Variability in natural behaviour, and observed reactions to an ROV, by mid-slope fish species

The behaviour of eight large benthopelagic fish taxa was analysed using video records collected with an ROV on the mid-slope of the Bay of Biscay. The studied species were roundnose grenadier (Coryphaenoides rupestris), orange roughy (Hoplostethus atlanticus), deep-sea scorpionfish (Trachyscorpia cristulata echinata), and black scabbardfish (Aphanopus carbo), as well as individuals belonging to the families Alepocephalidae, Chimaeridae, and Scyliorhinidae, and to the order Squaliformes. Some of the observed fish were grouped at the family taxonomical level due to visual identification to species being unreliable. Assumed natural (undisturbed) behaviour was categorised in terms of (i) body position with respect to the bottom sea floor, (ii) locomotion and (iii) activity type. Reaction (disturbed) behaviour to the approaching ROV was categorised in terms of reaction type and distance. Environmental conditions (depth, temperature, current speed and direction) and observation conditions (ROV speed and altitude) were recorded simultaneously with fish observations in order to explain the variability in the observed reaction behaviour. A multivariate analysis identified three groups corresponding to a behaviour pattern of a sit and wait strategist (one species), an active bottom hunter (three taxa), and a group of species displaying little activity in their bottom habitat (three taxa). At species level the environmental and observation conditions had some explanatory power for individual behaviour variability. It is hypothesised that the varied behaviour of mid-slope benthopelagic fish contributes to maintain a high species diversity of large predators in an energy poor environment.     

Culture, Speciation and the Genus Homo in Early Humans

Human behaviour, in addition to morphology, is essential to identify man. The characteristics of cultural behaviour are expressed by planning in tool making and territorial organization and by their meaning in the context of life. Cultural behaviour enriched the adaptive strategies of the human species and took on significance in the definition of the genus Homo since H. habilis/H. rudolfensis. Culture probably played a double role in the process of human speciation: (1) in isolation and differentiation from other groups of hominids that did not had such behaviour; and (2) in adaptation to the environment and in communication between groups that had the same cultural behaviour, thus slowing down or preventing the conditions of isolation that lead to new species.     

Androgens, aggressive behaviour and social relationships in higher mammals

This paper reviews the relationships between androgen levels, aggressive behaviour and social relationships in ungulates and primates. In these and most other mammalian species, aggressive behaviour is sexually dimorphic with males being generally more aggressive than females. This difference is evident very early in play behaviour. In males, and sometimes also in females, aggressive behaviour varies in relation with reproductive cycles and the hormonal changes which are involved in these cycles. The experimental manipulation of hormonal levels by castration or administration of exogenous hormones gives results that vary according to the species, sex, type of hormone (e.g. aromatizable or non-aromatizable androgens), and other factors (e.g. antlers state in stags). Nevertheless, it has generally been shown that aggressive behaviour in male ungulates depends largely on androgens and that in female ungulates androgen treatment consistently raises social rank, with or without modification in aggressiveness. Primates, on the other hand, seem to be less dependent on androgens for the expression of aggressive behaviour and social status.     

Latent behavioural toxicity of copper to sea catfish, Arius felis, and sheepshead, Archosargus probatocephalus

To assess quantitatively the latent (delayed) toxicity of acutely sublethal exposure to copper on the locomotor and orientation behaviour of marine teleosts, the movements of individual sea catfish, Arius felis , and sheepshead porgy, Archosargus probatocephalus , were monitored electronically in a multiple-choice rosette tank immediately after 72-h static exposure to copper (0.0, 0.1, 0.2, or 0.4 mg Cu l⁻¹) and 1 week later. Initial hyperactivity following copper-exposure was exhibited by all fish of both species (except controls), as indicated by significant changes in the behavioural variables used to quantify locomotor activity. In addition, the orientation angles of successive movements in the monitor tank increased significantly for sea catfish, producing a decrease in the frequency of turning. Orientation angles of sheepshead showed a significant enhancement of the 'normal' tendency of this species to make small-angle turns in the tank, and to return immediately to the compartment just vacated (indicative of an increase in the frequency of turning). One week following exposure, all copper-exposed fish exhibited extreme hypoactivity which was significantly different from their behaviour immediately after exposure, and from the behaviour of control fish. This hypoactivity did not correspond, therefore, to 'normal' activity in either species. The delayed effect of copper exposure on orientation was to exacerbate significantly the species specific turning behaviour seen immediately following exposure. These results are discussed in terms of presumed accumulated physiological damage resulting from the exposure to copper and the initial hyperactivity such exposure elicits, and of general behavioural ecology.     

