Behavioural Thermoregulation in a Small Neotropical Primate

The maintenance of body temperature in endothermic animals imposes considerable metabolic costs that vary with air temperature fluctuations. To minimise these costs, endotherms can adopt certain behaviours to adjust the pattern of heat transfer between their bodies and the environment. In this study, we evaluated whether a small Neotropical primate, the black‐fronted titi monkey (Callicebus nigrifrons), living in a seasonal environment can use behavioural mechanisms to cope with fluctuations in the air temperature. We monitored the air temperature and the titi monkeys’ behaviour over 1 yr. When the animals were inactive, we recorded the microhabitat used, the huddling between individuals and the body postures adopted. The monkeys primarily responded to air temperature fluctuations through microhabitat selection: they spent more time in sunny places and used higher strata of forest under lower temperatures. Moreover, they used sunny microhabitats during the first hour of their active period after colder nights. The monkeys did not huddle or change body postures in response to air temperature fluctuations. Huddling behaviour seemed to be primarily influenced by social interactions, and body postures were more energy conserving, regardless of temperature. Titi monkeys, however, used more energy‐conserving postures and huddling behaviour under cloudy conditions than sunny conditions, suggesting that these behaviours may be important when they are unable to thermoregulate by microhabitat selection. We concluded that fluctuations in air temperature can promote significant changes in the behaviour of titi monkeys and can impose important restrictions on mammals’ activities, even in tropical regions.     

Methodological approach to genetic-selection analysis of social behavior of animals (Using as an example domestic behavior of the silver fox

Social behaviour of animals, i.e. interspecies contacts, were studied in a population of silver foxes in the longitudinal model domestication experiment. Three social behaviour traits were analysed: contactibility, critical distance and domestication index. The latter trait is a linear function of elementary behaviour reactions, postures induced by man which is determined by the principal components method. The most valiable selection phenotype for further modelling of domestication, as shown by the capacity to adequately reflect a pattern of genotype--environment interaction, the structure of correlation ratios for different forms of behaviour and the level of genetic relationships between relatives, is the domestication index.     

An ethological analysis of the influence of perinatally-administered diazepam on murine behaviour

1. A number of studies have found that the perinatal exposure of rodents to various tranquillizing agents alters their adult behaviour.2. Given the known anti-aggressive influence of acute doses of diazepam it was hypothesized that, when administered during pregnancy, this drug would change the adult social behaviour.3. The social interactions of adult male mice whose mothers were treated with diazepam or appropriate controls during pregnancy were video-taped and subjected to an ethological analysis that involved counting the incidences of 43 distinct postures.4. Prenatal but not postnatal diazepam treatment was associated with a large increase in the incidence of the sideways offensive posture. No significant differences resulted, however, in the case of other postures; in general exposure to prenatal diazepam produced few changes in adult social behaviour.     

A comparative description of the mating behaviour of female rodents

This paper provides a comparative analysis of movements and postures of female rodents during copulation. Cinematographic techniques were used to assess details of movements and postures of the copulatory behaviour of laboratory (Norway) rats, Mongolian gerbils, and 14 other species of muroid rodents. Considerable variability, with potential evolutionary, ecological, and physiological implications, was found.     

Some behavioural observations on wild and captive sand monitors, Varanus gouldii (Sauria: Varanidae)

Behavioural observations were made on wild and captive sand monitors in Australia. Threat and defensive postures are described for V. gouldii and reference is made to V. varius and V. spenceri; such behaviour is compared to other species within the family Varanidae. With captive V. gouldii, one case of cannibalism occurred when space was restricted.     

Attempts to determine the status of electroshock-induced attack in male laboratory mice

An attempt was made using a combination of simple experimental manipulations and videotape recorder (VTR) analysis of bite targets employed to determine whether electroshock-induced attack on anosmic opponents in laboratory mice was an offensive or a defensive behaviour. VTR analysis suggested that ventral surface biting was more evident in this form of attack than in social conflict. Individually- and group-housed males showed similar levels of fighting on exposure to electroshock, but dominant males from pairs showed greater attack than their subordinate partners. Zinc sulphate-induced anosmia, 36 h of food deprivation, castration and lithium chloride treatment reduced electroshock-induced attack. Although significant changes were not obtained, there was some evidence that acute treatment with dexamethasone or ACTH augmented this behaviour. The direction of these changes is similar to that seen with social conflict, and it is suggested that electroshock-induced attack in the mouse (unlike the rat) is largely an aggressive offensive behaviour. The high incidence of ventral surface biting may be a consequence of the upright postures assumed on subjecting the animals to electroshock.     

