Parasite defensive limb movements enhance signal attraction in male little torrent frogs: insight into the evolution of multimodal signals

Many animals rely on complex sexual signals that target multiple senses to attract mates and repel rivals. These multimodal mating displays can however also attract unintended receivers, which can be an important driver of signal complexity. Despite being taxonomically widespread, we often lack insight into how multimodal signals evolve from unimodal signals and in particular what roles unintended eavesdroppers play. Here we assess whether the physical movements of parasite defense behavior increase the complexity and attractiveness of an acoustic sexual signal in the little torrent frog (Amolops torrentis). Calling males of this species often display limb movements in order to defend against blood sucking parasites such as frog biting midges that eavesdrop on their acoustic signal. Through mate choice tests we show that some of these midge evoked movements influence female preference for acoustic signals. Our data suggest that midge induced movements may be incorporated into a sexual display, targeting both hearing and vision in the intended receiver. Females may play an important role in incorporating these multiple components because they prefer signals which combine multiple programs. Our results thus help to understand the relationship between ecological and sexual selection pressure operating on signalers and how in turn this may influence multimodal signal evolution.

The Vocal Repertoire of the Bearded Capuchin (Cebidae: Sapajus libidinosus): Implications for Understanding the Complexity of Neotropical Primate Communication

Vocal communication is an essential aspect of primate social behaviour. The bearded capuchin <i>Sapajus libidinosus</i> is endemic to Brazil, and some studies have described specific vocalisation types for this species; however, there is still no complete description of its vocal repertoire. Thus, this study aimed to describe the vocal repertoire of a group of <i>S. libidinosus</i> living in the<i></i>Parque Nacional de Brasília, a protected area in the Cerrado area of Central Brazil. We carried out focal samplings and recording of vocalisations of members of an <i>S. libidinosus</i> troop in different behavioural contexts. The call analyses revealed 25 different types of vocalisations, and each call presented significant structural variation. We grouped these vocalisations according to the context of the emission or acoustic structure into the following categories: contact calls (contact note, infant babbling, trill, teeth- and lip-smacking, and sirena); foraging calls (chihui, grgr, and patinado); whistle series (food-associated, long-distance, and intergroup encounter); aggressive calls (aggressive contact note, ascending rapid staccato, cough cough, and pip); calls in response to aggression (scream, squeal, and pulsed scream), sexual display calls (chuck and raspy oestrous call), and stress-related calls (alarm call/bark, hiccup, hip, double hip, and wah wah). <i>S. libidinosus</i> presented a very rich vocal repertoire, revealing a pattern consistent with the repertoire of other capuchin monkey species. This is the first comprehensive description of the<i> S. libidinosus</i> vocal repertoire and highlights the complexity of neotropical primate communication.

Aggression towards neonates and possible infanticide in the boto, or Amazon river dolphin (Inia geoffrensis)

Recent observed attacks by male Amazon river dolphins on conspecific calves, together with post-mortem examinations, indicate that infanticide occurs in this species but that not all attacked calves are killed. If mortality occurs, it might therefore be an inadvertent consequence of the behaviour rather than the motive for it. Our observations suggest that males who commit infanticide are unlikely to gain direct fitness benefits. Evidence does not fit the sexual selection hypothesis. Aggression towards calves usually ‘drew a crowd’ and may represent socio-sexual display or simply be a form of social pathology, as found in other infanticidal mammals.

Social Networking Sites’ Gag Order: Commercial Content Moderation’s Adverse Implications for Fundamental Sexual Rights and Wellbeing

This article critically investigates the reasoning behind social media content policies and opaque data politics operations regarding sexual visual social media practices and sexual talk, asking what is at stake when social media giants govern sexual sociability on an international scale. Focusing on Facebook, in particular, this article proposes an alternative perspective for handling various expressions of sexuality in social media platforms by exploring the wide-ranging ramifications of community standards and commercial content moderation policies based on them. Given that sexuality is an integral part of human life and as such protected by fundamental human rights, we endorse the freedom of expression as an essential legal and ethical tool for supporting wellbeing, visibility, and non-discrimination. We suggest that social media content policies should be guided by the interpretive lens of fundamental human rights. Furthermore, we propose that social media content policies inclusive of the option to express consent to access sexual content are more ethical and just than those structurally erasing nudity and sexual display.

Three-dimensional geometric morphometric analysis of the skull of Protoceratops andrewsi supports a socio-sexual signalling role for the ceratopsian frill

Socio-sexual selection is predicted to be an important driver of evolution, influencing speciation, extinction and adaptation. The fossil record provides a means of testing these predictions, but detecting its signature from morphological data alone is difficult. There are, nonetheless, some specific patterns of growth and variation which are expected of traits under socio-sexual selection. The distinctive parietal-squamosal frill of ceratopsian dinosaurs has previously been suggested as a socio-sexual display trait, but evidence for this has been limited. Here, we perform a whole-skull shape analysis of an unprecedentedly large sample of specimens of Protoceratops andrewsi using a high-density landmark-based geometric morphometric approach to test four predictions regarding a potential socio-sexual signalling role for the frill. Three predictions—low integration with the rest of the skull, significantly higher rate of change in size and shape during ontogeny, and higher morphological variance than other skull regions—are supported. One prediction, sexual dimorphism in shape, is not supported, suggesting that sexual differences in P. andrewsi are likely to be small. Together, these findings are consistent with mutual mate choice or selection for signalling quality in more general social interactions, and support the hypothesis that the frill functioned as a socio-sexual signal in ceratopsian dinosaurs.