Prey-capture techniques and prey preferences of Chrysilla, Natta and Siler, ant-eating jumping spiders (Araneae, Salticidae) from Kenya and Sri Lanka

The predatory behaviour of Chrysilla lauta and Sliersemiglaucus from Sri Lanka, and four species of Natta from Kenya, was studied in the laboratory for the first time. These salticids eat ants, a prey most salticids avoid. These species' specialized behaviour for catching ants is described and compared to their behaviour for catching other insects. Three different types of tests of prey preference were carried out and, in each type, ants were taken in preference to other insects. Preference for ants, and prey-specific predatory behaviour did not depend on prior experience with ants. Results from this study are discussed in relation to recent findings on other ant-eating salticids.     

Interspecific relationships between emerging Atlantic salmon, Salmo salar, and coho salmon, Oncorhynchus kisutch, juveniles

Interspecific relationships between Atlantic salmon and coho salmon were studied at early life stages in laboratory and semi-natural stream channels. During emergence, the survival and dispersal patterns were similar for the two species in single or mixed populations. Survival of Atlantic salmon fry was reduced in the presence of older coho fry. However, no predation was observed. Microdistribution differed between the two species, with Atlantic salmon fry more numerous in riffles when coho were present.
Coho juveniles had a pelagic and gregarious distribution, in contrast to the benthic behaviour of the Atlantic salmon. In laboratory streams, Atlantic salmon fry moved out or adopted a subordinate cryptic behaviour which allowed them to escape predation while negatively affecting their growth.     

Fertilization mode, sperm characteristics, mate choice and parental care patterns in Artedius spp. (Cottidae)

The reproductive biology of three species in the genus Artedius ( A. harringtoni, A. lateralis and A. fenestralis ) was studied, including parental behaviour, mate choice, fertilization mode, gamete morphology and behaviour, and gonad morphology to help understand the coevolution of reproductive characteristics with potentially different modes of fertilization. In all three species, males guard multiple clutches at oviposition sites. In laboratory mate‐choice experiments, males appearred to prefer to defend sites containing eggs and were better able to attract mates at these sites. There was evidence that internal gomete association, although more pronounced in A. harringtoni , existed in all three species. Sperm behaviour and morphology and histological analysis of gonads suggested that A. fenestralis and A. lateralis were more likely to engage in typical external fertilization. The adoption of eggs and their effect on female mate‐choice patterns appearred to reduce the importance of certainty of paternity in these species, and probably increased the evolutionary stability of male parental care.     

Species divergence in field crickets: genetics,song, ecomorphology,and pre‐ and postzygotic isolation

Studies that simultaneously estimate levels of species divergence in genetics, reproductive and ecological traits, and pre‐ and postzygotic isolation are relatively rare. Here we compare levels of divergence in three allopatric sister species of field crickets. We compare divergence in both nuclear and mitochondrial DNA, male song, female ovipositor length, levels of pre‐ and postzygotic isolation, and male versus female contributions to prezygotic isolation. Taken together, our data show the accumulation of a multitude of potential reproductive isolating barriers if secondary contact were to become established. Furthermore, ecological and behavioural prezygotic isolation appear significantly more advanced than postzygotic isolation, with prezygotic isolation due to female behaviour exceeding that due to male behaviour.     

Host preference and survival in selected lines of a Drosophila parasitoid,Asobara tabida

Host selection behaviour of parasitoids has important fitness consequences, if hosts of different quality are available. Here the host selection behaviour, the ability to distinguish between hosts differing in their suitability, of the Drosophila parasitizing wasp Asobara tabida was studied. Females from five lines selected for higher survival in the encapsulating host species D. melanogaster ( 16 ) were compared with females from control lines. Females from all five selected lines more readily accepted the encapsulating host species for oviposition when offered together with a nonencapsulating host species than females from the control lines. We found no evidence for pleiotropic effects and suggest that host selection behaviour evolved parallel to the ability to escape encapsulation in the hosts. Our results also suggest that given the appropriate selection pressures, host selection behaviour can quickly evolve in parasitoids, enabling them to adapt fast to changing circumstances.     

