Attention-Seeking Displays

Discrete time model of sexual systems

Small factors are the biggest contributors to the biggest changes in an ecosystem which may lead to its demise. Simple things such as tweaking the humidity or tampering with the temperature can be the downfall of the habitants and the ecosystem itself. These changes can be observed right now with the consistent temperature increase on Earth along with the slew of issues that come with global warming. A small change in a few degrees in temperature can perish an entire food supply and the habitat of many already endangered beings forcing them to either adapt or die. Within such an ecosystem the main reason it withstands the test of time boils down to one simple thing; reproduction. This creates the natural question of asking oneself: How does an ecosystem replenish itself and is able to resist collapsing? To even begin considering this thought, one must realise that the size of the population is the key to gaining a deeper understanding as two constituents that are important from evolutionary theory are survival and reproduction. The case of asexual reproducers, it is not difficult to see any alterations that can be introduced to increase reproductivity. Meanwhile, for sexual reproducers, the evolution to increase reproductivity can be observed by looking into the generational data of the species. A certain group of time-based dynamic systems that are connected to a sexual system are the point of contention. The suggested model is a dynamic representation of a hermaphrodite population which is described through quadratic stochastic operators. The key findings offer fresh insights into the future of hermaphrodite populations, that is perhaps a probable solution to prevent the decline of endangered or at-risk species. This demonstrates a fresh perspective on reproduction, which is explored through a purely mathematical approach.

Motion: enhancing signals and concealing cues

Animal colour patterns remain a lively focus of evolutionary and behavioural ecology, despite the considerable conceptual and technical developments over the last four decades. Nevertheless, our current understanding of the function and efficacy of animal colour patterns remains largely shaped by a focus on stationary animals, typically in a static background. Yet, this rarely reflects the natural world: most animals are mobile in their search for food and mates, and their surrounding environment is usually dynamic. Thus, visual signalling involves not only animal colour patterns, but also the patterns of animal motion and behaviour, often in the context of a potentially dynamic background. While motion can reveal information about the signaller by attracting attention or revealing signaller attributes, motion can also be a means of concealing cues, by reducing the likelihood of detection (motion camouflage, motion masquerade and flicker-fusion effect) or the likelihood of capture following detection (motion dazzle and confusion effect). The interaction between the colour patterns of the animal and its local environment is further affected by the behaviour of the individual. Our review details how motion is intricately linked to signalling and suggests some avenues for future research.

This Review has an associated Future Leader to Watch interview with the first author.

Summary: While motion can reveal information about the signaller, motion can also be a means of concealing cues by reducing the likelihood of detection or the likelihood of capture following detection.

Strategic inattention in the Sir Philip Sidney Game

Infamously, the presence of honest communication in a signaling environment may be difficult to reconcile with small (relative) signaling costs or a low degree of common interest between sender (beneficiary) and receiver (donor). This paper posits that one mechanism through which such communication can arise is through inattention on the part of the receiver, which allows for honest communication in settings where-should the receiver be fully attentive-honest communication would be impossible. We explore this idea through the Sir Philip Sidney game in detail and show that some degree of inattention is always weakly better for the receiver and may be strictly better. We compare limited attention to Lachmann and Bergstrom's (1998) notion of a signaling medium and show that the receiver-optimal degree of inattention is equivalent to the receiver-optimal choice of medium.

Intraspecific variation in behaviour and ecology in a territorial agamid, Ctenophorus fionni

Intraspecific variation as a way to explore factors affecting the evolution of species traits in natural environments is well documented, and also important in the context of preserving biodiversity. In this study, we investigated the extent of behavioural, morphological and ecological variation in the peninsula dragon (Ctenophorus fionni), an endemic Australian agamid that displays extensive variation in colour across three allopatric populations. The aims of the study were to quantify variation across the different populations in terms of the environment, morphometric characteristics and behaviour. We found population level differences in habitat structure and encounter rates. Adult body size of C. fionni, as well as a range of morphometric traits, differed between populations, as well as the frequency of social interactions, which appears to be related to population density and abundance. Analysis of communicative signals showed differences between the southern and central populations, which appear consistent with variations in response to environmental differences between study sites. The findings of the present study, coupled with previous work examining colour variation in this species, show that the three populations of C. fionni have likely undergone substantial differentiation, and would make an interesting study system to explore trait variation in more detail.

A general structured model of a hermaphrodite population

Both empirical and theoretical studies, have dealt with the question how to best optimize reproductive fitness for hermaphrodites, using models such as game theory or complicated energetic costs and benefits of mating displays. However, hermaphrodites exhibit a broad spectrum of sexual behaviors like simultaneous, sequential or lifetime gonochorist that cannot be explained using a unique formalism. A possible explanation of this diversity relies on the way these species maximize their fitness: Does the individual hermaphrodite split its time between strategies maximizing its instantaneous reproductive fitness or its evolutionary fitness? Here, we compare these two points of view and extend a game theoretical formalism to a sex allocation model that underlies all sexual behaviors as a result of a dynamic game whose payoff depends on the costs and benefits of sexual reproduction. Using this formalism, we prove that a simultaneous hermaphrodites strategy is stable even for high values of sex changing costs. Moreover, we prove that the stability of a sequential hermaphrodite is linked to the average energy allocated to the pure female strategy.

Dark eyes in female sand gobies indicate readiness to spawn

In animals, colorful and conspicuous ornaments enhance individual attractiveness to potential mates, but are typically tempered by natural selection for crypsis and predator protection. In species where males compete for females, this can lead to highly ornamented males competing for mating opportunities with choosy females, and vice versa. However, even where males compete for mating opportunities, females may exhibit conspicuous displays. These female displays are often poorly understood and it may be unclear whether they declare mating intent, signal intrasexual aggression or form a target for male mate preference. We examined the function of the conspicuous dark eyes that female sand gobies temporarily display during courtship by experimentally testing if males preferred to associate with females with artificially darkened eyes and if dark eyes are displayed during female aggression. By observing interactions between a male and two females freely associating in an aquarium we also investigated in which context females naturally displayed dark eyes. We found that dark eyes were more likely to be displayed by more gravid females than less gravid females and possibly ahead of spawning, but that males did not respond behaviorally to dark eyes or prefer dark-eyed females. Females behaving aggressively did not display dark eyes. We suggest that dark eyes are not a signal per se but may be an aspect of female mate choice, possibly related to vision.