Bird song is used for mate attraction and is important for establishing reproductive isolation. Current research highlights performance constraints on song production that may be influenced by variation in bill morpho...Bird song is used for mate attraction and is important for establishing reproductive isolation. Current research highlights performance constraints on song production that may be influenced by variation in bill morphology. Darwin＇s finches are a model system for studying the relationship between morphology and song performance, with previous studies suggesting that lower vocal performance is correlated with larger bill size. Here, we tested for a relationship between bill morphology and vocal performance in Darwin＇s Small Tree Finch （Camarhynchus parvulus） on Floreana Island. We found no evidence of a correlation between bill morphology and vocal performance. This finding is in agreement with prior study of the Small Tree Finch, but contrasts a greater body of work addressing song in Darwin＇s Finches. We discussed our findings in the context of ecological divergence, and ecological variation across species.展开更多
Over-shadowed by eye-catching vocal and visual signals, chemical communication has long been overlooked in birds. This study aimed at exploring whether volatile composition of the uropygial gland secretion （UGS） of ...Over-shadowed by eye-catching vocal and visual signals, chemical communication has long been overlooked in birds. This study aimed at exploring whether volatile composition of the uropygial gland secretion （UGS） of birds was associated with the information about sex, individual and species. By using dichloromethane extraction and gas chromatography-mass spectrometry （GC-MS）, we analyzed the UGS volatiles of domesticated Bengalese finches （ Lonchura striata, Estrildiea） which is also known as white-rumped munias. We characterized 16 volatile molecules from the UGS, including eight n-alkanols, five diesters, an ester, an aldehyde and a fatty acid, and quantified them in terms of GC peak area percentages （relative abundances） . Among these compounds, hexadecanol and octadecanol were major components in both sexes. The former was richer in males than in females and the latter richer in females than in males, suggesting that they might be male and female pheromone candidates, respectively. The high inter-individual variations, in relative abundance, of the UGS volatiles implied that these compounds might carry information about individuality. The similarity between GC profiles of the UGS and wing feather from same individuals indicates that the birds might preen the secretion to their feathers to transmit chemical cues. Additionally, by comparing with three sympatric passerine species, i. e., zebra finches Taeniopygia guttata, yellow-bowed buntings Emberiza chrysophrys and rooks Corvus frugilegus, we found that the composition of C13 - C18 alkanols in the UGS might code for information about species. Our study also showed that quantitative differences （degree） of same UGS volatiles might be the key for the Bengalese finch to code for information about sex and individuality whereas both the kind and degree of UGS constituents could be utilized to code for information about species [ Current Zoology 55 （5）： 357-365, 2009].展开更多
BACKGROUND： Electrophysiological studies using brain slices have revealed that the developmental regulation of synaptic plasticity in vocal learning pathway is essential for song learning in zebra finches. Publicatio...BACKGROUND： Electrophysiological studies using brain slices have revealed that the developmental regulation of synaptic plasticity in vocal learning pathway is essential for song learning in zebra finches. Publications reporting in vivo electrophysiological investigation are scarce. Many aspects of neural mechanisms underlying song learning and production still remain uncertain. OBJECTIVE： To observe the efficacy of paired pulses and the effect on synaptic transmission induced by low-frequency stimulations, high-frequency stimulations, and theta-burst stimulations. DESIGN, TIME AND SETTING： A comparative observation. The experiment was conducted from October 2006 to October 2007 in the Neurophysiology Laboratory of South-China Normal University. MATERIALS： Twenty-four adult male zebra finches were supplied by the Department of Animal Experiment of College of Life Sciences, South China Normal University. A SEN-7203 stimulator （NIHON KOHDEN）, as well as a DSJ-731WF microelectrode amplifier and DSJ-F amplifier （provided by South-China Normal University）, were used to stimulate and record, respectively. METHODS： Animals were randomly divided into low-frequency, high-frequency, and theta-burst frequency stimulation groups. After recording evoked potentials, an input-output curve was evaluated. Subsequently, the efficacy of paired pulses with different stimulus intensity （1/3, 1/2, 2/3, or 3/4 of the value that induced the largest synaptic response）, as well as interpulse intervals （50, 75, and 100 ms）, was measured in each group. The test stimulus intensity was set to a level that evoked 1/2 or 1/3 amplitude of the maximum response. MAIN OUTCOME MEASURES： Changes in amplitude, slope, and area of evoked potentials elicited by different stimulus patterns. RESULTS： （1） Efficacy of paired pulses： there was significant paired-pulse facilitation in the high vocal center and robust nucleus of the arcopallium （HVC-RA） synapse. Efficacy decreased when paired-pulse intervals or stimulus intensities were increased. （2） Low-frequency stimulations at 1 Hz had a negligible effect on efficacy of synaptic transmission, while 5 Hz depressed synaptic transmission for only 5 minutes. （3） High-frequency stimulations at 50 Hz or 100 Hz induced synaptic depression that lasted for up to 30 minutes. （4） Theta-burst stimulation depressed synaptic transmission efficiency significantly for about 10 minutes. However, in contrast to low-frequency or high-frequency stimulations, theta-burst stimulations also induced slight potentiation of synaptic transmission for up to 60 minutes following depression phase, although the slope or area did not change. CONCLUSION： Paired pulses induced a remarkable efficacy of paired pulses in the high vocal center and robust nucleus of the arcopallium pathway. Low-frequency, high-frequency, or theta-burst frequency stimulation did not induce long-lasting changes in synaptic transmission.展开更多
BACKGROUND： Electrophysiological properties of the song nucleus have been revealed using conventional techniques, such as intracellular and extracellular recording. Research concerning the neuronal activation propert...BACKGROUND： Electrophysiological properties of the song nucleus have been revealed using conventional techniques, such as intracellular and extracellular recording. Research concerning the neuronal activation properties and regulations of the song system at the cellular and ion channel level may help reveal the neural mechanism of song learning. OBJECTIVE： To perform whole-cell recording of robust nucleus of the arcopallium （RA） neurons in brain slices from adult zebra finches （Taeniopygia guttata） and observe the action potential, sodium/potassium current and the spontaneous postsynaptic current of RA neurons. DESIGN, TIME AND SETTING： Self-controlled, neuroelectrophysiological experiment. The study was performed at the Neurophysiology Laboratory of South China Normal University from April to September 2008. MATERIALS： Flaming/Brown puller P-97 was purchased from Sutter Ins, USA; Axopatch 700B amplifier and Digidata 1332A converter were purchased from Axon Instrument, USA; pClamp software was provided by Axon Instrument, USA. METHODS： RA neurons were acutely isolated from 24 healthy male zebra finches. The action potential, voltage-gate sodium/potassium current and spontaneous postsynaptic current were recorded by