The 'after you' gesture in a bird.

Gestures are ubiquitous in human communication, involving movements of body parts produced for a variety of purposes, such as pointing out objects (deictic gestures) or conveying messages (symbolic gestures)1. While displays of body parts have been described in many animals2, their functional similarity to human gestures has primarily been explored in great apes3,4, with little research attention given to other animal groups. To date, only a few studies have provided evidence for deictic gestures in birds and fish5,6,7, but it is unclear whether non-primate animals can employ symbolic gestures, such as waving to mean 'goodbye', which are, in humans, more cognitively demanding than deictic gestures1. Here, we report that the Japanese tit (Parus minor), a socially monogamous bird, uses wing-fluttering to prompt their mated partner to enter the nest first, and that wing-fluttering functions as a symbolic gesture conveying a specific message ('after you'). Our findings encourage further research on animal gestures, which may help in understanding the evolution of complex communication, including language.

Experimental evidence for core-Merge in the vocal communication system of a wild passerine.

One of the cognitive capacities underlying language is core-Merge, which allows senders to combine two words into a sequence and receivers to recognize it as a single unit. Recent field studies suggest intriguing parallels in non-human animals, e.g., Japanese tits (Parus minor) combine two meaning-bearing calls into a sequence when prompting antipredator displays in other individuals. However, whether such examples represent core-Merge remains unclear; receivers may perceive a two-call sequence as two individual calls that are arbitrarily produced in close time proximity, not as a single unit. If an animal species has evolved core-Merge, its receivers should treat a two-call sequence produced by a single individual differently from the same two calls produced by two individuals with the same timing. Here, we show that Japanese tit receivers exhibit antipredator displays when perceiving two-call sequences broadcast from a single source, but not from two sources, providing evidence for core-Merge in animals.

Other Species' Alarm Calls Evoke a Predator-Specific Search Image in Birds.

Many animals produce vocal alarm signals when they detect a predator, and heterospecific species sharing predators often eavesdrop on and respond to these calls [1]. Despite the widespread occurrence of interspecific eavesdropping in animals, its underlying cognitive process remains to be elucidated. If alarm calls, like human referential words, denote a specific predator type (e.g., "snake!"), then receivers may retrieve a mental image of the predator when hearing these calls [2-4]. Here, using a recently developed experimental paradigm [5], I test whether heterospecific alarm calls evoke a predator-specific visual search image in wild birds. During playback of snake-specific alarm calls produced by Japanese tits (Parus minor), coal tits (Periparus ater) approach a wooden stick being moved in a snake-like manner. However, coal tits do not approach the same stick when hearing other call types or if the stick's movement is dissimilar to that of a snake. Thus, Japanese tit snake alarms cause coal tits to specifically enhance visual attention to snakelike objects. These results provide experimental evidence for the evocation of visual search images by heterospecific alarm calls, highlighting the importance of integrating cross-modal information in interspecific eavesdropping.

The syntax-semantics interface in animal vocal communication.

Syntax (rules for combining words or elements) and semantics (meaning of expressions) are two pivotal features of human language, and interaction between them allows us to generate a limitless number of meaningful expressions. While both features were traditionally thought to be unique to human language, research over the past four decades has revealed intriguing parallels in animal communication systems. Many birds and mammals produce specific calls with distinct meanings, and some species combine multiple meaningful calls into syntactically ordered sequences. However, it remains largely unclear whether, like phrases or sentences in human language, the meaning of these call sequences depends on both the meanings of the component calls and their syntactic order. Here, leveraging recently demonstrated examples of meaningful call combinations, we introduce a framework for exploring the interaction between syntax and semantics (i.e. the syntax-semantic interface) in animal vocal sequences. We outline methods to test the cognitive mechanisms underlying the production and perception of animal vocal sequences and suggest potential evolutionary scenarios for syntactic communication. We hope that this review will stimulate phenomenological studies on animal vocal sequences as well as experimental studies on the cognitive processes, which promise to provide further insights into the evolution of language. This article is part of the theme issue 'What can animal communication teach us about human language?'

