Vocalization Rate Research Articles

Contour variations and acoustic characteristics of whistle sounds emitted by Pacific white‐sided dolphins in shallow coastal waters of the Sea of Japan

AbstractPacific white‐sided dolphins, Lagenorhynchus obliquidens (PWSDs), migrate along the coast of Japan. PWSDs rarely emit whistles, instead utilizing pulses, unlike many other delphinid species that frequently emit whistle sounds. In the present study, we aimed to clarify the acoustic characteristics and repertoire of the whistle of PWSDs, which have not been reported so far. We analyzed PWSD whistle sound systems (e.g., acoustic parameters and contours) during boat surveys and using passive acoustic monitoring in shallow coastal waters in the northern Sea of Japan. PWSDs in Shakotan rarely emitted whistles, while the burst pulse frequently was as reported in previous studies in other waters. The PWSD whistle vocalization rates were higher during traveling than during foraging. The frequency and duration of their whistles did not appear to change between behaviors. Although complex multiloop whistles were not recorded, whistle contours were classified into seven types. Whistles are often recorded intensively in a short period as a sequence or bout. Considering the extremely low whistle vocalization rates, dolphins may choose whistles instead of pulsed sounds in limited contexts. Our results shed light on the differences in whistle sound usage within odontocete species.

Deficiency of the paternally inherited gene Magel2 alters the development of separation-induced vocalization and maternal behavior in mice.

The behavior of offspring results from the combined expression of maternal and paternal genes. Genomic imprinting silences some genes in a parent-of-origin specific manner, a process that, among all animals, occurs only in mammals. How genomic imprinting affects the behavior of mammalian offspring, however, remains poorly understood. Here, we studied how the loss of the paternally inherited gene Magel2 in mouse pups affects the emission of separation-induced ultrasonic vocalizations (USV). Using quantitative analysis of more than 1000 USVs, we characterized the rate of vocalizations as well as their spectral features from postnatal days 6-12 (P6-P12), a critical phase of mouse development that covers the peak of vocal behavior in pups. Our analyses show that Magel2 deficient offspring emit separation-induced vocalizations at lower rates and with altered spectral features mainly at P8. We also show that dams display altered behavior towards their own Magel2 deficient offspring at this age. In a test to compare the retrieval of two pups, dams retrieve wildtype control pups first and faster than Magel2 deficient offspring. These results suggest that the loss of Magel2 impairs the expression of separation-induced vocalization in pups as well as maternal behavior at a specific age of postnatal development, both of which support the pups' growth and development.

Are demographic correlates of white-faced capuchin monkey (Cebus capucinus) "Gargle and Twargle" vocalization rates consistent with the infanticide risk assessment hypothesis?

Zahavi's "Bond Testing Hypothesis" states that irritating stimuli are used to elicit honest information from social partners regarding their attitudes towards the relationship. Two elements of the Cebus capucinus vocal repertoire, the "gargle" and "twargle," have been hypothesized to serve such a bond-testing function. The greatest threat to C. capucinus infant survival, and to adult female reproductive success, is infanticide perpetrated by alpha males. Thus, we predicted that infants (<8 months), pregnant females and females with infants would gargle/twargle at higher rates than the rest of the population, directing these vocalizations primarily to the alpha male. Over 16 years, researchers collected data via focal follows in 11 habituated groups of wild capuchins in Lomas Barbudal, Costa Rica. We found some support for our hypothesis. Infants and females with infants (<8 months) vocalized at higher rates than the rest of the population. Pregnant females did not vocalize at relatively high rates. Infants (age 8-23 months) were the only target group that vocalized more when the alpha male was not their father. Monkeys gargled and twargled most frequently towards the alpha male, who is both the perpetrator of infanticide and the most effective protector against potentially infanticidal males.

Objectively measured teacher and preschooler vocalizations: Phonemic diversity is associated with language abilities.

