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The thyrohyoid muscle is one of the four infrahyoid muscles. Its role in vocalization and deglutition could be often overlooked, despite its crucial participation in these processes. Unlike other infrahyoid muscles, the thyrohyoid muscle receives innervation from the first cervical spinal nerves which contributes to its unique function. Its primary action involves hyolaryngeal elevation during swallowing, contributing to the opening of the upper esophageal sphincter. In conjunction with other muscles, it also protects the airway and facilitates the passage of food into the esophagus. Variations in the muscle’s thickness may exist, and its function can be influenced by chewing habits. Weakened muscles involved in swallowing are often associated with dysphagia, a common complication in stroke and brain-injured patients. Advanced imaging techniques and sleep studies have provided insights into the dynamics and frequency of swallowing. This review explores the anatomic structures, function in action, diagnosis and clinical implications of this muscle. Overall, understanding the significance of the thyrohyoid muscle enhances our comprehension of the intricate interplay of laryngeal muscles during vocalization and deglutition. [ABSTRACT FROM AUTHOR]

We applied an integrative taxonomic framework to evaluate the systematics of the Neotropical Black-and-white Becard (Pachyramphus albogriseus Sclater 1857). Combining phylogenomic (ultraconserved elements), morphological, and vocalization data, we confirmed that this species is polyphyletic; some individuals form a clade sister to P. polychopterus and should be afforded species rank as P. salvini Richmond 1899 (Slender-billed Becard), whereas the remaining subspecies of P. albogriseus (Broad-banded Becard) are sister to P. major. We found that P. salvini differs from P. albogriseus in song, color of the lores, wing-bar width, body size, and bill width. Whereas P. albogriseus occurs in montane forest in Costa Rica and Panama (ssp. ornatus) and along the eastern slope of the Andes from northern Venezuela to southern Peru (ssp. albogriseus), P. salvini is found in the lowlands from Pacific Colombia south to northwest Peru and in the Río Marañón drainage. The latter also occurs, possibly only seasonally, along the eastern slope of the Andes, where the two species' ranges approach closely. We treat P. a. guayaquilensis Zimmer 1936 as a junior synonym of P. salvini Richmond 1899, and P. a. coronatus Phelps and Phelps 1953 as a junior synonym of P. a. albogriseus Sclater 1857. This study provides a striking example of a major problem for comparative biology: underestimated and mischaracterized diversity. We argue that there are likely many more cases like this awaiting discovery. [ABSTRACT FROM AUTHOR]

We investigated whether context-specific behavior is responsible for the cohesion of mixed-species flocks of antshrikes and antwrens in Amazonian Peru. Antshrikes perform a behavior while spatially repositioning, to which antwrens respond by approaching. The cohesion of interspecific associations requires communication, although the mechanisms often are unexplored. In monospecific groups, cohesion among individuals is maintained with actions or vocalizations given in a certain context. Dusky-throated Antshrikes (Thamnomanes ardesiacus) vocalize while in flight and the number of times they vocalize covaries with the flight distance. We refer to this pairing of flight and vocalization as repositioning behavior. Furthermore, antshrikes pair a different call type with perching, which we refer to as perching behavior. We followed Long-winged (Myrmotherula longipennis) and White-flanked Antwrens (M. axillaris) and recorded their response following natural vocalizations (no playback used) given by the antshrikes. Long-winged Antwrens, but not White-flanked, flew toward an antshrike significantly sooner and were more likely to approach the antshrikes after the repositioning behavior than after perching behavior. In addition, Long-winged Antwrens, but not White-flanked, flew toward an antshrike sooner after a longer series of repositioning calls than after a shorter series. We did not distinguish between the Long-winged Antwrens' response as a function of movement vs. vocalizations of the antshrikes, although we argue that vocalizations are likely a more important communication component of repositioning behavior than movement. It remains unclear whether the antshrikes are deliberately signaling the Long-winged Antwrens or the antwrens are taking advantage of the repositioning behavior; active signaling is possible since antshrikes benefit from antwrens. White-flanked Antwrens may be less responsive to the antshrikes since they have a lower propensity to occur in a mixed-species flock. The results indicate that the repositioning behavior of Dusky-throated Antshrikes is a key mechanism of interspecific cohesion of Amazonian mixed-species flocks of the understory. [ABSTRACT FROM AUTHOR]