whole-cell recording technology. Data were analyzed by pClamp software. MAIN OUTCOME MEASURES： The amplitude and frequency of the action potential, and the amplitude of the voltage-dependent and spontaneous postsynaptic currents, were measured. RESULTS： （1） Testing of action potential： Cells exhibited a stable current-voltage relationship following a series of hyperpolarization stepped currents, and an action potential was triggered by the spike threshold. All the recorded cells displayed repetitive firing following depolarizing current injection, with a frequency beyond 100 Hz. （2） Testing of voltage-gate currents： The inward and outward whole-cell currents were observed after a series of depolarizing voltage steps. The inward current disappeared following the application of tetrodotoxin and the outward current was significantly inhibited by application of 4-aminopyfidione and tetraethylammonium chloride. （3） Testing of spontaneous postsynaptic current： The majority of recorded cells exhibited an inward synaptic current when the membrane potential was maintained at -60 mV, with some cells exhibiting a robustly outward current when the membrane potential was maintained at -30 mV. Tetrodotoxin was unable to affect the spontaneous postsynaptic current. Following application of bicuculline [y-aminobutyric acid （A） receptor antagonist] and high concentration kynurenic acid （ionotropic glutamate receptor antagonist）, the inward and outward currents were completely inhibited. CONCLUSION： Under these experimental conditions, the action potential, sodium/potassium current and spontaneous postsynaptic current were recorded successfully in RA neurons. This indicates that the cells preserved relatively intact synaptic connections and normal physiological activity, which is required for investigating ion channels. The inward and outward whole-cell currents were sodium and potassium currents, respectively. The postsynaptic y-aminobutyric acid （A） receptors and ionotropic glutamate receptors contributed to the spontaneous postsynaptic current.展开更多
Birdsong is a complex learned vocal behavior that relies on auditory experience for development. However, it appears that among different species of close-ended songbirds, there are some variations in the necessity of...Birdsong is a complex learned vocal behavior that relies on auditory experience for development. However, it appears that among different species of close-ended songbirds, there are some variations in the necessity of auditory feedback for maintaining stereotyped adult song. In zebra finches, the deterioration of adult songs following deafness depends on the birds＇ age. It is unknown whether this age effect is a general rule in other avian species as well. Therefore, we chose Bengalese finches, whose songs show more complexity and have much heavier dependency on auditory feedback than that of zebra finches, to compare the degree of song degradation after hearing loss in old （over 18 months old） and young adult birds （5 - 6 months old）. We found that both syllable sequence and syllable phonology were much less severely affected by deafening in old adults than that in young ones. Moreover, young adults almost lost their capability to sing trills over 6 months following deafening, while old birds continued to sing plenty of trills and trilled syllables after the same period of deafening. Our results suggest that age plays an important role in affecting the dependency of adult song maintenance on auditory feedback in Bengalese finches. Furthermore, the age dependency may be a general phenomenon in different species of close-ended songbirds [ Current Zoology 55 （3）： 212 - 218, 2009].展开更多
Background: Diet-derived carotenoid pigments are concentrated in the retinas of birds and serve a variety of functions, including photoprotection. In domesticated bird species(e.g., chickens and quail), retinal carote...Background: Diet-derived carotenoid pigments are concentrated in the retinas of birds and serve a variety of functions, including photoprotection. In domesticated bird species(e.g., chickens and quail), retinal carotenoid pigmentation has been shown to respond to large manipulations in light exposure and provide protection against photodamage. However, it is not known if or how wild birds respond to ecologically relevant variation in sun exposure.Methods: We manipulated the duration of natural sunlight exposure and dietary carotenoid levels in wild-caught captive House Finches(Haemorhous mexicanus), then measured carotenoid accumulation and oxidative stress in the retina.Results: We found no significant effects of sun exposure on retinal levels of carotenoids or lipid peroxidation, in replicate experiments, in winter(Jan–Mar) and spring/summer(May–June). Dietary carotenoid supplementation in the spring/summer experiment led to significantly higher retinal carotenoid levels, but did not affect lipid peroxidation. Carotenoid levels differed significantly between the winter and spring/summer experiments, with higher retinal and lower plasma carotenoid levels in birds from the later experiment.Conclusion: Our results suggest that variation in the duration of exposure to direct sunlight have limited influence on intraspecific variation in retinal carotenoid accumulation, but that accumulation may track other seasonal–environmental cues and physiological processes.展开更多
The Bengalese finch song has been widely studied for its unique features and similarity to human language. For com-putational analysis the songs must be represented in songnote sequences. An automated approach for thi...The Bengalese finch song has been widely studied for its unique features and similarity to human language. For com-putational analysis the songs must be represented in songnote sequences. An automated approach for this purpose is highly desired since manual processing makes human annotation cumbersome, and human annotation is very heu-ristic and easily lacks objectivity. In this paper, we propose a new approach for automatic detection and recognition of the songnote sequences via image processing. The proposed method is based on human recognition process to visually identify the patterns in a sonogram image. The songnotes of the Bengalese finch are dependent on the birds and similar pattern does not exist in two different birds. Considering this constraint, our experiments on real birdsong data of different Bengalese finch show high accuracy rates for automatic detection and recognition of the songnotes. These results indicate that the proposed approach is feasible and generalized for any Bengalese finch songs.展开更多
Harper Lee’s To Kill A Mockingbird has always been considered as one of the classic literary works in America.Once published,this novel won the Pulitzer Prize for Fiction and its author Harper Lee became one of the m...Harper Lee’s To Kill A Mockingbird has always been considered as one of the classic literary works in America.Once published,this novel won the Pulitzer Prize for Fiction and its author Harper Lee became one of the most popular writers.Related researches and articles by foreign and domestic scholars had been published.This paper is based on the previous studies,and discusses about the personality of Atticus Finch.The whole passage is divided into three chapters.Chapter one gives a brief introduction of Harper Lee and the background information of this novel,as well as the work’s synopsis.Chapter two analyzes the main character Atticus Finch’s personality,and presents his different characters when facing different people and in different situations.Chapter three explores Atticus Finch’s impact on people in To Kill A Mockingbird and its readers.In conclusion,by analyzing the personality of the main characters,we could have a more comprehensive view of the development of the story and a better understanding of the novel.展开更多
