scholarly journals Cuttlefish use visual cues to determine arm postures for camouflage

2011 ◽  
Vol 279 (1726) ◽  
pp. 84-90 ◽  
Author(s):  
Alexandra Barbosa ◽  
Justine J. Allen ◽  
Lydia M. Mäthger ◽  
Roger T. Hanlon

To achieve effective visual camouflage, prey organisms must combine cryptic coloration with the appropriate posture and behaviour to render them difficult to be detected or recognized. Body patterning has been studied in various taxa, yet body postures and their implementation on different backgrounds have seldom been studied experimentally. Here, we provide the first experimental evidence that cuttlefish ( Sepia officinalis ), masters of rapid adaptive camouflage, use visual cues from adjacent visual stimuli to control arm postures. Cuttlefish were presented with a square wave stimulus (period = 0.47 cm; black and white stripes) that was angled 0°, 45° or 90° relative to the animals' horizontal body axis. Cuttlefish positioned their arms parallel, obliquely or transversely to their body axis according to the orientation of the stripes. These experimental results corroborate our field observations of cuttlefish camouflage behaviour in which flexible, precise arm posture is often tailored to match nearby objects. By relating the cuttlefishes' visual perception of backgrounds to their versatile postural behaviour, our results highlight yet another of the many flexible and adaptive anti-predator tactics adopted by cephalopods.

Birds ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 138-146
Author(s):  
Eduardo J. Rodríguez-Rodríguez ◽  
Juan J. Negro

The family Ciconiidae comprises 19 extant species which are highly social when nesting and foraging. All species share similar morphotypes, with long necks, a bill, and legs, and are mostly coloured in the achromatic spectrum (white, black, black, and white, or shades of grey). Storks may have, however, brightly coloured integumentary areas in, for instance, the bill, legs, or the eyes. These chromatic patches are small in surface compared with the whole body. We have analyzed the conservatism degree of colouration in 10 body areas along an all-species stork phylogeny derived from BirdTRee using Geiger models. We obtained low conservatism in frontal areas (head and neck), contrasting with a high conservatism in the rest of the body. The frontal areas tend to concentrate the chromatic spectrum whereas the rear areas, much larger in surface, are basically achromatic. These results lead us to suggest that the divergent evolution of the colouration of frontal areas is related to species recognition through visual cue assessment in the short-range, when storks form mixed-species flocks in foraging or resting areas.


Author(s):  
Axelle Brémont
Keyword(s):  

Alice Stevenson & Joris van Wetering (eds.), The Many Histories of Naqada: Archaeology and Heritage in an Upper Egyptian Region. London: Golden House Publications, 2020. ISBN 9781906137694. Pp. Xviii + 171, 160 black and white illustrations. $120


Author(s):  
Jens Wolff

Luther was a point of reference in all three of the confessional cultures during the confessional age, though this was not something he had intended. His theological “self-fashioning” was not meant to secure, canonize, or stabilize his own works or his biography. Rather, he believed, and was convinced, that the hidden God rules in a strange way. He hides himself in the course of the world and realizes what we would have liked to realizes. Apart from this theological viewpoint, historiographic differentiation is needed: Luther had different impacts on each of the three confessions. Furthermore, one also has to differentiate between a deep impact and the unintended effects of Luther’s thinking. Luther was an extremely polarizing figure. From the beginning, he underwent a heroization and a diabolization by his contemporaries. Apart from this black-and-white reception of his person, it was, and still is, extremely difficult to analyze Luther, his work and medial effects. Historians have always been fixated on Luther: he was the one and only founder of Protestantism. His biography became a stereotype of writing and was an important element of Protestant (or anti-Protestant) identity politics. For some Protestants, his biography became identical with the history of salvation (Heilsgeschichte). For his enemies, his biography was identical with the history of the devil. In all historical fields, one has to differentiate between the different groups and people who protected or attacked Luther or shared his ideas. The history of Luther can only be written as a shared history with conflict and concordances: the so-called Anabaptists, for example, shared Luther’s antihierarchical ideal of Christian community, although on the other hand “they” were strongly opposed toward his theology and person. Luther or example, had conflicts with the humanists and with Erasmus especially; he argued about the Lord’s Supper with Zwingli, he criticized the Fuggers because of their financial transactions in an early capitalist society; and, last but not least, he was in conflict with the Roman Church. The legitimization of different pictures of Luther always depends upon the perspectives of the posterity: either Luther was intolerant against spiritualists, Anabaptists, or peasants who were willing to resort to violence; or he was defended by humanists like Sebastian Castellio for defending religious tolerance. During his lifetime Luther was an extremely polarizing figure. Hundreds of pro-Lutheran and polemical anti-Lutheran leaflets or texts were published. The many literary forms of parody, satire, caricature, the grotesque, and the absurd were cultivated during the confessional age. Luther’s biography was often used by Lutheran theologians as an instrument of heroization and identity politics in public discourse. Historically, one can differentiate between the time before and after Luther. The political and religious unity of the Holy Roman Empire was strongly disturbed, if not broken, through the Reformation. The end of the Universalist dreams of universal powers like theology and politics (pope and emperor) were some of the central preconditions for political, cultural, and theological differentiation of Europe. Religious differentiation was one of the unintended effects of theology and the interpretation of the scripture. Decades after Luther’s death, the Holy Roman Empire slowly and surprisingly turned into a poly-, multi- and interconfessional society.