Animal syntax.

Toshitaka Suzuki and Klaus Zuberbühler introduce the syntactical features found in the communication systems of non-human animals.

Imagery in wild birds: Retrieval of visual information from referential alarm calls.

Japanese tits (Parus minor) produce specific alarm calls when they encounter a predatory snake. A recent field experiment showed that receiver tits became visually perceptive to an object resembling a snake when hearing these calls. However, the tits did not respond to the same object when hearing other call types or when the object was dissimilar to a snake. These findings provide the first experimental evidence for the retrieval of a visual search image from specific alarm calls, offering a novel approach for investigating the cognitive mechanisms underlying referential communication in wild animals.

Clinical Characteristics of Nursing- and Healthcare-Associated Tuberculosis.

Tuberculosis remains a serious health problem worldwide. Patients with tuberculosis who also require nursing care due to aging and underlying diseases are considered to have a high mortality rate; however, there are few studies describing detailed examinations of such disease conditions. OBJECTIVE: The present study was conducted to investigate differences in clinical features of elderly tuberculosis patients according to the levels of nursing and healthcare required. DESIGN: The study participants included 146 elderly (≥65 years) patients diagnosed with active tuberculosis among patients hospitalized with tuberculosis at a single center. The patients were classified into two groups: a nursing- and healthcare-associated tuberculosis group (n = 71) and a community-acquired tuberculosis group (n = 75). RESULTS: The nursing- and healthcare-associated tuberculosis patients were older and had a higher frequency of comorbidities compared with the community-acquired tuberculosis group. Patients in the nursing- and healthcare-associated tuberculosis group had markedly lower levels of serum albumin and hemoglobin, and higher levels of C-reactive protein. The rate of in-hospital death was significantly higher in the nursing- and healthcare-associated tuberculosis group. This was attributed to malnutrition and comorbid conditions rather than the severity of tuberculosis. CONCLUSION: The prognosis was poor in elderly tuberculosis patients receiving nursing and healthcare.

[Usefulness of Nutritional Enforcement by Percutaneous Gastrostomy in Successful Omentoplasty for Empyema with Fistula].

Omentoplasty has been accepted as an effective surgical procedure for fistulated empyema. However, it is difficult for patients with poor nutritional status because their omental volume is often too poor to be applied for omentoplasty. Percutaneous endoscopic gastrostomy(PEG) is useful for long-term nutritional management. There is no report on safety and usefulness of PEG before omentoplasty. We report a case of omentoplasty that was successfully performed after nutritional enforcement by using percutaneous endoscopic gastrostomy in a patient of postoperative empyema with fistula.

Call combinations in birds and the evolution of compositional syntax.

Syntax is the set of rules for combining words into phrases, providing the basis for the generative power of linguistic expressions. In human language, the principle of compositionality governs how words are combined into a larger unit, the meaning of which depends on both the meanings of the words and the way in which they are combined. This linguistic capability, i.e., compositional syntax, has long been considered a trait unique to human language. Here, we review recent studies on call combinations in a passerine bird, the Japanese tit (Parus minor), that provide the first firm evidence for compositional syntax in a nonhuman animal. While it has been suggested that the findings of these studies fail to provide evidence for compositionality in Japanese tits, this criticism is based on misunderstanding of experimental design, misrepresentation of the importance of word order in human syntax, and necessitating linguistic capabilities beyond those given by the standard definition of compositionality. We argue that research on avian call combinations has provided the first steps in elucidating how compositional expressions could have emerged in animal communication systems.

Asynchrony between Antarctic temperature and CO2 associated with obliquity over the past 720,000 years.

