scholarly journals Description and comparison of Philippine hornbill (Bucerotidae) vocalizations

2019 ◽  
Vol 7 ◽  
Author(s):  
Shari Guerra ◽  
Juan Carlos Gonzalez ◽  
Emmanuel Francisco Rafael

The role of vocalisation for the Philippine hornbills' ecology and speciation and their implication in understanding speciation is not well understood. We described and compared recorded calls of seven hornbill taxa in captivity namely Mindanao Wrinkled hornbill (Rhabdotorrhinus leucocephalus), Rufous-headed hornbill (Rhabdotorrhinus waldeni), Luzon Rufous hornbill (Buceros hydrocorax hydrocorax), Samar Rufous hornbill (Buceros hydrocorax semigaleatus), Mindanao Rufous hornbill (Buceros hydrocorax mindanensis), Mindanao Tarictic hornbill (Penelopides affinis), Samar Tarictic hornbill (Penelopides samarensis), Visayan Tarictic hornbill (Penelopides panini) and Luzon Tarictic hornbill (Penelopides manillae), as well as comparison with the non-native Papuan hornbill (Rhyticeros plicatus). Vocalisation analysis included call duration, minimum frequency, maximum frequency, bandwidth and peak frequency. For each species in the sample, the mean and standard deviation were used to calculate the Cohen’s d statistic by using an effect size calculator. Results showed that the effect size for minimum frequency was small for P. panini vs. P. samarensis and B. hydrocorax vs. B. h. mindanensis. However, bandwidth, duration, minimum frequency, maximum frequency and peak frequency have large effect sizes for the rest of the allopatric species pairs. Hornbills' conspicuous resonating calls are sufficiently quantifiable for bioacoustic analysis and may provide new insights for their taxonomic review.

2016 ◽  
Vol 283 (1827) ◽  
pp. 20160047 ◽  
Author(s):  
Rachel M. Germain ◽  
Jason T. Weir ◽  
Benjamin Gilbert

Evolutionary biologists since Darwin have hypothesized that closely related species compete more intensely and are therefore less likely to coexist. However, recent theory posits that species diverge in two ways: either through the evolution of ‘stabilizing differences’ that promote coexistence by causing individuals to compete more strongly with conspecifics than individuals of other species, or through the evolution of ‘fitness differences’ that cause species to differ in competitive ability and lead to exclusion of the weaker competitor. We tested macroevolutionary patterns of divergence by competing pairs of annual plant species that differ in their phylogenetic relationships, and in whether they have historically occurred in the same region or different regions (sympatric versus allopatric occurrence). For sympatrically occurring species pairs, stabilizing differences rapidly increased with phylogenetic distance. However, fitness differences also increased with phylogenetic distance, resulting in coexistence outcomes that were unpredictable based on phylogenetic relationships. For allopatric species, stabilizing differences showed no trend with phylogenetic distance, whereas fitness differences increased, causing coexistence to become less likely among distant relatives. Our results illustrate the role of species' historical interactions in shaping how phylogenetic relationships structure competitive dynamics, and offer an explanation for the evolution of invasion potential of non-native species.


2004 ◽  
Vol 76 (2) ◽  
pp. 381-385 ◽  
Author(s):  
Claudia Erber ◽  
Sheila M. Simão

From July 2001 to June 2002, we recorded a total of 2h55min of Tucuxi Dolphin Sotalia fluviatilis vocalizations from Sepetiba Bay, Brazil (22º35'S-44º03'W). A total of 3350 whistles were analyzed quantitative and qualitatively and were divided into 124 types, by visual inspection of sonograms. The following parameters were measured: Initial Frequency, Final Frequency, Minimum Frequency, Maximum Frequency, Duration, Number of Inflections, Frequency at the Inflection Points, Frequency at 1/2, 1/4, and 3/4 of whistle duration, Presence of Frequency Modulation and Harmonics. Ascending type whistles (N=2719) were most common, representing 82% of the total. Dolphin behavior and average group size observed during recording influenced the whistle's quantitative and qualitative parameters. The results demonstrate the great diversity of whistles emitted and indicate a functional role of these vocalizations during the observed behaviors.