Over half of US children are enrolled in preschools, where the quantity and quality of language input from teachers are likely to affect children's language development. Leveraging repeated objective measurements, we examined the rate per minute and phonemic diversity of child and teacher speech-related vocalizations in preschool classrooms and their association with children's end-of-year receptive and expressive language abilities measured with the Preschool Language Scales (PLS-5). Phonemic diversity was computed as the number of unique consonants and vowels in a speech-related vocalization. We observed three successive cohorts of 2.5-3.5-year-old children enrolled in an oral language classroom that included children with and without hearing loss (N=29, 16 girls, 14 Hispanic). Vocalization data were collected using child-worn audio recorders over 34 observations spanning three successive school years, yielding 21.53 mean hours of audio recording per child. The rate of teacher vocalizations positively predicted the rate of children's speech-related vocalizations while the phonemic diversity of teacher vocalizations positively predicted the phonemic diversity of children's speech-related vocalizations. The phonemic diversity of children's speech-related vocalizations was a stronger predictor of end-of-year language abilities than the rate of children's speech-related vocalizations. Mediation analyses indicated that the phonemic diversity of teacher vocalizations was associated with children's receptive and expressive language abilities to the extent that it influenced the phonemic diversity of children's own speech-related vocalizations. The results suggest that qualitatively richer language input expands the phonemic diversity of children's speech, which in turn is associated with language abilities.

The origin of language and relative roles of voice and gesture in early communication development

Both vocalization and gesture are universal modes of communication and fundamental features of language development. The gestural origins theory proposes that language evolved out of early gestural use. However, evidence reported here suggests vocalization is much more prominent in early human communication than gesture is. To our knowledge no prior research has investigated the rates of emergence of both gesture and vocalization across the first year in human infants. We evaluated the rates of gestures and speech-like vocalizations (protophones) in 10 infants at 4, 7, and 11 months of age using parent-infant laboratory recordings. We found that infant protophones outnumbered gestures substantially at all three ages, ranging from >35 times more protophones than gestures at 3 months, to >2.5 times more protophones than gestures at 11 months. The results suggest vocalization, not gesture, is the predominant mode of communication in human infants in the first year.

Social distancing: High population density increases cub rejection and decreases maternal care in the giant panda

In conservation breeding centers, individuals are often housed in close proximity with an artificially high-population density. For many solitary species, these housing arrangements are in direct contrast to in-situ conditions. High-population density during pregnancy may lead to perceived competition for resources and danger to offspring, increasing stress and disturbance during gestation which has been shown to alter reproductive output, maternal care, and offspring behaviors. We conducted a retrospective analysis of reproductive outcomes for female giant pandas (Ailuropoda melanoleuca) and their infants housed in two different facilities with differing population density during gestation, birth, and postpartum. Our results indicate increased behaviors indicative of stress/anxiety in both mothers and cubs housed in high-density areas: mothers produced female-biased litters, rejected more cubs, and neglected their offspring more often, while infants increased squawking and vocalization rate. We suggest these findings may be explained by either higher levels of keeper activity causing external disturbances and/or the high-density of neighboring conspecifics as a form of social stress. Simultaneously, mothers in high-density areas also showed increased cub production and attentiveness toward their infants compared to mothers in low-density areas. The most plausible interpretation of maternal attentiveness findings is that higher levels of agitation in response to nearby conspecifics and/or keeper activity fostered higher levels of protective maternal behaviors. This, in turn, may have led to increased cub survivorship, or, alternatively, cubs at the high-density facility received more supportive care from keepers. We consider these findings preliminary due to the retrospective approach taken and the lack of replication across additional facilities with varying levels of social density. While experimental research is desirable to confirm these findings, we suggest that conservation breeding centers should prioritize research evaluating the effects of social density that are an inevitable but modifiable aspect of ex situ conservation.

Assessing the Effects of Observational Conditioning and Response-Contingent Pairing on the Vocalizations of Children With Autism Spectrum Disorder.

Children with autism spectrum disorder (ASD) often display impairments in communication, such as limited echoic behavior, few vocal-verbal responses, and a lack of functional communication. One potential way to foster the acquisition of vocal responses in individuals with disabilities is by conditioning vocalizations as reinforcers. Conditioning procedures include stimulus-stimulus pairing, response-contingent pairing (RCP), operant discrimination training, and observational conditioning (OC). However, previous research has not evaluated whether OC can be used to condition vocalizations as reinforcers. The current study assessed whether two conditioning procedures, RCP and OC, were effective in conditioning vocalizations as a reinforcer and also evaluated their effect on the rate of vocalizations. Participants included three children with ASD, ages 5-10 years old. During the conditioning phase, rates of vocalizations during the RCP and OC conditions and a control condition were compared within an adapted alternating-treatments design. Reinforcer assessments were completed in a multielement design, pre- and postconditioning, to assess whether the target vocalizations acquired reinforcing properties. A conditioning effect and an increase in the rate of vocalizations were observed for two of the three participants; however, the conditioning effect was minor for one participant. Overall, the results of this study indicate both the RCP and OC procedures may be beneficial in increasing vocalizations for some children and could be incorporated into clinical programs and further explored in future research.

