Environmental factors could constrain the use of long-range vocal signals in solitary tuco-tucos (Ctenomys; Rodentia, Ctenomyidae) reproduction

Ctenomys are mainly solitary subterranean rodents. Life underground has advantages (protection against predators, environmental control and reduced competition) but also implies disadvantages (digging costs, coping with hypercapnia, physiological and sensory changes, and communication problems) that can affect the social structure. Reproduction is a critical moment in the use of the signal repertoire, because individuals should locate in space, travel to, contact and copulate with a suitable partner. Energy expenditure involved in digging (connecting) tunnels makes difficult to attain a partner burrow system, but predation risk involved in moving above ground can counterbalance it and coupled with the spatial structure of the population, can determine the best communicative strategy to contact and locate a potential partner. Vocalisations allow to communicate over longer distances an with a reduced risk, while chemical signals, mostly aimed at vomerolfaction involve proximity or direct contact with the sample odour thus making information gathering more risky. As Ctenomys can use different signal types to gather different types of information leading to copulation, we propose that the use of these signals would be flexible, depending mostly on population spatial structure and type of predators living in the zone. This is because differences among species and/or populations in the use and characteristics of long-range vocalisations could be induced by environmental and/or social factors. This variation could be considered as a case of phenotypic plasticity, determining communication strategies variability in reproductive context, mostly dependent on long-range communication signals and the behaviour of males

‘Evolutionary Stories’: Narratives as Evolutionary Tools to Describe and Analyse Animal Behaviour and Animal Signals

Animal communication studies, and Ethology itself, deal with the analysis of behaviour in a way that can be understood as an analysis of signal sequences, mainly from a qualitative point of view. Thus, the main goal of behavioural analysis is to interpret the ‘semantic’ content of behavioural sequences and communicative signals. Considering these analyses as narratives to be interpreted, then hermeneutics, narrative schemas and structuralist techniques could be applied. Here, I propose that in fact when exploring and decoding animal behaviour sequences, we should use narrative analysis and biosemiotic techniques to interpret a type of information processing most effective in evolution, which could be called the analysis of ‘evolutionary stories’. Moreover, I think we do exactly that, but do not acknowledge it because is not considered ‘hard science’ (no maths involved). Nevertheless, this type of analysis seems to be the more flexible and appropriate way to interpret animal communication signals and systems, and also to interpret any general behavioural sequence, because it is mostly based on the cognitive capabilities of the involved species. This chapter will argue about the need for a re-evaluation of a cognitive and biosemiotic interpretation of behaviour and communication signals as central to biological behavioural analysis

Zamba by you: possible stridulation during courtship in a spider with bridal veil (Ctenidae)

Guasuctenus longipes es una araña asociada a ambientes de quebrada. El objetivo de este estudio fue explorar la existencia de estructuras estridulatorias y emisión de sonido. Se describe el raspador y la lira en los palpos de los machos. Al tratarse de una especie nocturna, sugerimos que el canal acústico es preponderante para el encuentro de los sexos.Guasuctenus longipes is a spider associated with stream environments. The objective of this study was to explore the presence of stridulatory organs and sound emission. Scraper and ridges on the pedipalps of males were described. As it is a nocturnal species, we suggest that the acoustic channel is preponderant for the meeting of the sexes

Evaluating potential effects of solar power facilities on wildlife from an animal behavior perspective

Solar power is a renewable energy source with great potential to help meetincreasing global energy demands and reduce our reliance on fossil fuels.However, research is scarce on how solar facilities affect wildlife. With inputfrom professionals in ecology, conservation, and energy, we conducted aresearch-prioritization process and identified key questions needed to betterunderstand impacts of solar facilities on wildlife. We focused on animalbehavior, which can be used to identify population responses before mortal-ity or other fitness consequences are documented. Behavioral studies canalso offer approaches to understand the mechanisms leading to negativeinteractions (e.g., collision, singeing, avoidance) and provide insight into mit-igating effects. Here, we review how behavioral responses to solar facilities, including perception, movement, habitat use, and interspecific interactionsare priority research areas. Addressing these themes will lead to a morecomprehensive understanding of the effects of solar power on wildlife andguide future mitigatio