Jurnal BIOMA ◽  
2018 ◽  
Vol 13 (2) ◽  
pp. 1-9
Author(s):  
Devi Fauzia Dermi ◽  
Agung Sedayu ◽  
Ratna Komala

Crested serpent eagle (Spilornis cheela) is a bird of prey with distinctive of uniue vocal. Based on several studies mentioned that there are differences in vocalization at the level of subspecies and is often used to study the role vocalization defining the subspecies in taxonomy. This research aimed to determine the role variation of vocalization pattern in taxonomy on subspecies eagle. The research was conducted from May to September 2017 at Kamojang Eagle Conservation Center. The method used is descriptive method with continuous sampling technique. The samples was an adult eagle from three subspecies serpent eagle. The location of observation determined by purposive sampling with the provisions listening post is less than 5 meters until 30 meters. The data is collected at 7 am to 5 pm. Data were analyzed using sound analysis software. The data taken are fundamental frequency, maximum frequency (MinF), minimum frequency (MinF) and duration. Differences between subspecies were analyzed using Kruskal Wallis and Mann-Whitney U statistical test with SPSS 17.0. The result of the research is The vocalizations can be utilized in the subspecies eagle taxonomy of the species to complement the morphological data, marked by significantly different results on each parameter of vocalization between (Spilornis cheela malayensis) and (Spilornis cheela natunensis). MaxF significantly different in (Spilornis cheela malayensis) and (Spilornis cheela bido), (Spilornis cheela natunensis) and (Spilornis cheela bido).


2021 ◽  
Vol 61 ◽  
pp. e20216159
Author(s):  
Ronan de Azevedo Monteiro ◽  
Carolina Demetrio Ferreira ◽  
Gilmar Perbiche-Neves

Vocal plasticity reflects the ability of animals to vary vocalizations according to context (vocal repertoire) as well as to develop vocal convergence (vocal group signature) in the interaction of members in social groups. This feature has been largely reported for oscine, psittacine and trochilid birds, but little has been investigated in birds that present innate vocalization. The smooth-billed ani (Crotophaga ani) is a social bird that lives in groups between two and twenty individuals, and which presents innate vocalization. Here we analyzed the vocal repertoire of this species during group activities, and further investigated the existence of a vocal group signature. The study was conducted in the Southeast of Brazil between May 2017 and April 2018. Two groups of smooth-billed anis were followed, Guararema and Charqueada groups, and their vocalizations were recorded and contextualized as to the performed behavior. The vocal repertoire was analyzed for its composition, context and acoustic variables. The acoustic parameters maximum peak frequency, maximum fundamental frequency, minimum frequency, maximum frequency and duration were analyzed. To verify the vocal signature of the group, we tested whether there was variation in the acoustic parameters between the monitored groups. We recorded ten vocalizations that constituted the vocal repertoire of the Smooth-billed Ani, five of which (“Ahnee”, “Whine”, “Pre-flight”, “Flight” and “Vigil”) were issued by the two groups and five exclusive to the Charqueada group. There were significant differences in the acoustic parameters for “Flight” and “Vigil” vocalizations between the groups, suggesting vocal group signature for these sounds. We established that the Smooth-billed Ani has a diverse vocal repertoire, with variations also occurring between groups of the same population. Moreover, we found evidence of vocal group signature in vocalizations used in the context of cohesion, defense and territory maintenance.


2019 ◽  
Author(s):  
Curtis David Von Gunten ◽  
Bruce D Bartholow

A primary psychometric concern with laboratory-based inhibition tasks has been their reliability. However, a reliable measure may not be necessary or sufficient for reliably detecting effects (statistical power). The current study used a bootstrap sampling approach to systematically examine how the number of participants, the number of trials, the magnitude of an effect, and study design (between- vs. within-subject) jointly contribute to power in five commonly used inhibition tasks. The results demonstrate the shortcomings of relying solely on measurement reliability when determining the number of trials to use in an inhibition task: high internal reliability can be accompanied with low power and low reliability can be accompanied with high power. For instance, adding additional trials once sufficient reliability has been reached can result in large gains in power. The dissociation between reliability and power was particularly apparent in between-subject designs where the number of participants contributed greatly to power but little to reliability, and where the number of trials contributed greatly to reliability but only modestly (depending on the task) to power. For between-subject designs, the probability of detecting small-to-medium-sized effects with 150 participants (total) was generally less than 55%. However, effect size was positively associated with number of trials. Thus, researchers have some control over effect size and this needs to be considered when conducting power analyses using analytic methods that take such effect sizes as an argument. Results are discussed in the context of recent claims regarding the role of inhibition tasks in experimental and individual difference designs.


