Agonistic Behavior Research Articles

Short-Term Changes in Food Spatial Distribution by Zoo Husbandry Practices Increase Agonism and Affect Feeding Behavior in Chilean Flamingos (Phoenicopterus chilensis): A Case Study

ABSTRACT Short-term modifications to animals’ enclosures, stemming from zoo husbandry practices, can significantly impact animal behavior and, consequently, their welfare. In this case study, we examined a captive-bred population of 23 adult Chilean flamingos (Phoenicopterus chilensis) during a non-breeding season to evaluate whether short-term alterations in the spatial distribution of feeders would affect the birds’ feeding and agonistic behaviors. Initially, we developed an ethogram to establish baseline behavioral data. Subsequently, we assessed individual (latency to approach the feeders) and group (feeding and agonism) responses to feeder changes using an ABA-type experimental design (A1 and A2 feeders at the original location; B feeder location changed). Latency to approach feeders was also correlated with the birds’ sex and body weight. The results revealed that during and immediately after the alterations, agonistic behaviors at the most frequently used feeding site by the flamingos increased, while the use of alternative food sources decreased significantly. Latency was not influenced by the birds’ sex or body weight. These findings emphasize the importance of closely monitoring even seemingly minor changes in food spatial distribution to prevent negative impacts on the behavior, and presumably, the welfare of flamingos.

Ultimate Fighting Crab: Agonistic Behaviour, Dominance, and Recognition in the Edible Crab, Cancer pagurus (L.)

Edible crabs (Cancer pagurus) are an economically important species for Scottish inshore fisheries, with an estimated annual landing value of GBP 16 million (2023). Research into the behaviour, particularly agonistic behaviour, of this species is currently lacking. This paper aims to investigate behaviour, social interactions, potential hierarchies, and the impact of claw size on the outcomes of agonistic interactions of male C. pagurus through behavioural trials and retrials. Crabs were semi-randomly assigned to pairs (based on allocated condition index rating) and introduced to one another in trial tanks. Each pair underwent two trials, 24 h apart (the “trial” and “retrial”). Analyses of video records of agonistic bouts revealed that 77% of retrials were won by the initial victors, with a significant decrease in fight time between trials and retrials. Fight time was not correlated with weapon size (claw length, height, and depth). There were no differences in weapon size of winners and losers of bouts. Winners exhibited a significantly higher frequency of aggressive and dominant behaviours (approach, aggressive contact, threat displays, and mounting), and losers exhibited higher frequencies of submissive behaviours (withdrawal, retracting limbs, and remaining motionless). These results suggest that individual behaviour may play more of a role in dominance than size or other morphometric characteristics.

First Evidence of Individual Sharks Involved in Multiple Predatory Bites on People

ABSTRACTIt is widely accepted that populations of terrestrial predators sometimes contain “problem individuals” that repeatedly attack humans, yet this phenomenon has never been demonstrated in sharks. Here, we present photographic and genetic evidence of individuals in populations of tiger Galeocerdo cuvier and oceanic whitetip Carcharhinus longimanus sharks that (1) demonstrated atypical behavior compared to the rest of the population, (2) engaged in repeated agonistic behavior directed toward humans, and (3) bit, or attempted to bite humans in probable foraging attempts. These case studies provide some of the first evidence for the existence of “problem individuals” among sharks. The percentage of fatalities due to the same shark individual are not known, so we recommend systematic swabbing of shark bite victims wounds to better understand the importance of this phenomenon and the possibility of identifying these animals. Environmentally conscientious management options for problem individuals range from prohibiting ocean activities (e.g., swimming and surfing) in their habitats to selectively removing the individual, although the latter would be challenging in the marine environment.

A multi-paradigm approach to characterize dominance behaviors in CD1 and C57BL6 male mice.

