to be important to the life history strategies of the region’s giant manta rays.
    • A novel method to optimise the utility of underused moulted plumulaceous feather samples for genetic analysis in bird conservation.

      Peters, Catherine; Nelson, Howard; Rusk, Bonnie; Muir, Anna P.; Rusk, Bonnie L.; University of Chester (Springer, 2019-10-24)
      Non-invasive sampling methods are increasingly being used in conservation research as they reduce or eliminate the stress and disturbance resulting from invasive sampling of blood or tissue. Here we present a protocol optimised for obtaining usable genetic material from moulted plumulaceous feather samples. The combination of simple alterations to a ‘user-developed’ method, comprised of increased incubation time and modification of temperature and volume of DNA elution buffer, are outlined to increase DNA yield and significantly increase DNA concentration (W = 81, p <0.01, Cohens’s d= 0.89). We also demonstrate that the use of a primerless Polymerase Chain Reaction (PCR) technique increases DNA quality and amplification success when used prior to PCR reactions targeting avian mitochondrial DNA (mtDNA). A small amplicon strategy proved effective for mtDNA amplification using PCR, targeting three overlapping 314-359bp regions of the cytochrome oxidase I barcoding region which, when combined, aligned with target-species reference sequences. We provide evidence that samples collected non-invasively in the field and kept in non-optimal conditions for DNA extraction can be used effectively to sequence a 650bp region of mtDNA for genetic analysis.
    • “You Can’t Really Hug a Tiger”: Zookeepers and Their Bonds with Animals

      Birke, Lynda; Hosey, Geoff; Melfi, Vicky (Informa UK Limited, 2019-09-20)
    • Preparation of Primary Rat Hepatocyte Spheroids Utilizing the Liquid-Overlay Technique.

      Kyffin, Jonathan A; Cox, Christopher R; Leedale, Joseph; Colley, Helen E; Murdoch, Craig; Mistry, Pratibha; Webb, Steven D; Sharma, Parveen (2019-09)
      Herein, we describe a protocol for the preparation and analysis of primary isolated rat hepatocytes in a 3D cell culture format described as spheroids. The hepatocyte cells spontaneously self-aggregate into spheroids without the need for synthetic extracellular matrices or hydrogels. Primary rat hepatocytes (PRHs) are a readily available source of primary differentiated liver cells and therefore conserve many of the required liver-specific functional markers, and elicit the natural in vivo phenotype when compared with common hepatic cells lines. We describe the liquid-overlay technique which provides an ultra-low attachment surface on which PRHs can be cultured as spheroids. © 2019 The Authors. Basic Protocol 1: Preparation of agarose-coated plates Basic Protocol 2: Primary rat hepatocyte isolation procedure Basic Protocol 3: Primary rat hepatocyte spheroid culture Basic Protocol 4: Immunofluorescent analysis of PRH spheroids. [Abstract copyright: © 2019 The Authors.]
    • Individual, social, and environmental factors affecting salivary and fecal cortisol levels in captive pied tamarins (Saguinus bicolor)

      Wormell, Dominic; Smith, Tessa E.; Price, Eluned E.; Ahsmann, J.; Glendewar, G.; Hunt, J.; Coleman, Robert, C.; University of Chester (Wiley, 2019-08-01)
      Pied tamarins (Saguinus bicolor) are endangered New World primates, and in captivity appear to be very susceptible to stress. We measured cortisol in 214 saliva samples from 36 tamarins and in 227 fecal samples from 27 tamarins, and investigated the effects of age, sex, pregnancy, rearing history, social status, weight, group composition, and enclosure type using generalized linear mixed models. There was no effect of age on either fecal or salivary cortisol levels. Female pied tamarins in late pregnancy had higher fecal cortisol levels than those in early pregnancy, or nonpregnant females, but there was no effect of pregnancy on salivary cortisol. Females had higher salivary cortisol levels than males, but there was no effect of rearing history. However, for fecal cortisol, there was an interaction between sex and rearing history. Hand‐reared tamarins overall had higher fecal cortisol levels, but while male parent‐reared tamarins had higher levels than females who were parent‐ reared, the reverse was true for hand‐reared individuals. There was a trend towards lower fecal cortisol levels in subordinate individuals, but no effect of status on salivary cortisol. Fecal but not salivary cortisol levels declined with increasing weight. We found little effect of group composition on cortisol levels in either saliva or feces, suggesting that as long as tamarins are housed socially, the nature of the group is of less importance. However, animals in off‐show enclosures had higher salivary and fecal cortisol levels than individuals housed on‐show. We suggest that large on‐show enclosures with permanent access to off‐exhibit areas may compensate for the effects of visitor disturbance, and a larger number of tamarins of the same species housed close together may explain the higher cortisol levels found in tamarins living in off‐show accommodation, but further research is needed.
    • The importance of research applicability