Behaviors and Interactions of Insects in Mid-Mesozoic Ecosystems of Northeastern China

During the past 20 years, more than 1,600 species of well-preserved fossil insects, including members of over 270 families within 24 orders, have been described from the Middle Jurassic Yanliao Entomofauna and Early Cretaceous Jehol Entomofauna in Northeastern China. Diversified fossil insects not only document the origin, systematics, and early evolution of many lineages, but also reveal these lineages’ behaviors and interactions with coexisting plants, vertebrates, and other insects in their ecosystems. Fossil evidence has been documented, for example, regarding insects’ feeding and pollination mutualism with gymnosperms; ectoparasitic feeding on blood of vertebrates; camouflage, mimicry of gymnosperm plants, and eyespot warning; sound stridulation for attracting potential mates; and sexual display, mating, egg-laying, and parental care. In this article, we review the diverse taxonomy of mid-Mesozoic insects of Northeastern China and elucidate their behaviors and interactions within their ecosystems, which have impacted their early evolution and development into extant insects.

Antiparasitic Effects of Plant Species from the Diet of Great Bustards

Background: Diets combine food types according to some trade-offs, as for example maximising nutrients and minimising toxins. But some diets include elements because of their activity against the host parasites and other pathogens. This so-called medicinal role of food is under-reported in the literature, either because toxic elements in diets of livestock and wildlife are infrequent, or because their activity against parasites and pathogens has not been fully documented. We contribute to fill this knowledge gap by testing the activity of extracts and essential oils from Papaver rhoeas and Echium plantagineum against a selection of laboratory pathogens. These plants are strongly selected by great bustards Otis tarda during the mating season. Results: During this season we found a significantly higher frequency of P. rhoeas in male than in female faeces. The activity of different extracts of these plants against some laboratory models including a flagellated protozoan (Trichomonas gallinae), a nematode (Meloidogyne javanica) and a fungus (Aspergillus niger) was evaluated. We found activity against nematodes and trichomonads in non-polar and polar extracts of the aerial parts of P. rhoeas, especially the extracts of flowers and capsules, and E. plantagineum, especially the extracts of leaves and flowers.Conclusions: Both plants showed anti-parasitic activity, a result compatible with the hypothesis that great bustards eat plants for non-nutritional purposes, likely to assist them in coping with parasites and other pathogens, and P. rhoeas could be especially helpful for males during the mating season, when their immune system is weakened by the investment in secondary sexual characters and sexual display. The self-medication properties of plants and animals included in diets should be considered in studies of foraging behaviour, habitat selection, and even conservation biology of wildlife.

Ontogenetic changes in the ventral colouration of post metamorphic Elachistocleis haroi Pereyra, Akmentins, Laufer, Vaira, 2013 (Anura: Microhylidae)

Ontogenetic colour change (OCC) is defined as the progressive and non-reversible process of changes in colouration of organisms associated with their development. Among the many vertebrate groups, amphibians are particularly impressive for their strikingly wide variety of colours, colour patterns, and signals, whose evolutionary and ecological significance have been poorly studied. Elachistocleis comprises 18 species currently separated into two main groups based on their ventral colour pattern: one immaculate and the other with specks and/or colour patches. Elachistocleis haroi is a small-sized species within the immaculate venter group, distributed in the Yungas and Dry Chaco ecoregions from which little information is known. In a comprehensive sampling of post-metamorphic individuals of E. haroi at different stages of development we identified a significant variation in ventral colour pattern, which could denote a progressive filling of yellow colour according to an ontogenetic pattern. To test this hypothesis, we analysed 39 post-metamorphic individuals of E. haroi at different stages of development with imaging procedures. We found that yellow spots and their intensity are significantly related to snout-vent length, as major expansion of colour on the sides, gular region and male chest, as almost no development on the belly. We briefly discuss our findings in relation to sexual display and predation avoidance. To our knowledge, this is the first analysis of post-metamorphic OCC in ventral colouration in the genus Elachistocleis.

Preferences for and use of light microhabitats differ among and within populations of a polytypic poison frog

Anti-predator strategies can influence trade-offs governing other activities important to fitness. Crypsis, for example, might make conspicuous sexual display especially costly, whereas aposematism might reduce or remove such costs. We tested for correlates of anti-predator strategy in Oophaga pumilio, a polytypic poison frog with morphs spanning the crypsis–aposematism continuum. In the wild, males of visually conspicuous morphs display from conspicuous perches and behave as if they perceive predation risk to be low. We thus predicted that, given a choice of ambient light microhabitats, these males would use high ambient light conditions the most and be most likely to perch in high-light conditions. We found no evidence that differently colored male O. pumilio preferentially used bright microhabitats or that ambient light influenced perching in a morph-specific manner. Independent of light conditions, males from the most conspicuous population perched the least, but the most conspicuous individuals from a polymorphic population perched the most. These patterns suggest that preferences do not necessarily underlie among-morph differences observed in the wild. This could be explained, and remain consistent with theory, if risk aversion is shaped, in part, by experience.