Social status and dominance are critical factors influencing well-being and survival across multiple species. However, dominance behaviors vary widely across species, from elaborate feather displays in birds to aggression in chimps. To effectively study dominance, it is essential to clearly define and reliably measure dominance behaviors. In laboratory settings, C57BL/6 mice are commonly used to study dominance due to their stable and linear social hierarchies. However, other mouse strains are also used for laboratory research. Despite substantial evidence for strain effects on behavioral repertoires, the impact of strain on dominance in mice remains largely unstudied. To address this gap, we compared dominance behaviors between CD1 and C57BL/6 male mice across four assays: observation of agonistic behaviors, urine marking, tube test, and a reward competition. We found that CD1 mice demonstrate increased fighting, increased territorial marking through urination, and increased pushing and resisting in the tube test. We used unsupervised machine learning and pose estimation data from the reward competitions to uncover behavioral differences across strains and across rank differences between competing pairs. Of the four assays, urine marking and agonistic behaviors showed the strongest correlation with dominance in both strains. Most notably, we found that CD1 dominance rankings based on the tube test negatively correlated with rankings from all three other assays, suggesting that the tube test may measure a different behavior in CD1 mice. Our results highlight that behaviors can be strain-specific in mice and studies that measure social rank should consider assays carefully to promote reproducibility.Significance Statement Recent studies have highlighted that social dominance can significantly impact behavior and the brain. As such, accurately measuring dominance behavior in laboratory settings is crucial in neuroscience research. In this study, we investigated the consistency of four dominance assays for male mice across two common mouse strains. We find that not all assays result in the same dominance rankings and dominance behaviors differ across strains. Our study sheds light on the importance of considering strains for assay selection, rigor, and reproducibility.

Hierarchies inferred from different agonistic behaviours are not always comparable.

Social hierarchies are widely used to predict life-history patterns and priority of access to resources. Yet, behavioural ecology and social sciences lack a consistent relationship between specific behaviours and social rank across studies. I used published data sets from 42 groups of 25 species representing several taxa to determine whether hierarchies inferred from different behaviours are similar or (in)consistently different at both individual and group levels. Ranks inferred from yielding interactions in the absence of aggression ('ritualized') were often comparable to ranks inferred from decided aggression (unambiguous outcome) but not to ranks inferred from undecided aggression. Accordingly, hierarchies inferred from data sets including only decided interactions were steeper than those inferred from data sets including undecided aggression. These results support the hypothesis that aggression can be context-dependent and might reflect less stable or mutually recognized relationships than (ritualized) yielding interactions. I discuss the consequences of choosing different behaviours to infer social hierarchies and the difficulty of making generalizations from one species or taxon to another. Finally, I recommend that the use of ritualized yielding and certainly the use of decided over undecided interactions to infer social hierarchies should be preferred, especially in comparative studies which go beyond taxon-specific idiosyncrasies.

Tolerance and efficient metabolization of extremely high ethanol concentrations by a social wasp

Ethanol, a natural by-product of sugar fermentation, can be found in various fruits and nectar. Although many animals routinely consume ethanol in low concentrations as part of their natural diets, its inherent toxicity can cause severe damage. Even species particularly well adapted to ethanol consumption face detrimental effects when exposed to concentrations above 4%. Here, we investigated the metabolism of ethanol and its impact on survival and behavior in the Oriental hornet (Vespa orientalis), a social wasp that naturally consumes ethanol. We show that chronic ethanol consumption, even at concentrations as high as 80%, had no impact on hornet mortality, construction behavior, or agonistic behavior. Using 13C1 labeled ethanol, we show that hornets efficiently metabolized ingested ethanol and at a much higher rate than honey bees. The presence of multiple copies of the alcohol dehydrogenase (NADP+) gene in the Vespa genera suggests a potential mechanism for ethanol tolerance. These findings support the hypothesis that the mutualistic relationship between ethanol-producing organisms and vespid hosts may be at the origin of their remarkable capacity to utilize and metabolize ethanol.