Fin Whale (Balaenoptera physalus) in the Ligurian Sea: Preliminary Study on Acoustics Demonstrates Their Regular Occurrence in Autumn

The patterns of movement of the fin whale (Balaenoptera physalus (Linnaeus, 1758)) in the Mediterranean Sea are still a matter of debate. Feeding aggregations are well known in the Corso-Liguro-Provençal Basin from July to September, but little is known for the autumn and winter seasons. Passive acoustic monitoring (PAM) was implemented in the Ligurian Sea to overcome this gap and to investigate the temporal and spatial variation of fin whale acoustic presence. From July to December 2011, five autonomous recorders were deployed at between 700 and 900 m depths. Fin whale calls were automatically detected almost every day, with higher vocalization rates in October, November, and December. Furthermore, daily vocalization rates were higher during light hours, and closer to the coast. These outcomes suggest that not all the individuals migrate, staying in the area also during autumn for feeding or breeding purposes. The dial cycle of vocalization might be related to feeding activities and zooplankton vertical migration, whereas the proximity to the coast can be explained by the morphology of the area that promotes the upwelling system. Although this work only represents a six-month period, certainly it suggests the need for a larger spatial and temporal PAM effort, crucial for species management and for mitigating possible impact of anthropogenic activities at the basin level.

Singing Fin Whale Swimming Behavior in the Central North Pacific

Male fin whales sing using 20 Hz pulses produced in regular patterns of inter-note intervals, but little is known about fin whale swimming behavior while they are singing. Even less is known about fin whales in Hawaiian waters because they have rarely been sighted during surveys and passive acoustic monitoring has been limited to sparse hydrophone systems that do not have localization capabilities. We hypothesized that fin whale kinematics may be related to their singing behavior, or external variables such as time and sea state. To investigate this hypothesis, we analyzed 115 tracks containing 50,034 unique notes generated from passive acoustic recordings on an array of 14 hydrophones from 2011 to 2017 at the U.S. Navy Pacific Missile Range Facility off Kauai, Hawaii. Fin whales swam at an average speed of 1.1 m/s over relatively direct paths. We incorporated the whales' speed and turning angle into hidden Markov models to identify different behavioral states based on the whales' movements. We found that fin whale kinematic behavioral state was related to the vocalization rate (also known as cue rate) and time of day. When cue rate was higher, fin whales were more likely to swim slower and turn more than when cue rate was lower. During the night, fin whales were also more likely to swim slower and turn more than during the day. In addition, we examined whether the presence of singing fin whales was related to time and sea state using generalized additive models. Fin whale track presence was affected by day of the year and song season, and possibly also wind speed and wave height. Although the track kinematics from the fin whale tracks presented here are limited to a subset of whales that are acoustically active, they provide some of the only detailed movements of fin whales in the region and can be compared against fin whale swim speeds in other regions. Understanding how fin whale swimming behavior varies based on their vocalization patterns, time, and environmental factors will help us to contextualize potential changes in whale behavior during Navy training and testing on the range.

Discomfort-related changes of call rate and acoustic variables of ultrasonic vocalizations in adult yellow steppe lemmings Eolagurus luteus

Potential of ultrasonic vocalizations (USVs) to reflect a degree of discomfort of a caller is mostly investigated in laboratory rats and mice but poorly known in other rodents. We examined 36 (19 male, 17 female) adult yellow steppe lemmings Eolagurus luteus for presence of USVs during 8-min experimental trials including 2-min test stages of increasing discomfort: isolation, touch, handling and body measure. We found that 33 of 36 individuals vocalized at isolation stage, i.e., without any human impact. For 14 (6 male and 8 female) individuals, a repeated measures approach revealed that increasing discomfort from isolation to handling stages resulted in increase of call power quartiles and fundamental frequency, whereas call rate remained unchanged. We discuss that, in adult yellow steppe lemmings, the discomfort-related changes of USV fundamental frequency and power variables follow the same common rule as the audible calls of most mammals, whereas call rate shows a different trend. These data contribute to research focused on searching the universal acoustic cues to discomfort in mammalian USVs.

