Ethologisch fundierte Empfehlungen für eine artgemäße Zoohaltung von Schwarzfußkatzen Felis nigripes Burchell, 1824

The Blackfooted Cat (Felis nigripes), also called Small Spotted Cat, is a species endemic to the drier areas of Southern Africa. Ethological observations can give insight into their specialised adaptations to their environment. The investigations were carried out at the base of Karoo Cat Research. The large nature-type enclosures allow the cats to show a wide range of their natural behaviour. This study was done in the hope that it will lead to improved zoo-keeping and husbandry of the Blackfooted Cat in zoological gardens.It is alarming to note that worldwide the zoo populations of these cats, having always been quite low, have dramatically decreased recently, especially in Europe, where at present only 5 males and 2 females are kept at 3 different sites. Worldwide, most cats die at a rather young age from either Amyloidosis, a kidney disease, or from respiratory tract infections. The possibility is discussed that both diseases are, at least partly, due to inadequate keeping conditions.It is imperative, though not always easily accomplished, that these cats are kept in enclosures that, at least in part, provide desert conditions: a dry climate (relative air humidity of 30 to 40%), and a preponderantly sandy substrate with fitting vegetation. As Blackfooted Cats habitually cover large distances during their nightly prowls, they would require larger enclosures than other cats of the Genus Felis. The enclosures should also give the cats adequate shelter to allow them to hide from disturbances caused by the public. Failing to provide this may be the cause of numerous, possibly lethal, stress-related diseases. Due to the Blackfooted Cat's extremely shy nature and solitary way of living, especially in respect of keeping their progeny healthy, the choice of the right curator is of utmost importance.The experiment of having young Blackfooted Cats reared simultaneously by their own mother and by humans aimed to avoid an imprinting-like bond but at the same time to create the basis for a lasting relationship of trust towards the human carers. The Karoo Cat Research Station proved to be a suitable observation area, offering the possibility of caring for three young Blackfooted Cats from the age of 6 to 16 weeks together with their mother. The behaviour patterns defining the opposites “tame” and “shy” were evaluated numerically and presented in diagram form. The result of this experiment was a stress-free and relaxed relationship between the animals and their carers that was not only observed in the kittens but was also maintained with the adult cats.The activity rhythm of seven Blackfooted Cats in human care in South Africa was studied throughout two seasons with considerable temperature variations.In graphic representations, data are presented, such as the weather or sexual differences, which could not be influenced by humans but have a clearly recognisable effect on the activity rhythm.Altered keeping conditions had an important influence on the divergence of the rest periods of the three young Blackfooted Cats from the usual diaphasic activity pattern of most felid species.The behaviour of wild-caught animals was studied and compared with that of well integrated or zoo-born individuals. Here too an important reduction in activity was noted. The effect of behavioural enrichment measures, such as play, feeding methods, olfactory stimuli, as well as the rearing of young, on a positive increase in diurnal activity is discussed.     

Social learning about egg-laying substrates in fruitflies

Social learning, defined as learning from other individuals, has had dramatic effects on some species, including humans, in whom it has generated a rich culture. As a first step in examining the evolution of and mechanisms underlying social learning in insects, we tested for social learning in fruitflies (Drosophila melanogaster). Focal females (observers) that experienced novel food together with mated females (models), who had laid eggs on that food, subsequently exhibited a stronger preference for laying eggs on that food over another novel food compared with focal females that experienced the food alone. We observed no social learning, however, when observers experienced food with potentially more ambiguous social information provided by the presence of either virgin models or aggregation pheromone. This first documentation of social learning about egg-laying substrates in fruitflies builds on recent data indicating intricate use of social information by fruitflies and opens up exciting avenues for research on the evolution and neurogenetics of social learning using biology''s major model system.     

Solitary and group nesting in the orchid bee <Emphasis Type="Italic">Euglossa hyacinthina</Emphasis> (Hymenoptera,Apidae)

Summary Orchid bees (Euglossini) provide a potentially informative contrast for examining origins of advanced social behaviour in bees because they are the only tribe in the apine clade that do not form large colonies or have queens and workers. We investigated natural nests of Euglossa hyacinthina Dressler, an orchid bee that nests singly or in groups. By comparing the two types of nests, we examined if individuals in a group merely share the nest (are communal) or exhibit a level of social organization where there is reproductive division of labour among the females. Observations are consistent with communal nesting, indicating that all females in group nests are reproductively similar to the solitary nesting females because the provisioning of young, as well as the ovary development and mating status of females sharing nests were not different than that of solitary-nesting females. Also, multiple female nests did not produce a female-biased brood as predicted for nests with reproductive division of labour. We also investigated potential advantages of group nesting vs. individual nesting. We demonstrate that per capita offspring production is lower in nests with more than one female. However, we found that nests with single females were left unattended for longer periods of time during foraging, and that there was a high incidence of natural enemy attack in nests when females were absent. Group and solitary nesting may be advantageous under different conditions.Received 3 December 2002; revised 7 March 2003; accepted 2 April 2003.     

