Differences in preference for species-specific female calls between acoustically experienced and acoustically naive maleRibautodelphax planthoppers (Homoptera: Delphacidae)

Males of the planthopper Ribautodelphax imitanswere exposed to playbacks of either conspecific or heterospecific (R. imitantoides)female calls during their development from egg to adult, and thereafter these, as well as naive males,were offered a two- way choice between these calls. Males of all treatments approached the conspecific call significantly more often. However, males primed by the conspecific call chose the heterospecific call almost four times less often than did males primed by heterospecific calls or naive males, thus showing that the preference for conspecific calls can be partly learned. Males primed by heterospecific calls performed very similarly to completely naive males, suggesting that the signal recognition mechanism is much less sensitive to heterospecific calls than to conspecific calls. Males with experience of the conspecific female call tended to take more time to reach the call source in the trials than both other types of males. The evolutionary implications of these findings are discussed.     

A study of Choughs'' vocal repertoire: variability related to individuals, sexes and ages

Summary The calls uttered by Choughs (Pyrrhocorax pyrrhocorax) on Islay (S-W Scotland) were recorded during the breeding season. We analysed the vocal repertoire and the degree of call variation, among and within individuals. Eight structurally different calls were identified in Choughs' vocal repertoire. Significant differences in temporal and frequency variables of calls were found between fledglings and adults, whereas females' and males' calls turned out to differ only in two parameters of the commonest call type (chwee-ow). Despite sex-related differences in this call, partners appeared to utter similar versions of it, which suggests that mate vocal mimicry might occur. A certain degree of individuality, i.e. a greater among than within individuals variability, was found in three call types, but the reverse was found in the commonest call of the species. Accordingly, we hypothesise that this call might promote effective species recognition, whereas the other call types would be involved in individual recognition.

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Das stimmliche Repertoire der Alpenkrähe: individuelle, geschlechtliche und altersabhängige Variabilität

Zusammenfassung Während der Brutzeit 1996 wurde das Rufinventar von Alpenkrähen (Pyrrhocorax pyrrhocorax) auf der Insel Islay (SW Schottland) aufgenommen und hinsichtlich individueller Variation und Unterschieden zwischen verschiedenen Individuen analysiert. Acht grundsätzlich verschiedene Rufe wurden unterschieden. Signifikante Unterschiede bestanden zwischen flüggen Jungvögeln und Altvögeln in der Ruffrequenz und der zeitlichen Abfolge der Rufe. Männchen und Weibchen unterschieden sich dagegen nur geringfügig in dem am häufigsten vorgetragenen Ruf. Ungeachtet dieser geringen sexuellen Unterschiede riefen Paarpartner sehr ähnlich, was als Hinweise auf eine Stimmenmimikrie angesehen wird. In drei Ruftypen fand sich eine gewisse Individualität mit größerer Variablität zwischen verschiedenen als innerhalb eines Rufers, wogegen der häufigste Ruf von allen Individuen sehr ähnlich vorgetragen wurde. Es wird geschlossen, daß dieser Ruf der Arterkennung dient, die anderen dagegen mehr der individuellen Erkennung.

     

Sexual Selection in Insect Choruses: Influences of Call Power and Relative Timing

Female preference for male song in acoustic insects is primarily influenced by call energy or power, but nonenergy features such as the relative timing of male calls may also be critical in preference. Preferences for leading calls, which may be a type of precedence effect, are an example of the latter factor. In various species, females preferentially orient toward the leading of two or more spatially separated calls presented in controlled playback experiments, however the importance of this effect on mate choice in actual choruses and natural populations is generally unknown. We studied the determinants of mate choice in reenacted choruses of the tettigoniid Ephippiger ephippiger, a species in which females prefer leading calls in two-choice experiments, and neighboring males adjust their relative call timing in a way that reduces the incidence of following calls. We found that mate choice, as indicated by the pattern of female settlement, largely reflects call rate and call constancy. But, we also found suggestions that female choice is influenced by the acoustic neighborhood in which a male sings, males in neighborhoods with more overall singing being preferred, and by a males incidence of leading calls relative to his neighbors. Although statistically inconclusive owing to few relevant samples, we note that the level of preference for leading calls observed in E. ephippiger choruses is comparable to that found in controlled playback experiments.     