2012 ◽  
Vol 279 (1742) ◽  
pp. 3520-3526 ◽  
Author(s):  
Brian Tilston Smith ◽  
Amei Amei ◽  
John Klicka

Climatic and geological changes across time are presumed to have shaped the rich biodiversity of tropical regions. However, the impact climatic drying and subsequent tropical rainforest contraction had on speciation has been controversial because of inconsistent palaeoecological and genetic data. Despite the strong interest in examining the role of climatic change on speciation in the Neotropics there has been few comparative studies, particularly, those that include non-rainforest taxa. We used bird species that inhabit humid or dry habitats that dispersed across the Panamanian Isthmus to characterize temporal and spatial patterns of speciation across this barrier. Here, we show that these two assemblages of birds exhibit temporally different speciation time patterns that supports multiple cycles of speciation. Evidence for these cycles is further corroborated by the finding that both assemblages consist of ‘young’ and ‘old’ species, despite dry habitat species pairs being geographically more distant than pairs of humid habitat species. The matrix of humid and dry habitats in the tropics not only allows for the maintenance of high species richness, but additionally this study suggests that these environments may have promoted speciation. We conclude that differentially expanding and contracting distributions of dry and humid habitats was probably an important contributor to speciation in the tropics.


1994 ◽  
Vol 64 (4) ◽  
pp. 479-530 ◽  
Author(s):  
Barak Rosenshine ◽  
Carla Meister

Reciprocal teaching is an instructional procedure designed to teach students cognitive strategies that might lead to improved reading comprehension. The learning of cognitive strategies such as summarization, question generation, clarification, and prediction is supported through dialogue between teacher and students as they attempt to gain meaning from text. This article is a review of sixteen studies on reciprocal teaching, which include published studies found in journal articles and unpublished studies indexed in Dissertation Abstracts International. All the studies included in this review were quantitative in methodology. When standardized tests were used to assess comprehension, the median effect size, favoring reciprocal teaching, was .32. When experimenter-developed comprehension tests were used, the median effect size was .88. We also discuss the role of cognitive strategies in enhancing comprehension, the strategies that were most helpful, instructional approaches for teaching cognitive strategies, the quality of the dialogue during reciprocal teaching, and suggestions for future research and practice.


Author(s):  
Charles E. Taylor ◽  
Yi-Ju Wang ◽  
Martin L. Cody

We explored how Yellow Warblers (Dendroica petechia) alter their songs when encountering noise in Grand Teton National Park. Different strategies for avoiding signal masking are used by other species of birds, yet there is a lack of information of birds’ responses to higher noise levels–above 65 dB; such levels are often found in National Parks that have many visitors. In this study, we investigated singing behavior of Yellow Warblers when facing noise that ranged from 30 dB to 80 dB. In these preliminary results, we found that some features of Yellow Warblers did not appear to change with background noise level, including mean minimum frequency, bandwidth and song length. Other song features we studied did show small but statistically significant changes with higher background noise, including the peak frequency and the mean minimum frequency, both of which were significantly negatively correlated with the level of background noise. This result is different from the positive correlations that are typically observed. We speculate that this difference is due to the very high dB levels of background noise that we observed.   Featured photo bywagon16 on Flickr. https://flic.kr/p/G2W6Bk


1986 ◽  
Vol 29 (3) ◽  
pp. 400-406 ◽  
Author(s):  
M. J. Penner

For 7 patients with sensorineural hearing loss and tinnitus, pitch and loudness matches were made to the tinnitus. These matches were followed by measurement of three psychometric functions (probability of a correct response as a function of signal level) for pure tones, one in the presumed tinnitus region (i.e., at the average frequency matching the pitch of the tinnitus), one below the minimum frequency of the matches, and one above the maximum frequency of the matches. The data reveal (a) that pitch-loudness matches are usually quite variable and (b) that the slope of the psychometric function is flattest in the presumed tinnitus region. The first result is consistent with the idea that tinnitus is an unstable signal. The second result is consistent with the notion that the unstable tinnitus acts as a source of "internal" noise.


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