Abstract: The ovine arena test in conjunction with multivariate statistical analysis (factor analysis) may be a means of measuring ovine temperament for practical purposes. Stability of factor construction over time and between groups of animals is considered to demonstrate trait consistency and is, therefore, one of the first steps in validating a temperament/personality test from this perspective. The aim of this study, therefore, was to assess the stability of factor construction, as a measure of trait consistency, using arena test data from three groups of animals with one group (Group 1) tested repeatedly over three rounds (twice at 8 months and once at 22 months of age). Group 1 consisted of 193 mule (Bluefaced Leicester Sire x Scottish Blackface/Welsh Speckled Face dam), ewe lambs (8 months old). Groups 2 and 3 consisted of 189 and 185 mules, respectively (14 months old). All animals were tested for 6 min in a 13 m x 3 m arena. Factor analysis (varimax rotation) was performed twice on the behavioural data (latency to bleat, total number of vocalisations, distance travelled, time spent in different areas of the arena and number of times crossing in and out of pertinent areas), initially using all data recorded on a per minute basis (`Per Minute') for all 6 min of the test (10 factors extracted) and then using total values (`Total'), the summation of the 6 min for each behaviour measured (4 factors extracted). Stability of factor loadings between rounds and between groups was tested using Kendall's coefficient of concordance. For the `Per Minute' data, 5 out of the 10 factors showed significant (p < 0.05) concordance between rounds whilst 9 out of 10 factors showed significant (p < 0.05) concordance between groups. All four factors generated from the `Total' data demonstrated significant (p < 0.05) concordance between rounds and between groups. The four factors generated from the `Total' data were considered to be of potential merit for future studies. These factors were named--`conspecific motivation-fear', `conspecific motivation-distress', `activity' and `low conspecific motivation'.

Abstract: The ability in animals to count and represent different numbers of objects has received a great deal of attention in the past few decades. Cumulative evidence from comparative studies on number discriminations report obvious analogies among human babies, non-human primates and birds and are consistent with the hypothesis of two distinct and widespread mechanisms, one for counting small numbers (<4) precisely, and one for quantifying large numbers approximately. We investigated the ability to discriminate among different numerosities, in a distantly related species, the mosquitofish, by using the spontaneous choice of a gravid female to join large groups of females as protection from a sexually harassing male. In one experiment, we found that females were able to discriminate between two shoals with a 1:2 numerosity ratio (2 vs. 4, 4 vs. 8 and 8 vs. 16 fish) but failed to discriminate a 2:3 ratio (8 vs. 12 fish). In the second experiment, we studied the ability to discriminate between shoals that differed by one element; females were able to select the larger shoal when the paired numbers were 2 vs. 3 or 3 vs. 4 but not 4 vs. 5 or 5 vs. 6. Our study indicates that numerical abilities in fish are comparable with those of other non-verbal creatures studied; results are in agreement with the hypothesis of the existence of two distinct systems for quantity discrimination in vertebrates.

Abstract: According to the socioecological framework, transitivity (or linearity) in dominance relationships is related to competition over critical resources. When a population is structured into groups, the intensity of between- versus within-group competition influences the form and function of its social organization. Few studies have compared the type and relative intensity of competition at these two levels. African elephants have well-structured social relations, providing an exemplary system for such a study. We report on dominance hierarchies among free-ranging elephants and evaluate the factors that drive their socioecological structure to lie in a region of the three-dimensional nepotism/despotism/tolerance space rarely observed among social species; namely, where non-nepotistic, transitive dominance hierarchies within groups emerge despite kin-based philopatry and infrequent agonistic interactions over widely distributed resources. We found significant transitivity in dominance hierarchies between groups. Dominance relations among the matriarchs of different social groups were primarily age based, rather than driven by physical or group size, and group matriarch rank influenced the dominance relationships among nonmatriarchal females in the population. Our results suggest that between-group dominance relationships induce tolerance among group members, which in combination with high group relatedness, reduces the benefits of nepotism. We postulate that cognitive abilities and high risk of injury in contests enhance winner and loser effects, facilitating the formation of transitive dominance relationships, despite widely distributed resources over which infrequent competition occurs. The interplay of cognitive abilities, winner and loser effects, resource distribution, and within- and between-group dominance relationships may produce behaviour in other strongly social mammals that differs from that predicted by a superficial application of current socioecological models.

Abstract: Transitive inference (TI) involves using known relationships to deduce unknown ones (for example, using A > B and B > C to infer A > C), and is thus essential to logical reasoning. First described as a developmental milestone in children, TI has since been reported in nonhuman primates, rats and birds. Still, how animals acquire and represent transitive relationships and why such abilities might have evolved remain open problems. Here we show that male fish (Astatotilapia burtoni) can successfully make inferences on a hierarchy implied by pairwise fights between rival males. These fish learned the implied hierarchy vicariously (as 'bystanders'), by watching fights between rivals arranged around them in separate tank units. Our findings show that fish use TI when trained on socially relevant stimuli, and that they can make such inferences by using indirect information alone. Further, these bystanders seem to have both spatial and featural representations related to rival abilities, which they can use to make correct inferences depending on what kind of information is available to them. Beyond extending TI to fish and experimentally demonstrating indirect TI learning in animals, these results indicate that a universal mechanism underlying TI is unlikely. Rather, animals probably use multiple domain-specific representations adapted to different social and ecological pressures that they encounter during the course of their natural lives.