Gabriel Francescoli

• PhD
• Professor (Retired) at Universidad de la República de Uruguay

Signals that inform prospective receivers of potential contingencies associated with the signaler or its environment may be innate, or may rely upon repeated association between signal production and a context relevant to the receiver, or theory of mind, such that signalers and/or receivers infer the state or contextual situation communicative part...

RESUMEN En especies donde los machos compiten por parejas, se espera que desarrollen comportamientos y/o adaptaciones morfológicas para aumentar su probabilidad de éxito. En el opilión Pachyloides thorellii Holmberg, 1878, se han observado enfrentamientos entre machos, aunque no presentan ningún rasgo llamativo de dimorfismo sexual que pueda indica...

Ecological factors may affect resource availability and distribution, impacting foraging and burrow construction behaviours. Clyomys laticeps is a caviomorph rodent with subterranean habits occurring on the Brazilian Cerrado domain (savanna-like) until the Paraguayan Chaco. We investigated their underground system's architecture taking into account...

Sound signals can travel through long distances, becoming an important communication channel between animals that need to establish contact beyond the visual form. They can then be considered a relevant form of communication between species living in the underground environment. Ctenomys torquatus and Ctenomys lami are solitary subterranean rodents...

C. S. Peirce defined the sign as a means to communicate a form or habit embodied in the object to the interpretant, thus constraining (through a sign) the behavior of an interpreter to a limited series of effects. This is part of the process of “semiotic scaffolding” in which sign relations interlock and reinforce one another, providing directional...

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 s...

Solar power is a renewable energy source with great potential to help meet increasing global energy demands and reduce our reliance on fossil fuels. However, research is scarce on how solar facilities affect wildlife. With input from professionals in ecology, conservation, and energy, we conducted a research-prioritization process and identified ke...

Density has been proposed as a factor that could determine 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 indi...

This article argues that many, if not most, behavior descriptions and sequencing are in essence an interpretation of signs, and are evaluated as sequences of signs by researchers. Thus, narrative analysis, as developed by Barthes and others, seems best suited to be used in behavioral/biosemiotic studies rather than mathematical modeling, and is ver...

Males of some spider species lay silk threads on the female’s body during courtship and/or copulation. There are several hypotheses trying to explain the function of this behavior, known as bridal veil deposition. One of them proposes that bridal veils could occur to immobilize females and prevent sexual cannibalism when females are larger than mal...

The subterranean environment has strongly influenced the evolution of the sensory biology of subterranean rodents. While dark and monotonous tunnels have led to reductions in the visual capabilities of some species, other senses appear to be highly developed in contrast. Among them, the emission of acoustic and seismic signals plays a major role in...

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...

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...

This paper tries to link Ethology to Biosemiotics by analysing the similarities between some triadic relationships like biosemiotics’ Object—Representamen—Interpretant and the one established in Ethology between Sign-stimuli— Innate Releasing Mechanism—Modal Action Pattern, or the one potentially established in communication networks comprising Sen...

In order to study how sexual selection takes place during mating, it is necessary to have a clear knowledge of the interactions that occur throughout mating and which morphological and behavioral traits are involved. Available information about harvestman reproductive biology is mainly restricted to anecdotal field observations, most of them lackin...

In this chapter we examine the mechanisms of communication in caviomorph rodents. Our aim was to review the available information, putting it into the context of social systems (social versus solitary species), while taking a look at different areas of social behavior for which signals in different modalities have been described and analyzed. We fo...

The state of the art of Ethology in five Latin America countries is briefly presented here. The overall outlook regarding research laboratories and themes is promising: the community is numerous, active and there are topics addressing all aspects of animal behavior, especially in large countries like Brazil and Argentina. Ethology as an undergradua...

Ctenomys pearsoni (Pearson's tuco-tuco) is a subterranean rodent native to Uruguay. We tested the amplification pattern of 12 microsatellite loci, designed for C. sociabilis and C. haigi in a C. pearsoni population. DNA extractions were made from hair samples, and PCR amplification products were run on an ABI 3100 microcapillary gel. Eight loci wer...

As subterranean rodents live in burrows and are constrained by the physics of their environment to vocalize, mainly in low frequencies, their expanded middle ear cavities are associated with enhanced lower-frequency hearing. Previous literature has widely acknowledged inflated tympanic bulla as a character to be found in the majority of the Ctenomy...

Tuco-tucos are subterranean rodents endemic of South America. Ctenomys pearsoni is a solitary species from southwestern Uruguay. Each individual occupies its own burrow and aggressively defends it, except for juveniles before dispersing and couples during reproduction. We tried to understand how these animals find a partner and how they know their...

Two different vocalization patterns for long-range (S-Type) vocal signals were detected in species of the genus Ctenomys. These patterns were described separately for C. pearsoni, C. mendocinus, and C. talarum. This paper gathers information about the vocalizations of other species, such as C. sociabilis, C. rionegrensis and C. torquatus. We confir...

The S-type vocalizations of three populations ofCtenomys from Uruguay were compared: two ofCtenomys pearsoni Lessa and Langguth, 1983 from Penino and Relincho and the third from a different karyomorph of the genus (Solís karyomorph). Ten rhythm and 3 frequency variables were used for discriminant analysis. The results showed that a set of nine vari...

Calls emitted by newborn pups ofCtenomys pearsoni Lessa and Langguth, 1983 away from the nest were frequency modulated succesive notes. The notes were characterized by mean maximum frequency under 5165 Hz, with mean main frequency under 2155 Hz, and mean note duration under 0.165 s. Their possible function as contact or distress calls, resulting in...

Subterranean rodents are interesting organisms for communication studies because of their fossorial way of life. Acoustic communication in the South American genus Ctenomys has not yet been studied even though this species is geographically widespread. This paper represents a preliminary survey of Ctenomys vocalizations. Three types of vocal signal...

Ecoetología y conservación de mamíferos subterráneos de distribución restringida: el caso de Ctenomys pearsoni (Rodentia, Octodontidae) en el Uruguay Recibido: 5 enero 1999; aceptado: 17 junio 1999. Resumen. Los roedores subterráneos del género Ctenomys («tucu-tucus») se distri-buyen entre los 17º y 54° de Latitud Sur, y desde el nivel del mar hast...

Here we discuss different factors that could influence the development of vocal and/or seismic communicative channels in subterranean rodents. We suggest that: 1) Highly social subterranean rodents that do not leave their burrows use essentially vocal signals in the vibrational channel; 2) Solitary and almost permanently fossorial species use vocal...

Three groups of spiders were raised from birth in the laboratory: Lycosa thorelli, L. carbonelli, and their experimentally obtained hybrid progeny. We analyzed the behaviour of the three male groups in the presence of a hybrid sexual pheromone. From the tests, 22 behaviour units were identified; 11 were simple and 11 were complex, the latter result...

Twenty-six juvenile wolf spiders belonging to each of three groups, Lycosa carbonelli and L. thorelli and their experimentally obtained hybrids, were raised; 11, 7, and 17, respectively, survived to the adult stage. Lycosa carbonelli averaged 8.1 moults to reach the adult stage, L. thorelli 9.7, and hybrids 8.6; no significant differences were obse...

Four experimental groups were used: (A) males Lycosa thorelli × female L. thorelli; (B) male Lycosa carbonelli × female L. carbonelli; (C) Male L. thorelli × female L. carbonelli; (D) male L. carbonelli × female L. thorelli. Males were placed in a field with conspecific sexual pheromone and confronted to anesthetized virgin females. Male L. thorell...