The Good,the Bad,and the Ugly: Agonistic Behaviour in Juvenile Crocodilians

We examined agonistic behaviour in seven species of hatchling and juvenile crocodilians held in small groups (N = 4) under similar laboratory conditions. Agonistic interactions occurred in all seven species, typically involved two individuals, were short in duration (5–15 seconds), and occurred between 1600–2200 h in open water. The nature and extent of agonistic interactions, the behaviours displayed, and the level of conspecific tolerance varied among species. Discrete postures, non-contact and contact movements are described. Three of these were species-specific: push downs by C. johnstoni; inflated tail sweeping by C. novaeguineae; and, side head striking combined with tail wagging by C. porosus. The two long-snouted species (C. johnstoni and G. gangeticus) avoided contact involving the head and often raised the head up out of the way during agonistic interactions. Several behaviours not associated with aggression are also described, including snout rubbing, raising the head up high while at rest, and the use of vocalizations. The two most aggressive species (C. porosus, C. novaeguineae) appeared to form dominance hierarchies, whereas the less aggressive species did not. Interspecific differences in agonistic behaviour may reflect evolutionary divergence associated with morphology, ecology, general life history and responses to interspecific conflict in areas where multiple species have co-existed. Understanding species-specific traits in agonistic behaviour and social tolerance has implications for the controlled raising of different species of hatchlings for conservation, management or production purposes.     

Relationship between morphology,dispersal and habitat distribution in three species of Libellula (Odonata: Anisoptera)

Morphology is an important determinant of flight performance and can shape species’ dispersal behaviour. This study contrasted the morphology of flight-related structures in dragonfly species with different dispersal behaviours to gain insights into the relationship between morphology and dispersal behaviour. Specifically, wing size, wing shape and thorax size were compared in three co-occurring species from different clades within the genus Libellula (Odonata: Anisoptera: Libellulidae) to assess how these morphological traits are related to differences in dispersal behaviour and to how broadly their larvae occur across a habitat gradient. Two species had broad larval habitat distributions as well as high rates and distances of dispersal. These two species had relatively larger wings and thoraces than the third species, which was found only in permanent lakes and had limited dispersal. The hind-wings of more dispersive species also had lower aspect ratios and a relatively wider basal portion of the wing than the less dispersive species. Broad hind-wings may facilitate the use of gliding flight and reduce the energetic costs of dispersal. Determining the morphological traits associated with alternative dispersal behaviours may be a useful tool to assess the differential dispersal capacities of species or populations.     

Reaction of Ants to, and Feeding Biology of, a Congeneric Myrmecophilous and Non-myrmecophilous Ladybird

Coccinella magnifica Redtenbacher lives only in close contact with species of the Formica rufa group. Laboratory experiments were set up to determine how this species may be adapted to living with ants by comparing its behaviour with that of the closely related Coccinella septempunctata L. Eggs and larvae of C. magnifica placed on the foraging trails of ants were bitten significantly less often by the ants than those of C. septempunctata. However, the ants responded similarly to the adults of both species. For these two species, the presence of ants resulted in a significant decrease in predation efficiency. However, C. magnifica was more efficient at catching aphids in the presence of ants than C. septempunctata. The behaviour of this myrmecophilous species is discussed by taking into account that it is a generalist in terms of prey specificity.     

Scent-marking in the tamarin, Saguinus oedipus: Sex differences and ontogeny

Many mammalian species which exhibit scent-marking behaviour show a pronounced sexual dimorphism in marking behaviour and scent gland morphology. However, several species of marmosets and tamarins do not show dimorphism in these traits. We examined sex differences in scent-marking structures and behaviour in cotton-top tamarins (Saguinus o. oedipus; Primates: Callitrichidae). While body size and weight were virtually identical in adult males and females, there were pronounced sex differences in scent gland size and in rates of marking behaviour. Females possessed larger anogenital and suprapubic glands and showed 10-fold higher rates of anogenital marking and slightly higher rates of suprapubic marking than males. Observations on the development of anogenital marking revealed a lack of dimorphism during the first 2 years. Adult rates of anogenital marking in females were only observed in females housed separately from their natal family group. The onset of adult levels of marking behaviour corresponds with the adoption of the role of a breeding adult female, suggesting that anogenital marking plays a role in sexual communication.     