The δD temperature proxy in Antarctic ice cores varies in parallel with CO2 through glacial cycles. However, these variables display a puzzling asynchrony. Well-dated records of Southern Ocean temperature will provide crucial information because the Southern Ocean is likely key in regulating CO2 variations. Here, we perform multiple isotopic analyses on an Antarctic ice core and estimate temperature variations at this site and in the oceanic moisture source over the past 720,000 years, which extend the longest records by 300,000 years. Antarctic temperature is affected by large variations in local insolation that are induced by obliquity. At the obliquity periodicity, the Antarctic and ocean temperatures lag annual mean insolation. Further, the magnitude of the phase lag is minimal during low eccentricity periods, suggesting that secular changes in the global carbon cycle and the ocean circulation modulate the phase relationship among temperatures, CO2 and insolation in the obliquity frequency band.

Alarm calls evoke a visual search image of a predator in birds.

One of the core features of human speech is that words cause listeners to retrieve corresponding visual mental images. However, whether vocalizations similarly evoke mental images in animal communication systems is surprisingly unknown. Japanese tits (Parus minor) produce specific alarm calls when and only when encountering a predatory snake. Here, I show that simply hearing these calls causes tits to become more visually perceptive to objects resembling snakes. During playback of snake-specific alarm calls, tits approach a wooden stick being moved in a snake-like fashion. However, tits do not respond to the same stick when hearing other call types or if the stick's movement is dissimilar to that of a snake. Thus, before detecting a real snake, tits retrieve its visual image from snake-specific alarm calls and use this to search out snakes. This study provides evidence for a call-evoked visual search image in a nonhuman animal, offering a paradigm to explore the cognitive basis for animal vocal communication in the wild.

Wild Birds Use an Ordering Rule to Decode Novel Call Sequences.

The generative power of human language depends on grammatical rules, such as word ordering, that allow us to produce and comprehend even novel combinations of words [1-3]. Several species of birds and mammals produce sequences of calls [4-6], and, like words in human sentences, their order may influence receiver responses [7]. However, it is unknown whether animals use call ordering to extract meaning from truly novel sequences. Here, we use a novel experimental approach to test this in a wild bird species, the Japanese tit (Parus minor). Japanese tits are attracted to mobbing a predator when they hear conspecific alert and recruitment calls ordered as alert-recruitment sequences [7]. They also approach in response to recruitment calls of heterospecific individuals in mixed-species flocks [8, 9]. Using experimental playbacks, we assess their responses to artificial sequences in which their own alert calls are combined into different orderings with heterospecific recruitment calls. We find that Japanese tits respond similarly to mixed-species alert-recruitment call sequences and to their own alert-recruitment sequences. Importantly, however, tits rarely respond to mixed-species sequences in which the call order is reversed. Thus, Japanese tits extract a compound meaning from novel call sequences using an ordering rule. These results demonstrate a new parallel between animal communication systems and human language, opening new avenues for exploring the evolution of ordering rules and compositionality in animal vocal sequences.

Foraging intention affects whether willow tits call to attract members of mixed-species flocks.

Understanding how individual behaviour influences the spatial and temporal distribution of other species is necessary to resolve the complex structure of species assemblages. Mixed-species bird flocks provide an ideal opportunity to investigate this issue, because members of the flocks are involved in a variety of behavioural interactions between species. Willow tits (Poecile montanus) often produce loud calls when visiting a new foraging patch to recruit other members of mixed-species flocks. The costs and benefits of flocking would differ with individual foraging behaviours (i.e. immediate consumption or caching); thus, willow tits may adjust the production of loud calls according to their foraging intention. In this study, we investigated the link between foraging decisions and calling behaviour in willow tits and tested its influence on the temporal cohesion with members of mixed-species flocks. Observations at experimental foraging patches showed that willow tits produced more calls when they consumed food items compared with when they cached them. Playback experiments revealed that these calls attracted flock members and helped to maintain their presence at foraging patches. Thus, willow tits adjusted calling behaviour according to their foraging intention, thereby coordinating the associations with members of mixed-species flocks. Our findings demonstrate the influence of individual decision-making on temporal cohesion with other species and highlight the importance of interspecific communication in mixed-species flocking dynamics.