Domestication‐related variation in social preferences in chickens is affected by genotype on a growth QTL

A growth‐related QTL on chicken chromosome 1 has previously been shown to influence domestication behaviour in chickens. In this study, we used Red Junglefowl (RJF) and White Leghorn (WL) as well as the intercross between them to investigate whether stress affects the way birds allocate their time between familiar and unfamiliar conspecifics in a social preference test (‘social support seeking’), and how this is related to genotype at specific loci within the growth QTL. Red Junglefowl males spent more time with unfamiliar chickens before the stressful event compared to the other birds, whereas all birds except WL males tended to spend less time with unfamiliar ones after stress. A significant QTL locus was found to influence both social preference under undisturbed circumstances and social support seeking. The WL allele at this QTL was associated not only with a preference for unfamiliar individuals but also with a shift towards familiar ones in response to stress (social support seeking). A second, suggestive QTL also affected social support seeking, but in the opposite direction; the WL allele was associated with increased time spent with unfamiliar individuals. The region contains several possible candidate genes, and gene expression analysis of a number of them showed differential expression between RJF and WL of AVPR2 (receptor for vasotocin), and possibly AVPR1a (another vasotocin receptor) and NRCAM (involved in neural development) in the lower frontal lobes of the brains of RJF and WL animals. These three genes continue to be interesting candidates for the observed behavioural effects .     

Automated identification of social interaction criteria in Drosophila melanogaster

The study of social behaviour within groups has relied on fixed definitions of an ‘interaction’. Criteria used in these definitions often involve a subjectively defined cut-off value for proximity, orientation and time (e.g. courtship, aggression and social interaction networks) and the same numerical values for these criteria are applied to all of the treatment groups within an experiment. One universal definition of an interaction could misidentify interactions within groups that differ in life histories, study treatments and/or genetic mutations. Here, we present an automated method for determining the values of interaction criteria using a pre-defined rule set rather than pre-defined values. We use this approach and show changing social behaviours in different manipulations of Drosophila melanogaster. We also show that chemosensory cues are an important modality of social spacing and interaction. This method will allow a more robust analysis of the properties of interacting groups, while helping us understand how specific groups regulate their social interaction space.     

Attraction to and learning from social cues in fruitfly larvae

We examined the use of social information in fruitfly larvae, which represent an ideal model system owing to their robust learning abilities, small number of neurons and well-studied neurogenetics. Focal larvae showed attraction to the distinct odour emanating from food occupied by other larvae. In controlled learning experiments, focal larvae preferred novel odours previously paired with food occupied by other larvae over novel odours previously paired with unoccupied food. When we gave groups of larvae a choice between food patches differing in quality, more larvae aggregated on the higher-quality food, suggesting that attraction to and learning about cues associated with other larvae can be beneficial. Furthermore, larvae were more likely to find the best available food patch in trials when that food patch was occupied by other larvae than in trials when that food patch was unoccupied. Our data suggest, however, that the benefits from joining others may be at least partially offset by the fitness costs of increased competition, because larvae reared in isolation did as well as or better than larvae reared in groups on three key fitness parameters: developmental rate, survival rate and adult dry body mass. Our work establishes fruitfly larvae as a highly tractable model species for further research on the mechanisms that modulate behaviour and learning in a social context.     

Consistency of fish‐shoal social network structure under laboratory conditions

We investigated the consistency of association network structure for groups of sticklebacks Gasterosteus aculeatus. Each group was observed twice and we varied the duration between observations and the size of the experimental arena that they were observed in. At the dyad level, we found positive correlations between dyad interaction frequencies across observations. At the group level we found variation in four network metrics between observations, but only in treatments where the duration between observations was short. Specifically, fish formed more and smaller groups in the second observation in this treatment. Fish were also organized into more subunits in the larger arenas. Finally, we saw positive correlations between some group network metrics across observations suggesting relative consistency at the group level. There are several processes that might drive these interaction patterns. Our findings have implications for experimental design and the comparison and integration of findings of experiments from different studies carried out under different conditions.     