Delivering behavior analytic services in an inclusive job setting for a young adult with autism spectrum disorder: A case example

BACKGROUND: The rate of employment for adults diagnosed with Autism Spectrum Disorder (ASD) is low. This may be due in part to repetitive or disruptive behaviors associated with the ASD diagnosis and challenges to delivering services in the workplace. OBJECTIVE: This paper outlines a behavior analytic approach to providing job coaching supports in collaboration with employers in an inclusive setting. METHODS: A case example for a 26-year-old male (22 at the time of this project) diagnosed with ASD, employed as a data entry specialist, is highlighted. An A-B design was used to evaluate the impact of behavior analytic interventions on the rate of disruptive vocalizations. Behavior analysts and job coaches from a university-based team worked with employers to identify feasible and effective strategies. RESULTS: Rates of vocalizations decreased and maintained for 5 months following intervention fading. Social acceptability ratings from key office personnel reflected improved coworker relations and a high degree of acceptability for procedures used by the team. CONCLUSIONS: Employer collaboration was necessary for intervention design and decision making. Service providers should consider response effort for employers, the degree of normalization of strategies, how to limit disruption to productivity and the work setting, and methods for fading interventions or components of interventions.

Spread the word: male manakins advertise the presence of display sites with neighbouring competitors

Reproductive behaviour is generally under strong natural and sexual selection, meaning that variation in mate attraction investment reveals important fitness trade-offs. Nevertheless, in many taxa with sex-specific displays, individuals differ considerably in such investment. Male white-ruffed manakins, Corapipo altera (Pipridae), exhibit dramatic variation in display investment, despite having a mating system shaped by strong sexual selection. We tested three alternative hypotheses that could explain this variation: (1) individual quality and condition, (2) competition or (3) cooperation. We manipulated the social environment of male manakins at display sites in two experiments. First, we increased the acoustic signalling around focal males’ display sites by broadcasting the sounds of other displaying males to simulate elevated display of neighbouring males. Second, we temporarily prevented neighbouring males from using their display sites, thereby increasing the competition at focal display sites. Males reduced rates of vocalization in response to elevated acoustic signalling, suggesting that males may cooperate with neighbours to advertise the locations of leks, minimizing their individual effort when possible. The number of individuals at the focal display site and the number of silent displays increased when neighbours were prevented from displaying nearby, consistent with the competition hypothesis. However, the constancy in time investment and rates of other display behaviours throughout both manipulations suggests that male quality or condition underlies much of the individual variation in behaviour at display sites. Overall, our results are consistent with cooperation and individual quality mediating individual investment in display site advertisement. While manipulations created opportunities for competition, the responses of focal males were not consistent with antagonist social interactions affecting investment in display. This work demonstrates the importance of both intrinsic and social drivers shaping investment in courtship behaviour and highlights the potential for multimodal displays to facilitate cooperation. • Mating display effort may reflect individual quality, competition or cooperation. • An experimentally increased acoustic signal reduced male manakin vocalizations. • Preventing neighbours from displaying increased male physical displays. • Results are consistent with cooperation and individual quality shaping investment. • Multimodal signalling may facilitate cooperative aspects in competitive interactions.

Singing in a fragmented landscape: wrens in a tropical dry forest show sex differences in the effects of neighbours, time of day, and time of year

Songbird vocalizations serve diverse functions including territory defence against neighbouring conspecific animals. In tropical and south-temperate regions, it is commonplace for both female and male songbirds to sing solo songs and coordinated vocal duets to defend their territories. The Area de Conservacion Guanacaste in Costa Rica is the site of an ambitious conservation effort to protect and regrow tropical dry forests; it consists of a mosaic of regenerating and mature forest patches, presenting a special opportunity to study the effect of different numbers of neighbours on male and female wrens living in these fragmented forests. We analyzed recordings of Rufous-and-white Wrens (Thryophilus rufalbus) over a 17-year period, focusing on vocal behaviour and variation in the number of territorial neighbours within the fragmented landscape in the conservation area, and on diel and seasonal variation in female and male song. We hypothesized that the number of conspecific neighbours would influence vocal behaviours, including female and male solo song rate, duet responsiveness rate, repertoire use, and song-switching rate. For females, we found that wrens change song-types more often in areas with more neighbours, whereas the other aspects of female vocal behaviour did not vary with the number of neighbours. For males, we found no aspect of vocal behaviour that varied with the number of neighbours. For both sexes, we found variation in vocal behaviours with time of day and time of year, in keeping with previous research. Our results underscore the idea that we must explore female and male birds independently, because the sexes may respond differently to external factors. We did not find strong links between wren vocal behaviour and variation in the number of neighbours, yet we encourage further behavioural studies on vocal behaviour of birds with varying numbers of neighbours in fragmented landscapes.