Naive Juveniles Are More Likely to Become Breeders after Witnessing Predator Mobbing.

Responding appropriately during the first predatory attack in life is often critical for survival. In many social species, naive juveniles acquire this skill from conspecifics, but its fitness consequences remain virtually unknown. Here we experimentally demonstrate how naive juvenile Siberian jays (Perisoreus infaustus) derive a long-term fitness benefit from witnessing knowledgeable adults mobbing their principal predator, the goshawk (Accipiter gentilis). Siberian jays live in family groups of two to six individuals that also can include unrelated nonbreeders. Field observations showed that Siberian jays encounter predators only rarely, and, indeed, naive juveniles do not respond to predator models when on their own but do when observing other individuals mobbing them. Predator exposure experiments demonstrated that naive juveniles had a substantially higher first-winter survival after observing knowledgeable group members mobbing a goshawk model, increasing their likelihood of acquiring a breeding position later in life. Previous research showed that naive individuals may learn from others how to respond to predators, care for offspring, or choose mates, generally assuming that social learning has long-term fitness consequences without empirical evidence. Our results demonstrate a long-term fitness benefit of vertical social learning for naive individuals in the wild, emphasizing its evolutionary importance in animals, including humans.

Referential calls coordinate multi-species mobbing in a forest bird community.

Japanese great tits (Parus minor) use a sophisticated system of anti-predator communication when defending their offspring: they produce different mobbing calls for different nest predators (snake versus non-snake predators) and thereby convey this information to conspecifics (i.e. functionally referential call system). The present playback experiments revealed that these calls also serve to coordinate multi-species mobbing at nests; snake-specific mobbing calls attracted heterospecific individuals close to the sound source and elicited snake-searching behaviour, whereas non-snake mobbing calls attracted these birds at a distance. This study demonstrates for the first time that referential mobbing calls trigger different formations of multi-species mobbing parties.

Occasional cooperative breeding in birds and the robustness of comparative analyses concerning the evolution of cooperative breeding.

Cooperative breeding is a widespread and intense form of cooperation, in which individuals help raise offspring that are not their own. This behaviour is particularly well studied in birds, using both long-term and comparative studies that have provided insights into the evolution of reproductive altruism. In most cooperatively breeding species, helpers are offspring that remain with their parents beyond independency and help in the raising of younger siblings. However, many cooperatively breeding species are poorly studied, and in 152 species, this behaviour only has been observed infrequently (i.e., occasional cooperative breeding). Here we argue that the parental care mode of these 152 species needs to be treated with caution, as factors associated with occasional cooperative breeding may differ from those associated with "regular" cooperative breeding. In most cooperatively breeding species, helpers provide alloparental care at the nests of their parents or close relatives; however, only in one occasionally cooperatively breeding species do offspring remain into the next breeding season with their parents. Accordingly, different factors are likely to be associated with regular and occasional cooperative breeding. The latter behaviour resembles interspecific feeding (i.e., individuals feed offspring of another species), which occurs when birds lose their brood and begin feeding at a nearby nest, or when birds mistakenly feed at another nest. Thus, we advise researchers to exclude occasional cooperative breeders in comparative analyses until their status is clarified, or to categorize them separately or according to the typically observed parental care mode. This approach will increase the robustness of comparative analyses and thereby improve our understanding of factors that drive the evolution of cooperative breeding.

Experimental evidence for compositional syntax in bird calls.

