Elder Barn Owl Nestlings Flexibly Redistribute Parental Food according to Siblings' Need or in Return for Allopreening.

Kin selection and reciprocation of biological services are distinct theories invoked to explain the origin and evolutionary maintenance of altruistic and cooperative behaviors. Although these behaviors are not considered to be mutually exclusive, the cost-benefit balance of behaving altruistically or cooperating reciprocally and the conditions promoting a switch between such different strategies have rarely been tested. Here, we examine the association between allofeeding, allopreening, and vocal solicitations in wild barn owl () broods under different food abundance conditions: natural food provisioning and after an experimental food supplementation.

'Nature Knows No Boundaries': The Role of Nature Conservation in Peacebuilding.

Humanity is facing a biodiversity crisis. To solve environmental problems, we bring people from Israel, Jordan, and the Palestinian Authority to the same table. Conservation efforts are beneficial for all communities and facilitate constructive dialog across divides in conflict zones.

Prosody Predicts Contest Outcome in Non-Verbal Dialogs.

Non-verbal communication has important implications for inter-individual relationships and negotiation success. However, to what extent humans can spontaneously use rhythm and prosody as a sole communication tool is largely unknown. We analysed human ability to resolve a conflict without verbal dialogs, independently of semantics.

Social huddling and physiological thermoregulation are related to melanism in the nocturnal barn owl.

Endothermic animals vary in their physiological ability to maintain a constant body temperature. Since melanin-based coloration is related to thermoregulation and energy homeostasis, we predict that dark and pale melanic individuals adopt different behaviours to regulate their body temperature. Young animals are particularly sensitive to a decrease in ambient temperature because their physiological system is not yet mature and growth may be traded-off against thermoregulation.

Nestling barn owls assess short-term variation in the amount of vocally competing siblings.

Assessing the amount of rivals is crucial to optimally adjust investment into a contest. If laboratory animals show numerical abilities, little is known about the ecological implications particularly in young animals. The two to nine barn owl (Tyto alba) siblings vocally compete for priority of access to food resources before parents actually deliver them.

Darker eumelanic barn owls better withstand food depletion through resistance to food deprivation and lower appetite.

The intensity of selection exerted on ornaments typically varies between environments. Reaction norms may help to identify the conditions under which ornamented individuals have a selective advantage over drab conspecifics. It has been recently hypothesized that in vertebrates eumelanin-based coloration reflects the ability to regulate the balance between energy intake and expenditure.

Passerine extrapair mating dynamics: a bayesian modeling approach comparing four species.

In many socially monogamous animals, females engage in extrapair copulation (EPC), causing some broods to contain both within-pair and extrapair young (EPY). The proportion of all young that are EPY varies across populations and species. Because an EPC that does not result in EPY leaves no forensic trace, this variation in the proportion of EPY reflects both variation in the tendency to engage in EPC and variation in the extrapair fertilization (EPF) process across populations and species.

Blue Tits use fledgling quantity and quality as public information in breeding site choice.

Public information (PI), which is the information that can be derived from the behavior and performance of conspecifics, has been demonstrated to be used in many fitness-enhancing decisions. In the context of breeding habitat choice, PI use has been called "habitat copying." We experimentally tested the existence of habitat copying in the Blue Tit (Cyanistes caeruleus), a nonmigratory, short-lived hole-nesting bird.