Promoting positive states: the effect of early human handling on play and exploratory behaviour in pigs

It is known that tactile stimulation (TS) during ontogeny modifies brain plasticity and enhances the motor and cognitive skills. Our hypothesis was that early handling including TS would increase play and exploratory behaviour in commercial pigs under standardized test conditions. Piglets from 13 litters were subjected to three handling treatments from 5 to 35 days of age: all the piglets were handled (H), none of the piglets were handled (NH) or half of the piglets in the litter were handled (50/50). At 42 days of age, the pigs’ behaviour was observed in pairs in a novel pen with a ‘toy’ (tug rope). The main results were that more locomotor play was performed by pigs from litters where all or half of them had been handled, whereas social exploratory behaviour was more pronounced in pigs from litters where half of them had been handled. Although behaviour was affected by the interaction of treatment with sex or with weight category, we propose that the handling procedure does seem to have acted to increase locomotor skills and that handling half of the piglets in the litter may have triggered a series of socio-emotional interactions that were beneficial for the whole group.     

Male aggression,limited female choice and the ontogeny of mating behaviour in the flesh fly Sarcophaga crassipalpis

Previous work has shown that male flesh flies (Sarcophaga crassipalpis Macquart) exhibit an ontogeny of behaviour from eclosion through sexual maturity that includes extensive changes in the expression of aggressive, non‐aggressive interactive and non‐interactive behaviours. To determine how the presence of a female flesh fly influences the manifestation of these behaviours, male flesh flies of different ages post‐eclosion are paired with same‐age females and their behaviours are monitored in a simple arena during a 50‐min observation period. All flies are socially isolated until pairing. Although the levels of expression of aggressive and non‐aggressive interactive behaviours are depressed relative to previous findings in male‐opponent pairs, the ontogeny of aggression still occurs as indicated by a significant increase, with age, in the agonistic behaviour ‘hold’. Similar to male‐opponent pairs and individual males, the performance by males of the non‐interactive behaviours ‘walking’ and ‘standing’ diminishes, whereas ‘upside‐down’ increases with age. By contrast, ‘grooming’ shows a significant age‐related decline. No courtship behaviours are observed in the males, although the aggressive behaviour ‘hold’ is a significant transition to mating. Females show no obvious courtship or rejection behaviours, although the significant increase in ‘upside‐down’ with age could possibly be a behavioural gateway to mating. The results of this study indicate that extensive age‐related changes encompassing the entire behavioural repertoire are intrinsic to male flesh flies and persist under a variety of different social contexts.     

Social play in wild brown bears of varying age-sex class

Social play behaviour is a well-described phenomenon, almost ubiquitous among mammals. Despite its prevalence, social play takes several forms and may vary in function across species. For solitary species, the function of play outside of the family group remains unclear. Here, we describe the motor patterns of play among non-littermate wild brown bears Ursus arctos of different age-sex class. Play was documented during a time of abundant food availability in three different scenarios: play among non-littermate subadults, play among non-littermate cubs, and play among a ‘group’ of bears of different age and sex class. We used a previously described behavioural ethogram to recognise play. Play followed typical motor patterns and postures expressed by bears during play-fighting: relaxed face, puckered-lip, ears partially flattened to crescent, wrestling, jaw gaping, play-biting, paw-swatting, and lunging. No vocalisations were conducted during play bouts. Older bears displayed ‘self-handicapping’ and ‘role-reversal’ in the play postures they selected when playing with younger bears, suggesting that tactics vary according to age class and dominance ranking. Playing likely allows for the evaluation of conspecifics in a non-aggressive way during times of reduced competition and could also relieve stress in complex social situations.     

