Generalization of predator recognition:Velvet geckos display anti-predator behaviours in response to chemicals from non-dangerous elapid snakes

<正> Many prey species detect chemical cues from predators and modify their behaviours in ways that reduce their risk ofpredation. Theory predicts that prey should modify their anti-predator responses according to the degree of threat posed by thepredator. That is, prey should show the strongest responses to chemicals of highly dangerous prey, but should ignore or respondweakly to chemicals from non-dangerous predators. However, if anti-predator behaviours are not costly, and predators are rarelyencountered, prey may exhibit generalised antipredator behaviours to dangerous and non-dangerous predators. In Australia, mostelapid snakes eat lizards, and are therefore potentially dangerous to lizard prey. Recently, we found that the nocturnal velvetgecko Oedura lesueurii responds to chemicals from dangerous and non-dangerous elapid snakes, suggesting that it displays generalisedanti-predator behaviours to chemicals from elapid snakes. To explore the generality of this result, we videotaped the behaviourof velvet geckos in the presence of chemical cues from two small elapid snakes that rarely consume geckos: the nocturnalgolden-crowned snake Cacophis squamulosus and the diurnal marsh snake Hemiaspis signata. We also videotaped geckos in trialsinvolving unscented cards (controls) and cologne-scented cards (pungency controls). In trials involving Cacophis and Hemiaspischemicals, 50% and 63% of geckos spent long time periods ( 3 min) freezing whilst pressed flat against the substrate, respectively.Over half the geckos tested exhibited anti-predator behaviours (tail waving, tail vibration, running) in response to Cacophis(67%) or Hemiaspis (63%) chemicals. These behaviours were not observed in control or pungency control trials. Our resultssupport the idea that the velvet gecko displays generalised anti-predator responses to chemical cues from elapid snakes.Generalised responses to predator chemicals may be common in prey species that co-occur with multiple, ecologically similar,dangerous predators [Current Zoology 56 (3): 337-342, 2010].     

Can an Invasive Prey Species Induce Morphological and Behavioral Changes in an Endemic Predator？ Evidence from a South Korean Snake （Oocatochus rufodorsatus）

Introduction of an invasive prey species into an ecosystem may affect an endemic predator＇s fitness by altering the prey-predator system. Successful adaptation may allow the endemic predator to eat and control the invasive species, while unsuccessful adaptation may result in extinction of the predator. We examine the possible effects of the invasive North American bullfrog （Rana [Lithobates] catesbeiana） on the endemic Red-backed rat snake （Oocatochus rufodorsatus） in South Korea. We do so by comparing the morphology and behavior of adult and hatchling snakes from bullfrog-exposed （Taean） and bullfrog-unexposed （Hongcheon） populations. Among the seven morphological characteristics investigated, relative tail length （tail length/snout-vent length） of both adults and hatchlings from Taean was significantly greater than that of adults and hatchlings from Hongcheon. Also, adult snakes from Taean had a signiifcantly shorter latency of ifrst tongue lfick in response to prey compared to adults from Hongcheon. This difference was not observed in hatchlings. In other snake species, a longer relative tail length and shorter latency of ifrst tongue lfick are known to improve foraging efifciency, and these characters may be adaptations ofO. rufodorsatus to prey on bullfrogs. This study provides preliminary evidence that the presence of an invasive prey species may cause morphological and behavioral changes in an endemic predator.     

Predatory Cues Influence the Behavioral Responses and Metamorphic Traits of Polypedates maculatus(Anura: Rhacophoridae)

Mechanisms of predator detection and the influence of the presence of nonlethal predators on antipredator defense behavior and metamorphic traits were studied in the Indian tree frog, Polypedates maculatus. Exposure of P. maculatus tadpoles to chemical cues of caged predator(crabs, Barytelphusa spp.) fed with either conspecific or heterogeneric tadpoles, or were starved elicited defense behavior(by avoiding predator zone) in them. Such a behavior was not evident when exposed to predators housed in a glass beaker(visual cues). Both early(Gosner stage 27–28) and later(Gosner stage 35–36) stage tadpoles when exposed to caged predators(fed with conspecific tadpoles), prey tadpoles spent less time swimming and remained motionless for longer periods. Yet, the time spent by prey in feeding was unaffected. Further, the predator avoidance behavior exhibited by them was of the same intensity regardless of whether the caged predators were fed or starved implying the influence of predator's kairomones. Tadpoles reared with caged predator reached the metamorphic climax stage(MC stage; Gosner stage 42) earlier than those reared without a predator. Size at emergence(Gosner stage 46) was comparable in both the groups. The findings suggest that P. maculatus tadpoles assess predation risk chiefly by sensing kairomones of the predator in eliciting antipredator defense behaviors. Accelerated development and early metamorphosis without any compromise of the size at emergence may be due to their unaltered feeding activity.     