Experimental response to density levels in the development of tadpoles and froglets of Boana pulchella (Anura: hylidae)

Density has been proposed as a factor that could determinate larval growth in anurans. We studied such effects on Boana pulchella. After hatching, we reared the tadpoles during 90 days and 93 tadpoles with similar size and developmental stages were chosen. We placed them in 800 cm3 cans with declorified water at five densities (1, 2, 4, 8 and 16 individuals/can) with three replicates for each treatment. In all the cans the feeding was ad libitum, and they were maintained until the end of the Gosner’s developmental stage 41. Each time that a tadpole was extracted, a proportional water volume was too, in order to maintain constant densities. We found significant differences among treatments for froglets’ length, mandibular width and mass, while these differences were not significant for metamorphic time. Since the tadpoles were feeding ad libitum an explanation by competitive trophic interactions for that significant differences could be discarded. These differences could be evidence that density has significant effects

Agonism Management Through Agonistic Vocal Signaling in Subterranean Rodents: A Neglected Factor Facilitating Sociality?

Communication is inherent to social relationships. Previous papers addressed the correlation between social and communicative complexity, and the origin of sociality in rodents. In subterranean social species, as the number of animals in the same burrow increases, so do interindividual contact rates. This is because of limitations in actually used tunnel length and diameter, leading to an increasing number of agonistic situations probably resulting in time loss, threatening, and fighting with danger of injuries. To avoid this, social species are expected to have an increase in the number of particular vocalizations. Comparison of the adult vocal repertoire of 12 species (7 genera) through regression and Phylogenetically Independent Contrasts (PIC) suggests three main conclusions: 1) social species increase their repertoire both in number and categories of vocal signals in relation to solitary species, although the coefficient was smaller in the PIC model; 2) the number of agonistic vocalizations was also different between solitary and social species, with the latter displaying higher numbers of these calls; 3) the percentage of agonistic vocalizations in relation to total repertoire was similar between social and solitary species, with no significant relationship between this parameter and the social structure. These results imply that agonistic vocalizations have also been increased in number in social species, indicating the importance of these calls in the establishment of new relationships. As repertoire changes are essential to cope with new and frequent kinds of interactions sociality originates these results suggest that, at least for these organisms, communicative changes, specially at the level of agonistic signals, could be a necessary condition to fulfill in the path to the possibility of group living.Fil: Francescoli, Gabriel. Universidad de la República; UruguayFil: Schleich, Cristian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Mechanisms of social communication in caviomorph rodents

The rodent suborder Caviomorpha comprises species with a diversity of social systems ranging from solitary to social species, including species with communal care of offspring (Ebensperger 2001; Chapters 2 and 7 in this book). Variation in sociality is thought to originate from different grouping alternatives that span from temporal aggregations to long-term associations in which juveniles remain in the natal nest (Ebensperger & Cofré 2001). From a theoretical point of view, the main way to coordinate common activities in social groups is through the use of communication signals. Sensory ecology and signal repertoires (in their respective communication modality or channel) should provide clues about the species’ capabilities to gather information, and the suitability of those signals for social coordination and communication (Pollard & Blumstein 2012). Communication is the means through which social coordination, group and/or individual recognition, communal breeding, cooperation, and other forms of social behavior could be inter-related.Fil: Francescoli, Gabriel. Universidad de la República; UruguayFil: Nogueira, Selene. Universidade Estadual de Santa Cruz; BrasilFil: Schleich, Cristian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

A COMPARATIVE STUDY OF SEXUAL BEHAVIOR IN TWO SYNMORPHIC SPECIES OF THE GENUS LYCOSA (ARANEAE, LYCOSIDAE) AND THEIR HYBRID PROGENY

Volume: 28Start Page: 237End Page: 24

Mating behavior of the solitary neotropical harvestmanPachyloides thorellii(Arachnida: Opiliones)

Volume: 44Start Page: 210End Page: 21