Lesions to the Medial Preoptic Area Affect Singing in the Male European Starling (Sturnus vulgaris)

The aromatization of testosterone (T) in the medial preoptic nucleus (POM) is known to regulate male courtship and sexual behaviors expressed prior to, and in anticipation of, copulation. Singing in male European starlings is used to attract mates prior to physical sexual contact, suggesting that the POM might be involved. The present study was performed to examine the effects of lesions targeting the POM on singing and courtship behavior in reproductively active male starlings. A significant decrease in song output and the gathering of green nest materials was observed in males with lesions to the POM compared to males with damage to brain areas outside of the POM. Lesions did not affect a male's tendency to remain near a female or to occupy a nestbox, suggesting that the effects of POM lesions were specific to courtship behaviors. Behavioral differences were not related to testis mass or volume, and GnRH immunoreactivity was observed within the hypothalamus and median eminence for each male, suggesting that the effects of POM lesions were related specifically to POM involvement in song expression rather than to a disruption of the GnRH axis. These results suggest a general role for the POM in the expression of behaviors related to sexual arousal or anticipation, including song.     

Changes in circadian LH-secretion patterns and annual gonadal cycles in the male European starling ( Sturnus vulgaris )

An analysis of the circadian and circannual patterns of luteinizing hormone (LH) secretion in male European starlings (Sturnus vulgaris) held in outdoor aviaries is presented. On the basis of six daily time points, eight calendar dates, and seven individuals per sampling unit, we present a mathematical model developed to compare the two temporal patterns of secretion, the circadian and the circannual one. The superposition of four orthonormal trigonometric base functions, plus a constant, is used to examine the daily fluctuations. The contribution of the second harmonic was not the same at each calendar date. From the subsequent regression functions, hourly estimates of LH concentration were calculated and used to construct circannual cubic splines and an LH(t,T) function over the whole year. The model features indicate strong circannual and circadian components in the data. In addition, there appear to be two daily time regions of LH secretion: morning and afternoon. In particular, the afternoon maxima occur during photorefractoriness and early gonadal development; the morning maxima at the onset of photoinduction and late gonadal development. At the peak of gonadal activity (end of April), the highest LH levels occur during the photic input phase. It appears, then, that the circadian acrophase of LH secretion in male starlings fluctuates over the annual cycle of gonadal activity in a highly predictive and biologically interpretable manner. John Dittami and Hermann Prossinger: both authors contributed equally.     

Flocking behaviour of Starlings (Sturnus vulgaris) during the day: A gradual gathering to the roost

Summary During winter, gathering of starlings is studied in 3 very different sites in western France. A positive correlation is found between the size of starling flocks and the time of the day.     

Reward Associated with Singing Behavior Correlates with Opioid-Related Gene Expression in the Medial Preoptic Nucleus in Male European Starlings

Birdsong consists of species-specific learned vocal sequences that are used primarily to attract mates and to repel competitors during the breeding season. However, many birds continue to sing at times when vocal production has no immediate or obvious impact on conspecific behavior. The mechanisms that ensure that animals produce important behaviors in contexts in which the function of these behaviors is not immediate or obvious are not known. One possibility is that animals engage in such behaviors because they are associated with pleasure. Here we examined the hypothesis that male European starlings sing outside of the breeding season in part because the act of singing in this context is facilitated and/or maintained by opioid-mediated reward. We measured song-associated reward using a conditioned place preference (CPP) test in male starlings producing fall, non-breeding season-typical song. We used quantitative real time PCR to measure expression of the enkephalin opioid precursor preproenkephalin (PENK) and mu opioid receptors (MOR) in the medial preoptic nucleus (POM; a region in which opioids are implicated in both reward and starling fall song) and additionally the song control region HVC as a control. Starlings developed a strong preference for a place that had been paired previously with the act of producing fall-typical song, indicating that fall song production was associated with a positive affective state. Both PENK and MOR mRNA expression in the POM, but not HVC, correlated positively with both individual reward state (as reflected in CPP) and undirected singing behavior. These results suggest that singing induces opioid receptor and enkephalin expression in the POM and consequent reward, and/or that opioid release in the POM induced by individual or environmental factors (e.g., the presence of food, safety of a flock or the absence of predators) induces a positive affective state which then facilitates singing behavior.     

