Arguments for the integration of the non-zero-sum logic of complex animal communication with information theory

The outstanding levels of knowledge attained today in the research on animal communication, and the new available technologies to study visual, vocal and chemical signalling, allow an ever increasing use of information theory as a sophisticated tool to improve our knowledge of the complexity of animal communication. Some considerations on the way information theory and intraspecific communication can be linked are presented here. Specifically, information theory may help us to explore interindividual variations in different environmental constraints and social scenarios, as well as the communicative features of social vs. solitary species. © 2010 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.Peer Reviewe

Conflict Animals, or Conflict People—That Is the Question

Managing conflictual sce­narios involving large carnivores is generally addressed from an animal-centric perspective. This is rather contradic­tory because such conflicts are mostly triggered by human conduct that acts on animal’s instinc­tive behaviors. Shifting conflict miti­gation perspectives to human behaviors may thus provide a more consistent management strategy than focusing only on animals. For example, human habituation and anthropogenic food conditioning are 2 main conflict drivers that mostly depend on human behavior. Thus, an approach that addresses the human dimension aspects of these conflicts needs to be reinforced. I offer 6 points to consider in prioritizing management to mitigate human–bear conflicts and, more generally, large carnivore conflicts. One of the most difficult challenges is not only managing habituated large carnivores, but also intensifying the human behavior-related management efforts

Arguments for the Integration of the Non-Zero-Sum Logic of Complex Animal Communication with Information Theory

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Supplementary feeding and the population dynamic of the Spanish imperial eagle

Supplementary feeding could be a useful technique to avoid losses of chicks in certain nests under peculiar circumstances, but it could be appropriate to prolong it until the end of the dependence period also. This would prevent the negative effects on breeders clearly pointed out by Blanco (2006). We have serious concerns about the real magnitude of siblicide in this species, as well as about the possible effect on the growth speed of the population that techniques aimed to improve fecundity would have. Consequently, the suggestion of extending this technique to a large proportion of the breeding population must be seriously reconsidered. The idea that breeding populations and their fecundity are the main target for conservation plans must be revised, according to most recent advances on population dynamics of long-lived species and structure of populations.Peer Reviewe

Brood-switching in Eagle Owl Bubo bubo fledglings

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Night visions

6 páginas, 6 fotos.-- Trabajo publicado en revista de divulgación científica.Even after sundown, Eurasian eagle owls rely on sight for social communication.Peer reviewe

Moonlight makes owls more chatty

Background: Lunar cycles seem to affect many of the rhythms, temporal patterns and behaviors of living things on Earth. Ambient light is known to affect visual communication in animals, with the conspicuousness of visual signals being largely determined by the light available for reflection by the sender. Although most previous studies in this context have focused on diurnal light, moonlight should not be neglected from the perspective of visual communication among nocturnal species. We recently discovered that eagle owls Bubo bubo communicate with conspecifics using a patch of white throat plumage that is repeatedly exposed during each call and is only visible during vocal displays. Methodology/Principal Findings: Here we provide evidence that this species uses moonlight to increase the conspicuousness of this visual signal during call displays. We found that call displays are directly influenced by the amount of moonlight, with silent nights being more frequent during periods with no-moonlight than moonlight. Furthermore, high numbers of calling bouts were more frequent at moonlight. Finally, call posts were located on higher positions on moonlit nights. Conclusions/Significance: Our results support the idea that moon phase affects the visual signaling behavior of this species, and provide a starting point for examination of this method of communication by nocturnal species. © 2010 Penteriani et al.Peer Reviewe

Changes of movement patterns from early dispersal to settlement

Moving and spatial learning are two intertwined processes: (a) changes in movement behavior determine the learning of the spatial environment, and (b) information plays a crucial role in several animal decision-making processes like movement decisions. A useful way to explore the interactions between movement decisions and learning of the spatial environment is by comparing individual behaviors during the different phases of natal dispersal (when individuals move across more or less unknown habitats) with movements and choices of breeders (who repeatedly move within fixed home ranges), that is, by comparing behaviors between individuals who are still acquiring information vs. individuals with a more complete knowledge of their surroundings. When analyzing movement patterns of eagle owls, Bubo bubo, belonging to three status classes (floaters wandering across unknown environments, floaters already settled in temporary settlement areas, and territory owners with a well-established home range), we found that: (1) wandering individuals move faster than when established in a more stable or fixed settlement area, traveling larger and straighter paths with longer move steps; and (2) when floaters settle in a permanent area, then they show movement behavior similar to territory owners. Thus, movement patterns show a transition from exploratory strategies, when animals have incomplete environmental information, to a more familiar way to exploit their activity areas as they get to know the environment better. © Springer-Verlag 2009.Peer Reviewe

The Dusk Chorus from an Owl Perspective : Eagle Owls Vocalize When Their White Throat Badge Contrasts Most

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Brightness variability in the white badge of the eagle owl Bubo bubo

The application of modern spectrometry to the study of avian colour variability has revealed ignored patterns of colour variation such as male-biased sexual dichromatism and seasonal variability in the plumage. However, the variation in the achromatic property of such traits, that is in the total light reflectance of the spectrum (i.e., brightness), has commonly been overlooked. The evolution of signals based on brightness should be favoured in those species that are active when light is scarce, i.e. at dawn and dusk. The eagle owl Bubo bubo is monogamous and apparently monomorphic in plumage-coloration. In this species, sexual and territorial call behaviour is mainly performed at dawn and dusk, during which a white patch on the throat is repeatedly exposed at each call. We measured the total light reflectance of the feathers of this badge in 39 eagle owl specimens from museum collections. We found seasonal variability and sexual dichromatism in the brightness of the plumage badge. The total reflectance of this trait peaked during the territorial-mating period. Moreover, females showed higher values of brightness than males, in agreement with the reversed body size dimorphism present in this and many other raptor species. Finally, female but not male body size was positively correlated with white badge reflectance. © Journal of Avian Biology.Peer Reviewe