From deception to frankness： Benefits of ontogenetic shift in the anti-predator strategy of alder moth Acronicta alni larvae

Animals can avoid predation by masquerading as objects that are not food to their predators. Alder moth Acronicta alni larvae go through an impressive ontogenetic change from masquerade to highly conspicuous appearance： early larval stages resemble bird droppings but in the last instar the larval coloration changes into striking yellow-and-black stripes. We hypothe- sized that such a change may be driven by differential predation favoring dissimilar anti-predator strategies in different life stages We show with a series of laboratory assays that larvae are distasteful to birds regardless of their developmental stage, suggesting that ontogenetic color change is not driven by the differential chemical defense. Birds showed higher variance in hesitation to- ward conspicuous prey; some individuals hesitated long time before attacking whereas all birds attacked instantly masqueraded prey. We also found that the activity level of the larvae increased with age, which fits to the fact that larvae need to move from foliage to pupation sites. In the field by using artificial larvae resembling the two life-history stages we found predation risk to vary during the season： In early summer larger yellow-and-black larvae were attacked most, whereas later in the summer small ＇bird-dropping-larvae＇ suffered the highest predation. We conclude that the ontogenetic switch from masquerading to aposema- tism is adaptive most likely because actively moving prey cannot mimic immotile objects and thus, aposematism during the ac- tive and vulnerable period when larvae are searching for pupation sites becomes beneficial     

Day length constrains the time budget of aphid predators

Phenology shifts and range expansions cause organisms to experience novel day length-temperature correlations.Depending on the temporal niche,organisms may benefit or suffer from changes in day length,thus potentially affecting phenological adaptation. We assessed the impact of day length changes on larvae of Chrysoperla carnea (Stephens) and Episyrphus balteatus (De Geer),both of which prey on aphids.Larvae ofE.balteatus are night-active,whereas those of C.carnea appear to be crepuscular.We subjected both species in climate chambers to day lengths of 16 :8 L :D and,to circumvent diapause responses,20 :4 L :D.We recorded development times and predation rates of both species. E.balteatus grew 13%faster in the 16 :8 L :D treatment and preyed on significantly more aphids.In contrast,C.carnea grew 13% faster in the 20 :4 L :D treatment and higher predation rates in 20 :4 L :D were marginally significant.Our results show that day length affects development and predation,but that the direction depends on species. Such differences in the use of day length may alter the efficiency ofbiocontrol agents in a changing climate.     

Encounters with aphid predators or their residues impede searching and oviposition by the aphid parasitoid Aphidius ervi （Hymenoptera： Aphidiinae）

Intraguild predation （IGP） can be an important factor influencing the effective- ness of aphid natural enemies in biological control. In particular, aphid parasitoid foraging could be influenced by the presence of predators. This study investigated the effect of larvae of the predatory hoverfly Episyrphus balteatus DeGeer （Diptera： Syrphidae） and the multicolored Asian ladybird Harmonia axyridis Pallas （Coleoptera： Coccinellidae） on the foraging behavior of the aphid parasitoid, Aphidius ervi Haliday （Hymenoptera： Aphidiidae） in choice experiments using a leaf disc bioassay. Wasp response to chemical tracks left by those predator larvae was also tested. Parasitoid behavior was recorded using the Observer （Noldus Information Technology, version 5.0, Wageningen, the Netherlands）. The experiments were conducted under controlled environmental conditions using leaves of the broad bean plant, Viciafaba L. （Fabaceae） with Myzus persicae Sulzer （Homoptera： Aphididae） as the host complex. A. ervi females avoided aphid patches when larvae of either predator were present. A similar avoidance response was shown by A. ervi to aphid patches with E. balteatus larval tracks, whereas no significant response was observed to tracks left by H. axyridis larvae. It was concluded that IG predator avoidance shown by the aphid parasitoid A. ervi may be a factor affecting their distribution among host patches.     