Context-Dependent Links between Song Production and Opioid-Mediated Analgesia in Male European Starlings (Sturnus vulgaris)

Little is known about the neural mechanisms that ensure appropriate vocal behaviors within specific social contexts. Male songbirds produce spontaneous (undirected) songs as well as female-directed courtship songs. Opioid neuropeptide activity in specific brain regions is rewarding, at least in mammals, and past studies suggest that the opioid met-enkephalin in such areas is more tightly linked to undirected than female-directed song. Recent data using a song-associated place preference paradigm further suggest that production of undirected but not directed song is tightly linked to intrinsic reward. Opioids have analgesic properties. Therefore, if production of undirected song is closely linked to opioid-mediated reward, the production of undirected but not directed song should be associated with analgesia. Consistent with this prediction, in male starlings we identified a positive correlation between analgesia (decreased reactivity to a hot water bath) and undirected song (in non-breeding season condition males in affiliative flocks) but not female-directed song (in breeding season condition males presented with females). When breeding condition males were divided according to social status, a negative correlation was found in subordinate males (i.e. males that failed to acquire a nest box). These data are consistent with the hypotheses 1) that the production of undirected song is facilitated or maintained by opioids (and/or other neuromodulators that also induce analgesia) and 2) that production of female-directed song is not linked in the same way to release of the same neuromodulators. Results also demonstrate a link between analgesia and song in subordinate individuals lacking a nesting territory within the breeding season. Overall, the findings indicate that distinct neural mechanisms regulate communication in different social contexts and support the working hypothesis that undirected but not directed song is tightly linked to opioid release.     

Song diversification and complexity in canaries and seedeaters (Serinus spp.)

Bird song is a composite trait that shows great variation in syntax and phonology between taxa, which hampers the precise quantification of complexity. This should be more feasible for closely-related species that share aspects of song organization. We conducted a comparative study of song and syllable characteristics in the largest fringillid genus, Serinus (canaries and seedeaters), with two objectives: (1) to describe and quantify song complexity in the genus and (2) to assess evolutionary dynamics of song, in particular whether interspecific song diversification evolved along intraspecific lines of covariation between syllable characteristics. We document a pattern of intense, very labile evolution of song in the genus. Well-known vocal constraints such as the relationship between frequency and body size did not appear to limit this evolution, and intraspecific trade-offs between different aspects of syllable complexity did not constrain interspecific diversification. Factor analysis returned an axis of variation that comprehensively expresses song complexity in the genus, and is defined by song speed, repertoire size, and also various aspects of syllable phonology. The species body size is not related to this axis of complexity, but to a minor axis that may indicate better respiratory capacity of larger birds. We discuss the pattern of song evolution in Serinus spp. in the context of the evolutionary dynamics of sexually selected traits.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 92 , 183–194.     

The Challenge Hypothesis and Seasonal Changes in Aggression and Steroids in Male Northern Fence Lizards (Sceloporus undulatus hyacinthinus)

The challenge hypothesis has been very successful in explaining patterns of testosterone secretion in response to social stimuli in avian species. However, there have been few studies in nonavian vertebrates. We tested the challenge hypothesis in male northern fence lizards (Sceloporus undulatus hyacinthinus). These males are highly territorial and nonparental. Consequently, the challenge hypothesis predicts that plasma testosterone concentrations will be insensitive to aggressive interactions. Testosterone concentrations indeed were not significantly affected by either a short (3–15 min) simulated territorial intrusion (“challenge”) in June or a longer (50–60 min) intrusion in July. Levels of corticosterone were elevated in challenged males in the long, but not the short, intrusion. Challenged males displayed significantly more intense territorial behaviors than did unchallenged control males. The intensity of territorial behavior changed significantly across the active season and was positively related to testosterone concentrations. Thus, while testosterone concentrations do not appear to be involved in rapid changes in aggressive behavior in the fence lizard, they probably are important in larger-scale behavioral changes throughout the season.     

Effects of Courtship Song in Interspecific Crosses Among the Species of the Drosophila auraria Complex (Diptera: Drosophilidae)

The courtship behavior and the effects of courtship song in inter- and intraspecific crosses were studied in the four sympatric species of the Drosophila auraria complex: D. auraria, D. biauraria, D. subauraria, and D. triauraria. Orientation, tapping, and vibration (the repertoires of male courtship) were observed in both inter- and intraspecific crosses, suggesting that signals from heterospecific females were enough to elicit such male behaviors. The crossability tests with wingless or winged heterospecific males (tests for wing effects) revealed that winged heterospecific males copulated less than wingless ones in all four species but not all the pairwise cases. Since the crossability tests with aristaless females (deaf) or normal females showed essentially the same results as the tests for wing effects, we concluded that the sound produced by wing vibration plays an important role and that the wing movement itself is less important. These findings suggest that courtship songs are of great importance in mate discrimination and the sexual isolation between the species of this complex.     