Nestling growth of birds can be affected by weather fluctuations.In general,it is expected that higher temper-atures favor growth by improving food availability and nestling metabolism,while rain hinders it by reducin...Nestling growth of birds can be affected by weather fluctuations.In general,it is expected that higher temper-atures favor growth by improving food availability and nestling metabolism,while rain hinders it by reducing foraging efficiency.However,most of these patterns have been described in insectivorous cavity-nesting birds in temperate forests.We tested these predictions in two neotropical grassland ground-nesting birds with contrasting nestling diets and therefore potentially different responses to weather.We measured nestlings of the Hellmayr’s Pipit(Anthus hellmayri,an insectivorous passerine)and the Grassland Yellow-Finch(Sicalis luteola,which feeds its nestlings exclusively with seeds)during three breeding seasons(2017-2020)in central-eastern Argentina.We took measurements of tarsus and body mass,modeled growth curves using nonlinear mixed-effects models,and evaluated the effects of minimum daily temperature and precipitation during the growth period and the 30 days prior to hatching.For pipits(60 nestlings from 21 nests),minimum temperatures during the growth period were positively associated with tarsus and body mass asymptotes.Also,there was a positive association between precipitation during the pre-hatching period and tarsus asymptote.Conversely,none of the weather variables analyzed had significant effects on nestling growth of finches(131 nestlings from 35 nests).Dietary contrast between species may explain the different results.Arthropod activity and abundance can be affected by weather variations within the span of a breeding season,whereas seeds may depend on conditions from previous years,making the effects harder to detect.Fledglings with reduced asymptotic size can have reduced chances of sur-vival.Hence,pipit populations could be impacted if they experience cold and dry conditions during their breeding season,which is of major relevance in the current context of climate change.展开更多
Objective To observe the sexual differences in electrophysiological properties of neurons in the robust nucleus of the arcopallium （RA） in adult zebra finches, and to provide the direct electrophysiological evidence...Objective To observe the sexual differences in electrophysiological properties of neurons in the robust nucleus of the arcopallium （RA） in adult zebra finches, and to provide the direct electrophysiological evidence for the sexual dimorphism of birdsong. Methods Whole-cell recording was used to record the spontaneous action potential firing rates from RA projection neurons in acute brain slices. Results The projection neurons of RA in male birds fired spontaneously at 10 Hz or above, while in female birds, the frequency was significantly lower, and even no firings could be detected. Conclusion There is a sexual difference in electrophysiological properties of projection neurons in RA, which may result from the difference in the levels of steroid hormones in birds.展开更多
The lesion of nucleus robustus archistriatalis (RA) has no effect on normal short calls in the bramble finch, but affects significantly the temporal and acoustic features of learned long calls.It causes the principal ...The lesion of nucleus robustus archistriatalis (RA) has no effect on normal short calls in the bramble finch, but affects significantly the temporal and acoustic features of learned long calls.It causes the principal frequency of basic sound in monotone long calls to increase 500 cents, and to lose two upper partials. The lesion of RA not only results in the increased sound length of loud-sound and shortened coda of variable-tone long calls by 13.4%-22.1% and 21.2%-24.2% on average, respectively, but also makes the frequency rising coefficient (FRC) of even order partial tone in loud-sound drop 18.5%-25.8% on an average, and the step-up rate decrease 22.7% -24.0% on an average with the increase of frequencies. These results show that the control of temporal and frequency features of learned calls by RA matches to each other. Moreover, the lesion of bilateral RA can confuse the vocal pattern, and the produced long call has the character of both the mono- and variable-tone long calls. The prelude shows rising frequency, and the loud sound is monotone sound.展开更多
On the Qinghai-Tibet Plateau,extreme environmental conditions have imposed intense selective pressure on the evolution of phenotypic traits of wild animals.To date,limited information is available on behavioral and ec...On the Qinghai-Tibet Plateau,extreme environmental conditions have imposed intense selective pressure on the evolution of phenotypic traits of wild animals.To date,limited information is available on behavioral and ecological traits concerning niche differentiation among sympatric animals on the Qinghai-Tibet Plateau,especially during winter when the environments are most severe.Here,we studied the seasonal variations in habitat occurrence,territorial behavior,and diet in two sympatric snow finches(the white-rumped snow finch,Onychostruthus taczanowskii,WRSF;and the rufous-necked snow finch,Pyrgilauda ruficollis,RNSF)to determine convergence and divergence of ecological traits in such severe climatic conditions.Our results showed that:(i)WRSF occupied rural areas as a dominant species throughout the annual cycle while RNSF occupied the rural areas in summer and then shifted to human-occupied areas in winter and spring;(ii)WRSFs exhibited robust aggressive behavior and territoriality during winter relative to RNSFs;(iii)the diets of both species varied with the season but did not vary between species except that WRSF ate significantly more seeds but RNSF consumed more starchy material derived from human food waste during winter.Therefore,the separations in the spatial niche and territoriality between WRSF and RNSF,especially in winter,may contribute to alleviating the pressure of interspecific competition,and promoting the coexistence of the two sympatric snow finches in the extreme environments on the Qinghai-Tibet Plateau.展开更多
The conservation behavior framework is useful to identify key linkages between behavior and conservation practice. We apply this framework to a novel host-parasite system on the Galapagos Islands and ask if there have...The conservation behavior framework is useful to identify key linkages between behavior and conservation practice. We apply this framework to a novel host-parasite system on the Galapagos Islands and ask if there have been changes in parasite oviposition behavior and host mortality patterns across the first decade （2004-2013） of its known association. The Dipteran parasite Philornis downsi was first discovered in Darwin＇s finch nests in 1997 and is the biggest threat to the survival of Galapagos land birds. Host mortality has increased over the past decade. In Dipterans, pupation and pupae size are determined by access to host resources. Here, we test the hypothesis that P downsi flies are laying eggs in finch nests earlier in the nestling phase to maximize larval feeding time and therefore chance of pupation success before host death. The results show fewer 1st instar larvae later in the host nesting cycle in support of earlier egg laying behavior by female flies. Between 2004 and 2013, parasite intensity increased from -28 to -48 parasites per nest, host mortality increased from -50% to -90%, and host age at death decreased from -11 to -5 days. The earlier age at host death was correlated with fewer pupae （from -50% to -20%） and smaller pupae size （-10% decrease）. Changes in parasite behavior reveal new fitness costs to both the parasite and Darwin＇s finches. These findings un- derscore the need for urgent conservation action to save Darwin＇s finches from extinction due to a novel, lethal and introduced parasite [Current Zoology 60 （4）： 542-550, 2014].展开更多
