Social rules govern vocal competition in the barn owl

To resolve the share of limited resources, animals often compete through exchange of signals about their relative motivation to compete. When two competitors are similarly motivated, the resolution of conflicts may be achieved in the course of an interactive process. In barn owls, Tyto alba, in which siblings vocally compete during the prolonged absence of parents over access to the next delivered food item, we investigated what governs the decision to leave or enter a contest, and at which level. Siblings alternated periods during which one of the two individuals vocalized more than the other. Individuals followed turn-taking rules to interrupt each other and momentarily dominate the vocal competition. These social rules were weakly sensitive to hunger level and age hierarchy. Hence, the investment in a conflict is determined not only by need and resource-holding potential, but also by social interactions. The use of turn-taking rules governing individual vocal investment has rarely been shown in a competitive context. We hypothesized that these rules would allow individuals to remain alert to one another's motivation while maintaining the cost of vocalizing at the lowest level. (C) 2015 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd

Blue Tits Use Fledgling Quantity And Quality As Public Information In Breeding Site Choice

International audiencePublic 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 fitnessenhancing 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. We manipulated the mean number of fledglings raised locally (quantity) and their condition (quality) as components of PI by transferring nestlings from Decreased (D) patches to Increased (I) patches. Our manipulations caused a negative relationship between fledgling quantity and quality that does not exist naturally: I patches had a higher number of fledglings that were in poorer condition, whereas D patches had a lower number in better condition. Control (C) patches, whether manipulated or not, had intermediate levels in terms of fledgling quantity and quality. Adult emigration the following year was higher from D than from C or I patches. Similarly, adult dispersal distance decreased for individuals coming from D to C to I patches. This suggests that resident breeders rely mainly on fledgling quantity to make emigration decisions. Emigration patterns of juveniles did not vary in relation to our patch manipulation. Immigration rates were higher and similar in I and D patches than in C patches. Hence, immigrant Blue Tits seem to rely on one of the manipulated components of PI and are insensitive to the discrepancy between fledgling quantity and quality. This shows that even nonmigratory species, such as Blue Tits, may use PI in their dispersal decisions but weigh its components differently for emigration and immigration. Differences among species in the importance of PI in breeding habitat choices may be explained by differences in life histories

Data from: 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. We analyzed data on the distribution of EPY in broods of four passerines (blue tit, great tit, collared flycatcher, and pied flycatcher), with 18,564 genotyped nestlings from 2,346 broods in two to nine populations per species. Our Bayesian modeling approach estimated the underlying probability function of EPC (assumed to be a Poisson function) and conditional binomial EPF probability. We used an information theoretical approach to show that the expected distribution of EPC per female varies across populations but that EPF probabilities vary on the above‐species level (tits vs. flycatchers). Hence, for these four passerines, our model suggests that the probability of an EPC mainly is determined by ecological (population‐specific) conditions, whereas EPF probabilities reflect processes that are fixed above the species level

Passerine extra-pair mating dynamics: a Bayesian model comparison of four species

abstract: 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. We analyzed data on the distribution of EPY in broods of four passerines (blue tit, great tit, collared flycatcher, and pied flycatcher), with 18,564 genotyped nestlings from 2,346 broods in two to nine populations per species. Our Bayesian modeling approach estimated the underlying probability function of EPC (assumed to be a Poisson function) and conditional binomial EPF probability. We used an information theoretical approach to show that the expected distribution of EPC per female varies across populations but that EPF probabilities vary on the above-species level (tits vs. flycatchers). Hence, for these four passerines, our model suggests that the probability of an EPC mainly is determined by ecological (population-specific) conditions, whereas EPF probabilities reflect processes that are fixed above the species level

Passerine extra-pair mating dynamics: A model-based comparison of 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. We analyzed data on the distribution of EPY in broods of four passerines (blue tit, great tit, collared flycatcher, and pied flycatcher), with 18,564 genotyped nestlings from 2,346 broods in two to nine populations per species. Our Bayesian modeling approach estimated the underlying probability function of EPC (assumed to be a Poisson function) and conditional binomial EPF probability.We used an information theoretical approach to show that the expected distribution of EPC per female varies across populations but that EPF probabilities vary on the above-species level (tits vs. flycatchers). Hence, for these four passerines, our model suggests that the probability of an EPC mainly is determined by ecological (population-specific) conditions, whereas EPF probabilities reflect processes that are fixed above the species level

DataPlottedInFig1.xlsx

Raw data for Figure 1 in original articl

RawDataFile.txt

RawDataFile.tx

Data from: 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. We analyzed data on the distribution of EPY in broods of four passerines (blue tit, great tit, collared flycatcher, and pied flycatcher), with 18,564 genotyped nestlings from 2,346 broods in two to nine populations per species. Our Bayesian modeling approach estimated the underlying probability function of EPC (assumed to be a Poisson function) and conditional binomial EPF probability. We used an information theoretical approach to show that the expected distribution of EPC per female varies across populations but that EPF probabilities vary on the above‐species level (tits vs. flycatchers). Hence, for these four passerines, our model suggests that the probability of an EPC mainly is determined by ecological (population‐specific) conditions, whereas EPF probabilities reflect processes that are fixed above the species level.,DataPlottedInFig1.xlsxRaw data for Figure 1 in original articleRawDataFile.txt