Patterns of molecular evolution in dioecious and non‐dioecious Silene

Dioecy (i.e. having separate sexes) is a rather rare breeding system in flowering plants. Such rareness may result from a high probability of extinction in dioecious species because of less efficient dispersal and the costs of sexual selection, which are expected to harm dioecious species' survival on the long term. These handicaps should decrease the effective population size () of dioecious species, which in turn should reduce the efficacy of selection. Moreover, sexual selection in dioecious species is expected to specifically affect some genes, which will evolve under positive selection. The relative contribution of these effects is currently unknown and we tried to disentangle them by comparing sequence evolution between dioecious and non‐dioecious species in the Silene genus (Caryophyllaceae), where dioecy has evolved at least twice. For the dioecious species in the section Melandrium, where dioecy is the oldest, we found a global reduction of purifying selection, while on some, male‐biased genes, positive selection was found. For section Otites, where dioecy evolved more recently, we found no significant differences between dioecious and non‐dioecious species. Our results are consistent with the view that dioecy is an evolutionary dead end in flowering plants, although other scenarios for explaining reduced cannot be ruled out. Our results also show that contrasting forces act on the genomes of dioecious plants, and suggest that some time is required before the genome of such plants bears the footprints of dioecy.     

Effects of male call pitch on female behaviour and mate fidelity in little penguins

Playback experiments with two loudspeakers were conducted to examine how female little penguins (Eudyptula minor) respond to bray calls of males that varied in (1) dominant frequency (low vs high) and (2) familiarity (current partner vs stranger). In the first experiment, there was no statistically significant difference in the number of approaching females between low- and high-pitch calls. In the second experiment, using calls from the current partner and a stranger, females were more likely to approach closer to their own partners calls, regardless of the pitch of the strangers call. We conclude that female little penguins may recognize their partners calls (or at least familiar male calls) and appear to maintain mate fidelity even when larger, potentially more successful, strangers are on offer.     

Acoustic characteristics of eight common Chinese anurans during the breeding season

Anurans often have species-specific vocalizations. To quantify and compare the characteristics of anuran calls in Gutianshan National Nature Reserve, Zhejiang Province, we recorded the advertisement calls of eight species belonging to four families (Ranidae, Microhylidae, Megophryidae and Bufonidae) from June to September 2012 using Sony ICD-FX8 IC recorders. All recordings were analyzed using the "Praat" software. Five acoustics parameters were measured, including temporal traits (call duration, number of notes or pulse number/call) and spectral traits (fundamental frequency, the first three formants and dominant frequency). The characteristic parameters of Microhyla ornate and Fejervarya limnocharis calls were different as were the calls of some populations of the same species recorded in different regions. The advertisement calls of the eight species were specific. Our study has provided a useful reference for identifying the calls of some common Chinese anurans.     

Two‐component calls in short‐finned pilot whales (Globicephala macrorhynchus)

Short‐finned pilot whales (Globicephala macrorhynchus) have complex vocal repertoires that include calls with two time‐frequency contours known as two‐component calls. We attached digital acoustic recording tags (DTAGs) to 23 short‐finned pilot whales off Cape Hatteras, North Carolina, and assessed the similarity of two‐component calls within and among tags. Two‐component calls made up <3% of the total number of calls on 19 of the 23 tag records. For the remaining four tags, two‐component calls comprised 9%, 23%, 24%, and 57% of the total calls recorded. Measurements of six acoustic parameters for both the low and high frequency components of all two‐component calls from the five tags were compared using a generalized linear model. There were significant differences in the acoustic parameters of two‐component calls between tags, verifying that acoustic parameters were more similar for two‐component calls recorded on the same tag than for calls between tags. Spectrograms of all two‐component calls from the five tags were visually graded and independently categorized by five observers. A test of inter‐rater reliability showed substantial agreement, suggesting that each tag contained a predominant two‐component call type that was not shared across tags.     

Infant distress vocalizations in the Southern African Lesser Bushbaby (Galago moholi)

Infant lesser bushbabies are typically able, from the earliest age, to utter distress vocalizations which appear to have major adaptive significance. Distress vocalizations of infant G. moholi were analyzed by means of a digital storage oscilloscope. Three kinds of sound analyses were carried out: analysis of the sound wave signal, sequential spectrum analysis, and fast Fourier transformation. We emphasize analysis of the frequency spectrum. Three distress calls were identified-the click call, the crackle, and the chirp-which we report for the first time. Click calls were typically composed of short, high-pitched pulses (clicks) uttered in fast, repetitive sequences with a broad band frequency spectrum containing frequencies up to 60 kHz. These acoustic characteristics appear to be particularly well suited for accurate spatial localization of the sound source. The main function of the click call is apparently to alert and to guide the mother to a lost or endangered infant. These basic acoustic characteristics-related to sound localization-are shared to some extent, with the other two distress calls. However, the three calls appear to represent different degrees of distress, with the click call being the basic, call, the crackle corresponding to a greater degree of distress, and the chirp possibly signaling extreme distress such as physical pain.We prefer the specific name,Galago moholi (A. Smith, 1836), for the southern African lesser bushbaby [instead ofGalago senegalensis moholi (A. Smith, 1839)] according to the new classification proposed by Olson (1979, 1986) and Nashet al. (1989).     