Oviposition behavior of the mirid Macrolophus pygmaeus under risk of intraguild predation and cannibalism

Zoophytophagous mirid species,that feed and develop either on prey or plant resources,are often found simultaneously on the same host.Hence,these species can engage in both intraguild predation and cannibalism,which can pose a threat to mirid eggs.Ovipositing females may respond to such risks of predation on their eggs by reducing the number of eggs laid or selecting safer oviposition sites.We tested the oviposition behavior of Macrolophus pygmaeus(Rambur)(Hemiptera:Miridae)females under the risk of cannibalism by M.pygmaeus males and intraguild predation by Nesidiocoris tenuis(Reuter)males(Hemiptera:Miridae)under laboratory conditions.Intraguild predators and cannibals were introduced during or after the oviposition period.The number of eggs laid(using counts of newly hatched nymphs)and their proportion on each part of a tomato plant were both measured.The results reveal that only cannibalism by M.pygmaeus males after the period of oviposition significantly decreased the number of hatched eggs.Cannibalism thus represents a greater risk to mirid eggs than intraguild predation.The M.pygmaeus female responded to the presence of potential intraguild predators(or competitors)by decreasing the nu mber of eggs laid in the upper leaves.The results suggest that M.pygmaeus females avoid competition by N.tenuis,by laying fewer eggs on upper leaves.Cannibalism could regulate zoophytophagous predator populations under prey scarcity conditions and minimize the risk of crop damage associated with those biological control agents.     

Size-dependent locomotory performance creates a behaviorally mediated prey size refuge in the marine snail Olivella sem istriata:a study in the natural habitat

The effects of the variability of individual prey locomotory performance on the vulnerability to predation are poorly understood,partly because individual performance is difficult to determine in natural habitats.To gain insights into the role(s)of individual variation in predatory relationships,we study a convenient model system,the neotropical sandy beach gastropod Olivella semistriata and its main predator,the carnivorous snail Agaronia propatula.The largest size class of O.semistriata is known to be missing from A.propatula's spectrum of subdued prey,although the predator regularly captures much larger individuals of other taxa.To resolve this conundrum,we analyzed predation attempts in the wild.While A.propatula attacked O.semistriata of all sizes,large prey specimens usually escaped by'sculling',an accelerated,stepping mode of locomotion.Olivella semistriata performed sculling locomotion regardless of size,but sculling velocities determined in the natural environment increased strongly with size.Thus,growth in size as such does not establish a prey size refuge in which O.semistriata is safe from predation.Rather,a behaviorally mediated size refuge is created through the size-dependence of sculling performance.Taken together,this work presents a rare quantitative characterization in the natural habitat of the causal sequence from the size-dependence of individual performance,to the prey size-dependent outcome of predation attempts,to the size bias in the predator's prey spectrum.     

Comparison of wormlion behavior under man-made and natural shelters:urban wormlions more strongly prefer shaded,fine-sand microhabitats,construct larger pits and respond faster to prey

Urban habitats differ from their natural surroundings in various aspects,such as a higher temperature and a distinct species composition.It is therefore not surprising that animal behavior too differs between these habitat types.We studied the foraging and habitat selection behavior of a pit-building predator,a wormlion,originating from either an urban or a more natural site.Wormlions occur in nature under structures that provide shelter from sunlight and rain,such as caves,and are also common in cities,occurring under artificial shelters.Wormlions construct pittraps to hunt arthropods,and the pits constructed by urban wormlions were larger than those constructed by wormlions from caves.Urban wormlions responded faster to prey falling into their pit,probably leading to a higher capture success.We suggest that these 2 findings indicate the higher investment of urban wormlions in foraging,resulting from the higher abundance of potential prey in the city.Urban wormlions were choosier regarding their preferred microhabitat.While both fine sand and shaded microhabitats were preferred by wormlions,urban wormlions demonstrated a greater preference for such conditions.We suggest that relocation is more likely to lead wormlions in cities to find microhabitats of a higher quality compared with wormlions inhabiting caves.This is probably due to the larger areas in the city available for wormlions.Wormlions from the caves possessed more lipids,suggesting that they employ a conservative growth strategy,intended to contend with the uncertainty of prey arrival,in contrast to the city,where potential prey are more abundant.     