Adaptive significance of death feigning posture as a specialized inducible defence against gape-limited predators

Death feigning is fairly common in a number of taxa, but the adaptive significance of this behaviour is still unclear and has seldom been tested. To date, all proposed hypotheses have assumed that prey manage to escape predation by sending a death-mimicking signal, although death-feigning postures are markedly different from those of dead animals. Moreover, the efficacy of this technique may largely depend on the foraging mode of the predator; death feigning seldom works with sit-and-wait predators that make the decision to attack and consume prey within a very brief time. We examined whether death feigning in the pygmy grasshopper Criotettix japonicus Haan was an inducible defence behaviour against the frog Rana nigromaculata, a sit-and-wait, gape-limited predator. The characteristic posture assumed by the grasshopper during death feigning enlarges its functional body size by stretching each of three body parts (pronotum, hind legs and lateral spines) in three different directions, thereby making it difficult for the predator to swallow the prey. Our result is the first consistent explanation for why death-mimicking animals do not always mimic the posture of dead animals.     

Characteristics of the behavior and adaptive reactions of amygdalectomized rats

The results are considered of the analysis of rats behaviour in tests of the open field, hot plate and passive avoidance, as well as data of temperature measurement and motor activity during repeated animals placing in conditions of moderate cold. It is shown, that in amygdalectomized rats the extinction of motor and vegetative reactions at their repeated placing in the open field and in cold is disturbed in comparison with the intact and partially with hippocampectomized animals. In contrast to intact and hippocampectomized rats, the amygdalectomized ones did not improve thermoregulatory stability at repeated cold exposures. Disturbance of activity of emotiogenic brain mechanisms modulating memory processes, is suggested as one of important causes of derangements of physiological functions adaptation after amygdalectomy. Existence of common mechanisms is postulated of emotiogenic regulation of adaptive transformations of behaviour and some physiological reactions to natural stimuli.     

Responses to agonistic postures by the spider crab Microphrys bicornutus †

Models were presented to 102 specimens of the spider crab Microphrys bicornutus to test the importance of several appendage and body postures, which occur during agonistic interactions. The double first ambulatory raise posture and the cheliped spread posture both elicited a significant number of agonistic responses. Multiple ambulatory raise postures and raised or lowered body postures did not elicit significantly different response spectra. Size and sex of test animals seemed to have little effect on their responses.     

Behavioral thermoregulation in a sexually and developmentally dichromatic neotropical primate,the black-and-gold howling monkey (Alouatta caraya)

Behavioral thermoregulation in primates may provide a means for the conservation of heat during periods of low ambient temperature and/or food shortage as well as a way to dissipate heat under hot conditions. This article focuses on behavioral thermoregulation in a sexually dichromatic primate, the black-and-gold howling monkey (Alouatta caraya). Two models have been proposed to explain the evolution of sexual dichromatism in this species: thermoregulation and sexual selection. Five hypotheses associated with thermoregulatory behaviors are tested. These are as follows: (1) energy-conserving postures are used mainly under low ambient temperatures; (2) sunny resting places are selected during periods of low temperature; (3) exposure of the less-insulated ventral region to sunlight decreases with increasing temperature; (4) black-colored adult males use energy-conserving postures, sunny places, and exposure of the ventral region to sunlight less frequently than do blonde-colored adult females; and (5) smaller individuals use energy-conserving postures, sunny places, and exposure of the ventral region to sunlight in significantly greater frequency than do larger individuals. Over a 12-month period, behavioral data were collected on a free-ranging habituated group of 15–17 howlers of all age-sex classes. Ambient temperature was measured each hour. The results indicate that during resting, howlers showed a consistent use of heat-conserving postures, showed a preference for sunny places, and exposed their ventral region to sunlight under low ambient temperatures. A preference for shady places, heat-dissipating postures, and exposure of the back were observed under high ambient temperatures. Despite sex differences in adult color patterns and differences in size between age classes, no significant age or sex differences in thermoregulatory behaviors were detected. Failure to confirm a thermoregulation model implies that sexual selection may be responsible for sexual dichromatism in this species. Am J Phys Anthropol 106:533–546, 1998. © 1998 Wiley-Liss, Inc.     

Multiunit activity of the inferior olive during a conditioned motor sequence]

Multinuit activity from the inferior olive was recorded in chronic cats during a learned motor task. The animals were trained to perform a succession of rapid flexion-extension arm movements alternating with two maintained postures. No significant differences were observed in the olivary activity during maintained postures. However an increase of activity occurred before the beginning of the flexion detected on the biceps EMG recordings. The first modifications of olivary activity occurred in synchrony with postural reorganization preceding the flexion. This latter involved primarily the triceps. The increase of activity took place during the execution of movement and ended after the reaching of the target.     