We provide a new class of interior solution of a(2+1)-dimensional anisotropic star in Finch and Skea spacetime corresponding to the BTZ black hole. We develop the model by considering the MIT bag model EOS and a parti...We provide a new class of interior solution of a(2+1)-dimensional anisotropic star in Finch and Skea spacetime corresponding to the BTZ black hole. We develop the model by considering the MIT bag model EOS and a particular ansatz for the metric function grrproposed by Finch and Skea [M.R. Finch and J.E.F. Skea, Class. Quantum.Grav. 6(1989) 467]. Our model is free from central singularity and satisfies all the physical requirements for the acceptability of the model.展开更多
Objective Motor control is encoded by neuronal activity. Small conductance Ca2＋-activated K＋ channels （SK channels） maintain the regularity and precision of firing by contributing to the afterhyperpolarization （...Objective Motor control is encoded by neuronal activity. Small conductance Ca2＋-activated K＋ channels （SK channels） maintain the regularity and precision of firing by contributing to the afterhyperpolarization （AHP） of the action potential in mammals. However, it is not clear how SK channels regulate the output of the vocal motor system in songbirds. The premotor robust nucleus of the arcopallium （RA） in the zebra finch is responsible for the output of song information. The temporal pattern of spike bursts in RA projection neurons is associated with the timing of the acoustic features of birdsong. Methods The firing properties of RA projection neurons were analyzed using patch clamp whole-cell and cell-attached recording techniques. Results SK channel blockade by apamin decreased the AHP amplitude and increased the evoked firing rate in RA projection neurons. It also caused reductions in the regularity and precision of firing. RA projection neurons displayed regular spontaneous action potentials, while apamin caused irregular spontaneous firing but had no effect on the firing rate. In the absence of synaptic inputs, RA projection neurons still had spontaneous firing, and apamin had an evident effect on the firing rate, but caused no significant change in the firing regularity, compared with apamin application in the presence of synaptic inputs. Conclusion SK channels contribute to the maintenance of firing regularity in RA projection neurons which requires synaptic activity, and consequently ensures the precision of song encoding.展开更多
Environmental stressors can negatively affect avian cognitive abilities, potentially reducing fitness, for example by altering response to predators, display to mates, or memory of locations of food. We expand on curr...Environmental stressors can negatively affect avian cognitive abilities, potentially reducing fitness, for example by altering response to predators, display to mates, or memory of locations of food. We expand on current knowledge by investigating the effects of dietary mercury, a ubiquitous en- vironmental pollutant and known neurotoxin, on avian cognition. Zebra finches Taeniopygia gut- tata were dosed for their entire lives with sub-lethal levels of mercury, at the environmentally rele- vant dose of 1.2 parts per million. In our first study, we compared the dosed birds with controls of the same age using tests of three cognitive abilities： spatial memory, inhibitory control, and color association. In the spatial memory assay, birds were tested on their ability to learn and remember the location of hidden food in their cage. The inhibitory control assay measured their ability to ig- nore visible but inaccessible food in favor of a learned behavior that provided the same reward. Finally, the color association task tested each bird＇s ability to associate a specific color with the presence of hidden food. Dietary mercury negatively affected spatial memory ability but not inhibi- tory control or color association. Our second study focused on three behavioral assays not tied to a specific skill or problem-solving： activity level, neophobia, and social dominance. Zebra finches exposed to dietary mercury throughout their lives were subordinate to, and more active than, con- trol birds. We found no evidence that mercury exposure influenced our metric of neophobia. Together, these results suggest that sub-lethal exposure to environmental mercury selectively harms neurological pathways that control different cognitive abilities, with complex effects on be- havior and fitness.展开更多
When the Chinese-language The Poison of Polygamy was translated into English,some critics identified the work as picaresque.Skeptical of this conclusion,the author of this paper broadens the field of inquiry to sugges...When the Chinese-language The Poison of Polygamy was translated into English,some critics identified the work as picaresque.Skeptical of this conclusion,the author of this paper broadens the field of inquiry to suggest classification in an emigrant sensational genre.Briefly,the first two plots of the multi-strand work unfold the adventures of Chinese emigrants travelling by sea and land to Melbourne’s Gold Mountain.Interestingly,we are also afforded a glimpse of emigrant miners’cooperation regardless of race and colour when a mine disaster occurs.The work provides sharp recognition of migrants’dilemmas,such as marriage,before tackling the bigamy issue,the gender war,the fallen lifestyle of the female protagonist and so on.As the work unfolds,further shocking tales of murders and indulgence are revealed.Unlike the picareque’s episodic style,the translated Poison of Polygamy is coherent,realistic,serious and critical,and completely lacking in both sarcasm and playfulness.To investigate the appropriateness of assigning the work to the picaresque genre,the paper compares briefly with representative Spanish picaresque works such as Lazarillo and Gusman and English canonical Moll Flanders,watching carefully for commonalities.However,The Poison of Polygamy would seem to resonate more with Braddon’s Lady Audley’s Secret,a sensational fiction which shocked the English world in the 1860s.The contexts of both novels are close,mid-Victorian and Edwardian,where the latter is a continuation of the Victorians.The author is further enlightened by research results of literary translators who advocate that a text,once translated into a target language,becomes a canon of that culture and is cherished as such by its readers-as in the case of Shakespeare being revered as a German poet when read in translation.From this experiment the paper deems that cross-lingual comparative literature is not only possible but significant and resourceful.展开更多
基金funded by Flinders University (Research Establishment Grant to SK, Overseas Field Trip Grant to RC), Conservation International and the American Bird Conservancy with awards to SK,and the Australian Federation of University Women SA with a Barbara Crase Bursary to RC
文摘Bird song is used for mate attraction and is important for establishing reproductive isolation. Current research highlights performance constraints on song production that may be influenced by variation in bill morphology. Darwin＇s finches are a model system for studying the relationship between morphology and song performance, with previous studies suggesting that lower vocal performance is correlated with larger bill size. Here, we tested for a relationship between bill morphology and vocal performance in Darwin＇s Small Tree Finch （Camarhynchus parvulus） on Floreana Island. We found no evidence of a correlation between bill morphology and vocal performance. This finding is in agreement with prior study of the Small Tree Finch, but contrasts a greater body of work addressing song in Darwin＇s Finches. We discussed our findings in the context of ecological divergence, and ecological variation across species.