      McLennan, Krista M.; University of Chester (The Humane Society Institute for Science and Policy, 2019-06-30)
      Marino & Merskin’s (2019) review contains key information about the complexity of sheep and their intelligence level, but lacks practical application. The key to making any long-term changes to sheep welfare at an industry level is by generating research that is practically relevant to the sector. The practical application of research should be considered at the design stage and in consultation with producers. Additionally, thought needs to be given to how the practical application of the research will be transferred to those people directly involved in animal care (e.g. producers, stockpersons, etc.). Focusing on the practical relevance and application of research at all stages of the process will foster changes to long-held beliefs and attitudes.
    • Ida Slater: A Collection Researcher in a Male World at the Beginning of the 20th Century

      Sendino, Consuelo; Ducker, Erik; Burek, Cynthia V. (SAGE Publications, 2019-06-27)
      Ida Lilian Slater (1881-1969) was one of the first women to work as a geologist in a male world, and although her career was short, she made important contributions to the Early Palaeozoic of Wales and Scotland. Her main work was based on a collection of a group of fossil scypho-zoan polyps gathered not by her but by another significant woman, Elizabeth Anderson, widely known as Mrs. Robert Gray (1831-1924). The majority of this collection is kept at the Natural History Museum (NHM), London, and the Sedgwick Museum, Cambridge. She worked in the former one for two years describing species and comparing specimens for her monograph on British conulariids. Although her work was based not only on this group, she will be remembered by her important contribution to the conulariids through collections. The NHM collection is considered the best in the world in terms of diversity and the second best in its number of specimens, while the Sedgwick Museum has a smaller collection that is still considered the second best in diversity and number of specimens in the United Kingdom. Her work has been cited for more than 100 years and continues to be cited to this day by researchers on this group of fossils.
    • Archibald Geikie: His influence on and support for the roles of female geologists

      Burek, Cynthia V.; University of Chester (Geological Society of London, 2019-06-19)
      This chapter explores the interaction between Archibald Geikie and female geologists in their many different roles and within the social context of his life time (1835-1924). The roles adopted by female geologists altered around 1875 due to a change in the educational and legal background. Geikie’s attitude to female fieldwork and research publications changes through time too. His life is divided up into 5 different stages according to his influence. Case studies of both single and married women are explored looking at the influence and interaction they had with Archibald Geikie. They include Maria Ogilvie Gordon, Catherine Raisin, Annie Greenly, Gertrude Elles, Ethel Skeat and Ethel Wood. Was one female role more acceptable to him than others? Geikie seems to accept most of the roles they undertook and he supported them wherever he could.
    • Conceptual and methodological issues relating to pain assessment in mammals: the development and utilisation of pain facial expression scales.

      McLennan, Krista M.; Miller, Amy, L.; Dalla Costa, Emanuela; Stucke, Diana; Corke, Murray J.; Broom, Donald M.; Leach, Matthew C.; University of Chester; Newcastle University; c Università degli Studi di Milano; Havelland Equine Clinic; University of Cambridge (Elsevier, 2019-06-12)
      Effective management of pain is critical to the improvement of animal welfare. For this to happen, pain must be recognised and assessed in a variety of contexts. Pain is a complex phenomenon, making reliable, valid, and feasible measurement challenging. The use of facial expressions as a technique to assess pain in non-verbal human patients has been widely utilised for many years. More recently this technique has been developed for use in a number of non-human species: rodents, rabbits, ferrets, cats, sheep, pigs and horses. Facial expression scoring has been demonstrated to provide an effective means of identifying animal pain and in assessing its severity, overcoming some of the limitations of other measures for pain assessment in animals. However, there remain limitations and challenges to the use of facial expression as a welfare assessment tool which must be investigated. This paper reviews current facial expression pain scales (“Grimace Scales"), discussing the general conceptual and methodological issues faced when assessing pain, and highlighting the advantages of using facial expression scales over other pain assessment methods. We provide guidance on how facial expression scales should be developed so as to be valid and reliable, but we also provide guidance on how they should be used in clinical practice.