Female Preferences for Male Song Characters in the Bush-Cricket Isophya camptoxypha (Orthoptera, Tettigonioidea)

Female preferences for two male song characters (duration of syllables [DS], syllable repetition period [SRP]) have been studied in Isophya camptoxypha, an Eastern European duetting bush-cricket. Songs with modified DS or SRP were presented to virgin females and their response songs were recorded and counted. Female preference functions were unimodal for both characters. But while in the case of SRP the obtained female preference function reached its maximum at the mean value of that character, in the case of DS females preferred modified songs with a DS slightly higher than the natural range of that character. A comparison between the obtained preference functions and the DS and SRP values measured in sympatric Isophya species (with similar song structure) suggests that the two examined characters and female preferences for them may be effective components of the species-specific mate recognition system of I. camptoxypha. Moreover DS values may also convey information about the quality of the singing male.     

Permanent and Seasonal Expressions of Sexual Dimorphisms in a Weakly Electric Fish, Mormyrus rume proboscirostris Boulenger 1898 (Mormyridae, Teleostei)

Several sexually dimorphic characters of the anal-fin complex in the mormyrid fish, Mormyrus rume proboscirostris, assist during courtship when the male envelops the female's anal fin with its own to form a common spawning pouch (anal-fin reflex). We found that developmental growth and seasonally cycling gonadal activity selectively affect their expression. The structures defining the anal fin undergo a permanent sexually dimorphic transformation at a time when ripe spermatozoa first appear in the testis of young males. However, the expression of a dorsally directed indentation of the posterior ventral body wall, affecting the dorsal margin of the anal fin, appeared to be more plastic as it correlated with the gonadosomatic index, that is, testis size. We surmised that this indentation is influenced by cyclic anabolic action on muscle involved with the execution of the anal-fin reflex.     

Seasonal phenotypic plasticity of wing melanisation in the cabbage white butterfly, Pieris rapae L. (Lepidoptera: Pieridae)

Abstract.  1. Effective thermoregulation is crucial for the fitness of small flying insects. Phenotypic plasticity of the ventral hindwing of pierid butterflies is widely recognised as adaptive for effective thermoregulation. Butterflies eclosing in cooler environments have more heavily melanised wings that absorb solar radiation, thus allowing flight under these cool conditions.
2. Many pierids also exhibit phenotypic plasticity of dorsal forewing melanisation but in this case, cooler environments reduce melanisation. It has been hypothesised that this plasticity is also adaptive because it increases solar reflection from the wing surfaces onto the body in certain basking postures.
3. The degree of seasonal variation in ventral hindwing and dorsal forewing melanisation of wild-caught Pieris rapae was quantified to determine if it shows patterns of plasticity similar to that documented for other Pieris species.
4. Male wing melanisation on both wing surfaces shows the characteristic seasonal, adaptive plasticity. However, only some dorsal forewing pattern elements of females conformed to the predictions of the hypothesis of adaptive dorsal forewing melanisation. Sexual dimorphism of wing pattern plasticity may result from, and/or affect, sexual dimorphism of behaviour and physiology of these butterflies.     

Respiratory water loss during rest and flight in European Starlings (Sturnus vulgaris)

Respiratory water loss in Starlings (Sturnus vulgaris) at rest and during flight at ambient temperatures (T(amb)) between 6 and 25 degrees C was calculated from respiratory airflow and exhaled air temperature. At rest, breathing frequency f (1.4+/-0.3 Hz) and tidal volume Vt (1.9+/-0.4 ml) were independent of T(amb), but negatively correlated with each other. Mean ventilation at rest was 156+/-28 ml min(-1) at all T(amb). Exhaled air temperature (T(exh)) at rest increased with T(amb) (T(exh) = 0.92.T(amb)+12.45). Respiratory water loss at rest averaged 0.18+/-0.09 ml h(-1) irrespective of T(amb). In flying Starlings f was 4.0+/-0.4 Hz and independent of T(amb). Vt during flight averaged 3.6+/-0.4 ml and increased with T(amb) (Vt = 0.06.T(amb)+2.83) as, correspondingly, did ventilation. T(exh) during flight increased with T(amb) (T(exh) = 0.85.T(amb)+17.29). Respiratory water loss during flight (average REWL(f) = 0.74+/-0.22 ml h(-1)) was significantly higher than at rest and increased with T(amb). Our measurements suggest that respiratory evaporation accounts for most water loss in flying Starlings and increases more than cutaneous evaporation with rising ambient temperature.     