Bird songs are fundamental for the communication and development of different bird activities. On the other hand, the noise coming from various sources make it difficult to receive bird songs, and therefore some bird species have changed the structure, frequency, energy, or time of their singing to ensure they can be heard. Particularly, the noise generated by rivers is constant and has greater intensity at low frequencies, so it could mask birds' songs. Hence, the objective of this work was to examine the song of Myiothlypis fulvicauda in environments with natural noise generated by water bodies in the municipality of Ibagué (Tolima), considering the climatic season and the degree of vegetation cover within this analysis. Recordings were performed during May, July, and October 2019 at 8 locations, which were assigned two types of noise treatment: high and low. Generalized linear models and variance and correlation analysis were used to evaluate the effect of noise, climatic season, and vegetation cover degree on the singing of this species of bird. We found that the maximum frequency, frequency bandwidth, and number of initial whistles were higher in high-noise habitats, while the frequency bandwidth was lower during the dry season. Besides, the number of repetitive elements and maximum frequencies were lower in highly dense vegetation locations. These changes in the song of M. fulvicauda denote a possible adaptation of this species in response to environmental noise and habitat characteristics such as vegetation cover and season patterns. [ABSTRACT FROM AUTHOR]

When the World Health Organization declared 2020 as the International Year of Nurses and Midwives, commemorating the Bicentennial of Florence Nightingale, no one could imagine that the appearance of a virus called COVID19 would put global health in check, placing the profession nurse in the foreground. It is in this scenario that the figure of Nightingale becomes relevant, which in this article is presented from another perspective with the aim of metaphorically analyzing, taking as a reference the meaning of his surname in Spanish, nightingale, the characteristics that have contributed to his survival in the time. The final result shows that there are certain affinities between the songbird and Nightingale, such as the connection with nature, seeking collaboration with the best or the way in which he made himself heard, with his writings, providing data. And he did it without being seen, which did not diminish his prominence since like the nightingale is the only protagonist of the night, Nightingale's song has pierced the timeline. This work shows that Nightingale is an inexhaustible source since it combines numerous aspects related to the meaning of our nursing profession, holistic care, so that it is interesting to explore its figure from other approaches. [ABSTRACT FROM AUTHOR]

Acoustic signals are one of the most important ways of communication for fauna. The study of acoustic signals constitutes a valuable tool to obtain information on ecology, behavior, taxonomic identification, and the effect of human activities in natural environments and different animal species. Furthermore, it offers the possibility of quantifying and monitoring biodiversity in different Colombian ecosystems. In this work, we present an analysis of the research on bioacoustics that have been developed in Colombia, to establish a baseline, identify gaps in knowledge, strengths, weaknesses and discuss future challenges for bioacoustics research in Colombia. We searched information on scientific publications, degree papers, and electronic database conference presentations, using different keywords. We obtained 321 results;studies using acoustic tools are much more common in birds (36.4%) and amphibians (35%) than in any other taxonomic group, and there is a bias towards studying bioacoustics in the Andean region. However, this is a field with growing interest, and, therefore, there is a need for collaborative and multidisciplinary work, a consensus on methodologies, along with the strengthening and enrichment of the country's sound collections. [ABSTRACT FROM AUTHOR]