On the evolutionary and ontogenetic origins of tool‐oriented behaviour in New Caledonian crows (Corvus moneduloides)

New Caledonian crows (Corvus moneduloides) are prolific tool users in captivity and in the wild, and have an inherited predisposition to express tool‐oriented behaviours. To further understand the evolution and development of tool use, we compared the development of object manipulation in New Caledonian crows and common ravens (Corvus corax), which do not routinely use tools. We found striking qualitative similarities in the ontogeny of tool‐oriented behaviour in New Caledonian crows and food‐caching behaviour in ravens. Given that the common ancestor of New Caledonian crows and ravens was almost certainly a caching species, we therefore propose that the basic action patterns for tool use in New Caledonian crows may have their evolutionary origins in caching behaviour. Noncombinatorial object manipulations had similar frequencies in the two species. However, frequencies of object combinations that are precursors to functional behaviour increased in New Caledonian crows and decreased in ravens throughout the study period, ending 6 weeks post‐fledging. These quantitative observations are consistent with the hypothesis that New Caledonian crows develop tool‐oriented behaviour because of an increased motivation to perform object combinations that facilitate the necessary learning. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 870–877.     

Effects of body size and resource value on fighting behaviour in a jumping spider

Fights between male Euophrys parvula, a New Zealand salticid spider, consist of a number of discrete ‘stages’, of increasing intensity. Two aspects of these contests were investigated: (1) relative body size of the two opponents, and (2) the presence of a ‘resource’ (a female model). In 92% of all contests where a size difference existed, the larger of the two opponents won. Contest intensity (measured as the highest intensity behaviour elicited during the contest) was inversely correlated with relative body size of the two opponents (measured as carapace width). Contests escalated further when the female model was present. No relationship was found between contest duration and either relative body size or the presence of the model. It is suggested that for contests in which a number of behaviours of different intensity are used, contest intensity may be a better estimate of contest cost than duration. The results are discussed in terms of theoretical models of contest behaviour.     

Quantitative Analysis of the Ontogeny of Play Behaviour in Canid Hybrids

The question how far the ontogeny of social behaviour shows similarities and to what extent it is genetically determined is investigated for 3 F2 canid hybrids of one litter by the example of contact play behaviour. It is known that jackals, especially the golden jackal (Canis aureus L.) display a number of differences in social behaviour and a very early ontogeny compared with the wolf (C. lupus L.) and the domesticated dog (C. I. forma familiaris). In this study behaviours were classified by timing the duration of single events from video records. The analysis bases on the duration of special patterns of behaviour and not, as is usually done, on single observations. Readiness to play is of special importance. It is measured by the number of plays initiated and behaviour during play. Whereas individual duration of play of these 3 F2 hybrids is greatly influenced by exogene factors, the maximum readiness to play, occurring over a marked time interval, seems endogenously determined. The different inborn development of readiness to play leads to very different frequencies of partner combinations during the various phases of development. Animals with much play initiative more often take part in contact play of their own accord. This establishes the order of frequencies of the playmates chosen. The frequency of successfully triggering contact play and the duration of the individual play initiative turn out to be a suitable measure of the — otherwise hardly recordable — genetically determined readiness to play.     

Drought limitations to leaf‐level gas exchange: results from a model linking stomatal optimization and cohesion–tension theory

We merge concepts from stomatal optimization theory and cohesion–tension theory to examine the dynamics of three mechanisms that are potentially limiting to leaf‐level gas exchange in trees during drought: (1) a ‘demand limitation’ driven by an assumption of optimal stomatal functioning; (2) ‘hydraulic limitation’ of water movement from the roots to the leaves; and (3) ‘non‐stomatal’ limitations imposed by declining leaf water status within the leaf. Model results suggest that species‐specific ‘economics’ of stomatal behaviour may play an important role in differentiating species along the continuum of isohydric to anisohydric behaviour; specifically, we show that non‐stomatal and demand limitations may reduce stomatal conductance and increase leaf water potential, promoting wide safety margins characteristic of isohydric species. We used model results to develop a diagnostic framework to identify the most likely limiting mechanism to stomatal functioning during drought and showed that many of those features were commonly observed in field observations of tree water use dynamics. Direct comparisons of modelled and measured stomatal conductance further indicated that non‐stomatal and demand limitations reproduced observed patterns of tree water use well for an isohydric species but that a hydraulic limitation likely applies in the case of an anisohydric species.     