Predating strategy of rodents on acorns of Quercusaliena var. acuteserrata under different predating risks and fate of acorns

The effects of rodents on forest regeneration have been highlighted in many ecological studies. In 2002 and 2003, the acorns of Quercus aliena var. acuteserrata were subjected to 12 different treatments. The daily dynamics and the amount of acorns that were finally left intact, predated in situ, or removed off were examined and documented. The ratios of acorns that were infested by bugs before and after predation by rodents were carefully documented. It was found that: (1) the ratios of acorns infested by bugs before and after predation by rodents showed significant difference (P > 0.05), suggesting that rodents would not prey on acorns during the predating process if acorns had been already infested by bugs. (2) When compared with the controls, the fate of acorns could be roughly classified into four types: acorns that were simply buried or placed on black paper showed no significant differences with the controls in their response to rodents, suggesting that rodents have no sensitivity to the little change of odor resulting from burying and may be more adapted to black background. Acorns attached with strings, dyed with black ink, cut into halves, or placed on white/green/red paper were predated in situ with much lower predation rates and lasted the same duration. Compared with the controls, the acorns were removed away by rodents with the same first day rate and the removal lasted longer. The final removal rate of the acorns by rodents was increased, whereas that of predation in situ was decreased, and none were left in the spot. This may suggest that rodents in this case increased their predation risk expectation and adopted a strategy of “less predation proportion in situ”. Acorns that were burnt were not predated in situ as well as removed in the first day, but the rates were raised to the maximum in the forth and fifth day and then declined to zero. Consequently, the final ratios of predation in situ and removal considerably decreased with many acorns, nearly 50%, being left intact. It can be hypothesized that the rodents responded to the change in odor of acorns by using the strategies of “less predation proportion in situ” and “less predating activities”, thereby resulting in larger number of acorns remained intact. Acorns that were enwrapped were barely predated in situ, removed in the first day with a normal predation rate, which declined to nearly zero in the second day and then increased till it declined again from the fourth day to the final day. The final rate of predation in situ was lower than 5% without acorns remained intact, and the rate of removal of acorns showed a considerable relative increase. This suggests that when there was a change in both odor and status of acorns, rodents also adopted the “spying” and “less predation proportion in situ” strategy, Because the predation risk is critical, the sense of sight would play an important role in rodent's living. (3) Definite amounts of acorns were predated in situ, discarded, removed away, predated ex situ, lost and hoarded separately.     

Predating strategy of rodents on acorns of Quercusaliena var. acuteserrata under different predating risks and fate of acorns

The effects of rodents on forest regeneration have been highlighted in many ecological studies. In 2002 and 2003, the acorns of Quercus aliena var. acuteserrata were subjected to 12 different treatments. The daily dynamics and the amount of acorns that were finally left intact, predated in situ, or removed off were examined and documented. The ratios of acorns that were infested by bugs before and after predation by rodents were carefully documented. It was found that: (1) the ratios of acorns infested by bugs before and after predation by rodents showed significant difference (P > 0.05), suggesting that rodents would not prey on acorns during the predating process if acorns had been already infested by bugs. (2) When compared with the controls, the fate of acorns could be roughly classified into four types: acorns that were simply buried or placed on black paper showed no significant differences with the controls in their response to rodents, suggesting that rodents have no sensitivity to the little change of odor resulting from burying and may be more adapted to black background. Acorns attached with strings, dyed with black ink, cut into halves, or placed on white/green/red paper were predated in situ with much lower predation rates and lasted the same duration. Compared with the controls, the acorns were removed away by rodents with the same first day rate and the removal lasted longer. The final removal rate of the acorns by rodents was increased, whereas that of predation in situ was decreased, and none were left in the spot. This may suggest that rodents in this case increased their predation risk expectation and adopted a strategy of “less predation proportion in situ”. Acorns that were burnt were not predated in situ as well as removed in the first day, but the rates were raised to the maximum in the forth and fifth day and then declined to zero. Consequently, the final ratios of predation in situ and removal considerably decreased with many acorns, nearly 50%, being left intact. It can be hypothesized that the rodents responded to the change in odor of acorns by using the strategies of “less predation proportion in situ” and “less predating activities”, thereby resulting in larger number of acorns remained intact. Acorns that were enwrapped were barely predated in situ, removed in the first day with a normal predation rate, which declined to nearly zero in the second day and then increased till it declined again from the fourth day to the final day. The final rate of predation in situ was lower than 5% without acorns remained intact, and the rate of removal of acorns showed a considerable relative increase. This suggests that when there was a change in both odor and status of acorns, rodents also adopted the “spying” and “less predation proportion in situ” strategy, Because the predation risk is critical, the sense of sight would play an important role in rodent's living. (3) Definite amounts of acorns were predated in situ, discarded, removed away, predated ex situ, lost and hoarded separately.     