1996 ◽  
Vol 74 (12) ◽  
pp. 2248-2253 ◽  
Author(s):  
Lamar A. Windberg

Individual coyotes (Canis latrans) are infrequently captured within their familiar areas of activity. Current hypotheses are that the differential capture vulnerability may involve neophobia or inattentiveness. To assess the effect of familiarity, I measured coyote responsiveness to sensory cues encountered in familiar and novel settings. Seventy-four captive coyotes were presented with visual and olfactory stimuli in familiar and unfamiliar 1-ha enclosures. The visual stimuli were black or white wooden cubes of three sizes (4, 8, and 16 cm per side). The olfactory stimuli were fatty acid scent, W-U lure (trimethylammonium decanoate plus sulfide additives), and coyote urine and liquefied feces. Overall, coyotes were more responsive to stimuli during exploration in unfamiliar than in familiar enclosures. None of 38 coyotes that responded were neophobic toward the olfactory stimuli. The frequency of coyote response, and the resulting degrees of neophobia, did not differ between the black and white visual stimuli. Regardless of context, the largest visual stimuli were recognized at the greatest distance and evoked the strongest neophobic response. A greater proportion of coyotes were neophobic toward the small and medium-sized stimuli in familiar than in unfamiliar enclosures. This study demonstrated that when encountered in familiar environments, visual cues are more likely to elicit neophobic responses by coyotes than are olfactory stimuli.


2013 ◽  
Vol 447 ◽  
pp. 128-131 ◽  
Author(s):  
Teresa Mattiello ◽  
Marco d'Ischia ◽  
Anna Palumbo

Author(s):  
Brian Stucky ◽  
John Deck ◽  
Ramona Walls ◽  
Robert Guralnick

Ideally, an information system that automates the integration of disparate datasets should be able to minimize the loss of information from any one dataset, achieve computational complexity suitable for working with large datasets, be flexible enough to easily incorporate new data sources, and produce output that is easily analyzed and understood by data users. Achieving all of these goals within highly heterogeneous and highly complex data domains is a major challenge. In this talk, we present the results of our recent efforts to develop such a system for data about plant phenology. Our data integration system, which is built around the Plant Phenology Ontology, currently supports semantically fine-grained integration of phenological data from both field observations and herbarium specimens. We show that even with a heavily axiomatized ontology and sophisticated, machine-reasoning-based data analysis, it is possible to implement a high-throughput data integration pipeline capable of processing millions of individual records in a matter of minutes while running on modest, server-class hardware. Success requires careful ontology design and judicious application of machine reasoning techniques. We also discuss some of the many challenges that remain for designing efficient, general-purpose data integration systems.


2019 ◽  
Vol 2 (1) ◽  
pp. 1-13
Author(s):  
Julia Skelly

This review of Thierry Mugler: Couturissime approaches the exhibition through a feminist art-historical lens and attends to the various ways that both Mugler’s clothing and the Montreal Museum of Fine Arts’ curatorial team has framed and constructed the powerful, threatening woman as a complex figure who is hard, cold, sensual, strong, hard-working, and spectacular, among many other valences. The exhibition, which had its world premiere at the MMFA in March 2019, is organized as a fashion opera in six acts, and each room illuminates disparate yet interconnected parts of Mugler’s body of work: his costumes for a 1985 performance of Macbeth in Paris; the decadent and excessive clothing worn and worshipped by past and present celebrities; the black-and-white power dressing that Helmut Newton and others have canonized in fashion photography; the astounding creations inspired by insects and reptiles; and finally, the cyborgian fembots that have been presented in both Vogue and music videos. The inclusion of photographs and videos — not a new strategy in blockbuster fashion exhibitions — is essential to the success of Thierry Mugler: Couturissime, as they reveal that while these clothes are works of art, they were made to be worn and mobilized. Although not explicitly a feminist exhibition, for viewers who are looking for feminist, political inspiration wherever they can find it Mugler’s warrior women and formidable clothing — whether made of metal, latex or feathers — provide a powerful reminder that clothing is just one of the many weapons in our arsenal.


1999 ◽  
Vol 52 (2) ◽  
pp. 255-298 ◽  
Author(s):  
Thomas Christensen

Throughout the nineteenth century, massive quantities of four-hand piano transcriptions were published of virtually every musical genre. Indeed, no other medium before the advent of the radio and phonograph was arguably so important for the dissemination and iterability of concert and chamber repertories. Yet such transcriptions proved to be anything but innocent vehicles of translation. Not only did these four-hand arrangements offer simplified facsimiles of most orchestral works blanched of their instrumental timbres (a result that was often compared to the many reproductive engravings and black-and-white lithographs of artworks that were churned out by publishers at the same time); such arrangements also destabilized traditional musical divisions between symphonic and chamber genres, professional and amateur music cultures, and even repertories gendered as masculine and feminine. By bringing music intended for the public sphere of the concert hall, opera house, and salon into the domestic space of the bourgeois home parlor, the four-hand transcription profoundly altered the generic identity and consequent reception of musical works.


Author(s):  
Erik Mathisen

This chapter examines the many ways in which loyalty became part of a struggle for property, a struggle that would have profound consequences for the shape of Reconstruction in the Mississippi Valley. The chapter examines how state-sponsored emancipation worked in lockstep with the wartime seizure of property to create an environment within which loyalty to the United States gave worthy individuals claim to their possessions and left disloyal traitors with the flimsiest of holds over their land, their homes, and the black laborers many once owned. African Americans seized on the language of loyalty to claim a meaningful freedom for themselves and knit their families together again. The twinned power of allegiance and property nearly proved the undoing of white supremacy in the state. In the claims and counterclaims of black and white alike, what emerged was potentially the most radical edge of American emancipation: a bold attempt to give to former slaves the property of their disloyal former owners. In this, the collective stepping back from the most revolutionary of Reconstruction measures also spelled the slow erosion of loyalty, leaving former slaves without the means to claim anything more than political rights.


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