Dynamic body acceleration increases by 20% during flight ontogeny of greylag geese Anser anser

Despite our knowledge of the biophysical and behavioural changes during flight ontogeny in juvenile birds, little is known about the changes in the mechanical aspects of energy expenditure during early flight development, particularly in migratory species. Here, we investigate in a unique experimental setup how energy expended during flights changes over time beginning with early ontogeny. We calculate overall dynamic body acceleration (ODBA) as a proxy for energy expenditure in a group of hand raised greylag geese Anser anser trained to fly behind a microlight aircraft. We propose two potential hypotheses; energy expenditure either increases with increasing physiological suitability (the ‘physical development hypothesis’), or decreases as a result of behavioural improvements mitigating flight costs (the ‘behavioural development hypothesis’). There was a significant temporal increase of flight duration and ODBA over time, supporting the ‘physical development hypothesis’. This suggests that early on in flight ontogeny behavioural development leading to flight efficiency plays a weaker role in shaping ODBA changes than the increased physical ability to expend energy in flight. We discuss these findings and the implications of flight development on the life history of migratory species.     

An informatics approach to distinguish RNA modifications in nanopore direct RNA sequencing

Modifications in RNA can influence their structure, function, and stability and play essential roles in gene expression and regulation. Methods to detect RNA modifications rely on biophysical techniques such as chromatography or mass spectrometry, which are low throughput, or on high throughput short-read sequencing techniques based on selectively reactive chemical probes. Recent studies have utilized nanopore-based fourth-generation sequencing methods to detect modifications by directly sequencing RNA in its native state. However, these approaches are based on modification-associated mismatch errors that are liable to be confounded by SNPs. Also, there is a need to generate matched knockout controls for reference, which is laborious. In this work, we introduce an internal comparison strategy termed “IndoC,” where features such as ‘trace’ and ‘current signal intensity’ of potentially modified sites are compared to similar sequence contexts on the same RNA molecule within the sample, alleviating the need for matched knockout controls. We first show that in an IVT model, ‘trace’ is able to distinguish between artificially generated SNPs and true pseudouridine (Ψ) modifications, both of which display highly similar mismatch profiles. We then apply IndoC on yeast and human ribosomal RNA to demonstrate that previously reported Ψ sites show marked changes in their trace and signal intensity profiles compared with their unmodified counterparts in the same dataset. Finally, we perform direct RNA sequencing of RNA containing Ψ intact with a chemical probe adduct (N-cyclohexyl-N′-β-(4-methylmorpholinium) ethylcarbodiimide [CMC]) and show that CMC reactivity also induces changes in trace and signal intensity distributions in a Ψ specific manner, allowing their separation from high mismatch sites that display SNP-like behavior.     

Prey or play: interactions between walruses and seabirds

Several anecdotal reports indicate that walruses (Odobenus rosmarus) occasionally attack seabirds, which potentially impacts local bird populations. However, the manner in which walruses interact with seabirds and the motivational basis of such interactions have not been investigated. Here, we describe and characterize the behaviour of wild Pacific walruses (O. r. divergens) directed at seabirds in water near the summer haulout in the Chukchi Sea. Although most walruses showed no interest in seabirds nearby, some individuals intentionally approached them both alone and in groups. A total of 74 seabird encounters for 71 individually identified walruses were registered. Behavioural analysis based on detailed observations, photography and video recording showed that the most common types of walrus behaviour toward a bird were approach by surfacing and splash, approach by surfacing and hit and attack from below. Immature individuals initiated 82% of encounters. The motivation to approach a bird was low in adult individuals, with the majority of encounters involving adults initiated by males. Walrus encounters with live birds showed a very low rate of bird kill. Encounters with dead birds were followed by further manipulations with bird carcasses, which included both the consumption of bird soft tissue and object play taking the form of drop–catch behaviour. In addition eight cases of the object-oriented play with a bird carcass in a group of walruses were observed. Object play in wild walruses is reported for the first time. Our results indicate that in seabird encounters, walruses display diverse behavioural patterns, not limited to predatory responses.     