基金supported by grants from Chinese NSF(No.30870297to J.X.ZNo.30370196to M.X.Z.)International Partnership Project of CAS(CXTD2005-4to L.S and J.X.Z)
文摘Over-shadowed by eye-catching vocal and visual signals, chemical communication has long been overlooked in birds. This study aimed at exploring whether volatile composition of the uropygial gland secretion （UGS） of birds was associated with the information about sex, individual and species. By using dichloromethane extraction and gas chromatography-mass spectrometry （GC-MS）, we analyzed the UGS volatiles of domesticated Bengalese finches （ Lonchura striata, Estrildiea） which is also known as white-rumped munias. We characterized 16 volatile molecules from the UGS, including eight n-alkanols, five diesters, an ester, an aldehyde and a fatty acid, and quantified them in terms of GC peak area percentages （relative abundances） . Among these compounds, hexadecanol and octadecanol were major components in both sexes. The former was richer in males than in females and the latter richer in females than in males, suggesting that they might be male and female pheromone candidates, respectively. The high inter-individual variations, in relative abundance, of the UGS volatiles implied that these compounds might carry information about individuality. The similarity between GC profiles of the UGS and wing feather from same individuals indicates that the birds might preen the secretion to their feathers to transmit chemical cues. Additionally, by comparing with three sympatric passerine species, i. e., zebra finches Taeniopygia guttata, yellow-bowed buntings Emberiza chrysophrys and rooks Corvus frugilegus, we found that the composition of C13 - C18 alkanols in the UGS might code for information about species. Our study also showed that quantitative differences （degree） of same UGS volatiles might be the key for the Bengalese finch to code for information about sex and individuality whereas both the kind and degree of UGS constituents could be utilized to code for information about species [ Current Zoology 55 （5）： 357-365, 2009].
基金the National Natural Science Foundation of China, No. 30370197,30570232
文摘BACKGROUND： Electrophysiological studies using brain slices have revealed that the developmental regulation of synaptic plasticity in vocal learning pathway is essential for song learning in zebra finches. Publications reporting in vivo electrophysiological investigation are scarce. Many aspects of neural mechanisms underlying song learning and production still remain uncertain. OBJECTIVE： To observe the efficacy of paired pulses and the effect on synaptic transmission induced by low-frequency stimulations, high-frequency stimulations, and theta-burst stimulations. DESIGN, TIME AND SETTING： A comparative observation. The experiment was conducted from October 2006 to October 2007 in the Neurophysiology Laboratory of South-China Normal University. MATERIALS： Twenty-four adult male zebra finches were supplied by the Department of Animal Experiment of College of Life Sciences, South China Normal University. A SEN-7203 stimulator （NIHON KOHDEN）, as well as a DSJ-731WF microelectrode amplifier and DSJ-F amplifier （provided by South-China Normal University）, were used to stimulate and record, respectively. METHODS： Animals were randomly divided into low-frequency, high-frequency, and theta-burst frequency stimulation groups. After recording evoked potentials, an input-output curve was evaluated. Subsequently, the efficacy of paired pulses with different stimulus intensity （1/3, 1/2, 2/3, or 3/4 of the value that induced the largest synaptic response）, as well as interpulse intervals （50, 75, and 100 ms）, was measured in each group. The test stimulus intensity was set to a level that evoked 1/2 or 1/3 amplitude of the maximum response. MAIN OUTCOME MEASURES： Changes in amplitude, slope, and area of evoked potentials elicited by different stimulus patterns. RESULTS： （1） Efficacy of paired pulses： there was significant paired-pulse facilitation in the high vocal center and robust nucleus of the arcopallium （HVC-RA） synapse. Efficacy decreased when paired-pulse intervals or stimulus intensities were increased. （2） Low-frequency stimulations at 1 Hz had a negligible effect on efficacy of synaptic transmission, while 5 Hz depressed synaptic transmission for only 5 minutes. （3） High-frequency stimulations at 50 Hz or 100 Hz induced synaptic depression that lasted for up to 30 minutes. （4） Theta-burst stimulation depressed synaptic transmission efficiency significantly for about 10 minutes. However, in contrast to low-frequency or high-frequency stimulations, theta-burst stimulations also induced slight potentiation of synaptic transmission for up to 60 minutes following depression phase, although the slope or area did not change. CONCLUSION： Paired pulses induced a remarkable efficacy of paired pulses in the high vocal center and robust nucleus of the arcopallium pathway. Low-frequency, high-frequency, or theta-burst frequency stimulation did not induce long-lasting changes in synaptic transmission.