Sweet mama: affiliative interactions are related to the reproductive success of dominant female Alpine marmots (Marmota marmota)

AbstractSociality is a complex phenomenon, able to influence multiple traits of an individual life history. In group-living mammals, sociality is likely to play a major role in the reproductive success of individuals. Here we investigate how sociality traits are associated to reproductive success in female Alpine marmots (Marmota marmota), a highly social and cooperative breeding ground squirrel distributed in the European Alps. We used social network analysis to calculate sociality metrics and hurdle generalized linear mixed models (hurdle GLMMs) to model the relationship between sociality metrics and reproductive success of individually tagged female Alpine marmots. Our results showed that centrality of a reproductive female within her social group and the number of social partners are positively related to reproductive success, while agonistic behavior was not related with reproduction. Our results highlight the importance of affiliative interactions with other group members in cooperative breeders, suggesting that in such systems female fitness could be more related to social cohesion than to costs of agonistic behaviors to maintain dominance status.

A history of susceptibility to parasites and divergence in solitary, gregarious and agonistic behaviors of embiopterans.

Two species of Haploembia Ramburi (Oligotomidae: Embioptera), nonnative detritivores found in the western USA, display solitary tendencies, not typical for webspinners that usually share silk galleries. Reports from the 1960s based on native populations in Italy highlighted the impact of a gregarine that depressed male sterility and female survivorship in Haploembia solieri (Rambur). Sympatric asexual Haploembia tarsalis (Ross) lives a normal lifespan when parasitized, albeit suffering from reduced fecundity. Our goal is to characterize behavioral repertoires as individuals interact and to develop methods for future investigations focused on the impact of the little-known parasite. We quantified individual responses to conspecifics or other species in 10-min dyadic interactions and, in a 3-day trial, determined whether they aggregated when given dispersed resources. Replicated groups of four adult female H. solieri or H. tarsalis settled away from each other over the 3-day trials. In 10-min bouts of same or different species pairs, focal insects bolted back, retreated and attempted to escape when they encountered one another, especially when the opponent was H. tarsalis. Males courted conspecific females, but were dramatically repelled by H. tarsalis. Serving as a positive control, Oligotoma nigra (Hagen) (Oligotomidae) adult females paired with conspecifics displayed typical webspinner behaviors by sitting together, sharing silk. Haploembia solieri males did not respond negatively to O. nigra, not known to be parasitized by the gregarine, but did so when paired with H. tarsalis. Results align with the prediction that susceptibility to parasitism may have led to antisocial behaviors observed in two Haploembia species.

Recording potential predators of herpetofauna in southern Mexico using camera traps and realistic models

ABSTRACT Knowledge of biotic predator–prey interactions is essential for understanding the role of species in the food web; however, information on these interactions is scarce for most species. Our aim in this study was to gather information on the potential predators of two species of herpetofauna abundant in the rainforest they inhabit, the frog Craugastor loki and the snake Ninia sebae. For this, realistic models of the two species were placed, and monitored using camera traps, in 13 sites located in a forest fragment belonging to a private protected natural area in southern Veracruz in three seasons (dry, rainy and windy) in 2019. In addition, the temporality and seasonality of the events and some behaviours of the potential predators are described. The recorded events were classified into four categories: presence, interest, contact and aggression. For C. loki, 159 events of appearances of potential predators were identified (32 with interaction: 18 events of interest, 2 contact and 12 aggressions). The aggressions were carried out by the mammals Didelphis marsupialis and Peromyscus sp. In the case of N. sebae, 201 appearances of potential predators were identified (75 with interaction: 36 events of interest, 7 contact and 32 aggressions). The aggressions were carried out by 10 species (seven birds and three mammals). Bird predation events towards models of both species occurred during daytime while the attacks by mammals occurred at night. Agonistic behaviours included pecking, biting and urine marking, previously unknown. Events of each category were recorded every season. Our results indicate that C. loki and N. sebae may have more predators than were previously known, and suggest that these species can be an important food resource for different species of birds and mammals in the environments where they live.