Characterization and biological activity of the main flavonoids from Swiss Chard (Beta vulgaris subspecies cycla)

The molecular components of a phenolic fraction (P2), obtained from liquid chromatography of a Swiss Chard (Beta vulgaris subsp. cycla) extract, were identified using HPLC-ESI-MS/MS. The primary P2 components were: vitexin-2'O-rhamnoside, its demethylated form 2'-xylosylvitexin, isorhamnetin 3-gentiobioside, and rutin. P2 "in toto" and the single components were characterized for antioxidant capacity, antimitotic activity on MCF-7 human breast cancer cells and for toxicity to human lymphocytes and macrophages. P2 inhibited MCF-7 cell proliferation (IC(50) value = 9 microg/ml) without inducing apoptosis, showed no toxicity to human lymphocytes and slight toxicity to macrophages. Vitexin-2'O-rhamnoside strongly inhibited DNA synthesis in MCF-7 cells, whereas 2'-xylosylvitexin and isorhamnetin 3-gentiobioside were activators; combinations of activators and inhibitors maintained the over-all inhibitory effect.     

The biological role of octopine in the squid,Loligo vulgaris (Lamarck)

Summary The enzymatic activities of glyceraldehyde-3-phosphate dehydrogenase, octopine dehydrogenase and lactate dehydrogenase were determined fromLoligo vulgaris. Octopine dehydrogenase displays the highest activity yet recorded for this enzyme, exceeding glyceraldehyde-3-phosphate dehydrogenase sixfold and lactate dehydrogenase 365-fold (Table 1).During jet propulsion swimming octopine accumulates instead of lactate (Table 2), while phosphoarginine, the phosphagen of the squid, is depleted (Table 3).The formation of octopine is discussed in relation to anaerobic metabolism which might occur during burst activity in cephalopods.The following abbreviations are used AK arginine kinase (2.7.3.3) - GAPDH glyceraldehyde-3-phosphate dehydrogenase (1.2.1.12) - LDH L-lactate - NAD oxidoreductase (1.1.1.27) - ODH octopine - NAD oxidoreductase (1.5.1.11) - DTT dithiothreitol - dw dry weight (about 20% of the fresh weight) This investigation was generously supported by The Deutsche Forschungsgemeinschaft grant No.: (Ze 40/13)     

Seasonal and diel plasticity of song type use in individual ovenbirds (Seiurus aurocapilla)

Animal communication is an important aspect of ecology across taxa, and there is a growing area of research that examines how animals plastically adjust their signals to account for both abiotic and biotic factors. Song type use and the temporal plasticity of song have been described in many bird species, but as of yet, few studies have examined how song type use may change across both seasonal and diel timeframes, and no studies have considered individual-level variation in plasticity. Using a hierarchical framework, we examined temporal patterns of primary and flight song use in ovenbirds (Seiurus aurocapilla; N = 21 individuals). We recorded ovenbird songs (N = 99,259) with autonomous recorders over 24-hr periods once per week across a breeding season near Sault Ste. Marie, Canada. As predicted, the occurrence and frequency of both song types significantly decreased over the season and showed temporal separation over diel periods. Primary songs peaked at dawn and declined throughout the day, while flight songs peaked at dusk and night. Our results support that primary songs have multiple functions as they remained more frequent during dawn and morning across the breeding season, while flight songs likely serve an intersexual function as they decreased similarly for all diel periods as mating opportunities decreased. Individuals were consistent in how frequently they sang their primary songs, but not their flight songs, suggesting that flight songs are more plastically expressed. We highlight the importance of examining plasticity in animal communication at the individual level as we show that males significantly differed in both their song behaviours (random intercepts) and the seasonal plasticity (random slopes) in these behaviours. Integrating themes such as song type use, temporal plasticity, and individual variation will be important for examining the evolutionary mechanisms that shape animal communication systems.     

