Jutta M Schneider

• Professor
• Professor (Full) at Hamburg University

ABSTR ACT Hybridization plays an important role in animal speciation. Mediterranean populations of the Palaearctic wasp spider Argiope bruennichi have recently undergone a range expansion northwards. Adaptation to colder winters was facilitated by introgressed alleles derived from Asian populations , hence the resulting hybrids were able to expand...

The current consensus is that sexual selection is responsible for the rapid and diverse evolution of genitalia, with several mutually exclusive mechanisms under debate, including non-antagonistic, antagonistic and stabilizing mechanisms. We used the orb-web spider, Argiope lobata (Araneidae), as a study model to quantify the allometric relationship...

Female chemical signals are crucial for sexual communication in spiders and convey detailed information about females' mating status or age. However, evidence for chemical communication in spiders is largely behavioral. Only a few spider pheromones are known and quantitative chemical analyses of individual spiders are especially scarce. In the Euro...

Cooperation should only evolve if the direct and/or indirect benefits exceed the costs. Hence, cooperators are expected to generate selective benefits for themselves and the kin-group while defectors will impose costs. The subsocial spider, Australomisidia ergandros, shows consistent cooperation and defection tactics while foraging. Cooperative ind...

Extended phenotypes engineered by animals can potentially improve safety and/or foraging. Whether the well-known trade-off between safety and foraging applies for extended phenotypes, and if so, how it is resolved has not been determined. Spiders build elaborate silk structures that serve as traps for their insect prey and often attach silken retre...

In species with separate sexes, females and males often differ in their morphology, physiology and behaviour. Such sex-specific traits are functionally linked to variation in reproductive competition, mate choice and parental care, which have all been linked to sex roles. At the 150th anniversary of Darwin's theory on sexual selection, the question...

Spiders, the most specious taxon of predators, have evolved an astounding range of predatory strategies, including group hunting, specialized silk traps, pheromone-loaded bolas, and aggressive mimicry. Spiders that hunt prey defended with behavioral, mechanical, or chemical means are under additional selection pressure to avoid injury and death. An...

Task specialization is a hallmark of social success as it can minimize among-individual conflict in task participation, and thereby optimize colony productivity. Task specialization is therefore predicted to manifest as a consequence of social evolution. While age or caste in some species explains task participation, a recent hypothesis states that...

Many ecological interactions of spiders with their potential prey and predators are affected by the visibility of their bodies and silk, especially in habitats with lower structural complexity that expose spiders. For instance, the surface of tree trunks harbours relatively limited structures to hide in and may expose residents to visual detection...

Emerging evidence shows that the cuticular and silk lipids of spiders are structurally more diverse than those of insects, although only a relatively low number of species have been investigated so far. As in insects, such lipids might play a role as signals in various contexts. The wasp spider Argiope bruennichi has probably the best investigated...

Sex pheromones function as species and sex recognition signals but can be equally important for mate assessment and choice. Adaptive mate choice requires the covariation of signal characteristics with fitness‐relevant traits, which can be achieved by condition‐dependent costs of signalling. Given a physiological link between signal production and o...

Examining the role of color in mate choice without testing what colors the study animal is capable of seeing can lead to ill-posed hypotheses and erroneous conclusions. Here, we test the seemingly reasonable assumption that the sexually dimorphic red coloration of the male jumping spider Saitis barbipes is distinguishable, by females, from adjacent...

Reproduction often requires finding a mating partner. To this end, females of many arthropods advertise their presence to searching males via volatile chemical signals. Such pheromones are considered low-cost signals, although this notion is based on little evidence and has recently been challenged. Even when using comparatively low-cost signals, f...

Emerging evidence shows that the cuticular and silk lipids of spiders are structurally more diverse than those of insects, although only a relatively low number of species have been investigated so far. As in insects, such lipids might play a role as signals in various context. The wasp spider Argiope bruennichi has probably the best investigated c...

Kin recognition, the ability to detect relatives, is important for cooperation, altruism and also inbreeding avoidance. A large body of research on kin recognition mechanisms exists for vertebrates and insects, while little is known for other arthropod taxa. In spiders, nepotism has been reported in social and solitary species. However, there are v...

The existence of consistent individual differences in behavior has been shown in a number of species, and several studies have found observable sex differences in these behaviors, yet their evolutionary implications remain unclear. Understanding the evolutionary dynamics of behavioral traits requires knowledge of their genetic architectures and whe...

Background: Mate choice is a taxonomically wide-spread phenomenon, mostly exerted by females although male mate choice occurs as well. While costs and benefits of choosiness have been well studied, the underlying mechanisms are largely unclear. Different models exist, namely best-of-n or threshold rules, based on sequential or simultaneous samplin...