Fight, retreat, repeat: The male-male agonistic behavior in the wood-feeding cockroach, Panesthia angustipennis spadica (Dictyoptera: Blattodea: Blaberidae).

Competition is one of the most critical factors affecting animal behaviors. Aggressive interactions are central to acquiring resources or mating partners. Agonistic behavior is more common among males than females. Although laboratory observations of these behaviors give detailed descriptions under controlled conditions, field observations without human intervention are required because those supply information that provides insights into their function. In this paper, we report on the field observation and auxiliary laboratory experiments of male-male agonistic behavior of a wood-feeding cockroach, Panesthia angustipennis, and discuss its strategy. In the field, a male pushed the opponent with the horn on the pronotum out of a gap between two logs, under which a female was. After pushing, the male repeatedly returned to a place close to the female, even if it did not subdue the opponent entirely. It suggests that the male-male agonistic behavior in P. angustipennis has both attack and avoidance. The bout was repeated as the ejected male reapproached the male. In contrast, the inferior male often escaped in the laboratory recording after field observation. Keeping the fighting experience for several days may contribute to the males avoiding a "losing battle." This study significantly enhances our understanding of the mating strategy of P. angustipennis through male-male agonistic behavior and provides possibilities for its cognitive aspects from the fighting experience.

Asymmetric competition for habitats between the temperate Japanese eel Anguilla japonica and the tropical Indo-Pacific eel A. marmorata

Habitat segregation is a common phenomenon among anguillids in rivers where multiple species coexist. However, despite the growing need to conserve their river habitats, the mechanisms underlying such segregation remain unknown. Here, we conducted tank experiments to investigate the competitive superiority for habitats between the temperate Japanese eel Anguilla japonica and the tropical Indo-Pacific eel Anguilla marmorata, which co-occur in East Asian subtropical rivers. Using eight interspecific pairs of these two species of comparable total length, we compared the use of a single pipe shelter, recorded over a 24-h experimental period, between solitary and paired conditions. The changes in shelter use patterns between conditions indicated that in the paired condition, the shelter was occupied by A. marmorata in five pairs (62.5%) by the end of the experiment while A. japonica appeared to occupy the shelter in only one pair (12.5%). Furthermore, agonistic behaviors, which occurred mainly at night, such as biting and head-butting, were observed much more frequently for A. marmorata toward A. japonica (mean ± standard deviation: 23.2 ± 36.6 times per individual) than for A. japonica toward A. marmorata (0.4 ± 0.5 times per individual), indicating an asymmetry in aggressiveness. These results suggest that A. marmorata can negatively affect the diurnal habitat use and nocturnal activities of sympatric A. japonica. These findings, combined with those from previous field studies, suggest that A. marmorata may competitively exclude A. japonica from stream habitats with large substrate sizes. This asymmetric competition can contribute to shaping their riverine distribution and composition within rivers where they co-occur.

Social networks of pregnant gilts during outdoor feeding and the effects on their offspring

