RESUMO
Environmental noise has a significant negative impact on acoustic communication in most situations, as it influences the production, transmission, and reception of acoustic signals. However, how animals respond to conspecific sounds when there is interference from environmental noise, and whether males and females display convergent behavioral responses in the face of noise masking remain poorly understood. In this study, we investigated the effects of conspecific male advertisement calls with different signal-to-noise ratios on male-male competition and female choice in the Anhui tree frog Rhacophorus zhoukaiyae using playback and phonotaxis experiments, respectively. The results showed that (1) female Anhui tree frogs preferentially selected the conspecific calls with higher SNR compared to calls with lower SNR; (2) males preferentially responded vocally to the conspecific calls with higher SNR compared to calls with lower SNR; and (3) males' competitive strategies were flexible in the face of noise interference. These results suggest that preferences of both sexes converge in outcome, and that male competitive strategies may depend on predictable female preferences. This study will provide an important basis for further research on decision-making in animals.
RESUMO
A new species of Xenodermid snake, Achalinus dabieshanensissp. nov., was described based on three specimens (two female and one male) collected from the Dabie Mountains of western Anhui Province. It can be distinguished from known congeners by a significant genetic divergence in the mitochondrial gene fragment COI (p-distance ≥ 9.4%) and the following combination of characteristics: (1) length of the suture between the internasals being distinctly shorter than between the prefrontals; (2) a single loreal; (3) dorsal scales strongly keeled, in 23 rows throughout the body; (4) two pairs of prefrontals; (5) six supralabials; (6) five infralabials; (7) temporals 2 + 2 + 3 (or 2 + 2 + 4); (8) 141-155 ventrals; (9) 45-55 subcaudals, unpaired; (10) anal entire; (11) weakly iridescent tinged, uniform, brown to black dorsum with vertebral scales and about three adjacent dorsal scales dark brown forming a longitudinal vertebral line from posterior margin of parietals to tail tip; (12) light brown venter, ventral shields wide, visible on both sides, light brown flanks, giving the appearance of a black subcaudal streak. The recognition of the new species increases the number of described Achalinus species to 22.
RESUMO
The ability to discriminate species and recognize individuals is crucial for reproductive success and/or survival in most animals. However, the temporal order and neural localization of these decision-making processes has remained unclear. In this study, event-related potentials (ERPs) were measured in the telencephalon, diencephalon, and mesencephalon of the music frog Nidirana daunchina. These ERPs were elicited by calls from 1 group of heterospecifics (recorded from a sympatric anuran species) and 2 groups of conspecifics that differed in their fundamental frequencies. In terms of the polarity and position within the ERP waveform, auditory ERPs generally consist of 4 main components that link to selective attention (N1), stimulus evaluation (P2), identification (N2), and classification (P3). These occur around 100, 200, 250, and 300 ms after stimulus onset, respectively. Our results show that the N1 amplitudes differed significantly between the heterospecific and conspecific calls, but not between the 2 groups of conspecific calls that differed in fundamental frequency. On the other hand, the N2 amplitudes were significantly different between the 2 groups of conspecific calls, suggesting that the music frogs discriminated the species first, followed by individual identification, since N1 and N2 relate to selective attention and stimuli identification, respectively. Moreover, the P2 amplitudes evoked in females were significantly greater than those in males, indicating the existence of sexual dimorphism in auditory discrimination. In addition, both the N1 amplitudes in the left diencephalon and the P2 amplitudes in the left telencephalon were greater than in other brain areas, suggesting left hemispheric dominance in auditory perception. Taken together, our results support the hypothesis that species discrimination and identification of individual characteristics are accomplished sequentially, and that auditory perception exhibits differences between sexes and in spatial dominance.