Decreased levels of alpha‐synuclein in cerebrospinal fluid of patients with clinically isolated syndrome and multiple sclerosis

Cerebrospinal fluid (CSF) α‐synuclein (ASYN) levels are emerging as a possible biomarker in a number of neurodegenerative conditions; however, there has been little study of such levels in demyelinating conditions with neurodegeneration such as multiple sclerosis (MS). In this study, we aimed to assess CSF ASYN levels in MS spectrum [clinically isolated syndrome (CIS) and MS] patients and compare them to those obtained in control subjects with benign neurological conditions (BNC). We used a recently developed, ultra‐sensitive sandwich enzyme‐linked immunosorbent assay to measure and compare CSF ASYN levels in three categories of subjects: BNC (n = 38), CIS (n = 36) and MS [Relapsing Remitting (RRMS, n = 22) and Primary Progressive (PPMS, n = 15)]. We also performed secondary analyses, including relationship of CSF ASYN levels to aging, gender, presence of CSF oligoclonal bands (OB) and gadolinium (Gd)‐enhancing demyelinating lesions on T1‐weighted MRIs. CSF ASYN levels were found to be significantly lower in the CIS (78.2 ± 7.5 pg/mL), RRMS (76.8 ± 5.1 pg/mL), and PPMS (76.3 ± 6.7 pg/mL) groups compared to the BNC (125.7 ± 13.6 pg/mL) group. Secondary analyses did not reveal additional correlations. Our results suggest that in a cohort of CIS and MS patients, CSF ASYN levels are decreased, thus providing another possible link between MS and neurodegeneration. Future studies will need to be performed to confirm and extend these findings, to lead to a fuller understanding of the possible biological link between ASYN and MS.

     

Geschlechtsspezifische Stimmentwicklung bei der Brandente (Tadorna tadorna)

Summary The juvenile call repertoire in both sexes consists of 7 calls which were put in 4 different categories. In the early stages, male and female development follows the same pattern: call pitch rises over around 5 days, then lowers continuously. The lowest pitch is reached at the age of 60 to 70 days. In both sexes the pure tonal elements of the duckling calls start to gain ill defined noise structures (breaking of the voice) in which the original element and its harmonics are still recognizable. All female calls have their direct structural equivalents in the duckling repertoire. In males breaking of the voice only occurs as a rudiment leading into a mute phase. Shortly later, tonal elements similar to those of the duckling reappear. Pitch rises again and calls are altered by emphasizing higher harmonics. In a second developmental process apparently new components (yu) are inserted between modified juvenile elements (ti) to form new calls (tyu-tyu). By high rate element repetition two different types of trills are created. Whereas the female repertoire is directly derived from the duckling calls, male vocalizations undergo secondary developmental changes.     

Geographic variation in advertisement calls of a Microhylid frog – testing the role of drift and ecology

Acoustic signals for mating are important traits that could drive population differentiation and speciation. Ecology may play a role in acoustic divergence through direct selection (e.g., local adaptation to abiotic environment), constraint of correlated traits (e.g., acoustic traits linked to another trait under selection), and/or interspecific competition (e.g., character displacement). However, genetic drift alone can also drive acoustic divergence. It is not always easy to differentiate the role of ecology versus drift in acoustic divergence. In this study, we tested the role of ecology and drift in shaping geographic variation in the advertisement calls of Microhyla fissipes. We examined three predictions based on ecological processes: (1) the correlation between temperature and call properties across M. fissipes populations; (2) the correlation between call properties and body size across M. fissipes populations; and (3) reproductive character displacement (RCD) in call properties between M. fissipes populations that are sympatric with and allopatric to a congener M. heymonsi. To test genetic drift, we examined correlations among call divergence, geographic distance, and genetic distance across M. fissipes populations. We recorded the advertisement calls from 11 populations of M. fissipes in Taiwan, five of which are sympatrically distributed with M. heymonsi. We found geographic variation in both temporal and spectral properties of the advertisement calls of M. fissipes. However, the call properties were not correlated with local temperature or the callers' body size. Furthermore, we did not detect RCD. By contrast, call divergence, geographic distance, and genetic distance between M. fissipes populations were all positively correlated. The comparisons between phenotypic Q_st (P_st) and F_st values did not show significant differences, suggesting a role of drift. We concluded that genetic drift, rather than ecological processes, is the more likely driver for the geographic variation in the advertisement calls of M. fissipes.     