Social relationships are important aspects of the behavioural biology of pigs and can be affected by the type of housing pigs are kept in. Exploring agonistic interactions and affiliative behaviours can reveal effects on adult pigs and their descendants. This research investigated the social dynamics among gilts throughout pregnancy during collective feeding in an outdoor housing system and the effects of these dynamics on the stability of the group and the offspring of the group members. For this study, 15 gilts were oestrus synchronised and artificially inseminated with three different semen pools. The paddocks where the gilts were housed contained a mud pool, natural tree shade, and two nipple drinkers. Two daily meals (∼2.5 kg/day/gilt) were provided to the group on the floor. Feeding behaviour was recorded for three continuous days (20 min in the morning and again in the afternoon) every gestational (a total of 42 h of video recording). Saliva samples were collected at 6:00 a.m. and 6:00 p.m. on these same days. A trained observer evaluated all the videos using Boris software to determine agonistic and affiliative behaviours. After farrowing, the piglet data collected included sex, mortality, and body weight (BW) at 10, 25, 29, and 36 d of age. Elo scores were calculated to quantify the relative hierarchy among the gilts based on the behaviour assessment. Generalised linear mixed models (GLMMs) were used for data analyses, and the significance of fixed effects was determined at p < 0.05. The tendency of the gilts to feed together decreased as gestation progressed. Heavier gilts had lower salivary cortisol concentrations, and higher gilt rank was correlated with higher morning salivary cortisol concentrations and heavier piglets. Maternal modulation of offspring performance in pigs warrant further investigation. Assessment of gilts' social feeding behaviours is relevant for considering pigs' behaviour in genetic selection and improving commercial facilities and management practices to improve animal welfare.

Temperament of the dairy cow relates to her maternal behaviour in a pasture-based extended suckling system

Cow-calf rearing is gaining interest in dairy systems as an alternative to calf separation soon after birth. One commonly articulated benefit of these ‘extended suckling’ systems is that they allow expression of highly motivated maternal behaviours. The quality of maternal expression is subject to natural variation, however, and could be influenced by the temperamental characteristics of the dam. This study assessed the relationship between cow temperamental characteristics and expression of maternal behaviours in a pasture-based extended suckling system. Sixteen dairy cows (Bos taurus) underwent social isolation, novel object and novel human tests at 4 months of pregnancy. A principal components analysis (PCA) was used to determine associations between cow responses in these tests. After parturition, the cows entered an extended suckling system (half-day contact) until calves were weaned. Cow-calf interactions at pasture were video recorded for 4 consecutive hours (∼09:00 AM – 1:00 PM) at weeks 3, 6 and 9 post-partum. These data were used to calculate a maternal behaviour score for cows by subtracting the frequency of “negative” maternal behaviours (i.e., agonistic behaviour delivered to own calf, rejecting own calf suckling attempt and rejecting attempted contact by own calf) from the frequency of “positive” maternal behaviours (i.e., nursing own calf, affiliative behaviour delivered to own calf and proximity to own calf). A Pearson correlation was then used to assess the relationship between factors scores and maternal scores. Three behavioural traits were identified from the PCA: boldness, anxiety and sociability. In general, cows delivered more affiliative behaviour to their calves than to other calves and to cows and nursed their own calf more than other calves. The maternal behaviour score varied (mean ± SD, 33 ± 13.4, minimum = 9, maximum = 49). Cows with higher loadings for boldness had a lower maternal behaviour score (p < 0.05). There was no correlation between maternal behaviour score and anxiety or sociability (p > 0.05). The lower maternal behaviour score of bold cows in this study might be influenced by their prioritisation of foraging and exploration over interactions with their calves. Despite the long-standing practice of calf separation soon after birth, the current study demonstrates that maternal abilities of pasture-based dairy dams persist. We conclude that cow temperamental characteristics are related to how the cows interacted with their calves.

The impact of restricted grazing systems on the behaviour and welfare of ponies.