基金the National Natural Science Foundation of China,No.30570232the Natural Science Foundation of Guangdong Province,No. 05005910Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education
文摘BACKGROUND： Electrophysiological properties of the song nucleus have been revealed using conventional techniques, such as intracellular and extracellular recording. Research concerning the neuronal activation properties and regulations of the song system at the cellular and ion channel level may help reveal the neural mechanism of song learning. OBJECTIVE： To perform whole-cell recording of robust nucleus of the arcopallium （RA） neurons in brain slices from adult zebra finches （Taeniopygia guttata） and observe the action potential, sodium/potassium current and the spontaneous postsynaptic current of RA neurons. DESIGN, TIME AND SETTING： Self-controlled, neuroelectrophysiological experiment. The study was performed at the Neurophysiology Laboratory of South China Normal University from April to September 2008. MATERIALS： Flaming/Brown puller P-97 was purchased from Sutter Ins, USA; Axopatch 700B amplifier and Digidata 1332A converter were purchased from Axon Instrument, USA; pClamp software was provided by Axon Instrument, USA. METHODS： RA neurons were acutely isolated from 24 healthy male zebra finches. The action potential, voltage-gate sodium/potassium current and spontaneous postsynaptic current were recorded by whole-cell recording technology. Data were analyzed by pClamp software. MAIN OUTCOME MEASURES： The amplitude and frequency of the action potential, and the amplitude of the voltage-dependent and spontaneous postsynaptic currents, were measured. RESULTS： （1） Testing of action potential： Cells exhibited a stable current-voltage relationship following a series of hyperpolarization stepped currents, and an action potential was triggered by the spike threshold. All the recorded cells displayed repetitive firing following depolarizing current injection, with a frequency beyond 100 Hz. （2） Testing of voltage-gate currents： The inward and outward whole-cell currents were observed after a series of depolarizing voltage steps. The inward current disappeared following the application of tetrodotoxin and the outward current was significantly inhibited by application of 4-aminopyfidione and tetraethylammonium chloride. （3） Testing of spontaneous postsynaptic current： The majority of recorded cells exhibited an inward synaptic current when the membrane potential was maintained at -60 mV, with some cells exhibiting a robustly outward current when the membrane potential was maintained at -30 mV. Tetrodotoxin was unable to affect the spontaneous postsynaptic current. Following application of bicuculline [y-aminobutyric acid （A） receptor antagonist] and high concentration kynurenic acid （ionotropic glutamate receptor antagonist）, the inward and outward currents were completely inhibited. CONCLUSION： Under these experimental conditions, the action potential, sodium/potassium current and spontaneous postsynaptic current were recorded successfully in RA neurons. This indicates that the cells preserved relatively intact synaptic connections and normal physiological activity, which is required for investigating ion channels. The inward and outward whole-cell currents were sodium and potassium currents, respectively. The postsynaptic y-aminobutyric acid （A） receptors and ionotropic glutamate receptors contributed to the spontaneous postsynaptic current.
基金supported by grants from the National Natural Science Foundation of China(No.30670685 and No.30870307 to Mingxue Zuo)
文摘Birdsong is a complex learned vocal behavior that relies on auditory experience for development. However, it appears that among different species of close-ended songbirds, there are some variations in the necessity of auditory feedback for maintaining stereotyped adult song. In zebra finches, the deterioration of adult songs following deafness depends on the birds＇ age. It is unknown whether this age effect is a general rule in other avian species as well. Therefore, we chose Bengalese finches, whose songs show more complexity and have much heavier dependency on auditory feedback than that of zebra finches, to compare the degree of song degradation after hearing loss in old （over 18 months old） and young adult birds （5 - 6 months old）. We found that both syllable sequence and syllable phonology were much less severely affected by deafening in old adults than that in young ones. Moreover, young adults almost lost their capability to sing trills over 6 months following deafening, while old birds continued to sing plenty of trills and trilled syllables after the same period of deafening. Our results suggest that age plays an important role in affecting the dependency of adult song maintenance on auditory feedback in Bengalese finches. Furthermore, the age dependency may be a general phenomenon in different species of close-ended songbirds [ Current Zoology 55 （3）： 212 - 218, 2009].
基金funded by Grants from the National Science Foundation(IOS-0910357 to MBT and KJM,0923694 to KJM)supported by fellowships from the National Science Foundation(Award#1202776)+1 种基金National Institutes of Health(T32EY013360)the McDonnell Center for Cellular and Molecular Neurobiology at Washington University,St.Louis
文摘Background: Diet-derived carotenoid pigments are concentrated in the retinas of birds and serve a variety of functions, including photoprotection. In domesticated bird species(e.g., chickens and quail), retinal carotenoid pigmentation has been shown to respond to large manipulations in light exposure and provide protection against photodamage. However, it is not known if or how wild birds respond to ecologically relevant variation in sun exposure.Methods: We manipulated the duration of natural sunlight exposure and dietary carotenoid levels in wild-caught captive House Finches(Haemorhous mexicanus), then measured carotenoid accumulation and oxidative stress in the retina.Results: We found no significant effects of sun exposure on retinal levels of carotenoids or lipid peroxidation, in replicate experiments, in winter(Jan–Mar) and spring/summer(May–June). Dietary carotenoid supplementation in the spring/summer experiment led to significantly higher retinal carotenoid levels, but did not affect lipid peroxidation. Carotenoid levels differed significantly between the winter and spring/summer experiments, with higher retinal and lower plasma carotenoid levels in birds from the later experiment.Conclusion: Our results suggest that variation in the duration of exposure to direct sunlight have limited influence on intraspecific variation in retinal carotenoid accumulation, but that accumulation may track other seasonal–environmental cues and physiological processes.
文摘The Bengalese finch song has been widely studied for its unique features and similarity to human language. For com-putational analysis the songs must be represented in songnote sequences. An automated approach for this purpose is highly desired since manual processing makes human annotation cumbersome, and human annotation is very heu-ristic and easily lacks objectivity. In this paper, we propose a new approach for automatic detection and recognition of the songnote sequences via image processing. The proposed method is based on human recognition process to visually identify the patterns in a sonogram image. The songnotes of the Bengalese finch are dependent on the birds and similar pattern does not exist in two different birds. Considering this constraint, our experiments on real birdsong data of different Bengalese finch show high accuracy rates for automatic detection and recognition of the songnotes. These results indicate that the proposed approach is feasible and generalized for any Bengalese finch songs.
