The role of introductory alarm calls for song discrimination in Ficedula flycatchers

Assortative mating depends on species distinctiveness in mating traits and preferences, which can be challenging to maintain when traits and/or preferences are learned. This is because learning may cause individuals to copy heterospecific signals. Juvenile songbirds possess innate sensory biases favouring them to learn and to prefer conspecific songs, but the effectiveness of these biases relies on consistent and sufficient differences between the songs produced by different species. However, mating signals, including learned songs, sometimes converge in sympatry, and the species-specific cues that individuals use to shape their preferences are often unknown. In Ficedula flycatchers, a stereotyped and highly species-specific alarm call is often incorporated as the first syllable of their songs. However, where the two species co-occur, pied flycatchers, Ficedula hypoleuca, learn to incorporate the introductory calls of the closely related collared flycatcher, Ficedula albicollis, into their songs. In this study, we investigated the role of introductory alarm calls for song discrimination in collared flycatchers, using playback experiments of both manipulated and unmanipulated songs on adults and nestlings within the hybrid zone of Öland, Sweden. We predicted that the introductory alarm call would be sufficient to trigger song responses, such that adults and nestlings would respond similarly to song phrases including the call, whether it is followed by conspecific or heterospecific notes. Our results provide evidence that the introductory alarm call is sufficient to trigger song discrimination in nestlings, but not in adult males, potentially due to their greater experience with songs and, therefore, subtler discrimination. Altogether, this study highlights the often-overlooked importance of calls within or associated with songs

Differences in incubation behaviour and niche separation of two competing flycatcher species

Food availability sets the stage for incubation behaviour of a female bird and thereby indirectly determines the nest temperature, which in turn affects development and metabolism of avian embryos. Changes in development and metabolism in turn are known to influence offspring's ability to adjust to environmental changes later in life. However, few studies have investigated the role of interspecific differences in incubation behaviour in relation to niche separation between competing sibling species. We studied the effects of habitat quality (in terms of caterpillar availability) on incubation behaviour of two ecologically similar and closely related species, collared and pied flycatchers (Ficedula albicollisandF. hypoleuca), in their hybrid zone on the island of oland, Sweden. Even though both species prefer caterpillar-rich deciduous forests as nesting sites, collared flycatchers, whose nestlings have higher energetic demands, are able to nest only in deciduous forests, whereas pied flycatchers have more flexible habitat requirements. Overall, higher food availability was associated with increased nest attendance, higher incubation temperature and a lower number of foraging trips across species. In addition, collared flycatchers had more frequent and shorter foraging trips across habitat types, allocated more heat to eggs and therefore maintained higher nest temperatures compared to pied flycatchers. We argue that the higher heat allocation or the need to maintain a higher nest temperature for embryo development may constrain collared flycatchers to focus on relatively more profitable prey. Our results highlight the importance of considering incubation behaviour in the context of understanding species differences in niche use. Significance statement Niche separation plays an important role in mitigating effects of competition between closely related species. Whether species differences in incubation behaviour relate to differences in niche use remains unknown. We compared incubation behaviour of two sympatric flycatcher species that differ in sensitivity to food availability. The competitively more dominant and larger species, the collared flycatcher, whose nestlings are more sensitive to food shortages, made more frequent foraging trips but allocated more heat to eggs, leading to higher nest temperature despite lower nest attendance, compared to pied flycatchers. These interspecific differences may be a result of differences in embryo sensitivity or female physiology and contribute to the niche separation between the species, which in turn can facilitate coexistence.Peer reviewe

Совершенствование деятельности служб материально-технического снабжения производства

Материалы VI Междунар. науч. конф. студентов, аспирантов и молодых ученых, Гомель, 26 апр. 2013 г

Temporal differences in food abundance promote coexistence between two congeneric passerines