Equine obesity is a growing concern. Much of the current management advice centres on dietary restrictions, including the removal or limitation of grazing. Little is known about the impact of these approaches on the welfare of the horse. This study investigates the effect of two commonly used grazing systems advocated for the control of weight-the 'strip-grazing' and the 'track' systems-on the behaviour and welfare of outdoor-living ponies. A within-subject cross-over experimental design with four groups of pasture-kept ponies experiencing each system for 4 weeks in a random order. Time budgets and behavioural indicators of welfare were measured using 24-h electronic surveillance, morphometric parameters including weight, body condition score and cresty neck score were measured weekly and activity levels were tracked. The effect of grazing system on movement and behaviour was tested using a general linear model. Ponies moved more [median (IQR) % time spent moving, track: 3.23% (2.08%), strip: 2.02% (0.90%); p = 0.001] and travelled a greater distance [median (IQR) metres/24 h, track: 7013.47 m (1761.49 m), strip: 5331.91 m (494.16 m); p < 0.001] and engaged in less overt agonistic behaviour on the track system compared with the strip system [median (IQR) prevalence per hour; track: 0.14 (0.30), strip: 0.21 (0.37) p = 0.02]. A relatively short time period of exposure to each grazing system. Ponies on strip systems moved less and exhibited increased agonistic interactions compared with the track system, maybe as a result of a perceived reduction in space or concentration of resources, although the accessible areas were matched. These results suggest that there may be physical as well as psychological health benefits to the track system.

271 Does social buffering amongst familiar weaned beef calves mitigate castration stressors?

Abstract Co-mingling of beef feeder calves from multiple sources results in biological and behavioral stressors. This study is part of a project exploring social relationships between individual beef cattle and potential benefits of social buffering during stress events. Here, the specific objective was to explore whether feeder calves form preferential relationships which buffer them from surgical castration pain. Within the experiment, two treatment groups were established: Familiar calves were defined as calves who shared a source farm with two other calves in the pen, and Unfamiliar calves were defined as calves who did not share a source with any other pen-mates. It was hypothesized that Familiar calves would exhibit more lying, fewer pain-related behaviors, and fewer agonistic interactions following surgical castration than Unfamiliar pen-mates. Weaned beef bull calves [n = 102, body weight (BW) range ± SD = 112.95 to 370.10 ± 67.8 kg] from 23 source farms were randomly assigned to home pens, each comprised of three Familiar calves and three Unfamiliar calves. Cameras placed above the pens recorded video from which postural (standing and lying), social (agonistic and bunk displacements) and pain-related behaviors (wound checking and hind leg stamping) were quantified. Cattle were handled through a hydraulic squeeze chute once weekly over four consecutive weeks for data collection and standard processing procedures. On d 14 relative to arrival, calves were surgically castrated with multimodal pain mitigation. During all processing events, calves were marked with livestock paint for behavioral observations. Behavior was observed continuously for 15 min at five different time points (0 h, 1 h, 4 h, 24 h, 48 h) relative to when the last calf returned to the home pen after processing, and researchers were blind to treatment allocation. These time periods corresponded to expected periods when pain was absent and present based on duration of local anesthesia and systemic pain relief. Calf was the experimental unit. For the purpose of this abstract, data from the 48 h periods following d 7 and 14 were analyzed using the PROC GLIMMIX procedure of SAS; the model included treatment (Familiar, Unfamiliar) by week interaction. A P-value of ≤ 0.05 was considered significantly different. Regardless of treatment, preliminary analyses identified decreased lying (P &amp;lt; 0.02) and increased wound checking (P &amp;lt; 0.01) 48h following castration (d 14) when compared with the previous week (d 7). There were no observed differences for hindleg stamping (P = 0.2), agonistic behaviors (P &amp;gt; 0.06) or bunk displacement (P = 0.09). Based on preliminary analyses, we did not observe evidence of social buffering effects on castration stress during the immediate post-surgical period.

