Individual recognition of song repertoires in two wood warblers

We examined recognition of individual neighbors in hooded warblers (Wilsonia citrina) and Kentucky warblers (Oporornis formosus) by comparing responses to playbacks of neighbors' songs from appropriate and inappropriate boundaries of the subjects' territories. Kentucky warblers, which sing one song type each, responded more strongly to the songs of neighbors broadcast from incorrect than from correct boundaries. Hooded warblers use their repertoires of three to nine song types in two distinct modes of singing: repeat mode involves repeated presentation of one song type; mixed mode involves presentation of two or more song types in irregular sequence. Playbacks of neighbors' mixed-mode songs from appropriate and inappropriate boundaries indicated capabilities of individual recognition similar to those reported previously for repeat-mode songs (Godard 1991) and to those of Kentucky warblers. Repertoires of moderate size, therefore, have no pronounced influence on eventual recognition of individual neighbors in hooded warblers.     

扬沸过程燃烧噪声的谱分析（Ⅱ）──扬沸前兆噪声的工程：识别模型

本文通过对数字时间序列分析中最大熵谱法的研究，给出了分辨率比传统谱方法高得多的功率谱，针对扬沸过程燃烧噪声的谱特性，建立了扬沸前兆噪声的工程识别模型。本文第二部分讨论了该模型的建立方法，并在实验中得到验证。     

家居安防远程通信系统的设计与实现

设计并实现了一种基于单片机的家居安防远程通信控制系统,主芯片采用凌阳16位单片机,利用传感器和GPRS模块技术,通过手机短信的方式了解家用电器所处环境的温度情况;采用语音识别系统和传感器实时监测家庭安全状况,若有异常,系统会及时发送短信通知主人;利用单片机控制固态继电器并通过GPRS模块远程启动家用电器。设计引入手机短信,通过短信来远程控制家用电器的使用以及自动接收来自家庭安防的各种信息,给人们的家居生活带来便利性和时效性。给出系统总体设计方案、各子系统硬件电路实现和软件设计,并对系统的关键技术进行说明。     

Kin recognition in the common lizard

The ability to recognize parents has never been reported in species in which parents do not provide care to their young; in such species, only sibling recognition has been found. However, there may be several advantages of parent recognition, even in the absence of parental care. We investigated the ability of neonates to recognize olfactory cues from both their mother and siblings in the common lizard, Lacerta vivipara, a species without parental care. Juveniles from 264 gravid females were reared for 2 days either with their mother, with another female, or separated from all other adults. Juveniles from some families were split into two or three groups so that each juvenile was unfamiliar with a subset of its siblings. After 2 days, we offered the juveniles a choice of two nocturnal shelters: one containing a lizard odor and the other without odor. The response to the odor of an unrelated and unfamiliar adult was influenced by both the sex of the adult and the sex of the juvenile. Juveniles of both sexes recognized the odor of their mother whether they were familiar with her or not (pre-natal determinism). Juveniles recognized familiar but not unfamiliar siblings (post-natal determinism). In the wild, spatial association with kin declines shortly after birth. Thus, recognition of the mother is likely to have biological relevance. Recognition of the mother may reduce competition and/or enhance juvenile establishment. Received: 15 May 1997 / Accepted after revision: 29 December 1997     

Nestmate recognition in the ant Cataglyphis niger : do queens matter?

This study compares two basic models for the origin and maintenance of colony gestalt odor in the polygynous ant species Cataglyphis niger. In the first model, queens are centers of de novo biosynthesis and distribution of recognition odors (“queen-centered” model); in the second, colony odors are primarily synthesized and distributed by workers (“worker-centered” model). We tested the behavioral patterns that are predicted from each model, and verified by biochemical means the distributional directionality of these signals. Encounters between nestmates originating from split colonies were as amicable as between nestmates from non-split colonies; queenless ants were as aggressive as their queenright nestmates, and both were equally aggressed by alien ants. These results indicate that queens have little impact on the recognition system of this species, and lend credence to the worker-centered model. The queen-centered model predicts that unique queen substances should be produced in appreciable quantities and that, in this respect, queens should be more metabolically active than workers. Analysis of the chemical composition of postpharyngeal glands (PPGs) or cuticular extracts of queens and workers revealed high similarity. Quantitatively, queens possessed significantly greater amounts of hydrocarbons in the PPG than workers, but the amount on the thoracic epicuticle was the same. Queens, however, possess a lower hydrocarbon biosynthesis capability than workers. The biochemical evidence thus refutes the queen-centered model and supports a worker-centered model. To elucidate the directionality of cue distribution, we investigated exchange of hydrocarbons between the castes in dyadic or group encounters in which selective participants were prelabeled. Queens tended to receive more and give less PPG content, whereas transfer to the epicuticle was low and similar in all encounters, as predicted from the worker-centered hypothesis. In the group encounters, workers transferred, in most cases, more hydrocarbons to the queen than to a worker. This slight preference for the queen is presumably amplified in a whole colony and can explain their copious PPG content. We hypothesize that preferential transfer to the queen may reflect selection to maintain her individual odor as close to the average colony odor as possible. Received: 4 November 1997 / Accepted after revision: 5 February 1998     

Chemosensory mate recognition may facilitate prolonged mate guarding by male snow skinks, Niveoscincus microlepidotus