Differential foraging for resources, and structural plasticity in plants

Although ecologists have spent much effort in analysing the foraging behaviour of animals, the study of plants as foraging organisms is a relatively unexplored subject. There is often, however, much greater potential for analysis of foraging behaviour in plants than in animals. Unlike most animals, many plant species leave permanent or semi-permanent records of their foraging activities because their resource-acquiring structures (primarily leaves and roots), persist for a considerable time, as also do the structures (trunks, branches, stolons, runners or rhizomes) which enable leaves or roots to be projected into particular positions in the habitat. In addition, plant ecologists are not burdened with the difficulties associated with determining how changes in foraging behaviour affect fitness in animals(1), because plant mass (or, in the case of clonal species, number of ramets produced), is usually closely correlated with fitness.     

Molecular approaches identify known species, reveal cryptic species and verify host specificity of Chinese Philotrypesis (Hymenoptera: Pteromalidae)

Philotrypesis, a major component of the fig wasp community (Hymenoptera: Pteromalidae), is a model taxon for studying male fighting and mating behaviour. Its extreme sexual dimorphism and male polymorphism render species identification uncertain and in-depth research on its ecology, behaviour and other evolutionary topics challenging. The fig wasps' enclosed habitat within the syconia makes their mating behaviour inaccessible, to the extent of matching conspecific females and males. In this study, we combine morphological and molecular analyses to identify species of Philotrypesis sampled from south China and to associate their extraordinarily dimorphic genders and labile male morphologies. Morphological evaluations of females identify 22 species and 28 male morphs. The mitochondrial cytochrome c oxidase I and nuclear internal transcribed spacer 2 data detect 21 species using females, and 15 species among the males. Most of the males match the species as delimited by females. Both markers reveal cryptic species in P. quadrisetosa on Ficus vasculosa. Most species of wasps live on one species of fig but three species co-occur in two hosts (F. microcarpa and F. benjamina), which indicates host switching.     

From kissing to belly stridulation: comparative analysis reveals surprising diversity,rapid evolution,and much homoplasy in the mating behaviour of 27 species of sepsid flies (Diptera: Sepsidae)

Our understanding of how fast mating behaviour evolves in insects is rather poor due to a lack of comparative studies among insect groups for which phylogenetic relationships are known. Here, we present a detailed study of the mating behaviour of 27 species of Sepsidae (Diptera) for which a well‐resolved and supported phylogeny is available. We demonstrate that mating behaviour is extremely diverse in sepsids with each species having its own mating profile. We define 32 behavioural characters and document them with video clips. Based on sister species comparisons, we provide several examples where mating behaviour evolves faster than all sexually dimorphic morphological traits. Mapping the behaviours onto the molecular tree reveals much homoplasy, comparable to that observed for third positions of mitochondrial protein‐encoding genes. A partitioned Bremer support (PBS) analysis reveals conflict between the molecular and behavioural data, but behavioural characters have higher PBS values per parsimony‐informative character than DNA sequence characters.     

Cryptic castes,social context and colony defence in a social bee,Tetragonula carbonaria

Division of labour in social insect colonies is facilitated in two ways: through temporal sharing of tasks or by morphologically specialised castes. In casteless species, colony defence is maintained by morphologically indistinct workers, who lack the obvious defensive specialisation of polymorphic species. Discrimination of intruders is carried out via antenna, which also detects defensive social cues such as alarm pheromones. Despite their functional importance however, antennal morphology is rarely considered in studies of nestmate recognition. We investigated antennal morphology and the necessity of social cues in mediating defensive behaviour across differentially tasked workers of a casteless social bee, Tetragonula carbonaria. Our results suggest that the current understanding of division of labour in casteless worker species remains poorly understood, with differences in antennal morphology and aggression creating morphologically and behaviourally distinct ‘cryptic castes’. Further, we found that defensive behaviour was only elicited near nest odours, highlighting the importance of mediating aggression among workers.     