162 The role of functional amino acids in optimizing nutrition and health

Abstract The ability of a diet or an individual protein-containing ingredient to satisfy the indispensable amino acid (IAA) requirements of an individual is a reflection of protein quality. In human nutrition, the concept of PQ is well recognized and widely applied to facilitate guidance on the extensive range of food items we consume. In the pet food industry, the concept of PQ is gaining recognition as a way in which to identify ideal candidate ingredients for diet formulation and our laboratory has recently completed a large data base of PQ estimates of typical ingredients used in the pet food industry to compliment the emerging PQ ingredient data. Our laboratory has also used more advanced methodologies, specifically the IAAO technique, to measure the dietary Phe, Trp, Met, Thr, and Lys requirements for adult dogs of small, medium and large breed dogs. The role of AA beyond support of protein turnover (adults) or protein deposition (growth) is being explored, such as the role of certain AA in behavior, immune function and inflammation. For example, the ratio of tryptophan to the large neutral amino acids of 0.75:1.0 in contrast to 0.46:1.0 resulted in better indices of gut health and may reduce agonistic behaviors both of which are underpinned by improved serotonergic status. The role of the sulfur AA in the development of dilated cardiomyopathy further highlights the role of IAA as sources for secondary metabolites, such as taurine and glutathione in supporting animal health. Indeed, many AA are becoming referred to as functional AA and the requirement of these AA may differ in healthy and challenged animals and deserve attention in dog and cat nutrition as well. Overall, the pattern of AA that defines the requirement of healthy dogs and cats, may not be the pattern that would support the animal under challenging conditions. Research into supporting different physiological challenges and how these may affect amino acid requirements is warranted.

Agonistic behaviors of boxer shrimps (Stenopus Species): Insights into the importance of antennae, antennules and tactile contact

Agonistic behaviors are crucial and ubiquitous among animals for the competition of limited resources. Although the study of aggression has been a popular topic, plenty of studies focused on model organisms, and typically on crayfish and lobsters for crustaceans. Variations of the agonistic behaviors and the underpinning eliciting cues of other crustaceans therefore have not been fully explored. In the present study, we targeted Stenopus, a genus of shrimp-like crustaceans that displays prominent agonistic behaviors when encountering conspecifics of the same sex owing to their monogamous social structure. Using S. hispidus (Olivier, 1811) and S. cyanoscelis (Goy, 1984) as representatives, we characterized their agonistic behaviors and fighting pattern, conducted experiments to investigate the contribution of visual, olfactory and tactile cues to inducing aggression, and examined the effects of antennal and antennular ablation on their agonistic interactions. A total of seven agonistic behaviors were documented, where antennal entwining and tactile contact is the major driver and seemingly important cue, respectively, in inducing agonistic behaviors in Stenopus. Although ablation of antennae and antennules did not inhibit fighting, behavioral changes, such as the prolonged agonistic interactions and the delayed establishment of dominance were observed, suggesting a reduction of aggressiveness. A comparison of agonistic behaviors with other crustaceans showed that certain features appeared to be unique or distinct in Stenopus, including the potential functional overlap of antennae and antennules, a higher aggressiveness of the fighting behaviors, and the exhibition of crouching behavior by submissive individuals. The present study provides a crucial background understanding for subsequent research on Stenopus and paves the way for its establishment as another crustacean model for studying aggression.

Cross-seasonal and diurnal variation in physical contact between sub-adult pigs

Social touch is an important aspect of social relationships and has a major influence on development and health. However, in many species the occurrence and function of social touch is unknown. Pigs have frequent physical contact but this behaviour is largely unexplored. The aim of this study was to investigate the undisturbed variation in physical contact between pigs, and to assess diurnal and seasonal influences. A stable group of ten Puławska sub-adult female pigs was observed for 406 h across four seasons during the day and night, by continuous observations on an individual level (406 h / pig). They were housed indoors (112 m2 pen) on straw bedding. The ethogram distinguished the amount of surface contact between pigs when lying, the orientation to others, social nosing, other non-agonistic social behaviour and agonistic behaviours. Resting location within the pen was recorded 48 times per pig, and dominance relationships were calculated from agonistic interactions. Data were analysed with mixed models accounting for repeated observations. Pigs spent on average 40 % of their time lying in body contact, most often lying with their extremities in contact (71 %), followed by lying in partial body contact (16 %) or full body contact (13 %) and were frequently nosing the head and body of others. The duration of lying in any type of contact, as well as agonistic behaviour, was influenced by season, with the longest durations in autumn. In summer, the duration of partial body contact was lowest, but full body contact was unaffected by season. Nosing behaviour remained constant throughout the year. Pigs lay in contact more during the night, while showing more social behaviours during the day. Pigs mostly lay in nonparallel orientation or head-to-head, but clearly least in the head-to-tail orientation. Season influenced the frequency of lying head-to-head and head-to-tail, but not lying nonparallel. The coefficient of variation of the lying location was influenced by season. Allo-grooming, mounting, and nudging were shown infrequently and mostly by specific individuals. In conclusion, when at a large space allowance, pigs spend nearly half of their time in body contact, even during the higher temperatures in summer. This shows that social touch, including affiliative behaviour, has an important role in pigs’ social life, and remains largely unaffected by external influences.