We provide evidence that male lizards can use chemosensory cues to identify individual females and probably therefore maintain long-term associations with these females in the wild. In the laboratory, males preferentially followed the scent trail of their vitellogenic female “partner” rather than that of another vitellogenic female. Our 5-year field study of the small viviparous scincid lizard (Niveoscincus microlepidotus) in alpine Tasmania showed that sexually mature males and females commonly formed “pairs” for long periods (on average 29 days). These pairs occurred primarily during the mating season, always involved one adult male and one adult female, and usually involved vitellogenic rather than gravid females. Our laboratory experiments suggest that a significant factor in maintaining those prolonged partnerships is male scent trailing of partners. Received: 28 October 1997 / Accepted after revision: 28 May 1998     

Forecasting Up to Year 2000 on Shanghai's Environmental Quality

The capabilities of third world countries in dealing withenvironmental problems are often limited by available resources and the tremendous costs of environmental monitoring.This paper attempts to introduce a newmethodology that can be used to derive information aboutenvironmental quality in its spatial and temporal dimensions.This methodology, based on an inquiry-feedback network of 8,000families and iteration with controlled-feedback of expertcommunity, has been first tested in Shanghai, China andprocedurally can be divided into two steps: Base-year evaluationand forecasting. Fuzzy pattern recognition is introduced for thesubjective assessment of the citizens' feelings theirperceived environment and a four-round Delphi-Cross Impactanalysis is conducted for forecasting the environmental changesup to 2000. Results show that the base-year environmentalsituations were poor. In the foreseeable future, the conditionsfor housing, social services, public health, greenspace anddrinking water will be substantially improved. Due to the rapidgrowth of manufacturing, the city will continue its deteriorating trend of air and water quality into the next century according to the forecast.     

All at sea: aquatic life modifies mate-recognition modalities in sea snakes (Emydocephalus annulatus, Hydrophiidae)

Alternative sensory modalities (e.g. vision, chemoreception) differ in the spatial scale, permanence and reliability of cues they provide to mate-searching males. Males of terrestrial snake species use chemoreception to locate females over large distances, but phylogenetic shifts to aquatic life render such cues unavailable. Do male sea snakes use alternative modalities for identifying potential sexual partners and if so, are the novel systems as effective for mate-finding as the ancestral ones? Observations and experiments show that free-ranging male turtle-headed sea snakes (Emydocephalus annulatus) in shallow-water reef habitats in New Caledonia use visual cues (including size, movement and color pattern) to assess whether snake-shaped objects are potential sexual partners. Skin lipids (pheromones) are important only after the male comes into physical contact with the stimulus. Visual cues provide unreliable information about potential mates, and function over short distances only (generally, <1 m). In consequence, mate-searching male snakes frequently failed to find nearby females, rarely managed to maintain contact with females they did find, and wasted time and energy investigating inappropriate stimuli (e.g. fishes, sea cucumbers, divers). The loss of effective pheromonal mate-location systems means that mate recognition by aquatic snakes functions over smaller distances than in their terrestrial relatives. Phylogenetic transitions among habitat types thus may directly modify central features of the mating system.     

Queen acceptance and the complexity of nestmate discrimination in the Argentine ant

In most social insect species, individuals recognize and behave aggressively towards non-nestmate conspecifics to maintain colony integrity. However, introduced populations of the invasive Argentine ant, Linepithema humile, exhibit pronounced variation in intraspecific aggression denoting diversity in nestmate recognition behavior, which possibly shapes their social structure and the varying levels of unicoloniality observed among these populations. One approach to better understand differential aggression behaviors towards conspecifics and recognition cue perception and response in L. humile is to examine variation in nestmate discrimination capability among genetically distinct colonies under different social contexts. Consequently, we investigated the dynamics of queen and worker recognition in southeastern US L. humile queenless and queenright colonies by measuring rates of non-nestmate worker and queen adoption and intercolony genetic similarity. Aggression levels between colony pairs differed and were associated with non-nestmate worker, but not queen adoption. Adoption of queens and workers was a function of host colony origin, while colony queen number affected adoption of queens, but not workers, with queens more readily accepted by queenless hosts. Fecundity of adopted non-nestmate queens was comparable to that of rejected non-nestmate and host colony queens, suggesting that queen fecundity did not affect adoption decisions. Genetic similarity between colonies ranged from 30 to 77% alleles shared, with more genetically similar colonies showing lower levels of intraspecific aggression. Non-nestmate queens and workers that were more genetically similar to host colony workers were more likely to be adopted. We provide the first evidence for the role of L. humile colony queen number on queen discrimination and suggest an effect of resident queens on worker conspecific acceptance thresholds. Our findings indicate a role for genetically based cues in L. humile nestmate recognition. However, subtle discrimination capability seems to be influenced by the social context, as demonstrated by more frequent recognition errors in queenless colonies.     

The interplay between genetic and environmental effects on colony insularity in the clonal invasive little fire ant <Emphasis Type="Italic">Wasmannia auropunctata</Emphasis>

The little fire ant, Wasmannia auropunctata, constitutes one clonal supercolony throughout Israel, providing an opportunity to examine the effects of genotype versus environment on nestmate recognition. Intraspecific encounters among field-collected or among laboratory-maintained colonies were nonaggressive, but encounters between freshly collected and laboratory-maintained colonies were highly aggressive. Analyses of cuticular hydrocarbons revealed that freshly field-collected colonies had distinguishable profiles. Moreover, freshly collected colonies had profiles disparate from those of the same colonies after 4 months in the laboratory. These results indicate a strong interplay between genetic-based and environmentally based effects on the recognition cues. We propose that in the field the ants’ diet breadth is broad and consequently the incorporation of diet-borne substances is insufficient to mask the genetically determined cues. In the laboratory, however, the restricted diet promoted the incorporation of alien hydrocarbons at high levels, thus altering the genetically based cues to the point of alienation. These results shed a new light on the mechanisms by which environmental cues may affect label and/or template formation in ants. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.