Genotyping of Single Nucleotide Polymorphisms in DNA Isolated from Serum Using Sequenom MassARRAY Technology

Background

Large epidemiologic studies have the potential to make valuable contributions to the assessment of gene-environment interactions because they prospectively collected detailed exposure data. Some of these studies, however, have only serum or plasma samples as a low quantity source of DNA.

Methods

We examined whether DNA isolated from serum can be used to reliably and accurately genotype single nucleotide polymorphisms (SNPs) using Sequenom multiplex SNP genotyping technology. We genotyped 81 SNPs using samples from 158 participants in the NYU Women’s Health Study. Each participant had DNA from serum and at least one paired DNA sample isolated from a high quality source of DNA, i.e. clots and/or cell precipitates, for comparison.

Results

We observed that 60 of the 81 SNPs (74%) had high call frequencies (≥95%) using DNA from serum, only slightly lower than the 85% of SNPs with high call frequencies in DNA from clots or cell precipitates. Of the 57 SNPs with high call frequencies for serum, clot, and cell precipitate DNA, 54 (95%) had highly concordant (>98%) genotype calls across all three sample types. High purity was not a critical factor to successful genotyping.

Conclusions

Our results suggest that this multiplex SNP genotyping method can be used reliably on DNA from serum in large-scale epidemiologic studies.     

Sensory ecology of predator–prey interactions: responses of the AN2 interneuron in the field cricket, <Emphasis Type="Italic">Teleogryllus oceanicus</Emphasis> to the echolocation calls of sympatric bats

We observed the responses of the AN2 interneuron in the Pacific field cricket, Teleogryllus oceanicus, a cell implicated in eliciting avoidance flight away from bats, to acoustic stimuli representing the echolocation calls of bats as well as field recordings of search and gleaning attack calls of six species of insectivorous sympatric bats (West Australia, Australia: Tadarida australis, Chalinolobus goudii, Nyctophilus geoffroyi; Queensland, Australia: Vespadelus pumilus, Myotis adversus; Kauai, Hawaii: Lasiurus cinereus). The broad frequency sensitivity of the AN2 cell indicates that T. oceanicus has evolved to detect a wide range of echolocation call frequencies. The reduced sensitivity of this cell at frequencies higher than 70 kHz suggests that some bats (e.g., the gleaning species, N. geoffroyi) may circumvent this insects auditory defences by using frequency-mismatched (allotonic) calls. The calls of the freetail bat, T. australis evoked the strongest response in the AN2 cell but, ironically, this may allow this bat to prey upon T. oceanicus as previous studies report that under certain conditions, flying crickets exhibit ambiguous directional responses towards frequencies similar to those emitted by this bat. Short duration calls (1–2 ms) are sufficient to evoke AN2 responses with instantaneous spike periods capable of causing defensive flight behaviours; most bats tested emit calls of durations greater than this. The short calls of N. geoffroyi produced during gleaning attacks may reduce this species acoustic conspicuousness to this cricket.     

Acoustic,auditory, and morphological divergence in three species of neotropical frog

Advertisement calls, auditory tuning, and larynx and ear morphology were examined in 3 neotropical frogs, Hyla microcephala, H. phlebodes and H. ebraccata, H. microcephala has the highest call dominant frequency (6.068 kHz) and basilar papilla tuning (5.36 kHz). H. phlebodes and H. ebraccata calls have lower dominant frequencies (3.832 and 3.197 kHz respectively) and basilar papilla tuning (2.79 and 2.56 kHz). The primary call notes of H. ebraccata are longer (181.6 ms) than those of H. microcephala (95.5 ms) or H. phlebodes (87.3 ms). Morphometric analysis suggests that temporal call features differ as laryngeal musculature changes, in the process changing the overall size of the larynx. The spectral aspects of the call differ as head size, and hence the size of its resonating and radiating structures, changes, modifying the dominant frequency of calls by accentuating their higher harmonics when head size decreases. Decreasing head size decreases the size of the middle and inner ear chambers, changing the mechanical tuning of the ear in the same direction as the change in dominant frequency. These changes result in divergent spectral-temporal characteristics of both the sending and receiving portions of the acoustic communication system underlying social behavior in these frogs.Abbreviations AP amphibian papilla - BEF best excitatory frequency - BP basilar papilla - dB SPL decibels sound pressure level re:20 N/m²     