Many related species share the same environment and utilize similar resources. This is surprising because based on the principle of competitive exclusion one would predict that the superior competitor would drive the other species to extinction; coexistence is only predicted if interspecific competition is weaker than intraspecific competition. Interspecific competition is frequently reduced by differential resource use, resulting in habitat segregation. In this paper, we use the closely related collared and pied flycatcher to assess the potential of habitat differences to affect interspecific competition through a different mechanism, namely by generating temporal differences in availability of similar food resources between the two species. We found that the tree species composition of the breeding territories of the two species differed, mainly by a higher abundance of coniferous species around nest-boxes occupied by pied flycatchers. The temporal availability of caterpillars was measured using frass traps under four deciduous and two coniferous tree species. Deciduous tree species showed an early and narrow peak in abundance, which contrasted with the steady increase in caterpillar abundance in the coniferous tree species through the season. We subsequently calculated the predicted total caterpillar biomass available in each flycatcher territory. This differed between the species, with biomass decreasing more slowly in pied flycatcher territories. Caterpillar biomass is strongly correlated with the reproductive success of collared flycatchers, but much less so with pied flycatchers. However, caterpillar availability can only partly explain the differences in seasonal decline of reproductive success between the two species; we discuss additional factors that may contribute to this species difference. Overall, our results are consistent with the suggestion that minor habitat differences between these two species may contribute to promoting their coexistence

Load control speed screw conveyer

<p>The flight paths of two blue bottle flies (<i>Calliphora vomitoria</i>) sampled from high-speed video (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0151099#pone.0151099.s002" target="_blank">S1 Movie</a>): A) at the rate of the visual system of a human (40 frames/s) and B) at the rate of a pied flycatcher (120 frames/s) at a light intensity of approximately 500 cdm^-2. The flycatcher refreshes visual input almost three times faster, resulting in a much more detailed view of the flight paths of the flies.</p

Increasing the power of genome wide association studies in natural populations using repeated measures - evaluation and implementation

1. Genomewide association studies (GWAS) enable detailed dissections of the genetic basis for organisms' ability to adapt to a changing environment. In long-term studies of natural populations, individuals are often marked at one point in their life and then repeatedly recaptured. It is therefore essential that a method for GWAS includes the process of repeated sampling. In a GWAS, the effects of thousands of single-nucleotide polymorphisms (SNPs) need to be fitted and any model development is constrained by the computational requirements. A method is therefore required that can fit a highly hierarchical model and at the same time is computationally fast enough to be useful. 2. Our method fits fixed SNP effects in a linear mixed model that can include both random polygenic effects and permanent environmental effects. In this way, the model can correct for population structure and model repeated measures. The covariance structure of the linear mixed model is first estimated and subsequently used in a generalized least squares setting to fit the SNP effects. The method was evaluated in a simulation study based on observed genotypes from a long-term study of collared flycatchers in Sweden. 3. The method we present here was successful in estimating permanent environmental effects from simulated repeated measures data. Additionally, we found that especially for variable phenotypes having large variation between years, the repeated measurements model has a substantial increase in power compared to a model using average phenotypes as a response. 4. The method is available in the R package RepeatABEL. It increases the power in GWAS having repeated measures, especially for long-term studies of natural populations, and the R implementation is expected to facilitate modelling of longitudinal data for studies of both animal and human populations.Peer reviewe

Hybrid Dysfunction Expressed as Elevated Metabolic Rate in Male Ficedula Flycatchers

Peer reviewe

Совершенствование информационного обеспечения управления краткосрочными материальными активами

Исследованы сущностные характеристики категорий «затраты», «расходы», особенности их трансформации по стадиям кругооборота средств коммерческой организации, обоснована авторская позиция по их идентификации. С учетом этого даны рекомендации по совершенствованию методики учета затрат по приобретению товаров, материалов и иных краткосрочных материальных активов в Республике Беларусь. Представлены новые методы распределения затрат по приобретению материалов и товаров по отчетным периодам, не включенных в их учетную цену. Также предложено уточнить состав статей затрат по приобретению материалов и товаров и осуществлять их распределение с учетом фактического времени оборота текущих активов.Essential characteristics of the categories “costs” and “expenses”, specific features of their transformation in accordance with the stages of the profit organization’s assets circulation are studied, the author’s position on their identification is validated. Taking this into consideration the recommendations about the improvement of the methods of calculation of the costs of purchasing goods, materials and other short-term tangible assets in the Republic of Belarus are given. New methods of distributing the costs of purchasing the materials and the goods by accounting periods not included in their accounting price are proposed. It is also proposed to define more exactly the structure of the items of the costs of purchasing materials and goods and provide their distribution allowing for actual time of the current assets turnover