Evaluation of a non‐invasive tagging system for laboratory studies using three‐spined sticklebacks Gasterosteus aculeatus

A non‐invasive tagging system for individual identification of three‐spined sticklebacks Gasterosteus aculeatus was evaluated. The tags were easily detected via video, and tagged and non‐tagged fish did not differ in terms of growth, activity levels or shoaling behaviour.     

Effects of group size on school structure and behaviour in yellow‐eyed mullet Aldrichetta forsteri

Schooling behaviour in yellow‐eyed mullet Aldrichetta forsteri, a common fish species in New Zealand estuarine habitats, was investigated to identify interaction rules associated with group formation. Tank‐based three‐dimensional studies of three group sizes (15, 75 and 150 individuals) were carried out to measure the effects of these different group sizes on school structure during control, predation risk and foraging behavioural states. Increased group size positively correlated with nearest‐neighbour distance in control and foraging states. Swimming speed was the lowest in all three behavioural states in groups of 15 fish compared with 75 or 150. Immediate behavioural response following visual exposure to a simulated avian predator differed between groups resulting in loss of structure in larger groups. School shape was an oblong–oblate spheroid with a length, breadth and height ratio of 5:2:1 and the area of free space surrounding individual fish was spherical in shape with a high degree of spatial isotropy present in all size groups. These findings challenge traditional theories based on either local or global properties as key drivers of group structure. Instead, our results suggest that a more collaborative approach involving both group size and rules pertaining to nearest‐neighbour interactions affects collective behaviours in this species.     

Where sociality and relatedness diverge: the genetic basis for hierarchical social organization in African elephants

Hierarchical properties characterize elephant fission–fusion social organization whereby stable groups of individuals coalesce into higher order groups or split in a predictable manner. This hierarchical complexity is rare among animals and, as such, an examination of the factors driving its emergence offers unique insight into the evolution of social behaviour. Investigation of the genetic basis for such social affiliation demonstrates that while the majority of core social groups (second-tier affiliates) are significantly related, this is not exclusively the case. As such, direct benefits received through membership of these groups appear to be salient to their formation and maintenance. Further analysis revealed that the majority of groups in the two higher social echelons (third and fourth tiers) are typically not significantly related. The majority of third-tier members are matrilocal, carrying the same mtDNA control region haplotype, while matrilocality among fourth-tier groups was slightly less than expected at random. Comparison of results to those from a less disturbed population suggests that human depredation, leading to social disruption, altered the genetic underpinning of social relations in the study population. These results suggest that inclusive fitness benefits may crystallize elephant hierarchical social structuring along genetic lines when populations are undisturbed. However, indirect benefits are not critical to the formation and maintenance of second-, third- or fourth-tier level bonds, indicating the importance of direct benefits in the emergence of complex, hierarchical social relations among elephants. Future directions and conservation implications are discussed.     

Genetics and developmental biology of cooperation

Despite essential progress towards understanding the evolution of cooperative behaviour, we still lack detailed knowledge about its underlying molecular mechanisms, genetic basis, evolutionary dynamics and ontogeny. An international workshop “Genetics and Development of Cooperation,” organized by the University of Bern (Switzerland), aimed at discussing the current progress in this research field and suggesting avenues for future research. This review uses the major themes of the meeting as a springboard to synthesize the concepts of genetic and nongenetic inheritance of cooperation, and to review a quantitative genetic framework that allows for the inclusion of indirect genetic effects. Furthermore, we argue that including nongenetic inheritance, such as transgenerational epigenetic effects, parental effects, ecological and cultural inheritance, provides a more nuanced view of the evolution of cooperation. We summarize those genes and molecular pathways in a range of species that seem promising candidates for mechanisms underlying cooperative behaviours. Concerning the neurobiological substrate of cooperation, we suggest three cognitive skills necessary for the ability to cooperate: (i) event memory, (ii) synchrony with others and (iii) responsiveness to others. Taking a closer look at the developmental trajectories that lead to the expression of cooperative behaviours, we discuss the dichotomy between early morphological specialization in social insects and more flexible behavioural specialization in cooperatively breeding vertebrates. Finally, we provide recommendations for which biological systems and species may be particularly suitable, which specific traits and parameters should be measured, what type of approaches should be followed, and which methods should be employed in studies of cooperation to better understand how cooperation evolves and manifests in nature.