Search results for "cognit."
showing 10 items of 15244 documents
Do peahens not prefer peacocks with more elaborate trains?
2008
Ever since Darwin (1871), the peacock’s train has been cited as the icon of an extravagant conspicuous secondary sexual trait that has evolved through female mate choice. However, Takahashi et al. (2008) recently challenged this idea. They monitored female mate choice during 7 years in a feral peafowl, Pavo cristatus, population in Japan and found no correlation between male mating success and three morphological train traits. They concluded that ‘combined with previous results, our findings indicate that the peacock’s train is not currently the universal target of female choice’ and proposed ‘that the peacock’s train is an obsolete signal for which female preference has already been lost o…
Acoustic signalling in a wolf spider: can signal characteristics predict male quality?
2000
While there has been considerable interest in female choice for male sexual signals, there have been few studies of the underlying information that different aspects of the signal calls convey. Such studies, however, are essential to understand the significance of signals as honest handicaps, arbitrary Fisherian traits and/or in species recognition. We studied the somewhat exceptional system of audible drumming in the wolf spider Hygrolycosa rubrofasciata. We estimated the repeatabilities of signal components, the levels of between-male variance, the symmetry of the signal, the correlations between different aspects of drumming and their correlations with body weight. While in other taxa th…
Asymmetrical interspecific communication of predatory threat in mixed-species colonies of lesser kestrels (Falco naumanni) and jackdaws (Corvus moned…
2019
Sympatric species derive benefits by attending to information conveyed by heterospecifics. Our previous finding of reduced vigilance among jackdaws and lesser kestrels residing in mixed-species colonies suggested a reliance on interspecific communication of information regarding predatory threats. To test for interspecific communication of threat, we first determined whether jackdaw and lesser kestrel call structure varied with perceived threat. In this call production phase of our study, free-living birds in mixed-species colonies were presented with models representing a potential nest predator (European magpie) or with non-threatening stimuli (wood pigeon or wooden dowel) in proximity to…
European Formalism and Empiriocriticism : Formalism within the International Empiriocritical Movement
2020
Abstract This paper argues that Russian Formalism is to be considered a constitutive part of the international empiriocritical movement—Ernst Mach (1838—1916) and Richard Avenarius’s (1843—1896). The conceptual parallelism between Empiriocriticism and Formalism is striking indeed. Thus, the cornerstones of the empiriocritical approach—the concept of series [Reihe] and the concept of elements [Elemente], understood as sensations [Empfindungen]—are plainly recognizable within formalist theories: the notion of ‘series’ (for example, the notion of ‘literary series’ or ‘poetic series’, leading to the famous concept of ‘literariness’, literaturnost’) and the very formalist idea of a necessarily p…
Can video playback provide social information for foraging blue tits?
2017
Video playback is becoming a common method for manipulating social stimuli in experiments. Parid tits are one of the most commonly studied groups of wild birds. However, it is not yet clear if tits respond to video playback or how their behavioural responses should be measured. Behaviours may also differ depending on what they observe demonstrators encountering. Here we present blue tits (Cyanistes caeruleus) videos of demonstrators discovering palatable or aversive prey (injected with bittertasting Bitrex) from coloured feeding cups. First we quantify variation in demonstrators’ responses to the prey items: aversive prey provoked high rates of beak wiping and head shaking. We then show tha…
Female mate choice in convict cichlids is transitive and consistent with a self-referent directional preference
2013
10 pages; International audience; INTRODUCTION: One of the most important decisions that an animal has to make in its life is choosing a mate. Although most studies in sexual selection assume that mate choice is rational, this assumption has not been tested seriously. A crucial component of rationality is that animals exhibit transitive choices: if an individual prefers option A over B, and B over C, then it also prefers A over C. RESULTS: We assessed transitivity in mate choice: 40 female convict cichlids had to make a series of binary choices between males of varying size. Ninety percent of females showed transitive choices. The mean preference index was significantly higher when a female…
Evolutionary significance of antiparasite, antipredator and learning phenotypes of avian nest defence.
2018
AbstractAvian nest defence, which is expected to serve both antiparasite and antipredator functions, may benefit or be detrimental to birds, although selective forces that potentially operate on nest defence have not been quantified as a whole. Together with fitness values, we analysed two traits of nest defence, intensity and plasticity, in two distantly related passerine species, yellow warbler (Setophaga petechia) in North America and reed warbler (Acrocephalus scirpaceus) in Europe, both favourite host species for brood parasites. Breeders that escaped parasitism were the most vocal among reed warblers, whereas there was no specific defence phenotype that predicted prevention of parasit…
Parasitism and queen presence interactively shape worker behaviour and fertility in an ant host
2019
Parasites with complex life cycles regularly alter host traits in their own interest. In social hosts, phenotypic alterations induced by parasites can also affect uninfected group members. The tapeworm Anomotaenia brevis uses Temnothorax nylanderi ants as intermediate hosts, reducing host activity and behavioural repertoire, but increasing life span. Uninfected nestmates are less active and less aggressive and suffer from higher mortality. Next to parasites, the social environment, such as the queen, influences worker behaviour, reproduction and longevity. Here, we studied how tapeworm parasitism interacts with the queen to affect the behaviour and reproductive potential of ant workers. We …
Null models for animal social network analysis and data collected via focal sampling: Pre‐network or node network permutation?
2020
In social networks analysis, two different approaches have predominated in creating null models for hypothesis testing, namely pre‐network and node network permutation approaches. Although the pre‐network permutation approach appears more advantageous, its use has mainly been restricted to data on associations and sampling methods such as ‘group follows’. The pre‐network permutation approach has recently been adapted to data on interactions and the focal sampling method, but its performance in different scenarios has not been thoroughly explored. Here, we assessed the performance of the pre‐network and node network permutation approach in several simulated scenarios based on proneness to fa…
The effect of maze complexity on maze-solving time in a desert ant
2019
One neglected aspect of research on foraging behavior is that of the effect of obstacles that increase habitat complexity on foraging efficiency. Here, we explored how long it takes individually foraging desert ant workers (Cataglyphis niger) to reach a food reward in a maze, and examined whether maze complexity affects maze-solving time (the time elapsed till the first worker reached the food reward). The test mazes differed in their complexity level, or the relative number of correct paths leading to the food reward, vs. wrong paths leading to dead-ends. Maze-solving time steeply increased with maze complexity, but was unaffected by colony size, despite the positive correlation between co…