Aggressive and cannibalistic female spiders can impose strong selection on male mating and fertilization strategies. Furthermore, the distinctive reproductive morphology of spiders is predicted to influence the outcome of sperm competition. Polyandry is common in spiders, leading to defensive male strategies that include guarding, plugging and self...

Few spider species show truly cosmopolitan distributions. Among them is the banded garden spider Argiope trifasciata that is reported from six continents across major climatic gradients and geographical boundaries. In orbweb spiders, such global distributions may be a result of lively dispersal via ballooning. However, wide distributions may also b...

Females mate multiply despite numerous costs. It is well established that polyandry can result in sexual conflict, favoring male adaptations that prevent sperm competition often to the disadvantage of the female. Such adaptations are extreme in spiders with one-shot genitalia of which parts break off and act as mating plugs, rendering them dysfunct...

Insects live in a dangerous world and may fall prey to a wide variety of predators, encompassing multiple taxa. As a result, selection may favour defences that are effective against multiple predator types, or target-specific defences that can reduce predation risk from particular groups of predators. Given the variation in sensory systems and hunt...

Sex differences in behavioral traits are common, but we know little about the role of sexual selection in shaping these traits. Estimating sex-specific genetic effects and cross-sex genetic correlations can provide insights into sex-specific selection and on whether evolution can shape independent expression of behavioral traits across the sexes. W...

Sexual reproduction is pervasive in animals and has led to the evolution of sexual dimorphism. In most animals, males and females show marked differences in primary and secondary sexual traits. The formation of sex-specific organs and eventually sex-specific behaviors is defined during the development of an organism. Sex determination processes hav...

Monogynous male mating strategies have repeatedly evolved in spiders along with female-biased sexual size dimorphism (SSD) and extreme male mating investment. As a manifestation of sexual conflict, male African golden-silk spiders, Trichonephila fenestrata, are regularly attacked by females during copulation, and sexual cannibalism is common. Curio...

High throughput sequencing (HTS) has emerged as a valuable tool for the rapid isolation of genetic markers for population genetics and pedigree analysis. HTS-based SNP (single nucleotide polymorphism) genotyping protocols like RAD (Restriction-site associated DNA) sequencing or hybrid capture allow for the isolation of thousands of markers from any...

Background Sexual selection theory predicts that male investment in a current female should be a function of female density and male competition. While many studies have focused on male competition, the impact of female density on male mating investment has been widely neglected. Here, we aimed to close this gap and tested effects of mate density o...

Among group‐living spiders, subsocial representatives in the family of crab spiders (Thomisidae) are a special case, as they build protective communal leaf nests instead of extensive communal capture webs. It could thus be inferred that antipredator benefits (e.g., enhanced protection in larger nests) rather than foraging‐related advantages (e.g.,...

The central nervous system is known to be plastic in volume and structure depending on the stimuli the organism is subjected to. We tested in the jumping spider Marpissa muscosa (Clerck, 1757), whether rearing environments affect the volume of two target higher-order brain centers: the mushroom body (MB) and the arcuate body (AB). We reared female...

Background Animal growth is often constrained by unfavourable conditions and divergences from optimal body size can be detrimental to an individual’s fitness, particularly in species with determinate growth and a narrow time-frame for life-time reproduction. Growth restriction in early juvenile stages can later be compensated by means of plastic de...

There is a long-standing debate as to whether social or physical environmental aspects drive the evolution and development of cognitive abilities. Surprisingly few studies make use of developmental plasticity to compare the effects of these two domains during development on behaviour later in life. Here, we present rearing effects on the developmen...

Informed mating decisions are often based on social cues providing information about prospective mating opportunities. Social information early in life can trigger developmental modifications and influence later mating decisions. A high adaptive value of such adjustments is particularly obvious in systems where potential mating rates are extremely...

Many hypotheses explaining the evolution and maintenance of sexual cannibalism incorporate the nutritional aspect of the consumption of males. Most studies have focused on a fecundity advantage through consumption of a male, however recent studies have raised the intriguing possibility that consumption of a male may also affect offspring quality. I...

Sexual cannibalism has long been hypothesized to be a foraging decision in which females consume males for the nutrients in their bodies. While few studies have documented fecundity benefits of sexual cannibalism, several recent studies have documented benefits of cannibalism to egg hatching success or offspring survival. We tested if small supplem...

Jumping spiders are known for their extraordinary cognitive abilities. The underlying nervous system structures, however, are largely unknown. Here, we explore and describe the anatomy of the brain in the jumping spider Marpissa muscosa (Clerck, 1757) by means of paraffin histology, X-ray microCT analysis and immunohistochemistry as well as three-d...

In mating systems with strictly limited male mating opportunities, a male's reproductive success depends strongly on the quality of his mate. Female quality is often linked to body size and mass. Hence, males with limited mating opportunities should choose large and heavy females to maximize their reproductive success. However, high-quality females...