Analysis of a predator-prey model with herd behavior and disease in prey incorporating prey refuge

In this work,we have introduced an eco-epidemiological model of an infected predator prey system.Incorporation of prey refuge gives that a fraction of the infected prey is available to the predator for consumption.Moreover,to make the model more realistic to the environment,we have introduced strong Allee effect in the susceptible population.Boundedness and positivity of the solution have been established.Local stability conditions of the equilibrium points have been found with the help of Routh-Hurwitz criterion and it has been observed that if a prey population is infected with a lethal disease,then both the prey(susceptible and infected)and predator cannot survive simultaneously in the system for any parametric values.The disease transmission rate and the attack rate on the susceptible have an important role to control the system dynamics.For different values of these two key parameters,we have got only healthy or disease-free or predation-free or a fluctuating disease-free or even a fluctuating predator-free system with some certain parametric conditions.     

Predator-induced changes of male and female mating preferences: innate and learned components

While many mati ng pref ere nces have a genetic basis, the question remai ns as to whether and how learning/experience can modify individual mate choice decisions. We used wild-caught (predator-experienced) and Fi laboratory-reared (predator-naive) invasive Western mosquitofish Gambusia affinis from China to test whether mating preferences (assessed in a first mate choice test) would change under immediate predation threat. The same individuals were tested in a second mate choice test during which 1 of 3 types of animated predators was presented: 1) a co-occurring predator, 2) a co-evolved but not currently co-occurring predator, and 3) a non-piscivorous species as control. We compared preference scores derived from both mate choice tests to separate innate from experiential effects of predation. We also asked whether predator-induced changes in mating preferences would differ betwee n sexes or depend on the choosing individual's personality type and/or body size. Wild-caught fish altered their mate choice decisions most when exposed to the co-occurring predator whereas laboratory-reared individuals responded most to the co-evolved predator, suggesting that both innate mechanisms and learning effects are involved. This behavior likely reduces individuals' risk of falling victim to predation by temporarily moving away from high-quality (i.e., conspicuous) mating partners. Accordingly, effects were stronger in bolder than shyer, large- compared with small-bodied, and female compared with male focal individuals, likely because those phenotypes face an increased predation risk overall. Our study adds to the growing body of literature appreciating the complexity of the mate choice process, where an array of intrinsic and extrinsic factors interacts during decision-making.     

Potential cotton aphid,Aphis gossypii,population suppression by arthropod predators in upland cotton

The cotton aphid, Aphis gossypii Glover, predation rate of convergent lady beetle, Hippodamia convergens Guerin-Meneville, was determined by assigning a single predator randomly to each of four prey density treatments in the laboratory. Prey densities included 25, 50, 100, and 200 aphids per Petri dish arena. Predation response was recorded at 1, 4, 8, 16, 24, and 48 h after assigning predators to their prey treatments. Rate of consumption increased through time, with all 25 aphids consumed during the first 4 h of the experiment. At the highest density, adult lady beetle consumed on average 49, 99, 131, 163, 183, and 200 aphids within 1, 4, 8, 16, 24 and 48 h, respectively. Predators showed a curvilinear feeding response in relation to total available time, indicating that convergent lady beetles have the potential to suppress larger populations of aphids through continuous feeding by regulating their predation efficiency during feeding. The analysis of age-specific mortality in absence of prey revealed that lady beetles could survive for an extended period of time （more than 2 weeks） without prey. The ability of a predator to survive without prey delays or prevents the rebound of pest populations that is a significant factor in natural biological control. A two-year field sampling of 10 cotton arthropod predator species showed that spiders （27%） were the most dominant foliage dwelling predators in the Texas High Plains cotton followed by convergent lady beetles （23.5%）, hooded beetles （13.5%）, minute pirate bugs （11%）, green lacewings （9.5%）, bigeyed bugs （7.5%）, scymnus beetles （3%）, soft-winged flower beetles （2%）, damsel bugs （1.5%）, and assassin bugs （1.5%）. A field cage study showed that one H. convergens adult per plant released at prey density of one aphid per leaf kept the aphid population below economic threshold for the entire growing season.     

新疆棉区主要捕食性天敌对棉铃虫捕食功能反应的研究

Field insect population survey indicated that the principal natural predation enemies of cotton bollworm (Helicover-pa armigera Hubner ) were EHngonidium graminicola Sundevall, Adonia variegata Goeze, Nabis sinoferus Hsiao. The results from experiments showed that the amount of prey consumed of these principal natural enemies in-creased when the density of prey rised, and decreased when the density of natural enemies increased. The predation function response fitted Holling's predation response equation 11 , and could be fit with the Disk Equation.     