Exploring Growth in Expressive Communication of Infants and Toddlers With Autism Spectrum Disorder.

One of the earliest indicators of autism spectrum disorder (ASD) is delay in language and social communication. Despite consensus on the benefits of earlier diagnosis and intervention, our understanding of the language growth of children with ASD during the first years of life remains limited. Therefore, this study compared communication growth patterns of infants and toddlers with ASD to growth benchmarks of a standardized language assessment. We conducted a retrospective analysis of growth on the Early Communication Indicator (ECI) of 23 infants and toddlers who received an ASD diagnosis in the future. At 42 months of age, children with ASD had significantly lower rates of gestures, single words, and multiple words, but significantly higher rates of nonword vocalizations. Children with ASD had significantly slower growth of single and multiple words, but their rate of vocalization growth was significantly greater than benchmark. Although more research is needed with larger samples, because the ECI was designed for practitioners to monitor children's response to intervention over time, these findings show promise for the ECI's use as a progress monitoring measure for young children with ASD. Limitations and the need for future research are discussed.

Effect of a Synbiotic Supplement on Fear Response and Memory Assessment of Broiler Chickens Subjected to Heat Stress.

Simple SummaryHeat stress is a serious environmental problem, challenging poultry health and welfare globally, especially during summer season. The breeding program of faster-growing broiler chickens affects their biological homeostasis, causing structural and functional damage to the brain, leading to mental disorders. Improvement in the gut microbiota with synbiotic dietary supplements has become a useful biotherapeutic method for treating various diseases, including neuroinflammation-induced mental illness and memory damage. Therefore, this study aimed to assess the effect of a dietary synbiotic supplement on fear response and memory assessment in heat-stressed broiler chickens. We used 360 1-day-old broiler chicks and assigned them to one of three dietary treatments: a regular diet mixed with a synbiotic containing a probiotic (Enterococcus faecium, Pediococcus acidilactici, Bifidobacterium animalis, and Lactobacillus reuteri) and a prebiotic (fructooligosaccharides) at 0, 0.5, and 1.0 g/kg. Object memory, touch, novel object, isolation, and tonic immobility tests were conducted at relative days of age. At 42 day, blood was collected for detecting corticosterone and tryptophan concentrations and examining heterophile/lymphocyte ratios. The data suggest that the synbiotic-reduced heat-stress responses and related emotional disorder may be mainly caused by increasing the activation of the serotonergic system via the microbiota–gut–brain axis. The aim of this study was to evaluate the effect of a synbiotic containing a probiotic (Enterococcus faecium, Pediococcus acidilactici, Bifidobacterium animalis, and Lactobacillus reuteri) and a prebiotic (fructooligosaccharides) on fear response, memory assessment, and selected stress indicators in broilers subjected to heat stress. A total of 360 1-day-old Ross 708 chicks were evenly divided among three treatments: a basal diet mixed with a synbiotic at 0 (G-C), 0.5 (G-0.5X), and 1.0 (G-1.0X) g/kg. After 15 d, the broilers were exposed to 32 °C for 9 h daily until 42 d. The object memory test was conducted at 15 day; touch, novel object, and isolation tests were conducted at 35 day; tonic immobility (TI) took place at 41 day. At 42 day, plasma corticosterone and tryptophan concentrations and heterophile/lymphocyte (H/L) ratios were measured. Compared to controls, synbiotic-fed broilers, regardless of concentration, had a shorter latency to make the first vocalization, with higher vocalization rates during the isolation test (p = 0.001). the G-1.0 group had the lowest H/L ratio (p = 0.001), but higher plasma tryptophan concentrations and a greater number of birds could reach the observer during the touch test (p = 0.001 and 0.043, respectively). The current results indicate that the synbiotic can be used as a growth promoter to reduce the fear response and stress state of heat-stressed broilers.