Background Socially cued anticipatory plasticity (SCAP) has been proposed as a widespread mechanism of adaptive life-history shifts in semelparous species with extreme male mating investment. Such mating systems evolved several times independently in spiders and male reproductive success should critically depend on timely maturation and rapid locat...

Background Genital diversity may arise through sexual conflict over polyandry, where male genital features function to manipulate female mating frequency against her interest. Correlated genital evolution across animal groups is consistent with this view, but a link between genital complexity and mating rates remains to be established. In sexually...

A common male adaptation to prevent sperm competition is the placement of a mating plug. Such plugs are considered as an extreme investment if they comprise parts of the genital systems and render the male sterile. Genital mutilation occurs in monogynous spiders of several families and may co-occur with permanent sperm depletion, meaning that sperm...

Background. In many insects and spider species, females attract males with volatile sex pheromones, but we know surprisingly little about the costs and benefits of female pheromone emission. Here, we test the hypothesis that mate attraction by females is dynamic and strategic in the sense that investment in mate attraction is matched to the needs o...

Raw data

In groups of socially foraging animals, feeding behaviour may change with group size in response to varying cost–benefit trade-offs. Numerous studies have described group-size effects on group-average feeding behaviour, particularly emphasizing an increase in scrounging incidence for larger groups, where individuals (scroungers) feed from the food...

High male mating investment may favor selection on male mate choice particularly if females vary in quality. Terminal investment strategies constitute a maximal mating effort and have evolved independently in the absence of paternal investment in several spider taxa including the genus Argiope. To test for male mate preferences in the above context...

Background: One may expect inbreeding avoidance via mate choice to evolve if two circumstances arise: The risk of inbreeding is high but avoidable, and there is sufficiently severe inbreeding depression. Organism: The European wasp spider (Argiope bruennichi) in which males are monogynous or conditionally bigynous and polyandrous females cannibaliz...

Individuals of many species across the animal kingdom are found to be less plastic than expected, even in behavioral traits. The existence of consistent behavioral differences between individuals, termed “personality differences”, is puzzling, since plastic behavior is considered ideal to enable animals to adaptively respond to changes in environme...

Sexual cannibalism is a particularly extreme example of conflict between the sexes, depriving the male of future reproduction. Theory predicts that sexual conflict should induce counter-adaptations in the victim. Observations of male spiders mating with moulting and hence largely immobile females suggest that this behaviour functions to circumvent...

In group-living animals, an individual’s fitness is predicted by non-random interactions with other group members and social network analysis has become a powerful tool to study these interactions. We experimentally studied the social network structure in group-foraging subsocial spiders that naturally live in kin groups but accept immigrants. Spid...

This timely book revisits cryptic female choice in arthropods, gathering detailed contributions from around the world to address key behavioral, ecological and evolutionary questions. The reader will find a critical summary of major breakthroughs in taxon-oriented chapters that offer many new perspectives and cases to explore and in many cases unpu...

The orb-web spider genus Argiope (Araneae ) offers an excellent opportunity to detect cryptic female choice and to identify the species-specific traits that might lead to its evolution and maintenance. All studied species of the genus Argiope are characterized by low male mating rates . While males of some species are strictly mono- or bigynous , o...

Sexually selected variation in male body size is often associated with alternative reproductive strategies that may persist under frequency-dependent selection or result from 'making the best of a bad job' in inferior individuals. The spider genus Nephila is well known for female gigantism and male dwarfism, serving as an established model system t...

Sexual cannibalism is a well-known example for sexual conflict and has many facets that determine the costs and benefits for the cannibal and the victim. Here, I focus on species in which sexual cannibalism is a general component of a mating system in which males invest maximally in mating with a single (monogyny) or two (bigyny) females. Sexual ca...

Many spiders use airborne silk threads for locomotion purposes or web initiation. In the case of bridging, the thread is used to span and cross a gap between two microhabitat structures. In this chapter we report some observations and experiments on bridging behaviour, structure and function of the bridging lines, hoping to inspire new biomechanica...

Spiders are highly efficient predators in possession of exquisite sensory capacities for ambushing prey, combined with machinery for launching rapid and determined attacks. As a consequence, any sexually motivated approach carries a risk of ending up as prey rather than as a mate. Sexual selection has shaped courtship to effectively communicate the...

Food availability can vary widely for animals in nature and can have large effects on growth, reproduction and survival. While the consequences of food limitation for animals have been extensively studied, significant questions still remain including how ontogenetic variation in food availability contributes to lifetime reproductive success. We tes...

Few studies investigated whether rapid range expansion is associated with an individual's short-term fitness costs due to an increased risk of inbred mating at the front of expansion. In mating systems with low male mating rates both sexes share potential inbreeding costs and general mechanisms to avoid or reduce these costs are expected. The spide...