The Arabidopsis root stele transporter NPF2.3 contributes to nitrate translocation to shoots under salt stress

In most plants, constitutes the major source of nitrogen, and its assimilation into amino acids is mainly achieved in shoots. Furthermore, recent reports have revealed that reduction of translocation from roots to shoots is involved in plant acclimation to abiotic stress. NPF2.3, a member of the NAXT (nitrate excretion transporter) sub‐group of the NRT1/PTR family (NPF) from Arabidopsis, is expressed in root pericycle cells, where it is targeted to the plasma membrane. Transport assays using NPF2.3‐enriched Lactococcus lactis membranes showed that this protein is endowed with transport activity, displaying a strong selectivity for against Cl^?. In response to salt stress, translocation to shoots is reduced, at least partly because expression of the root stele transporter gene NPF7.3 is decreased. In contrast, NPF2.3 expression was maintained under these conditions. A loss‐of‐function mutation in NPF2.3 resulted in decreased root‐to‐shoot translocation and reduced shoot content in plants grown under salt stress. Also, the mutant displayed impaired shoot biomass production when plants were grown under mild salt stress. These mutant phenotypes were dependent on the presence of Na⁺ in the external medium. Our data indicate that NPF2.3 is a constitutively expressed transporter whose contribution to translocation to the shoots is quantitatively and physiologically significant under salinity.     

A comparison of individual distinctiveness in three vocalizations of the dwarf mongoose (Helogale parvula)

Individual specificity can be found in the vocalizations of many avian and mammalian species. However, it is often difficult to determine whether these vocal cues to identity rise from “unselected” individual differences in vocal morphology or whether they have been accentuated by selection for the purposes of advertising caller identity. By comparing the level of acoustic individuality of different vocalizations within the repertoire of a single species, it is possible to ascertain whether selection for individual recognition has modified the vocal cues to identity in particular contexts. We used discriminant function analyses to determine the level of accuracy with which calls could be classified to the correct individual caller, for three dwarf mongoose (Helogale parvula) vocalizations: contact, snake, and isolation calls. These calls were similar in acoustic structure but divergent in context and function. We found that all three call types showed individual specificity but levels varied with call type (increasing from snake to contact to isolation call). The individual distinctiveness of each call type appeared to be directly related to the degree of benefit that signalers were likely to accrue from advertising their identity within that call context. We conclude that dwarf mongoose signalers have undergone selection to facilitate vocal individual recognition, particularly in relation to the species’ isolation call.     

Underwater acoustic behavior of bearded seals (Erignathus barbatus) in the northeastern Chukchi Sea, 2007–2010

Bearded seal (Erignathus barbatus) calls were recorded using autonomous passive acoustic recorders deployed in the northeastern Chukchi Sea between October 2007 and October 2010. Continuous acoustic data were acquired during summer (August to mid‐October), and overwinter data (mid‐October through July) were acquired on a duty cycle of 40/48 min every 4 h. We investigated the spatio‐temporal distribution and acoustic behavior of vocalizing bearded seals in this multiyear data set. Peaks in calling occurred in spring, coinciding with the mating period, and calls stopped abruptly in late June/early July. Fewer calls were detected in summer, and the vocal presence of seals increased with the formation of pack ice in winter. Vocal activity was higher at night than during the day, with a peak around 0400 (AKST). Monthly patterns in proportional use of each call type and call duration were examined for the first time. The proportion and duration of AL1(T) and AL2(T) call types increased during the mating period, suggesting that males advertise their breeding condition by producing those specific longer trills. The observed seasonal and diel trends were consistent between years. These results improve our understanding of occurrence and acoustic behavior of bearded seals across the northeastern Chukchi Sea.     

Die akustische Unterscheidung von Steinkauzm?nnchen und -weibchen(Athene noctua)

Summary The primary call Guhk of male Little Owls functions in pair formation and territory defense. According to literature this call is uttered exclusively by the male. A similar call given by female Little Owls has been recorded on tape; both calls were analysed by means of a sound spectrograph.In comparison to the call of the female the male's call lasted longer, the pitch being higher in the main part. The call was uttered louder and clearer by the male than by the female. During the main time of courtship the male repeated the Guhk-call often monotonously for several minutes, whereas spacing between the notes was irregular and the number of calls given in a group varied only between three and five, or the notes occured singly when the call was uttered by the female. Because of these differences it should be possible to distinguish male and female Little Owls by their vocalizations. This can be important for census work.