文摘Harper Lee’s To Kill A Mockingbird has always been considered as one of the classic literary works in America.Once published,this novel won the Pulitzer Prize for Fiction and its author Harper Lee became one of the most popular writers.Related researches and articles by foreign and domestic scholars had been published.This paper is based on the previous studies,and discusses about the personality of Atticus Finch.The whole passage is divided into three chapters.Chapter one gives a brief introduction of Harper Lee and the background information of this novel,as well as the work’s synopsis.Chapter two analyzes the main character Atticus Finch’s personality,and presents his different characters when facing different people and in different situations.Chapter three explores Atticus Finch’s impact on people in To Kill A Mockingbird and its readers.In conclusion,by analyzing the personality of the main characters,we could have a more comprehensive view of the development of the story and a better understanding of the novel.
基金supported by Agencia Nacional de Promocion Científica y Tecnologica,Grant[PICT-2014-3347].
文摘Nestling growth of birds can be affected by weather fluctuations.In general,it is expected that higher temper-atures favor growth by improving food availability and nestling metabolism,while rain hinders it by reducing foraging efficiency.However,most of these patterns have been described in insectivorous cavity-nesting birds in temperate forests.We tested these predictions in two neotropical grassland ground-nesting birds with contrasting nestling diets and therefore potentially different responses to weather.We measured nestlings of the Hellmayr’s Pipit(Anthus hellmayri,an insectivorous passerine)and the Grassland Yellow-Finch(Sicalis luteola,which feeds its nestlings exclusively with seeds)during three breeding seasons(2017-2020)in central-eastern Argentina.We took measurements of tarsus and body mass,modeled growth curves using nonlinear mixed-effects models,and evaluated the effects of minimum daily temperature and precipitation during the growth period and the 30 days prior to hatching.For pipits(60 nestlings from 21 nests),minimum temperatures during the growth period were positively associated with tarsus and body mass asymptotes.Also,there was a positive association between precipitation during the pre-hatching period and tarsus asymptote.Conversely,none of the weather variables analyzed had significant effects on nestling growth of finches(131 nestlings from 35 nests).Dietary contrast between species may explain the different results.Arthropod activity and abundance can be affected by weather variations within the span of a breeding season,whereas seeds may depend on conditions from previous years,making the effects harder to detect.Fledglings with reduced asymptotic size can have reduced chances of sur-vival.Hence,pipit populations could be impacted if they experience cold and dry conditions during their breeding season,which is of major relevance in the current context of climate change.
基金supported by the National Natural Science Foundation of China (No. 30970363,30570232)the Natural Science Foundation of Guangdong Province, China (No. 05005910)
文摘Objective To observe the sexual differences in electrophysiological properties of neurons in the robust nucleus of the arcopallium （RA） in adult zebra finches, and to provide the direct electrophysiological evidence for the sexual dimorphism of birdsong. Methods Whole-cell recording was used to record the spontaneous action potential firing rates from RA projection neurons in acute brain slices. Results The projection neurons of RA in male birds fired spontaneously at 10 Hz or above, while in female birds, the frequency was significantly lower, and even no firings could be detected. Conclusion There is a sexual difference in electrophysiological properties of projection neurons in RA, which may result from the difference in the levels of steroid hormones in birds.
基金the National Natural Science Foundation of China (Grant No. 39570195) and Outstanding Youth Foundation of Ministry of Education of China.
文摘The lesion of nucleus robustus archistriatalis (RA) has no effect on normal short calls in the bramble finch, but affects significantly the temporal and acoustic features of learned long calls.It causes the principal frequency of basic sound in monotone long calls to increase 500 cents, and to lose two upper partials. The lesion of RA not only results in the increased sound length of loud-sound and shortened coda of variable-tone long calls by 13.4%-22.1% and 21.2%-24.2% on average, respectively, but also makes the frequency rising coefficient (FRC) of even order partial tone in loud-sound drop 18.5%-25.8% on an average, and the step-up rate decrease 22.7% -24.0% on an average with the increase of frequencies. These results show that the control of temporal and frequency features of learned calls by RA matches to each other. Moreover, the lesion of bilateral RA can confuse the vocal pattern, and the produced long call has the character of both the mono- and variable-tone long calls. The prelude shows rising frequency, and the loud sound is monotone sound.
文摘On the Qinghai-Tibet Plateau,extreme environmental conditions have imposed intense selective pressure on the evolution of phenotypic traits of wild animals.To date,limited information is available on behavioral and ecological traits concerning niche differentiation among sympatric animals on the Qinghai-Tibet Plateau,especially during winter when the environments are most severe.Here,we studied the seasonal variations in habitat occurrence,territorial behavior,and diet in two sympatric snow finches(the white-rumped snow finch,Onychostruthus taczanowskii,WRSF;and the rufous-necked snow finch,Pyrgilauda ruficollis,RNSF)to determine convergence and divergence of ecological traits in such severe climatic conditions.Our results showed that:(i)WRSF occupied rural areas as a dominant species throughout the annual cycle while RNSF occupied the rural areas in summer and then shifted to human-occupied areas in winter and spring;(ii)WRSFs exhibited robust aggressive behavior and territoriality during winter relative to RNSFs;(iii)the diets of both species varied with the season but did not vary between species except that WRSF ate significantly more seeds but RNSF consumed more starchy material derived from human food waste during winter.Therefore,the separations in the spatial niche and territoriality between WRSF and RNSF,especially in winter,may contribute to alleviating the pressure of interspecific competition,and promoting the coexistence of the two sympatric snow finches in the extreme environments on the Qinghai-Tibet Plateau.