The group size effect and synchronization of vigilance in the Tibetan wild ass

Vigilance behavior is considered as an effective strategy for prey species to detect predators.An individual benefits from living in a group by reducing the time spent being vigilant without affecting the probability of detecting a predator.However,the mechanism producing a decrease in vigilance with increasing group size is unclear.Many models of vigilance assume that group members scan independently of one another.Yet in recent studies,the other 2 patterns of vigilance,coordination and synchronization,were reported in some species.In 2 summers(2018 and 2019),we studied the group-size effect on vigilance and foraging of Tibetan wild ass in Chang Tang Nature Reserve of Tibet.We also tested whether individuals scan the environment independently,tend to coordinate their scans,or tend to synchronize their vigilance.The results showed that individuals decreased the time spent on vigilance with increasing group size,while increased the time spent foraging.Group members scanned the environment at the same time more frequently and there was a positive correlation between group members'behaviors,indicating that Tibetan wild asses tend to synchronize their vigilance.     

Functional response of the ladybird, Cydonia vicina nilotica to cowpea aphid, Aphis craccivora in the laboratory

The functional response of Cydonia vicina nilotica Muls. （Coleoptera： Coccinellidae） to six densities of Aphis craccivora Koch （Homoptera： Aphididae） nymphs on broad bean （Viciafaba Linn.） was investigated in the laboratory. A linear relationship between the rate of consumption and prey density was observed with r^2 values between 0.58 and 0.97. Plotting prey density against prey killed by four larval instars, and adult males and females of C. vicina nilotica fit well with the type Ⅱ model of Holling＇ s disc equation. Adult females consumed the highest number of prey, followed by fourth instars and adult males. Based on the functional response data, the model predicts a maximum of 144.9, 116.3, 86.2, 80.0, 72.5 and 20.0 nymphs to be consumed per day by an individual adult female, fourth instar, adult male, third, second and first instars, respectively. The differences in the responses of the predator to aphid densities are discussed.     

What is the sound of fear？ Behavioral responses of white-crowned sparrows Zonotrichia leucophrys to synthesized nonlinear acoustic phenomena

Fear and anxiety may be adaptive responses to life-threatening situations, and animals may communicate fear to others vocally. A fundamental understanding of fear inducing sounds is important for both wildlife conservation and management because it helps us understand how to design repellents and also how （and why） animals may be negatively impacted by anthropogenic sounds. Nonlinear phenomena--sounds produced by the desynchronization of vibrations in a sound production system-are commonly found in stress-induced animal vocalizations, such as in alarm calls, mobbing calls, and fear screams. There are several functional hypotheses for these nonlinear phenomena. One specific hypothesis is the unpredictability hypothesis, which suggests that because nonlinear phenomena are more variable and somewhat unpredictable, animals are less likely to habituate to them. Animals should, therefore, have a prolonged response to sounds with nonlinear phenomena than sounds without them. Most of the studies involving nonlinear phenomena have used mammalian subjects and conspecific stimuli. Our study fo- cused on white-crowned sparrows （Zonotrichia leucophrys ssp. oriantha） and used synthesized acoustic stimuli to investigate behavioral responses to stimuli with and without nonlinear phenomena. We predicted that birds would be less relaxed after hearing a stimulus with a nonlinear component. We calculated the difference from baseline of proportion of time spent in relaxed behaviors and performed pair-wise comparisons between a pure tone control stimulus and each of three experimental stimuli, including a frequency jump up, a frequency jump down, and white noise. These comparisons showed that in the 30q50 s after the playback experiment, birds were significantly less relaxed after hearing noise or an abrupt frequency jump down an octave but not an abrupt frequency jump up an octave or a pure tone. Nonlinear phenomena, therefore, may be generally arousing to animals and may explain why these acoustic properties are commonly fou     

Regulation and function of stimulus-induced phosphorylation of MeCP2

DNA methylation-dependent epigenetic regulation plays important roles in the development and function of the mammalian nervous system. MeCP2 is a key player in recognizing methylated DNA and interpreting the epigenetic information encoded in different DNA methylation patterns. Mutations in the MECP2 gene cause Rett syndrome, a devastating neurological disease that shares many features with autism. One interesting aspect of MeCP2 function is that it can be phosphorylated in response to diverse stimuli. Insights into the regulation and function of MeCP2 phosphorylation will help improve our understanding of how MeCP2 integrates environmental stimuli in neuronal nuclei to generate adaptive responses and may eventually lead to treatments for patients.