A narrative review of factors affecting the welfare of dairy cows in larger Australasian pasture-based production systems

On the basis of current growth trajectories, pasture-based dairies of the future are likely to be bigger, have higher stocking rates and feed more concentrate to cows. This review uses the five-domains framework to consider risks to the welfare of dairy cows in these larger intensified pasture-based production systems. The factors considered in this review can be broadly categorised as (1) emerging welfare risks that can be managed, (2) emerging welfare risks that require research to be managed, or (3) persisting and/or exacerbated welfare risks. First, large herds could be subject to welfare risks associated with more stock per labour unit, longer milking times and longer distances walked to and from the dairy. To counter this, the time that cows in large herds spend off pasture can be reduced by splitting the herd into several more manageable groups, and animal-monitoring technologies can help identify health challenges with a reduced stockperson to animal ratio. Cow body condition and productivity can be maintained at high stocking rates by improving pasture production and feeding a higher proportion of concentrate. The risk of ruminal acidosis may then be reduced by appropriate transition feeding regimes and rumen buffers. Second, ensuring social stability and reducing competition may become difficult as herd sizes increase and feeding becomes more intensive. The resulting variability in feed intake, increased agonistic behaviour and social stress present emerging risks to cow welfare. Research is needed to better understand the social behaviour of cows in large intensive pasture-based herds, and how the design of the pre-milking area, the feeding pad and pasture feeding regimes (i.e. quantity and timing of pasture allocation) can improve accessibility for more vulnerable animals. Finally, intensive pasture-based dairies of the future will continue to face welfare challenges relating to lameness, mastitis and cull-cow management, whereas risks due to environmental exposure may be exacerbated by the removal of shelterbelts to facilitate irrigation. These require continued efforts in research (e.g. ways of incorporating shelter into intensive grazing systems), development (e.g. pathway to market for aged beef) and extension (e.g. improved record keeping and benchmarking of lameness and mastitis).

Effects of a veterinary functional music-based enrichment program on the psychophysiological responses of farm pigs

Intensification of swine production can predispose pigs to chronic stress, with adverse effects on the neuroendocrine and immune systems that can lead to health problems, poor welfare, and reduced production performance. Consequently, there is an interest in developing tools to prevent or eliminate chronic stress. Music is widely used as a therapeutic strategy for stress management in humans and may have similar benefits in non-human animals. This study evaluated the effects of a music-based auditory enrichment program in pigs from a multidimensional perspective by assessing psychophysiological responses. Two experimental groups of 20 pigs each were selected for the study: one enriched, exposed to a program of functional veterinary music designed for pigs, and a control group without auditory stimulation. Qualitative behavior assessment (QBA) and skin lesions indicative of agonistic behavior were used to evaluate the psychological determinants underlying the observed behaviors. Physiological assessment included hemograms, with the determination of the neutrophil:lymphocyte ratio and daily measurements of cortisol and salivary alpha-amylase levels. The results demonstrated a positive effect of a music-based auditory program on psychophysiological responses. Therefore, this strategy developed for environmental enrichment may be beneficial in reducing stress and contributing to the welfare and health of pigs under production conditions.