This study aimed to identify if sensor technology could be used to detect sickness-type signs (caused by a live vaccine) in laying hens compared to physiological and clinical sign scoring and behaviour observation. The experiment comprised 5 replicate batches (4 hens and 12 days per batch) using previously non-vaccinated hens (n = 20). Hens were moved on day 1 to a large experimental room with various designated zones (e.g., litter, perches, nest box), where they wore two sensors (FitBark, TrackLab). Saline was applied using ocular and nasal drops on day 3 as a control. A live vaccine (Infectious Laryngotracheitis, ILT, vaccine), applied using the same method on day 6, was used to induce mild respiratory and other responses. Physiological and clinical signs, and behaviour from videos were also recorded by a single observer. There were significant changes in body weight (p < 0.001), feed intake (p = 0.031), cloacal temperature (p < 0.001) and three out of five clinical signs (ocular discharge (p < 0.001), conjunctivitis (p < 0.001) and depression (p = 0.009)) over days. A significant decrease (p < 0.001) in activity level (FitBark) and distance travelled (both sensors) were identified over the study days, and activity and distance travelled were highly significantly associated (p < 0.001) with total clinical scores, with hens showing reduced activity and distance travelled with worsening total clinical scores. With behaviour observations from videos, the proportions of sitting, foraging and feeding behaviours (p = 0.044, 0.036 and 0.004, respectively), the proportion of total visit duration to the litter zone (p < 0.001) and perch (p = 0.037) with TrackLab and the proportions of visit counts of hens in the litter zone (p = 0.012) from video scanning changed significantly with days. This study suggests that the vaccine challenge caused associated changes in clinical/physiological signs and activity/distance travelled data from the sensors. Sensors may have a role in detecting changes in activity and movement in individual hens indicative of health or welfare problems.

Pregnant (dry) sows are fed a restricted food ration to ensure good health, production and longevity, but this results in behavioural signs of hunger: oral behaviours increase and may be redirected 'unnaturally' towards non-food, prompting welfare concerns. 'Dietary fibre' encompasses a variety of chemical classes, with a variety of physiochemical properties. It reduces abnormal oral behaviours, and fibres that are soluble and fermentable in the hindgut appear to prolong satiety, reduce activity and improve welfare. EU rules require fibre in dry sow diets and access to foraging materials but implementation differs across member states. Diet, feeding system, number of meals and social structure combine to affect welfare of the sow and developing piglets, e.g., through pre-natal stress. Current breeding trends to increasing litter size and associated practices like the use of 'nurse sows' may require a rethink of sow nutrition to safeguard longevity and welfare.

Animal welfare assessments have struggled to investigate the emotional states of animals while focusing solely on available empirical evidence. Qualitative Behavioural Assessment (QBA) may provide insights into an animal's subjective experiences without compromising scientific rigor. Rather than assessing explicit, physical behaviours (i.e., what animals are doing, such as swimming or feeding), QBA describes and quantifies the overall expressive manner in which animals execute those behaviours (i.e., how relaxed or agitated they appear). While QBA has been successfully applied to scientific welfare assessments in a variety of species, its application within aquaculture remains largely unexplored. This study aimed to assess QBA's effectiveness in capturing changes in the emotional behaviour of Atlantic salmon following exposure to a stressful challenge. Nine tanks of juvenile Atlantic salmon were video-recorded every morning for 15 min over a 7-day period, in the middle of which a stressful challenge (intrusive sampling) was conducted on the salmon. The resultant 1-min, 63 video clips were then semi-randomised to avoid predictability and treatment bias for QBA scorers. Twelve salmon-industry professionals generated a list of 16 qualitative descriptors (e.g., relaxed, agitated, stressed) after viewing unrelated video-recordings depicting varying expressive characteristics of salmon in different contexts. A different group of 5 observers, with varied experience of salmon farming, subsequently scored the 16 descriptors for each clip using a Visual Analogue Scale (VAS). Principal Components Analysis (correlation matrix, no rotation) was used to identify perceived patterns of expressive characteristics across the video-clips, which revealed 4 dimensions explaining 74.5% of the variation between clips. PC1, ranging from 'relaxed/content/positive active' to 'unsettled/stressed/spooked/skittish' explained the highest percentage of variation (37%). QBA scores for video-clips on PC1, PC2, and PC4 achieved good inter- and intra-observer reliability. Linear Mixed Effects Models, controlled for observer variation in PC1 scores, showed a significant difference between PC1 scores before and after sampling (p = 0.03), with salmon being perceived as more stressed afterwards. PC1 scores also correlated positively with darting behaviours (r = 0.42, p < 0.001). These results are the first to report QBA's sensitivity to changes in expressive characteristics of salmon following a putatively stressful challenge, demonstrating QBA's potential as a welfare indicator within aquaculture.