文摘The conservation behavior framework is useful to identify key linkages between behavior and conservation practice. We apply this framework to a novel host-parasite system on the Galapagos Islands and ask if there have been changes in parasite oviposition behavior and host mortality patterns across the first decade （2004-2013） of its known association. The Dipteran parasite Philornis downsi was first discovered in Darwin＇s finch nests in 1997 and is the biggest threat to the survival of Galapagos land birds. Host mortality has increased over the past decade. In Dipterans, pupation and pupae size are determined by access to host resources. Here, we test the hypothesis that P downsi flies are laying eggs in finch nests earlier in the nestling phase to maximize larval feeding time and therefore chance of pupation success before host death. The results show fewer 1st instar larvae later in the host nesting cycle in support of earlier egg laying behavior by female flies. Between 2004 and 2013, parasite intensity increased from -28 to -48 parasites per nest, host mortality increased from -50% to -90%, and host age at death decreased from -11 to -5 days. The earlier age at host death was correlated with fewer pupae （from -50% to -20%） and smaller pupae size （-10% decrease）. Changes in parasite behavior reveal new fitness costs to both the parasite and Darwin＇s finches. These findings un- derscore the need for urgent conservation action to save Darwin＇s finches from extinction due to a novel, lethal and introduced parasite [Current Zoology 60 （4）： 542-550, 2014].
文摘We provide a new class of interior solution of a(2+1)-dimensional anisotropic star in Finch and Skea spacetime corresponding to the BTZ black hole. We develop the model by considering the MIT bag model EOS and a particular ansatz for the metric function grrproposed by Finch and Skea [M.R. Finch and J.E.F. Skea, Class. Quantum.Grav. 6(1989) 467]. Our model is free from central singularity and satisfies all the physical requirements for the acceptability of the model.
基金supported by grants from the National Natural Science Foundation of China (30970363 and 31172092)
文摘Objective Motor control is encoded by neuronal activity. Small conductance Ca2＋-activated K＋ channels （SK channels） maintain the regularity and precision of firing by contributing to the afterhyperpolarization （AHP） of the action potential in mammals. However, it is not clear how SK channels regulate the output of the vocal motor system in songbirds. The premotor robust nucleus of the arcopallium （RA） in the zebra finch is responsible for the output of song information. The temporal pattern of spike bursts in RA projection neurons is associated with the timing of the acoustic features of birdsong. Methods The firing properties of RA projection neurons were analyzed using patch clamp whole-cell and cell-attached recording techniques. Results SK channel blockade by apamin decreased the AHP amplitude and increased the evoked firing rate in RA projection neurons. It also caused reductions in the regularity and precision of firing. RA projection neurons displayed regular spontaneous action potentials, while apamin caused irregular spontaneous firing but had no effect on the firing rate. In the absence of synaptic inputs, RA projection neurons still had spontaneous firing, and apamin had an evident effect on the firing rate, but caused no significant change in the firing regularity, compared with apamin application in the presence of synaptic inputs. Conclusion SK channels contribute to the maintenance of firing regularity in RA projection neurons which requires synaptic activity, and consequently ensures the precision of song encoding.
基金This work was funded by an award from the National Science Foundation [to J.P.S. and D.A.C.] （IOS1257590} and an English-Stonehouse fellowship [to J.P.S. and A.S.F.] awarded by the College of William and Mary.
文摘Environmental stressors can negatively affect avian cognitive abilities, potentially reducing fitness, for example by altering response to predators, display to mates, or memory of locations of food. We expand on current knowledge by investigating the effects of dietary mercury, a ubiquitous en- vironmental pollutant and known neurotoxin, on avian cognition. Zebra finches Taeniopygia gut- tata were dosed for their entire lives with sub-lethal levels of mercury, at the environmentally rele- vant dose of 1.2 parts per million. In our first study, we compared the dosed birds with controls of the same age using tests of three cognitive abilities： spatial memory, inhibitory control, and color association. In the spatial memory assay, birds were tested on their ability to learn and remember the location of hidden food in their cage. The inhibitory control assay measured their ability to ig- nore visible but inaccessible food in favor of a learned behavior that provided the same reward. Finally, the color association task tested each bird＇s ability to associate a specific color with the presence of hidden food. Dietary mercury negatively affected spatial memory ability but not inhibi- tory control or color association. Our second study focused on three behavioral assays not tied to a specific skill or problem-solving： activity level, neophobia, and social dominance. Zebra finches exposed to dietary mercury throughout their lives were subordinate to, and more active than, con- trol birds. We found no evidence that mercury exposure influenced our metric of neophobia. Together, these results suggest that sub-lethal exposure to environmental mercury selectively harms neurological pathways that control different cognitive abilities, with complex effects on be- havior and fitness.
文摘When the Chinese-language The Poison of Polygamy was translated into English,some critics identified the work as picaresque.Skeptical of this conclusion,the author of this paper broadens the field of inquiry to suggest classification in an emigrant sensational genre.Briefly,the first two plots of the multi-strand work unfold the adventures of Chinese emigrants travelling by sea and land to Melbourne’s Gold Mountain.Interestingly,we are also afforded a glimpse of emigrant miners’cooperation regardless of race and colour when a mine disaster occurs.The work provides sharp recognition of migrants’dilemmas,such as marriage,before tackling the bigamy issue,the gender war,the fallen lifestyle of the female protagonist and so on.As the work unfolds,further shocking tales of murders and indulgence are revealed.Unlike the picareque’s episodic style,the translated Poison of Polygamy is coherent,realistic,serious and critical,and completely lacking in both sarcasm and playfulness.To investigate the appropriateness of assigning the work to the picaresque genre,the paper compares briefly with representative Spanish picaresque works such as Lazarillo and Gusman and English canonical Moll Flanders,watching carefully for commonalities.However,The Poison of Polygamy would seem to resonate more with Braddon’s Lady Audley’s Secret,a sensational fiction which shocked the English world in the 1860s.The contexts of both novels are close,mid-Victorian and Edwardian,where the latter is a continuation of the Victorians.The author is further enlightened by research results of literary translators who advocate that a text,once translated into a target language,becomes a canon of that culture and is cherished as such by its readers-as in the case of Shakespeare being revered as a German poet when read in translation.From this experiment the paper deems that cross-lingual comparative literature is not only possible but significant and resourceful.