Longterm effects of incubation temperatures on the morphology and locomotor performance of hatchling lizards (Bassiana duperreyi, Scincidae)

The phenotypes of hatchling reptiles are known to be affected by the thermal environments they experience during incubation, but the evolutionary and ecological significance of this phenotypic plasticity remains unclear. Crucial issues include: (i) the magnitude of effects elicited by thermal regimes in natural nests (as opposed to constant-temperature incubation); (ii) the persistence of these effects during ontogeny; and (iii) the consistency of these effects across different test conditions (does the thermal regime during embryogenesis simply shift the hatchling's thermal optimum for performance, or actually modify overall performance ability regardless of temperature?). We examined these questions by incubating eggs of scincid lizards (Bassiana duperreyi) from montane southeastern Australia, under two fluctuating-temperature regimes that simulated ‘cold’ and ‘hot’ natural nests. These thermal regimes substantially modified hatchling morphology (mass, body length, tail length, and the relationship between these variables), locomotor performance (running speeds over distances of 25 cm and lm), anti-predator ‘tactics’ and survival rates. The differences in locomotor performance persisted throughout the 20 weeks of our experiment. Lizards that emerged after ‘hot’ incubation were faster runners than their ‘cold’-incubated siblings under all thermal conditions that we tested. Thus, incubation temperatures modified overall locomotor ability, with only a minor effect on the set-point for optimum performance. The magnitude, persistence and consistency of these incubation-induced phenotypic modifications suggest that they may play an important role in evolutionary and ecological processes within lizard populations.     

The adaptive significance of behavioural ontogeny in some. centrarchid fishes

Synopsis Studies on the ontogeny of behaviour in fish have seldom considered the adaptive significance of the order of appearance of the behaviours. Results of laboratory studies and field observations on the ontogeny of feeding, predator-avoidance, and agonistic behaviour in largemouth bass, Micropterus salmoides, rock bass, Ambloplites rupestris, and pumpkinseed, Lepomis gibbosus, young indicate that the order of appearance of the various behavioural systems enhances the survival of the young. In the laboratory, all species spend significantly more time feeding during the first weeks of free-swimming than the later weeks. During a corresponding period in the field the young are either occupying an offshore area low in predators (rock bass, pumpkinseed) or are being guarded by a parent (largemouth bass); thus the risk of predation is low. When the young are in a predator-rich environment (inshore) both the predator-avoidance response and agonistic behaviour are well developed. Agonistic behaviour is the last to appear and may serve to disperse the young. Dispersal may relate to the feeding mode of the various species and may also reduce the probability of predation. It is apparent that the sequential onsets of the behavioural systems are in concert with ecological events and selective pressures confronting centarchid young.     

Why Do You Dance? Development of the Dance Motivation Inventory (DMI)

Dancing is a popular form of physical exercise and studies have show that dancing can decrease anxiety, increase self-esteem, and improve psychological wellbeing. The aim of the current study was to explore the motivational basis of recreational social dancing and develop a new psychometric instrument to assess dancing motivation. The sample comprised 447 salsa and/or ballroom dancers (68% female; mean age 32.8 years) who completed an online survey. Eight motivational factors were identified via exploratory factor analysis and comprise a new Dance Motivation Inventory: Fitness, Mood Enhancement, Intimacy, Socialising, Trance, Mastery, Self-confidence and Escapism. Mood Enhancement was the strongest motivational factor for both males and females, although motives differed according to gender. Dancing intensity was predicted by three motivational factors: Mood Enhancement, Socialising, and Escapism. The eight dimensions identified cover possible motives for social recreational dancing, and the DMI proved to be a suitable measurement tool to assess these motives. The explored motives such as Mood Enhancement, Socialising and Escapism appear to be similar to those identified in other forms of behaviour such as drinking alcohol, exercise, gambling, and gaming.     