The intensification of Scottish salmon farming has been associated with increasing demands for the monitoring and safeguarding of farmed salmon welfare. Continued growth of farm productivity, while avoiding adverse effects on salmon welfare, will require the development of effective welfare assessment tools. This paper reports on a survey of the Scottish salmon farming industry, which was conducted to understand current salmon welfare concerns and priorities for research. As part of a broader aim for further developing tools for on-farm salmon welfare assessment, a total of 61 individuals working in the Scottish salmon farming industry took part. This survey intentionally focused on industry stakeholders to provide insights into current practices and challenges associated with monitoring and assessing salmon welfare. Participants were recruited through authors' industry contacts, online advertisements, and searches of company websites. In terms of production stages, survey participants believed that the seawater rearing stage is a major area of concern, largely due to the challenges presented by sea lice. Gill health and environmental challenges, mainly relating to water quality, were two other highly ranked welfare concerns. Methods to monitor salmon welfare during husbandry practices, where disturbances and contact with the salmon is unavoidable (particularly during crowding, grading, and interventions), were emphasised as a priority. Although these were identified as the major concerns, the survey indicated that there are other significant welfare concerns specific to each production stage that also require consideration. Participants highlighted non-invasive, remote, and animal-based welfare measures as important areas for further development for on-farm welfare assessments. Behavioural measures were identified as having the potential to make a major contribution in this context. This survey presents the first collection of opinions from professionals employed across the Scottish salmon farming industry regarding the current overall state of farmed salmon welfare. This study upholds the importance of using an integrated approach to welfare assessments, and that behavioural measures could play an important role in ensuring these assessments benefit both salmon welfare and farm productivity.

Undesirable behaviours (UBs) in dogs are common and important issues with serious potential welfare consequences for both the dogs and their owners. This study aimed to investigate the usage of drug therapy for UBs in dogs and assess demographic risk factors for drug-prescribed UBs within the dog population under primary-care veterinary care in the UK in 2013. Dogs receiving drug therapy for UB were identified through the retrospective analysis of anonymised electronic patient records in VetCompass™. Risk factor analysis used multivariable logistic regression modelling. The study population comprised 103,597 dogs under veterinary care in the UK during 2013. There were 413 drug-prescribed UBs recorded among 404 dogs. The prevalence of dogs with at least one UB event treated with a drug in 2013 was 0.4%. Multivariable modelling identified 3 breeds with increased odds of drug-prescribed UB compared with crossbred dogs: Toy Poodle (OR 2.75), Tibetan Terrier (OR 2.68) and Shih-tzu (OR 1.95). Increasing age was associated with increased odds of drug-prescribed UB, with dogs ≥ 12 years showing 3.1 times the odds compared with dogs < 3 years. Neutered males (OR 1.82) and entire males (OR 1.50) had increased odds compared with entire females. The relatively low prevalence of dogs with at least one UB event that was treated with a drug in 2013 could suggest that opportunities for useful psychopharmaceutical intervention in UBs may be being missed in first opinion veterinary practice. While bodyweight was not a significant factor, the 3 individual breeds at higher odds of an UB treated with a behaviour modifying drug all have a relatively low average bodyweight. The current results also support previous research of a male predisposition to UBs and it is possible that this higher risk resulted in the increased likelihood of being prescribed a behaviour modifying drug, regardless of neuter status.