Human language can express limitless meanings from a finite set of words based on combinatorial rules (i.e., compositional syntax). Although animal vocalizations may be comprised of different basic elements (notes), it remains unknown whether compositional syntax has also evolved in animals. Here we report the first experimental evidence for compositional syntax in a wild animal species, the Japanese great tit (Parus minor). Tits have over ten different notes in their vocal repertoire and use them either solely or in combination with other notes. Experiments reveal that receivers extract different meanings from 'ABC' (scan for danger) and 'D' notes (approach the caller), and a compound meaning from 'ABC-D' combinations. However, receivers rarely scan and approach when note ordering is artificially reversed ('D-ABC'). Thus, compositional syntax is not unique to human language but may have evolved independently in animals as one of the basic mechanisms of information transmission.

A phase II study of nab-paclitaxel plus carboplatin in combination with thoracic radiation in patients with locally advanced non-small-cell lung cancer.

We investigated the efficacy and safety of albumin-bound paclitaxel (nab-PTX) and carboplatin (CBDCA) with concurrent radiotherapy for unresectable locally advanced non-small-cell lung cancer (NSCLC). Patients with Stage III NSCLC and an Eastern Cooperative Oncology Group performance status of 0 or 1 were eligible. Concurrent chemoradiotherapy consisted of weekly administration of nab-PTX (40 mg/m(2)) plus CBDCA (area under the plasma concentration time curve (AUC) 2) and thoracic radiotherapy (60 Gy/30 fractions) for a total of 6 weeks. After concurrent chemoradiotherapy, patients received an additional two cycles of consolidation phase chemotherapy that consisted of 4-week cycles of nab-PTX (100 mg/m(2) on Days 1, 8 and 15)/CBDCA (AUC 5 mg/ml/min on Day 1). Response was evaluated in accordance with the Response Evaluation Criteria in Solid Tumors. Progression-free survival and overall survival were estimated using the Kaplan-Meier method. Toxicity was graded using the National Cancer Institute Common Terminology Criteria for Adverse Events. A total of 10 patients were enrolled in this trial between September 2013 and January 2014 from three institutes. The overall response rate was 40.0% and the median progression-free survival was 6.7 months. Treatment-related death occurred in two patients. Grade 2 or worse severe radiation pneumonitis was observed in all three patients that had the volume of lung receiving at least 20 Gy (V20) >30%. The results of this study indicate that no further investigation is warranted into nab-PTX and CBDCA with concurrent thoracic radiation for Stage III NSCLC with V20 > 30% due to severe toxicity.

Mass-based condition measures and their relationship with fitness: in what condition is condition?

Mass or body-size measures of 'condition' are of central importance to the study of ecology and evolution, and it is often assumed that differences in condition measures are positively and linearly related to fitness. Using examples drawn from ecological studies, we show that indices of condition frequently are unlikely to be related to fitness in a linear fashion. Researchers need to be more explicit in acknowledging the limitations of mass-based condition measures and accept that, under some circumstances, they may not relate to fitness as traditionally assumed. Any relationship between a particular condition measure and fitness should first be empirically validated before condition is used as a proxy for fitness. In the absence of such evidence, researchers should explicitly acknowledge that assuming such a relationship may be unrealistic.

Assessment of predation risk through referential communication in incubating birds.

Parents of many bird species produce alarm calls when they approach and deter a nest predator in order to defend their offspring. Alarm calls have been shown to warn nestlings about predatory threats, but parents also face a similar risk of predation when incubating eggs in their nests. Here, I show that incubating female Japanese great tits, Parus minor, assess predation risk by conspecific alarm calls given outside the nest cavity. Tits produce acoustically discrete alarm calls for different nest predators: "jar" calls for snakes and "chicka" calls for other predators such as crows and martens. Playback experiments revealed that incubating females responded to "jar" calls by leaving their nest, whereas they responded to "chicka" calls by looking out of the nest entrance. Since snakes invade the nest cavity, escaping from the nest helps females avoid snake predation. In contrast, "chicka" calls are used for a variety of predator types, and therefore, looking out of the nest entrance helps females gather information about the type and location of approaching predators. These results show that incubating females derive information about predator type from different types of alarm calls, providing a novel example of functionally referential communication.