Avoidance behaviour and anxiety in rats irradiated with a sublethal dose of gamma-rays

The aim of this study was to assess, whether a sublethal dose of gamma-rays will influence the avoidance behaviour and anxiety in rats and whether the response to radiation depends on time of day of its application. Adult male Wistar rats were tested in elevated plus-maze, in hot plate test and in the light/dark box in 4 regular intervals during a day. After two weeks the animals were irradiated with a whole-body dose 6 Gy of gamma-rays. One day after irradiation the animals were repeatedly tested in the same way, as before irradiation. In the plus-maze test an increased level of anxiety was established. The irradiation significantly decreased the locomotor activity of rats, but the extent of exploratory and comfortable behaviour were not altered. After irradiation, an elevated aversion to the thermal stimulus was observed in the hot plate test. The effects of radiation were more pronounced in the light period of the day, than in the dark one. No significant differences in aversion to light were detected after irradiation. The obtained results indicate, that sublethal doses of ionizing radiation can markedly influence the reactivity of animals to adverse stimuli, their motoric activity and emotional status, as well.     

Aposematic Behaviour in the Striped Skunk,Mephitis mephitis

From April to August, 1993 to 1995, we studied the aposematic behaviour patterns of striped skunks, Mephitis mephitis, incidentally while ground-tracking radio-marked animals. During 2668 h of tracking, 207 defensive postures were displayed by 34 radio-collared (27 females, 7 males) and 21 unidentified skunks. Skunks most often advertised their noxiousness using Tail-up (69.1 % occurrence) and Stomp (17.4%). Encounters were frequently (42.5 %) terminated by the skunk running away from the source of disturbance. Most warning behaviour was directed at radio-trackers (95.7 %), and the remainder was displayed to a variety of predatory and non-predatory animals or objects. Stomp occurred more frequently in taller vegetation, where visual advertisement was limited. Reaction distance of skunks disturbed by observers (median = 6 m) was not affected by wind, movement or vegetation height. The small awareness circle and high tolerance of skunks to disturbance are consistent with the life history traits of aposematic animals.     

Vertical clingers and gougers: Rapid acquisition of adult limb proportions facilitates feeding behaviours in young Javan slow lorises (Nycticebus javanicus)

Animals of all ages need to access essential food resources, either on their own or with the assistance of conspecifics. Rapid physical and behavioural development is one strategy to help young animals reach adulthood. Specialized gum-feeding mammals exploit a food type that is relatively difficult to access and digest and must possess the appropriate adaptions to access large vertical substrates, i.e. tree trunks. Unlike other gum feeding mammals, the Javan slow loris (Nycticebus javanicus) lacks physical structures, such as keeled nails or claws, which animals commonly use to secure themselves to large vertical substrates. To understand how slow lorises of all ages exploit gum, we examined their vertical gouging posture, locomotor behaviour, habitat use during feeding, and their morphometric measures across three age classes (adult, sub-adult, juvenile). Using data collected in Cipaganti, Java, Indonesia between April 2012 and April 2016, we found that individuals of N. javanicus rely on their hand, foot, and limb morphology to maintain vertical gouging postures, in place of claws or keeled nails. Locomotor behaviour, position in tree, and tree DBH showed no significant difference across age classes while feeding. Juveniles were indistinguishable from adults and sub-adults in regards to limb proportion indices, lower leg length, hand span and foot span. Some morphometric measures scaled isometrically e.g. arm length, but those highlighted during prolonged vertical postures scaled allometrically e.g. leg, hand, and foot measures. These findings suggest that the rapid behavioural and physical development of key features may act as an ontogenetic adaptation to facilitate access to a stable food resource at a young age. The Javan slow loris exemplifies the complex relationship that exists between an animal’s diet and the specializations that facilitate access to these food resources.     

Effect of prenatal alprazolam exposure on anxiety patterns in rat offspring

Prenatal alprazolam (APZ) treatment in 0.1 and 0.2 mg/kg/day doses during 13-20 days of gestation induced significant increase in open-field ambulation, rearings, self-grooming and faecal pellets in rat offspring. Prenatal APZ treated rats displayed significantly increased anxiogenic behaviour on elevated plus maze (spent less time on open arms, more time on enclosed arms and made less number of entries on open arms) and increased anxiogenecity on elevated zero maz e(APZ treated rats spent less time on open arms and made less number of head dips and stretched attend postures in comparison to control rat offspring). The results indicate persistent behavioural alterations in the rat offspring after prenatal exposure to APZ.     