There is a growing scientific and legislative consensus that fish are sentient, and therefore have the capacity to experience pain and suffering. The assessment of the welfare of farmed fish is challenging due to the aquatic environment and the number of animals housed together. However, with increasing global production and intensification of aquaculture comes greater impetus for developing effective tools which are suitable for the aquatic environment to assess the emotional experience and welfare of farmed fish. This study therefore aimed to investigate the use of Qualitative Behavioral Assessment (QBA), originally developed for terrestrial farmed animals, in farmed salmon and evaluate its potential for use as a welfare monitoring tool. QBA is a “whole animal” approach based on the description and quantification of the expressive qualities of an animal's dynamic style of behaving, using descriptors such as relaxed, agitated, lethargic, or confident. A list of 20 qualitative descriptors was generated by fish farmers after viewing video-footage showing behavior expressions representative of the full repertoire of salmon in this context. A separate, non-experienced group of 10 observers subsequently watched 25 video clips of farmed salmon, and scored the 20 descriptors for each clip using a Visual Analog Scale (VAS). To assess intra-observer reliability each observer viewed the same 25 video clips twice, in two sessions 10 days apart, with the second clip set presented in a different order. The observers were unaware that the two sets of video clips were identical. Data were analyzed using Principal Component (PC) Analysis (correlation matrix, no rotation), revealing four dimensions that together explained 79% of the variation between video clips, with PC1 (Tense/anxious/skittish—Calm/mellow/relaxed) explaining the greatest percentage of variation (56%). PC1 was the only dimension to show acceptable inter- and intra-observer reliability, and mean PC1 scores correlated significantly to durations of slow and erratic physical movements measured for the same 25 video clips. Further refinements to the methodology may be necessary, but this study is the first to provide evidence for the potential of Qualitative Behavioral Assessment to serve as a time-efficient welfare assessment tool for juvenile salmon under farmed conditions.

Undesirable behaviours (UBs) are common in dogs and can jeopardise animal and human health, leading to dog abandonment and euthanasia. Dogs exhibiting UBs may have compromised welfare from underlying emotional motivations for the behaviour (eg anxiety) or from the methods used by owners to resolve the problem (eg aversive techniques). The objective of this study was to estimate proportional mortality due to UBs and risk factors for death due to UBs, including death from road traffic accidents, in dogs under three years of age attending primary-care veterinary practices in England from 2009-2014. Cases were identified by searching de-identified electronic patient records from primary-care veterinary practices participating in the VetCompass Programme. The findings highlight that dogs under three years of age are at a proportionately high risk of death due to UBs (33.7%) compared with other specific causes of death (eg gastrointestinal issues: 14.5%). Male dogs had 1 .40x the odds of death from UB compared with females. The proportional mortality from UB for male dogs where information on the cause of death was available was 0.41. Neutered dogs had 1.94x the odds of death due to a UB compared with entire dogs. Aggression was the most prevalent UB overall. Veterinarians had recommended referral in 10.3% of cases where dogs died due to exhibiting a UB and had dispensed nutraceutical, pheromone or pharmacological treatment to 3.0% of the UB cases that died. This study shows that undesirable behaviours require better preventive measures and treatment, through further research and education of veterinarians, other professionals within the dog industry and owners.

Giving birth is a critical time for many species and is often the most painful event ever experienced by females. In domestic species, like the pig, pain associated with parturition represents a potential welfare concern, and the consequences of pain can cause economic losses (e.g., by indirectly contributing to piglet mortality as pain could slow post-farrowing recovery, reduce food and water intake, reducing milk let-down). This study investigated pain assessment and its management in primiparous (gilts) and multiparous (sows) breeding pigs, including the provision of a non-steroidal anti-inflammatory drug (NSAID) post-parturition. Individuals were randomly allocated to receive the NSAID ketoprofen (3 mg/kg bodyweight) (n = 11 gilts, 16 sows) or the equivalent volume of saline (n = 13 gilts, 16 sows) by intramuscular injection 1.5 h after the birth of the last piglet. Data collected included putative behavioral indicators of pain (back leg forward, tremble, back arch), salivary cortisol concentrations pre-farrowing and up to 7 days post-injection. In addition, post-partum biomarkers of inflammation, including the acute phase protein C-reactive protein (CRP) and 3 porcine cytokines [interleukin-1 β (IL1 β), interleukin-6 (IL6), and tumor necrosis factor α (TNF α)] were measured in plasma collected 6 h following the injection. Behaviors were analyzed using generalized linear mixed models, and physiological variables with linear mixed models. No difference in putative pain behaviors, salivary cortisol, CRP, or cytokines were found between individuals treated with ketoprofen or those administered the saline control. However, there were some differences between gilts and sows, as sows exhibited more putative pain behavior than gilts, had higher salivary cortisol on the day of farrowing and had higher plasma TNF α. Conversely, gilts had higher salivary cortisol than sows on day 3 post-farrowing and had higher CRP. This indicates that, like human females, multiparous sows experience more pain from uterine activity following birth than primiparas. This study provides useful information for developing management practices relating to post-farrowing care for breeding pigs.