人工选择下旱地小麦生长塑性与产量形成特征

旱地小麦在进化过程中经受了自然和人工的双重选择,其中人工选择在品种驯化和改良过程中扮演了关键的角色.本文综述了人工选择下旱地小麦进化特征、生理可塑性、形态可塑性和种群属性演变等几个相对独立、但又相互联系的问题,探讨了旱地小麦适应逆境胁迫的生理生态机理,并勾画了其进化路线.在旱地小麦从二倍体到六倍体的漫长进化历程中,自然选择对小麦适应外界环境起到关键作用;随着人工选择的介入,以产量为主要目标的性状选择不断得到强化,从群体上呈现适应逆境的形态特征.人工选择下旱地小麦的水分及养分利用效率不断提升,生物量分配呈现出地下部减少、地上部增加的分配特征,对密度胁迫和高温胁迫的耐受性不断增强,但单位面积光合速率呈逐渐降低趋势.旱地小麦生产是复杂的群体过程,而非简单的个体反应.人工选择提高了旱地小麦的种群适合度和个体繁殖分配,强化了与环境的协同性,却弱化了其自然种群属性.本文还对旱地小麦的进化图进行了描绘,对气候变化下旱地小麦育种和栽培管理提出几点建议.     

Nestling body mass and nestling mortality associated with the application of the ligature method in the Spotless Starling (Sturnus unicolor)

Summary Nestling mortality and nestling mass in the Spotless StarlingSturnus unicolor is tested associated with the application of the ligature method to nestlings of 3–14 days old. Direct mortality during ligature application was 8.5%. Mortality was unaffected, because ligatured and control nestlings during the nestling period had similar mortality. Nestling mass at day 14 was negatively affected by the ligature method. Nestlings with ligatures were always lighter than control ones, these differences being more pronounced in late broods and in nests with 5 nestlings. Differences in mass between control and ligatured nestlings were observed in birds with 8 or more hours of ligature application. The possible consequences mass reduction in ligatured young on postfledging survival is discussed.

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Zusammenfassung Sterblichkeit und Körpermasse von 3–14 Tagen alten Nestjungen des Einfarbstars wurden im Zusammenhang mit der Anwendung der Halsringmethode untersucht. Die direkte Sterblichkeit während der Anwendungszeit betrug 8.5%. Die Sterblichkeit durch natürliche Faktoren wurde durch unsere Methode nicht beeinflußt, da Halsring- und Kontrollnestlinge eine ähnliche Sterblichkeit während der Nestlingszeit aufwiesen. Hingegen war die Masse bei den Halsringnestlingen am 14. Tag geringer. Nestlinge mit Halsring waren immer leichter als die der Kontrollgruppe, wobei der Unterschied bei Spätbruten und in Nestern mit 5 Nestlingen größer war. Statistisch signifikante Massenunterschiede zur Kontrollgruppe wurden bei einer Anwendungszeit des Halsringes von 8 oder mehr Stunden festgestellt. Die Folgen für das Überleben nach dem Ausfliegen werden kurz diskutiert.

     

圈养雄獐领域行为和粪便睾酮水平变化的关系

2011年8月到2012年4月间,在上海市浦东新区华夏公园獐重引入试点,采用目标取样、扫描取样和全事件记录法,对圈养条件下6只成体雄獐(Hydropotes inermis)的6种领域行为进行观察,并利用放射免疫分析法(RIA)测定雄獐粪便中的睾酮水平变化.结果表明,雄獐的许多领域行为发生频次表现出明显的月间变化,包括打斗、威胁、取代、追逐和粪尿标记;擦额标记行为频次虽月间差异不显著,但与其他领域行为一样在11月份出现频次峰值.发情期(2011年10月～2012年1月)和非发情期(2011年9月、2012年2～4月),打斗、威胁、粪尿标记和擦额标记行为发生频次差异显著;取代和追逐行为频次差异不显著.6种领域行为的发生频次均在发情期明显高于非发情期.粪便睾酮含量在发情期和非发情期差异显著,发情期明显高于非发情期,其含量在12月份达到峰值(51.16±9.85) ng/g.雄獐的威胁、擦额标记、粪尿标记和打斗行为发生频次与睾酮水平呈显著的正相关性,而取代和追逐行为与睾酮水平变化不具有显著相关性.