Group activities that require an initial investment are liable to be exploited. This situation can, for example, be found in group-hunting lions, but also in subsocial and social spiders, in which several individuals capture single large prey items. Individuals could save investment by contributing less to the hunt but also during feeding by saving...

Testing animals individually in problem-solving tasks limits distractions of the subjects during the test, so that they can fully concentrate on the problem. However, such individual performance may not indicate the problem-solving capacity that is commonly employed in the wild when individuals are faced with a novel problem in their social groups,...

Female reproductive status can have strong selective effects on male mating strategies due to the threat of sperm competition, which may explain why males prefer virgin over mated females. However, in mating systems with female multiple mating rates and mating plugs, males should not only respond to the risk but also to the level of sperm competiti...

In brood-caring species, family members are faced with a conflict over resource distribution. While parents are selected to adapt the amount of care according to their offspring's needs, offspring might be selected to demand more care than optimal for parents. Recent studies on birds have shown that the social network structure of offspring affects...

Testing animals in cognitive tasks individually limit distractions to the subjects during the task so that they can focus their full attention on the problem. However, such a test situation may only represent a maximal but not a realistic performance. Under natural conditions, particularly in group-living animals, individuals that are faced with a...

Pre‐copulatory cannibalism – females devouring males during courtship – may bring no benefit to either sex. The ‘aggressive spillover hypothesis’ (ASH) posits that pre‐copulatory cannibalism represents a spillover of female aggressiveness from the juvenile foraging context, when aggressiveness is advantageous, to the adult mating context, when aggr...

Animals within a population differ consistently in behavior over time and/or across conditions. A general question is how such differences referred to as personalities are maintained through evolution. One suggested mechanism is a nonrandom mate choice, which has been supported in species in which mate choice associates with direct material benefit...

A reduced predation risk is considered to be a major adaptive advantage of sociality. While most studies are concerned with non-predatory prey species, group-living predators are likely to face similar threats from higher-order predators. We studied the relationship between group size and predation risk in the subsocial crab spider Diaea ergandros...

Sexual cannibalism particularly before mating is costly for the male victim but also for the female aggressor if she risks remaining unmated. The aggressive spillover hypothesis explains the persistence of this behavior as a maladaptive side effect of positive selection on aggressiveness in a foraging context. The hypothesis predicts that the occur...

Monogynous males in various species actively limit themselves to mating with a single female in their lifetime. Whereas previous models have considered monogyny as an obligate mating strategy, here we explore the potential of monogyny to evolve as a context-specific (conditional) behavior. Using a state-dependent dynamic game model based on the bio...

Mating plugs have been described in many species, and their presence often implies a function in protecting a male's ejaculate. Yet, explicit functions are not always tested. In this study, we test whether fragments of male genitalia lodged in the female genital opening of the St Andrew's Cross spider (Argiope keyserlingi) are mating plugs and prev...

Male monogyny in the absence of paternal investment is arguably one of the most puzzling mating systems. Recent evidence suggests that males of monogynous species adjust their life-history and their mating decision to shifting spatial and temporal selection regimes. In the cannibalistic wasp spider Argiope bruennichi males can be either monogynous...

Available online xxx MS. number 11-01000 Keywords: aggression behavioural polymorphism behavioural syndrome frequency-dependent selection heritability personality Behaviour is generally plastic to some degree and allows an animal to react appropriately to changing and novel conditions. Consequently, a degree of plasticity is predicted to be a key d...

Monogynous mating systems (low male mating rates) occur in various taxa and have evolved several times independently in spiders. Monogyny is associated with remarkable male mating strategies and predicted to evolve under a male-biased sex ratio. While male reproductive strategies are well documented and male mating rates are easy to quantify, espec...

Nearest neighbour distances in metre between females. (DOC)

Polyandry may provide females with benefits that directly affect her condition and fecundity and/or that enhance the quality of her offspring through receiving better or more compatible paternal genes. In polyandrous species with sexual cannibalism, females may gain considerable nutritional benefits through consuming a mating partner. However, in m...

In many mating systems, males strive for securing paternity through monopolizing females. As male monopolization attempts often contradict female interests, this conflict may fuel an evolutionary arms race. In the widow spider genus Latrodectus, females are commonly polyandrous, whereas males are monogynous, hence restricted to mate with a single f...

Spatial and temporal variation in ecological parameters selects for plastic responses to prevailing conditions. Males of web spiders have been shown to adjust developmental decisions to cues that relate to the degree of competition from other males. Here, we explore experimentally whether males of the spider Nephila senegalensis base behavioural de...

Sexual cannibalism particularly before mating is costly for the male victim but also for the female aggressor if she risks remaining unmated. The aggressive spillover hypothesis explains the persistence of this behavior as a maladaptive side effect of positive selection on aggressiveness in a foraging context. The hypothesis predicts that the occur...