Although vertical (mother-to-offspring) information transfer has been reported in dolphins, it is unclear whether horizontal information transfer takes place between peers of non-parental individuals. We hypothesized that horizontal information transmission takes place within juvenile social play-forage subgroups and within pairs of juveniles in the form of social learning, as a way for older juveniles to contribute to the further development of younger juveniles’ foraging skills. Since 1985, a long-term study in the Bahamas has involved the collection of underwater videos and sound recordings on the social structure of a resident community of free-ranging Atlantic spotted dolphins Stenella frontalis. Foraging behaviors of juvenile dolphins were analyzed in 24 independent foraging events recorded on video from 1994 to 2013. Forty-nine juveniles in total were observed, including eight individually identified juveniles foraging alone, eight individually identified juveniles foraging in pairs, and 33 juveniles foraging in eight subgroups of three or more dolphins. The comparison of older juveniles' behavior against younger juveniles' behavior in juvenile play-forage subgroups suggested the potential for horizontal transmission of information about prey location. However, we found no direct evidence for social learning or of teaching in pairs. This new information about wild Atlantic spotted dolphin social structure is a starting point in horizontal information transmission research and is important in terms of cognitive processes and welfare implications.

Farrowing is a critical time for sows and piglets. Poor post-farrowing sow recovery, and piglet mortality represent a welfare concern, as well as an economic loss to the pig industry. Providing a non-steroidal anti-inflammatory drug (NSAID) to the sow post-farrowing may improve sow welfare and productivity and thereby improve health status and welfare of the piglets, which would be of economic benefit to pig producers. This study investigated the production effects of providing the NSAID ketoprofen post-farrowing, to 24 primiparous (gilts) and 32 multiparous (sows) breeding pigs, in a randomised, blinded, placebo-controlled trial. Gilts and sows were allocated to receive ketoprofen (treated) or the equivalent volume of saline (control) by intramuscular injection 1.5h after the last piglet birth. Data collected included sow feed intake, immune transfer (colostrum and piglet serum immunoglobulin-G (IgG)), nursing behaviour and piglet weight, and mortality. An additional factor in this study was that 13 individuals required additional treatment in the days after farrowing for post-farrowing illness. Therefore, data were analysed using mixed models, including treatment (treated or control), parity group (gilt or sow), and additional treatment (yes or no) as fixed factors. Stepwise binomial logistic regression was used to analyse the association between the experimental factors (treatment, additional treatment, gilt or sow), along with other gilt/sow, litter, and piglet-based measures, with piglet death before weaning. Few treatment effects were seen, with parameters being more affected by whether gilts and sows were treated for illness, or between gilts and sows. The only variable to differ by treatment was suckle grunt duration, which was greater for control compared with treated dams (P = 0.05). Feed consumption was greater for sows compared with gilts on days 6 and 7 post-farrowing, and serum IgG was greater in piglets from sows than gilts (P < 0.05). Feed consumption was reduced in dams needing additional treatment, from days 2–7 post-farrowing, and those developing illness consumed less feed overall (P = 0.004). The best regression model for predicting the odds of a piglet dying before weaning included number born alive (P = 0.03), requiring additional treatment (P = 0.006), being male (P = 0.0005), and pre-farrowing gilt/sow back-fat (P < 0.0001), which increased the log-odds of death, whereas, piglet body weight decreased the log-odds of death (P < 0.0001). This study did not demonstrate clear benefits to ketoprofen, however, high individual variation in piglet mortality, indicates potential for targeted NSAID use.

Knowledge of Cuvier’s (Ziphius cavirostris) and Blainville’s (Mesoplodon densirostris) beaked whales’ distinct dive and vocal behavior has allowed for the development of multiple methods of passive acoustic abundance and density estimation (Marques et al., 2009, Moretti et al., 2010). These methods are being applied to multiple years of data to estimate long-term trends in abundance for Blainville’s beaked whales at the Atlantic Undersea Test and Evaluation Center (AUTEC) in the Bahamas and at the Pacific Missile Range Facility (PMRF) in Hawaii, and for Cuvier’s beaked whales at the Southern California Offshore Range (SCORE). These passive acoustic beaked whale dive data were combined with sonar and Range ship-track data to derive a behavioral risk function for Blainville’s beaked whales at AUTEC, and are being extended to Cuvier’s beaked whales at SCORE and Blainville’s beaked whales at PMRF. The behavioral risk function maps the probability of beaked whale dive disruption as a function of the receive level of mid-frequency active sonar. The risk function and long-term trend analysis will help inform environmental policy going forward.