Effects of light intensity and spectrum on fish behaviour in laboratory aquaria

Teleost fish are commonly used as model species in laboratory studies of behaviour and ecology. In comparison to other groups of vertebrates used routinely in such studies, however, relatively little attention has been paid to their environmental requirements from a welfare perspective. Fish naturally inhabit a wide variety of aquatic habitats that differ enormously in the range of light environments they provide, and light regime has enormous potential to affect behaviour. Yet the level and quality of illumination (in terms of intensity and wavelength spectrum) provided in experimental studies of fish behaviour is generally designed to maximize ease of recording by the observer. In addition, display or home aquaria provide illumination that maximizes the ‘viewing pleasure’ of the observer, and specialist lighting tubes are available to stimulate rapid plant growth and to ‘show off’ the colours of fish, rather than to provide ‘natural’ light environments. Here we present the results of three studies designed to examine the effects of light intensity, wavelength spectrum and their interactions on the behaviour of a model species commonly used in behavioural studies, the three‐spined stickleback Gasterosteus aculeatus. Our aims are to determine whether unnatural light environments, generated by manipulating light intensity and wavelength spectrum, affect behaviour in ways that may lead to concern for the welfare of fish as research animals or pets.     

Specificity of fungal associations of Pyroleae and Monotropa hypopitys during germination and seedling development

Mycoheterotrophic plants obtain organic carbon from associated mycorrhizal fungi, fully or partially. Angiosperms with this form of nutrition possess exceptionally small ‘dust seeds’ which after germination develop ‘seedlings’ that remain subterranean for several years, fully dependent on fungi for supply of carbon. Mycoheterotrophs which as adults have photosynthesis thus develop from full to partial mycoheterotrophy, or autotrophy, during ontogeny. Mycoheterotrophic plants may represent a gradient of variation in a parasitism–mutualism continuum, both among and within species. Previous studies on plant–fungal associations in mycoheterotrophs have focused on either germination or the adult life stages of the plant. Much less is known about the fungal associations during development of the subterranean seedlings. We investigated germination and seedling development and the diversity of fungi associated with germinating seeds and subterranean seedlings (juveniles) in five Monotropoideae (Ericaceae) species, the full mycoheterotroph Monotropa hypopitys and the putatively partial mycoheterotrophs Pyrola chlorantha, P. rotundifolia, Moneses uniflora and Chimaphila umbellata. Seedlings retrieved from seed sowing experiments in the field were used to examine diversity of fungal associates, using pyrosequencing analysis of ITS2 region for fungal identification. The investigated species varied with regard to germination, seedling development and diversity of associated fungi during juvenile ontogeny. Results suggest that fungal host specificity increases during juvenile ontogeny, most pronounced in the fully mycoheterotrophic species, but a narrowing of fungal associates was found also in two partially mycoheterotrophic species. We suggest that variation in specificity of associated fungi during seedling ontogeny in mycoheterotrophs represents ongoing evolution along a parasitism–mutualism continuum.     

Does the environmental background (intensive v. outdoor systems) influence the behaviour of piglets at weaning?

Under intensive pig husbandry, outdoor systems offer a more complex physical and social environment compared with indoor systems (farrowing sheds). As the rearing environment affects behavioural development, it can, therefore, influence behavioural responses of pigs to stressful environments in later stages of production. We tested how the rearing environment influenced behavioural responses to a novel arena test in piglets on the day that they were weaned and mixed into large groups. We recorded video footage and compared the behavioural responses of 30 outdoor-raised and 30 farrowing shed-raised piglets tested in an experimental arena and sequentially exposed to four challenges (each for 5 min) on the day of weaning. Quantitative and qualitative behavioural measures were recorded using time budgets and scoring demeanour or ‘qualitative behavioural expression’ (using Qualitative Behavioural Assessment (QBA)). When held in isolation (challenge 1), both groups were scored as more ‘scared/worried’, while outdoor-raised piglets spent more time eating and jumping against the arena walls. Both groups interacted with a plastic ball (challenge 2: exposure to a novel object) during which they were scored as more ‘playful/curious’ than other challenges. When a food bowl was introduced (challenge 3), farrowing shed-raised piglets were more interested in playing with the food bowl itself, whereas outdoor-raised piglets spent more time eating the feed. Finally, there were no significant differences in social behaviour (challenge 4: introduction of another piglet) between the two groups in terms of the latency to contact each other, amount of time recorded engaged in aggressive/non-aggressive social interactions or QBA scores. Although piglets spent 30% of their time interacting with the other piglet, and half of this time (47%) was engaged in negative interactions (pushing, biting), the levels of aggression were not different between the two groups. Overall, outdoor-raised piglets ate more and were scored as more ‘calm/passive’, whereas farrowing shed-raised piglets spent more time investigating their environment and were scored as more ‘playful/inquisitive’. In conclusion, we did not find differences in behaviour between outdoor-raised and farrowing shed-raised piglets that would highlight welfare issues. The differences found in this study may reflect conflicting affective states, with responses to confinement, neophobia and motivation for exploration evident.     