Repeatable individual differences in behaviour and physiology in juvenile horses from an early age

Most people living or working in close association with animals are familiar with individual differences in their behaviour, and awareness is growing that understanding such differences can contribute to improved management, production and welfare. Nevertheless, due to the considerable logistic and financial difficulties of conducting longitudinal studies, particularly in the large, slow-growing mammalian species comprising an important part of the world’s domestic animals, there is still little information on how early such differences emerge and whether they persist across different developmental stages. In an extension of a previous study of the behavioural and physiological (heart rate variability, HRV) response of 30 Azteca-breed foals of both sexes to repeated brief maternal separation from birth to weaning, we tested the same animals post-weaning in two tests of brief separation from their social group when they were approximately nine months and one year old, and recording the same behavioural and physiological variables as previously. As in the earlier study, we found stable individual differences in several behavioural variables: vocalization rate (R = 0.54, P < 0.01), duration of locomotion (R = 0.46, P = 0.02), duration of high tail carriage (R = 0.31, P = 0.05), and head tosses (R = 0.49, P=0.02), also in three of the four HRV measures at the two ages; change in heart rate (R = 0.47, P < 0.001), in STDRR (R = 0.39, P = 0.02) and in RMSSD (R = 0.39, P = 0.02) from baseline to the separation. These corresponded to the individual differences we had found pre-weaning. In contrast to our previous study, however, we no longer found an association between the behavioural and physiological measurements at this later age. Including previous measurement from the same animals we conclude there is considerable stability in individual differences in behaviour and physiology in response to a brief and ecologically relevant stressor from as early as the first week of age, even though close correspondence between behavioural and physiological changes disappear through development. These differences might be reliable indicators of individuals’ suitability for later use in particular applied contexts.

Short- and long-term effects of temporary early cow–calf separation or restricted suckling on well-being and performance in zebu cattle

Information on weaning techniques in the tropics is scarce, particularly regarding the long-term effect of temporary early cow–calf separation or restricted suckling. Therefore, we studied the effects of these two handling practices on well-being and performance at 150 days postpartum in fifteen zebu cow–calf pairs randomly assigned to three treatments. Continuous suckling (CS) where calves remained with their dams from birth to weaning; restricted suckling (RS) calves were allowed to suckle 30 min/day from Day 34 until weaning at Day 150 and kept separated the rest of the time; temporary separation (TS) calves were separated for 72 h from their dams from Day 33 to 36 but remained with their dams the rest of the time. Blood samples and behavioral data were collected on Days 32–36 (1st period) and 149–153 (2nd period). In the 1st period, a greater percentage of RS and TS calves were observed close to the fence line (<10 m) that separated them from their dams (P < 0.0001) and vocalized more than CS calves (P < 0.0001), while in the 2nd period, RS calves had the highest cortisol concentration and vocalization rate (P < 0.05). Similarly, during the 1st period, a greater percentage of RS and TS cows were observed close to the fence line than CS cows (P < 0.0001), with TS cows vocalizing the most (P = 0.001). In the 2nd period, RS cows had greater cortisol concentration than TS (P = 0.037) and CS cows (P = 0.003). More TS and CS cows than RS were observed close to the fence line (P = 0.03 and P = 0.05). On Day 150, TS calves and cows vocalized more than RS and CS animals (P < 0.0001). Before calf–cow separation, 27 out of 45 cows were cycling (CS = 10; RS = 6; TS = 11). After separation, 12 of the remaining 18 cows resumed ovarian activity (CS = 3; RS = 5; TS = 4), and all cows were cycling after estrous synchronization treatment. The pregnancy rate was similar between CS, RS, and TS (60, 53, and 60% respectively). In conclusion, temporary separation increased calf distress response to definitive weaning even four months later, while restricted suckling seemed to reduce it.

Primed to vocalize: Wild-derived male house mice increase vocalization rate and diversity after a previous encounter with a female.