The U.S. Navy maintains several instrumented ranges equipped with large arrays of bottom-mounted hydrophones that are typically used to track undersea vehicles. The major ranges include the Atlantic Undersea Test and Evaluation Center (AUTEC) located in the Bahamas, the Southern California Offshore Range (SCORE) located off San Clemente Island, and the Pacific Missile Range Facility (PMRF) located off the western side of Kauai, HI. Each of these ranges provides tracking arrays covering an area in excess of 1200 km2. These hydrophone arrays are being used to develop marine mammal passive acoustic detection, classification, localization, and density estimation methods. Hardware systems installed at all three facilities allow real-time monitoring of vocalizing marine mammals. Using these systems, Blainville’s beaked whales have been detected at AUTEC and PMRF. Cuvier’s beaked whales have been detected at SCORE and to a lesser extent at AUTEC. These “sonar sensitive” species are present despite the repeated use of sonar. Based on passive acoustics, the movement of these species in response to sonar has been documented. By combining passive acoustic beaked whale and sonar data with AUTEC ship track data, a risk function for Blainville’s beaked whales was developed. In addition, by combining hydrophone with recording tag data, the beam pattern and source level of Blainville’s beaked whale were measured along with the system’s detection function. This enabled the development of passive acoustic density estimation algorithms. These algorithms are being applied to the long-term, in situ monitoring of beaked whale population at all three facilities.

Farrowing is an important period in pig production, with sow health and piglet mortality representing a welfare issue and an economic loss. Sow health and welfare is critical for piglet survival and good management can improve welfare and productivity. This study investigated the management of sows around farrowing and attitudes of UK pig farmers towards sow pain and difficulty farrowing. Farmers were asked how often they provided night checks, used farrowing induction and administered pharmaceutical products during and after farrowing. Farmers and veterinarians were asked if they used or prescribed anti-inflammatories for farrowing-related health issues. Farmers were asked if pain at farrowing was a problem for gilts and sows and what percentage they considered to have difficulty farrowing. Convenience sampling using a number of distribution methods was used. Sixty-one farmers and 52 veterinarians responded. Of the farmer respondents, ten worked on outdoor and 51 on indoor farms. Night checks were reported as frequently provided and farrowing induction was rare. Many respondents reported using oxytocin substitutes at least sometimes during (74%) or after (54%) farrowing. Azaperone was reported to be used at least sometimes by 45% of respondents during and 33% after farrowing. Farmers indicated that pain at farrowing was more often a problem for gilts than sows and 5% of gilts and 4% of sows were considered to have farrowing difficulty. The high level of supervision around farrowing, with the use of night checks, is encouraging and could improve welfare. Frequent use of oxytocin substitutes, which promote farrowing and milk let-down may negatively impact sow and piglet welfare and could be masking poor mothers that fail to perform well without intervention. This study provides interesting information regarding the management of sows around farrowing, which could inform future research and education to improve sow and piglet welfare in the periparturient period.

Periparturient pain is a welfare concern and could contribute to piglet losses. This has led to studies investigating post-farrowing analgesia. A clear reduction in pain has not been demonstrated, partly due to a lack of pain indicators. This study quantified behaviours as potential pain indicators (PPIn) in sows: i) before, during and after farrowing, and ii) 2min before and after piglet births. Twenty-five sows were observed during and after, and ten pre-farrowing. Behaviour recorded included: 1) back leg forward (back leg pulled forward and/or in); 2) tremble (movement as if shivering); 3) back arch (leg(s) stretch forming an arched back); 4) paw (leg scraped in pawing motion); and 5) tail flick (tail moved rapidly up and down). Behaviours were analysed using generalized linear models and Spearman's rank correlations. All PPIn were rare or absent pre-farrowing, highest during farrowing, and back leg forward, tremble and back arch were greater in the early post-farrowing period. Several significant positive correlations between PPIn during and post-farrowing were found. Back arch, tail flick and paw were higher before than after a piglet birth, and were more frequent earlier in the birth order. Back leg forward and tremble did not differ before and after births, and tremble increased with birth order. These behaviours, which were absent or rare pre-farrowing, present during farrowing and were lower afterwards, and showed consistent individual variation, may be quantitatively associated with pain. Spontaneous behaviours could be used to test the efficacy of analgesics or identify sows that may benefit.