This study contributes empirical evidence regarding communicative functions in the pre-grammatical period. The aim was to explore these functions in child-adult dyadic interactions during what in language acquisition research has been called the two-word period. The study draws from the data corpus of a child 19–29 months old and the system of sign categories (gestures, non-verbal vocalizations, verbal vocalizations, uni- and bimodal compositions) developed by Rodríguez & Español. In order to study the communicative functions in this period, an observational code was developed in accordance with Strauss and Corbin's Constant Comparative Method, which is suitable for encompassing the entire repertoire of a child's sign use. The study in general allowed some functions absent in adult communication to be identified, and the qualitative analysis in particular revealed a use of semiotic resources that supports the idea of a cognitive processing structure common to gesture and word. [ABSTRACT FROM AUTHOR]

Bird song has been extensively studied in oscine passerines, but far less is known about song in hummingbirds, which are distantly related to passerines. Song is generally thought of as a male trait. Here we document song in 2 wild female Costa's Hummingbirds (Calypte costae) of 10 examined. Their vocalizations closely resembled male song and were produced, undirected, on territories just prior to the breeding season. Both birds were confirmed as female and not young males, which resemble females: one had an enlarged ovary, and the other laid eggs. Our results imply that at least some female hummingbirds may learn song as well as males and have similar song capacity as males. The function, if any, of female song was not immediately clear. Female song seemed rarer in this population than in males and thus easy to overlook. Presence of female song could also be an overlooked phenomenon in other hummingbird species. [ABSTRACT FROM AUTHOR]

We describe a new species of climbing rat of the genusRhipidomysbased on cranial and external morphology, morphometrics, and phylogenetic analyses of cytochromebgene. This taxon was compared with species ofRhipidomyspresent in Ecuador, principallyR. latimanus, which is a closely related species based on molecular analysis, and with several species from Colombia and Peru. The new species is easily distinguished from congeneric species by the relatively small size of its body (average head–body length 123 mm) and its distinctive cranial morphology including: Interorbital region constricted; postorbital crest almost imperceptible in females and evident only slightly in males; braincase wide and round; nasals narrow in their posterior and gradually expand forward; anteromedian flexus is well defined and deep; m3 with hypoflexid large and deep; mesopterygoid fossa extends beyond the third molar and capsular process on mandible well developed, forming an evident projection. The new species is only known from the southeastern portion of Sangay National Park in Ecuador and is therefore likely endemic to the Cordillera Oriental of Ecuador. We also provide natural history and reproductive observations, vocalization analysis, habitat preference, and phylogenetic placement of this species. [ABSTRACT FROM AUTHOR]

Phenotypic traits are important for assessing differences between populations, especially in groups with poorly resolved taxonomy. One such group, the House Wren complex, presents extensive taxonomic controversy and is thought to comprise many independent evolutionary units. Although the songs and morphological features of House Wrens (Troglodytes aedon) show extensive variation, differences between populations have not been quantified. We assessed variation in acoustic and morphometric traits within this complex and compared patterns of variation with currently recognized subspecies boundaries. First, we compared songs and morphology among eight recognized subspecies (T. a. aedon, T. a. parkmanii, T. a. cahooni, T. a. brunneicollis, T. a. nitidus, T. a. musculus, T. a. beam, and T. a. rufescens), controlling for significant effects of latitude. Second, we used variation in male song, a trait with an important role in mate choice and male-male competition, to assess divergence among subspecies. We compared variation among subspecies to variation across seven currently recognized Troglodytes species (T. hiemalis, T. pacificas, T. tanner!, T. sissonii, T. cobbi, T. rufociliatus, and T. ochraceus). Our results, based on broad sampling of songs (n = 786) and morphological traits (n = 401) from 609 locations throughout the Americas, show that most of the subspecies examined diverge in song, morphology, or both. In addition, the acoustic differences between subspecies are similar to, and in some instances greater than, the divergence between pairs of currently recognized species. Our results suggest that at least four allopatric subspecies-T. a. nitidus, T. a. musculus, T. a. beani, and T. a. rufescens-are likely different species, and we identify many other vocally and morphologically differentiated subspecies that may, upon further detailed genetic analysis, result in new species. [ABSTRACT FROM AUTHOR]