Males in a wide variety of taxa, including insects, birds and mammals, produce vocalizations to attract females. Male house mice emit ultrasonic vocalizations (USVs), especially during courtship and mating, which are surprising complex. It is often suggested that male mice vocalize at higher rates after interacting with a female, but the evidence is mixed depending upon the strain of mice. We conducted a study with wild-derived house mice (Mus musculus musculus) to test whether male courtship vocalizations (i.e., vocalizations emitted in a sexual context) are influenced by a prior direct interaction with a female, and if so, determine how long the effect lasts. We allowed sexually naïve males to directly interact with a female for five minutes (sexual priming), and then we recorded males’vocalizations either 1, 10, 20, or 30 days later when presented with an unfamiliar female (separated by a perforated partition) and female scent. We automatically detected USVs and processed recordings using the Automatic Mouse Ultrasound Detector (A-MUD version 3.2), and we describe our improved version of this tool and tests of its performance. We measured vocalization rate and spectro-temporal features and we manually classified USVs into 15 types to investigate priming effects on vocal repertoire diversity and composition. After sexual priming, males emitted nearly three times as many USVs, they had a larger repertoire diversity, and their vocalizations had different spectro-temporal features (USV length, slope and variability in USV frequency) compared to unprimed controls. Unprimed control males had the most distinctive repertoire composition compared to the primed groups. Most of the effects were found when comparing unprimed to all primed males (treatment models), irrespective of the time since priming. Timepoint models showed that USV length increased 1 day after priming, that repertoire diversity increased 1 and 20 days after priming, and that the variability of USV frequencies was lower 20 and 30 days after priming. Our results show that wild-derived male mice increased the number and diversity of courtship vocalizations if they previously interacted with a female. Thus, the USVs of house mice are not only context-dependent, they depend upon previous social experience and perhaps the contexts of these experiences. The effect of sexual priming on male courtship vocalizations is likely mediated by neuro-endocrine-mechanisms, which may function to advertise males’ sexual arousal and facilitate social recognition.

An intelligent method for detecting poultry eating behaviour based on vocalization signals

As the poultry farming industry attaches great importance to the welfare of poultry, an understanding of the daily behaviours of poultry is becoming more important. Eating behaviour is an important daily behaviour in poultry. Based on the difference between the eating vocalization and the normal vocalization of poultry, this study proposed an automatic detection method for the eating behaviour of poultry based on an audio analysis and a time sequence model. First, the short time energy (STE) and short time zero crossing rates (STZ) of poultry vocalizations and environmental sounds were analysed, and a four-threshold poultry vocalization automatic selection method based on the STE and STZ was proposed. Then, these poultry vocalizations were characterized according to variations in time. Three types of poultry vocalization network (PV-net) were proposed for classify the eating vocalization and the normal vocalization of poultry: PV-net1, PV-net2 and PV-net3. In the experiments, vocalization of 18 chickens was collected. Results showed that the recognition rates of PV-net1, PV-net2 and PV-net3 were 93.5%, 94.5% and 96%, respectively; their sensitivities were 96%, 97% and 96%, respectively; and their specificities were 91%, 92% and 96%, respectively. This method is beneficial to the protection of poultry welfare and will be significant for use in monitoring and controlling the eating behaviour of poultry in the poultry farming industry.

Evaluation of associations between owner presence and indicators of fear in dogs during routine veterinary examinations.

To evaluate the influence of owner presence on behavioral and physiologic indicators of fear in dogs during routine physical examinations. 32 client-owned dogs. Dogs underwent a standardized, video-recorded examination consisting of 6 phases (examination of the head, lymph node palpation, body palpation, axillary temperature measurement, heart rate assessment, and respiratory rate assessment) with or without their owner present in a randomized, controlled study. Behaviors reported to be indicative of fear, including reduced posture, avoidance, escape, lip licking, body shaking, yawning, and vocalizing, were assessed during each phase, and physiologic measurements were assessed during relevant phases by the investigator. Owner presence and sex and age of dogs were investigated for associations with behavioral signs of fear; behavioral and physiologic measurements were compared between groups (owner present vs owner absent). Dogs in the owner-present group had a lower rate of vocalizations, lower mean axillary temperature, and higher rate of yawning than dogs in the owner-absent group. Female dogs in the owner-absent group had a higher heart rate than females and males in the owner-present group and males in the owner-absent group, and the rate of lip licking decreased as age increased in the owner-present group. The presence of reduced body posture and rates of lip licking, avoidance behavior, and escape behavior were associated with examination phase. Results suggested that, when practical, owners should be encouraged to remain with their dog during routine veterinary examinations. However, effects of owner presence during procedures require further investigation. (J Am Vet Med Assoc 2020;257:1031-1040).