RESUMO
Species belonging to the genus Microhyla are small-sized frogs that are widely distributed in southern, eastern, and south-eastern Asia. In China, the genus harbors many cryptic species, on two of which-M. beilunensis and M. fanjinshanensis-studies were recently published. In this study, we collected specimens from the Dabie Mountain range, which is at the junction of Anhui, Henan and Hubei Provinces, East China; these specimens belonged to a species previously identified as M. mixtura. Based on phylogenetic analyses, species delimitation analyses, morphological comparisons and advertisement calls comparisons, we found they were significantly different from other known congeners, and thus we describe them as a new species. This study enriches the diversity of Microhylidae, and clarifies the species of the genus Microhyla in the Dabie Mountains.
RESUMO
Attention, referring to selective processing of task-related information, is central to cognition. It has been proposed that voluntary attention (driven by current goals or tasks and under top-down control) and reflexive attention (driven by stimulus salience and under bottom-up control) struggle to control the focus of attention with interaction in a push-pull fashion for everyday perception in higher vertebrates. However, how auditory attention engages in auditory perception in lower vertebrates remains unclear. In this study, each component of auditory event-related potentials (ERP) related to attention was measured for the telencephalon, diencephalon and mesencephalon in the Emei music frog (Nidirana daunchina), during the broadcasting of acoustic stimuli invoking voluntary attention (using binary playback paradigm with silence replacement) and reflexive attention (using equiprobably random playback paradigm), respectively. Results showed that (1) when the sequence of acoustic stimuli could be predicted, the amplitudes of stimulus preceding negativity (SPN) evoked by silence replacement in the forebrain were significantly greater than that in the mesencephalon, suggesting voluntary attention may engage in auditory perception in this species because of the correlation between the SPN component and top-down control such as expectation and/or prediction; (2) alternately, when the sequence of acoustic stimuli could not be predicted, the N1 amplitudes evoked in the mesencephalon were significantly greater than those in other brain areas, implying that reflexive attention may be involved in auditory signal processing because the N1 components relate to selective attention; and (3) both SPN and N1 components could be evoked by the predicted stimuli, suggesting auditory perception of the music frogs might invoke the two kind of attention resources simultaneously. The present results show that human-like ERP components related to voluntary attention and reflexive attention exist in the lower vertebrates also.
RESUMO
Climate fluctuations in the past and in the future are likely to result in population expansions, shifts, or the contraction of the ecological niche of many species, and potentially leading to the changes in their geographical distributions. Prediction of suitable habitats has been developed as a useful tool for the assessment of habitat suitability and resource conservation to protect wildlife. Here, we model the ancestral demographic history of the extant modern Chinese Muntjac Muntiacus reevesi populations using approximate Bayesian computation (ABC) and used the maximum entropy model to simulate the past and predict the future spatial dynamics of the species under climate oscillations. Our results indicated that the suitable habitats for the M. reevesi shifted to the Southeast and contracted during the Last Glacial Maximum, whereas they covered a broader and more northern position in the Middle Holocene. The ABC analyses revealed that the modern M. reevesi populations diverged in the Middle Holocene coinciding with the significant contraction of the highly suitable habitat areas. Furthermore, our predictions suggest that the potentially suitable environment distribution for the species will expand under all future climate scenarios. These results indicated that the M. reevesi diverged in the recent time after the glacial period and simultaneously as its habitat's expanded in the Middle Holocene. Furthermore, the past and future climate fluctuation triggered the change of Chinese muntjac spatial distribution, which has great influence on the Chinese muntjac's population demographic history.
RESUMO
During a terrestrial vertebrate survey of the Dabie Mountains in Anhui Province, eastern China, we collected four Asian shrew mole specimens (hereafter, shrew moles). Based on published literature and comparison with previously collected materials, the four specimens were similar to shrew moles from the mountains of Southwest China; however, no species in this group has been previously recorded from the Dabie Mountains. The genetic and morphological characteristics of the specimens were analyzed, based upon which a new species of shrew mole is described, named Uropsilus dabieshanensis sp. nov.