The Paraguayan caiman (Caiman yacare) is the main Caimaninae species occurring in the Brazilian Pantanal Wetland. Despite the relative availability of works focused on biology and conservation of the Paraguayan caiman, almost nothing is known about its vocal structure and behavior. We recorded aggressive calls of adult caiman females guarding nests and, afterwards, the distress calls of the new born juvenile caimans in seasonally flooded areas of the Nhecolândia (Southern Pantanal). The results of both observations and sonographic analyses diverged from studies with other crocodilian species. Aggressive vocalization of adult females of the Paraguayan caiman was longer and more complex than the same vocalization of larger Alligatoridae species. Vocalizations of the young caimans presented interspecific differences with other crocodilian offsprings. Moreover, we found statistically significant intraspecific variation in the distress call structure among different pods, even separated by few kilometers. Differences in distress call structure were tested by Canonical Discriminant Analysis (CDA). We obtained the squared Mahalanobis distances between the acoustic multivariate spaces of each pod provided by the CDA and compared with the geographic distance between the bays of origin of each pod through Mantel Test. The geographic distance by itself did not explain the differences found in the structure of the vocalization of young caimans from different pods. The adult females of Paraguayan caiman positively responded to playbacks of calls from juvenile caimans from pods of other regions, as well as to rough imitations of distress call. Since the adult caimans showed protective responses to quite heterogeneous vocalizations of distress by juveniles, we hypothesized that the variation in the distress call pattern may be associated to a low specificity in sound recognition by adult caimans. [ABSTRACT FROM AUTHOR]

Species' conservation relies on understanding their seasonal habitats and migration routes. North Atlantic right whales (Eubalaena glacialis ), listed as endangered under the U.S. Endangered Species Act, migrate from the southeastern U.S. coast to Cape Cod Bay, Massachusetts, a federally designated critical habitat, from February through May to feed. The whales then continue north across the Gulf of Maine to northern waters (e.g., Bay of Fundy). To enter Cape Cod Bay, right whales must traverse an area of dense shipping and fishing activity in Massachusetts Bay, where there are no mandatory regulations for the protection of right whales or management of their habitat. We used passive acoustic recordings of right whales collected in Massachusetts Bay from May 2007 through October 2010 to determine the annual spatial and temporal distribution of the whales and their calling activity. We detected right whales in the bay throughout the year, in contrast to results from visual surveys. Right whales were detected on at least 24% of days in each month, with the exception of June 2007, in which there were no detections. Averaged over all years, right whale calls were most abundant from February through May. During this period, calls were most frequent between 17:00 and 20:00 local time; no diel pattern was apparent in other months. The spatial distribution of the approximate locations of calling whales suggests they may use Massachusetts Bay as a conduit to Cape Cod Bay in the spring and as they move between the Gulf of Maine and waters to the south in September through December. Although it is unclear how dependent right whales are on the bay, the discovery of their widespread presence in Massachusetts Bay throughout the year suggests this region may need to be managed to reduce the probability of collisions with ships and entanglement in fishing gear. [ABSTRACT FROM AUTHOR]

We describe the frog species Diasporus citrinobapheus sp. n. from the Cordillera Central of western Panama. The new species differs from all other species in its genus in coloration, disk cover and disk pad shape, skin texture, advertisement call, and size. It is most similar to D. tigrillo, from which it differs in dorsal skin texture, relative tibia length, number of vomerine teeth, ventral coloration, dorsal markings, and relative tympanum size, and to D. gularis, from which it can be distinguished by the lack of membranes between the toes, adult size, posterior thigh coloration, and position of the choanae. We provide data on morphology, vocalization, and distribution of the new species, as well as brief information on its natural history. [ABSTRACT FROM AUTHOR]