Gravity is a minor determinant of pulmonary blood flow distribution

Regional pulmonary blood flow in dogs under zone 3 conditions was measured in supine and prone postures to evaluate the linear gravitational model of perfusion distribution. Flow to regions of lung that were 1.9 cm3 in volume was determined by injection of radiolabeled microspheres in both postures. There was marked perfusion heterogeneity within isogravitational planes (coefficient of variation = 42.5%) as well as within gravitational planes (coefficient of variation = 44.2 and 39.2% in supine and prone postures, respectively; P = 0.02). On average, vertical height explained only 5.8 and 2.4% of the flow variability in the supine and prone postures, respectively. Whereas the gravitational model predicts that regional flows should be negatively correlated when measured in supine and prone postures, flows in the two postures were positively correlated, with an r2 of 0.708 +/- 0.050. Regional perfusion as a function of distance from the center of a lung explained 13.4 and 10.8% of the flow variability in the supine and prone postures, respectively. A linear combination of vertical height and radial distance from the centers of each lung provided a better-fitting model but still explained only 20.0 and 12.0% of the flow variability in the supine and prone postures, respectively. The entire lung was searched for a region of contiguous lung pieces (22.8 cm3) with high flow. Such a region was found in the dorsal area of the lower lobes in six of seven animals, and flow to this region was independent of posture. Under zone 3 conditions, neither gravity nor radial location is the principal determinant of regional perfusion distribution in supine and prone dogs.     

An ethogram of the common marmoset (Calithrix jacchus jacchus): General behavioural repertoire

The behavioural repertoire of four captive breeding pairs of Callithrix jacchus jacchus is described. Social communication took the form of postures, facial expressions, vocalizations and piloerection displays. Detailed analyses were made of piloerection displays, adult play, copulatory, aggressive, and prey-catching behaviour. Aggressive behaviour was uncommon in adult mated pairs. Play between adults showed a degree of temporal organization. Vocalizations were the main methods of intragroup communication whilst piloerection displays were directed towards members of other groups and also to unfamiliar objects. The behavioural repertoire of C. jacchus jacchus is compared with that of other Primates.     

Changes in behaviour and eye-morphology of BoreomysisMegalops G.O. Sars (Crustacea : Mysidacea) following exposure to short periods of artificial and natural daylight

Boreomysis megalops G.O. Sars were collected from 240 m depth using a protective cod-end, which shielded the eyes from light exposure. Animals were divided into groups which were exposed to darkness (DE) or to natural or artificial daylight (LE) for periods of 1–15 min or 4 h. Some animals were thereafter kept in aquaria under simulated habitat light conditions (light/dark cycles). The animals were observed in infra-red (IR) light. DE animals showed a vertical zonation behaviour in the laboratory similar to that obtained from sledge data: i.e. the animals stayed close to the bottom during daytime (light) and spread out vertically at night (darkness).LE individuals showed putative pathological changes both in zonation behaviour in the laboratory and in eye-morphology. The photoreceptor membranes of the six main retinula cells were damaged. The seventh cell was unaffected by light exposures. A correlation was found between the extent of damage to the eye and the degree of modification of vertical zonation behaviour. The groups exposed to the least light showed the smallest changes in zonation behaviour and eye-morphology. The light induced changes were not reversed even after 4 days in the aquarium under simulated habitat light conditions. In conclusion, deep living animals with well-developed and very light sensitive eyes should be protected from daylight during sampling and handling. IR light should be used for observation purposes.     

Effects of nostril plugging and of habenulectomy on sexual behaviour in the male crested newt

In an attempt to gain some insight into the possible involvement of the habenulae in the control of sexual behaviour in the male crested newt, a comparison was made between the effects of olfactory deprivation by bilateral nostril plugging and of habenulectomy on courtship performance and locomotor activity. Both treatments led to a decrease in spontaneous locomotion and to a drastic abolition of the complex courtship ritual characterized by the sequence of male postures displayed prior to spermatophore deposition. Following nostril plug removal, the animals resumed their normal activities. Unilateral plugging had no effect. These results seem to lend further support to the importance of specific olfactory stimuli in sexual behaviour. The main finding obtained here was the strict comparability between the behavioural changes resulting from habenulectomy and the olfactory-related changes following nostril plugging, linking from a functional point of view the habenulae with the olfactory system. According to recent reports available in the literature, the morphological organization of the habenular nuclei in urodeles still needs further clarification. On the basis of the present results, the possible importance of the habenulae in olfactory integration in the crested newt might be postulated.     

Sexual behaviour of male rats rehabilitated after early protein-calorie malnutrition.

The effect of early protein-calorie malnutrition (from birth to the age of 55 days) followed by nutritional rehabilitation (from the 58th day) on sexual behaviour was studied in male rats aged about 125 days. The sexual stimulation conditions on the part of the oestrus female were made as optimal as possible and were fully controlled. About half the malnourished males displayed precopulatory and copulatory behaviour, while in the control group these values were almost 100%. When malnourished males copulated, their copulatory performance did not differ very greatly from that of the well-nourished controls. The other experimental males displayed no signs of sexual behaviour during the testing period. Exposure of the males to the scent of a female in the latter's absence greatly stimulated their interest in the odour (sniffing the floor of the experimental box) in both the control and the malnourished animals which afterwards copulated. The results indicate that the sexual behaviour of males subjected to protein-calorie deficiency in early ontogenesis is at the very least delayed, if not completely suppressed.