Behaviour is not Reliably Inferred from End-Product Structure in Caddisflies

Many animals engage in elaborate behavioural sequences in order to build structures. The ‘end‐products’ (e.g., nests of birds, cases of caddisflies) of these behaviours have occasionally been used either to infer details of building behaviour or to infer that structures similar in appearance are constructed by similar behavioural sequences. However, behavioural information can be extrapolated from end‐products only if there is congruence between the end‐product structure and the animal's movements. Case building behaviour was studied in caddisflies (Trichoptera) to examine the relationship between end‐products and behaviour. We found examples of taxa that built similar structures using different behavioural patterns, and taxa that built different structures using similar behaviours, regardless of whether these taxa were closely or distantly related. These findings question the reliability of behavioural inferences based solely on details of their associated end‐products and suggest that end‐product structure should be removed from the definition of animal behaviour.     

Molecular evolution of Aldolase A pseudogenes in mice: multiple origins, subsequent duplications, and heterogeneity of evolutionary rates

The Aldolase multigene family comprises three functional genes (A, B, and C) with tissue-specific expression regulated during ontogeny. DGGE analysis and nucleotide sequencing reveal a family of retropseudogenes of type A in species of MUS: Significant variation in rates of evolution of Aldolase A retropseudogenes is apparent. Our analyses demonstrate that (1) multiple events of retrotransposition are needed to account for the diversity of Aldolase A processed pseudogenes found in mice; (2) some of these sequences have undergone further duplication subsequent to the original retrotransposition event; (3) the patterns of nucleotide substitution are broadly comparable with previous estimates; and (4) estimates of rates of divergence for this array of sequences are up to four times higher than those reported in the literature.     

Agonistic behaviour of juvenile gulls,a neuroethological study

The results relating to agonistic behaviour obtained during an exploration of the brain of juvenile herring and lesser black-backed gulls (Larus argentatus and fuscus) with electrical stimulation are reported. As an introduction the normal agonistic behaviour of immature gulls is described. While the flight and aggressive behaviour is largely unritualized the threat behaviour is more stereotyped. Three basic threat patterns are distinguished: the arched, hunched, and squat postures. The relationship of these juvenile agonistic patterns with adult courtship is considered. A large number of sites evoking fear behaviour were found, anatomically widely and incoherently distributed. It is demonstrated that the spontaneous fearfulness levels of individual subjects influences the likelihood of obtaining escape eliciting loci. Stimulation of a nubmer of these sites had an after-effect: a persistent, increased probability of escape behaviour. It seems likely that a proportion of the fear sequences elicited were secondary responses to evoked sensory hallucinations and forced small movements. None of the sites explored yielded outright attack behaviour. Thirteen sites yielded characteristic threat sequences. About half of them produced changes in ‘mood’ persisting for some 15 min. The sites were clustered in a paleostriatal-septal periventricular and an infundibular area. Histological differentiation of the neuroventricular interface at these areas is noted. Based on these it is argued that the secretion of ‘liquormones’ is responsible for the changes in ‘mood’ that followed stimulation.