The temporal occurrence of deep diving cetaceans in the Josephine Seamount High Seas Marine Protected Area (JSHSMPA), south-west Portugal, was monitored using a passive acoustic recorder. The recorder was deployed on 13 May 2010 at a depth of 814 m during the North Atlantic Treaty Organization Centre for Maritime Research and Experimentation cruise "Sirena10" and recovered on 6 June 2010. The recorder was programmed to record 40 s of data every 2 min. Acoustic data analysis, for the detection and classification of echolocation clicks, was performed using automatic detector/classification systems: M3R (Marine Mammal Monitoring on Navy Ranges), a custom matlab program, and an operator-supervised custom matlab program to assess the classification performance of the detector/classification systems. M3R CS-SVM algorithm contains templates to detect beaked whales, sperm whales, blackfish (pilot and false killer whales), and Risso's dolphins. The detections of each group of odontocetes was monitored as a function of time. Blackfish and Risso's dolphins were detected every day, while beaked whales and sperm whales were detected almost every day. The hourly distribution of detections reveals that blackfish and Risso's dolphins were more active at night, while beaked whales and sperm whales were more active during daylight hours.

Numerous studies have shown that prenatal stress (PNS) can have profound effects on postnatal well-being. Here, the domestic pig (Sus scrofa) was used to investigate PNS effects owing to the direct relevance for farm animal welfare and the developing status of the pig as a large animal model in translational research. Pregnant primiparous sows were exposed, in mid-gestation, to either a social stressor (mixing with unfamiliar conspecifics) or were kept in stable social groups. The ratio of levels of mRNAs for corticotropin releasing hormone (CRH) receptors 1 and 2 in the amygdala, measured for the first time in the pig, was substantially increased in 10-week-old female, but not male, PNS progeny indicating a neurobiological propensity for anxiety-related behaviour. Mature female offspring were observed at parturition in either a behaviourally restrictive crate or open pen. Such PNS sows showed abnormal maternal behaviour in either environment, following the birth of their first piglet. They spent more time lying ventrally, more time standing and showed a higher frequency of posture changes. They were also more reactive towards their piglets, and spent longer visually attending to their piglets compared to controls. Associated with this abnormal maternal care, piglet mortality was increased in the open pen environment, where protection for piglets is reduced. Overall, these data indicate that PNS females have their brain development shifted towards a pro-anxiety phenotype and that PNS can be causally related to subsequent impaired maternal behaviour in adult female offspring.

There is increasing concern about the potential effects of noise pollution on marine life in the world’s oceans. For marine mammals, anthropogenic sounds may cause behavioral disruption, and this can be quantified using a risk function that relates sound exposure to a measured behavioral response. Beaked whales are a taxon of deep diving whales that may be particularly susceptible to naval sonar as the species has been associated with sonar-related mass stranding events. Here we derive the first empirical risk function for Blainville’s beaked whales (Mesoplodon densirostris) by combining in situ data from passive acoustic monitoring of animal vocalizations and navy sonar operations with precise ship tracks and sound field modeling. The hydrophone array at the Atlantic Undersea Test and Evaluation Center, Bahamas, was used to locate vocalizing groups of Blainville’s beaked whales and identify sonar transmissions before, during, and after Mid-Frequency Active (MFA) sonar operations. Sonar transmission times and source levels were combined with ship tracks using a sound propagation model to estimate the received level (RL) at each hydrophone. A generalized additive model was fitted to data to model the presence or absence of the start of foraging dives in 30-minute periods as a function of the corresponding sonar RL at the hydrophone closest to the center of each group. This model was then used to construct a risk function that can be used to estimate the probability of a behavioral change (cessation of foraging) the individual members of a Blainville’s beaked whale population might experience as a function of sonar RL. The function predicts a 0.5 probability of disturbance at a RL of 150dBrms re µPa (CI: 144 to 155) This is 15dB lower than the level used historically by the US Navy in their risk assessments but 10 dB higher than the current 140 dB step-function.

Ecological acoustic recorders (EARs) were moored off the bottom in relatively deep depths (609-710 m) at five locations around the island of Kauai. Initially, the EARs had an analog-to-digital sample rate of 64 kHz with 30-s recordings every 5 min. After the second deployment the sampling rate was increased to 80 kHz in order to better record beaked whale biosonar signals. The results of the 80 kHz recording are discussed in this manuscript and are the results of three deployments over a year's period (January 2010 to January 2011). Five categories of the biosonar signal detection of deep diving odontocetes were created, short-finned pilot whales, sperm whales, beaked whales, Risso's dolphins, and unknown dolphins. During any given day, at least one species of these deep diving odontocetes were detected. On many days, several species were detected. The biosonar signals of short-finned pilot whales were detected the most often with approximately 30% of all the signals, followed by beaked and sperm whales approximately 22% and 21% of all clicks, respectively. The seasonal patterns were not very strong except in the SW location with distinct peak in detection during the months of April-June 2010 period.