Reproductive Biology of Phrynichus dhofarensis Weygoldt, Pohl & Polak, 2002 (Chelicerata, Amblypygi, Phrynichidae)

The Phrynichus deflersi species group is a well-defined group inhabiting the Arabian deserts and adjacent areas. The relationship of this group to other species of Phrynichus (the P. ceylonicus group) is obscure. The study of mating behaviour and spermatophore morphology of a member of the Phrynichus deflersi species group allows comparison with other species of Phrynichus and with Euphrynichus and evidence concerning the interrelationships of these three groups. Features of morphology, mating behaviour and spermatophore morphology of Phrynichus dhofarensis suggest that the P. deflersi species group and the P. ceylonicus species group are sister groups and that both (the genus Phrynichus) comprise the sister group of Euphrynichus. This conclusion remains tentative given that only two members of the P. ceylonicus species group and one of the P. deflersi species group have been studied. Mating success is quite variable, suggesting sexual selection.     

Elephant behaviour and conservation: social relationships, the effects of poaching, and genetic tools for management

Genetic tools are increasingly valuable for understanding the behaviour, evolution, and conservation of social species. In African elephants, for instance, genetic data provide basic information on the population genetic causes and consequences of social behaviour, and how human activities alter elephants' social and genetic structures. As such, African elephants provide a useful case study to understand the relationships between social behaviour and population genetic structure in a conservation framework. Here, we review three areas where genetic methods have made important contributions to elephant behavioural ecology and conservation: (1) understanding kin-based relationships in females and the effects of poaching on the adaptive value of elephant relationships, (2) understanding patterns of paternity in elephants and how poaching can alter these patterns, and (3) conservation genetic tools to census elusive populations, track ivory, and understand the behavioural ecology of crop-raiding. By comparing studies from populations that have experienced a range of poaching intensities, we find that human activities have a large effect on elephant behaviour and genetic structure. Poaching disrupts kin-based association patterns, decreases the quality of elephant social relationships, and increases male reproductive skew, with important consequences for population health and the maintenance of genetic diversity. In addition, we find that genetic tools to census populations or gather forensic information are almost always more accurate than non-genetic alternatives. These results contribute to a growing understanding of poaching on animal behaviour, and how genetic tools can be used to understand and conserve social species.     

Effects of body size,sex, parental care and moult strategies on auk diving behaviour outside the breeding season

Information on seabird foraging behaviour outside the breeding season is currently limited. This knowledge gap is critical as this period is energetically demanding due to post‐fledging parental care, feather moult and changing environmental conditions. Based on species’ body size, post‐fledging parental strategy and primary moult schedule we tested predictions for key aspects of foraging behaviour (maximum dive depth (MDD), daily time submerged (DTS) and diurnal dive activity (DDA)) using dive depth data collected from three seabird species (common guillemot Uria aalge, razorbill Alca torda and Atlantic puffin Fratercula arctica) from the end of the breeding season (July) to mid‐winter (January). We found partial support for predictions associated with body size; guillemots had greater MDD than razorbills but MDD did not differ between razorbills and puffins, despite the former being 35% heavier. In accordance with sexual monomorphism in all three species, MDD did not differ overall between the sexes. However, in guillemots and razorbills there were sex‐specific differences, such that male guillemots made deeper dives than females, and males of both species had higher DTS. In contrast, there were no marked sex differences in dive behaviour of puffins in July and August in accordance with their lack of post‐fledging parental care and variable moult schedule. We found support for the prediction that diving effort would be greater in mid‐winter compared to the period after the breeding season. Despite reduced daylight in mid‐winter, this increase in DTS occurred predominantly during the day and only guillemots appeared to dive nocturnally to any great extent. In comparison to diving behaviour of these species recorded during the breeding season, MDD was shallower and DTS was greater during the non‐breeding period. Such differences in diving behaviour during the post‐breeding period are relevant when identifying potential energetic bottlenecks, known to be key drivers of seabird population dynamics.